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Posted to commits@tapestry.apache.org by bu...@apache.org on 2018/02/03 18:21:37 UTC
svn commit: r1024785 [4/18] - in /websites/production/tapestry/content: ./
cache/
Modified: websites/production/tapestry/content/error-page-recipe.html
==============================================================================
--- websites/production/tapestry/content/error-page-recipe.html (original)
+++ websites/production/tapestry/content/error-page-recipe.html Sat Feb 3 18:21:36 2018
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css' rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet' type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js' type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,7 +77,50 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><p><plain-text-body>{scrollbar}</plain-text-body></p><parameter ac:name="hidden">true</parameter><parameter ac:name="atlassian-macro-output-type">BLOCK</parameter><rich-text-body><p>Serving up a Tapestry page as your site's custom 404 response page</p></rich-text-body><h1 id="ErrorPageRecipe-ServingTapestryPagesasServletErrorPages">Serving Tapestry Pages as Servlet Error Pages</h1><p>Do you want to dress up your site and use a snazzy Tapestry page instead of the default 404 error page? Using modern servlet containers, this is a snap!</p><parameter ac:name="style">float:right</parameter><parameter ac:name="title">Related Articles</parameter><parameter ac:name="class">aui-label</parameter><rich-text-body><parameter ac:name="showLabels">false</parameter><parameter ac:name="showSpace">false</parameter><parameter ac:name="title">Related Articles</parameter><parameter ac:name="cql">label = "errors" and space = currentSpace()</parameter></rich-te
xt-body><p>Simply upgrade your application web.xml to the 2.4 version, and make a couple of changes:</p><parameter ac:name="language">xml</parameter><parameter ac:name="title">web.xml</parameter><plain-text-body><?xml version="1.0" encoding="UTF-8"?>
+ <div id="ConfluenceContent"><h1 id="ErrorPageRecipe-ServingTapestryPagesasServletErrorPages">Serving Tapestry Pages as Servlet Error Pages</h1><p>Do you want to dress up your site and use a snazzy Tapestry page instead of the default 404 error page? Using modern servlet containers, this is a snap!</p><div class="aui-label" style="float:right" title="Related Articles">
+
+
+
+
+
+
+
+
+<h3>Related Articles</h3>
+
+<ul class="content-by-label"><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="error-page-recipe.html">Error Page Recipe</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="specific-errors-faq.html">Specific Errors FAQ</a>
+
+
+ </div>
+ </li><li>
+ <div>
+ <span class="icon aui-icon aui-icon-small aui-iconfont-page-default" title="Page">Page:</span> </div>
+
+ <div class="details">
+ <a href="overriding-exception-reporting.html">Overriding Exception Reporting</a>
+
+
+ </div>
+ </li></ul>
+</div>
+
+
+<p>Simply upgrade your application web.xml to the 2.4 version, and make a couple of changes:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>web.xml</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default" style="font-size:12px;"><?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
@@ -96,7 +149,9 @@
</error-page>
</web-app>
-</plain-text-body><p>Tapestry's filter must be marked as a handler for both standard requests and errors. That's accomplished with the <code><dispatcher></code> elements inside the <code><filter-mapping></code> section.</p><p>You must then map error codes to Tapestry URLs. In this case, the 404 error is send to the <code>/error404</code> resource, which is really the "Error404" Tapestry page.</p><p>We'll create a simple Error404 page, one that displays a message and (in development mode) displays the details about the incoming request.</p><parameter ac:name="language">xml</parameter><parameter ac:name="title">Error404.tml</parameter><plain-text-body><html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_4.xsd">
+</pre>
+</div></div><p>Tapestry's filter must be marked as a handler for both standard requests and errors. That's accomplished with the <code><dispatcher></code> elements inside the <code><filter-mapping></code> section.</p><p>You must then map error codes to Tapestry URLs. In this case, the 404 error is send to the <code>/error404</code> resource, which is really the "Error404" Tapestry page.</p><p>We'll create a simple Error404 page, one that displays a message and (in development mode) displays the details about the incoming request.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>Error404.tml</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default" style="font-size:12px;"><html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_4.xsd">
<head>
<title>Resource not found.</title>
@@ -113,7 +168,9 @@
</div>
</body>
-</html></plain-text-body><p>The page simply makes the request and productionMode properties available:</p><parameter ac:name="language">java</parameter><parameter ac:name="title">Error404.java</parameter><plain-text-body>package com.example.newapp.pages;
+</html></pre>
+</div></div><p>The page simply makes the request and productionMode properties available:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>Error404.java</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">package com.example.newapp.pages;
import org.apache.tapestry5.SymbolConstants;
import org.apache.tapestry5.annotations.Property;
@@ -134,7 +191,8 @@ public class Error404
}
-</plain-text-body><p>The end-result, in when <em>not</em> in production mode, looks like this:</p><p><span class="confluence-embedded-file-wrapper image-center-wrapper confluence-embedded-manual-size"><img class="confluence-embedded-image confluence-content-image-border image-center" width="500" src="error-page-recipe.data/Resource_not_found_.png"></span></p><rich-text-body><p>An issue with an application that has a root Index page is that any invalid path, which would normally generate a 404 error, is instead routed to the Index page (because the invalid path looks like page's activation context). See <a class="external-link" href="https://issues.apache.org/jira/browse/TAP5-2070">Issue TAP5-2070</a>.</p></rich-text-body></div>
+</pre>
+</div></div><p>The end-result, in when <em>not</em> in production mode, looks like this:</p><p> </p><p><span class="confluence-embedded-file-wrapper image-center-wrapper confluence-embedded-manual-size"><img class="confluence-embedded-image confluence-content-image-border image-center" width="500" src="error-page-recipe.data/Resource_not_found_.png"></span></p><div class="confluence-information-macro confluence-information-macro-information"><span class="aui-icon aui-icon-small aui-iconfont-info confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>An issue with an application that has a root Index page is that any invalid path, which would normally generate a 404 error, is instead routed to the Index page (because the invalid path looks like page's activation context). See <a class="external-link" href="https://issues.apache.org/jira/browse/TAP5-2070">Issue TAP5-2070</a>.</p></div></div></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/extending-the-if-component.html
==============================================================================
--- websites/production/tapestry/content/extending-the-if-component.html (original)
+++ websites/production/tapestry/content/extending-the-if-component.html Sat Feb 3 18:21:36 2018
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css' rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet' type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js' type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,7 +77,8 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><plain-text-body>{scrollbar}</plain-text-body><parameter ac:name="hidden">true</parameter><parameter ac:name="atlassian-macro-output-type">BLOCK</parameter><rich-text-body><p>Adding a type coercion to enable the If component to test for anything</p></rich-text-body><h1 id="ExtendingtheIfComponent-ExtendingtheIfComponent">Extending the If Component</h1><p>The <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/If.html">If</a> component can be made very flexible; its main parameter, <code>test</code>, does not <em>have</em> to be bound to a boolean value, it merely has to be bound to a value that can be <a href="type-coercion.html">coerced</a> to boolean.</p><p>For example, you may be working on an application that does a lot of <a class="external-link" href="http://lucene.apache.org/java/docs/index.html">Lucene</a> searches, and you represent the results as a SearchResult obje
ct:</p><parameter ac:name="language">java</parameter><parameter ac:name="title">SearchResult.java</parameter><plain-text-body>public class SearchResult<T> {
+ <div id="ConfluenceContent"><h1 id="ExtendingtheIfComponent-ExtendingtheIfComponent">Extending the If Component</h1><p>The <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/components/If.html">If</a> component can be made very flexible; its main parameter, <code>test</code>, does not <em>have</em> to be bound to a boolean value, it merely has to be bound to a value that can be <a href="extending-the-if-component.html">coerced</a> to boolean.</p><p>For example, you may be working on an application that does a lot of <a class="external-link" href="http://lucene.apache.org/java/docs/index.html">Lucene</a> searches, and you represent the results as a SearchResult object:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>SearchResult.java</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">public class SearchResult<T> {
public final Class<T> itemType;
public final List<T> items;
public final int size;
@@ -89,12 +100,16 @@
return size == 0;
}
}
-</plain-text-body><p>In a SearchResult, the <code>size</code> property is the overall number of results from the search. The <code>items</code> list is a single "page" of those results to present to the user, consisting of items from <code>firstIndex</code> to <code>lastIndex</code> within the overall set.</p><p>In your templates, you have to check to see if the SearchResult exists, then see if it is empty, before you can get to the part that displays the content:</p><parameter ac:name="language">xml</parameter><plain-text-body><t:if test="searchResult">
+</pre>
+</div></div><p>In a SearchResult, the <code>size</code> property is the overall number of results from the search. The <code>items</code> list is a single "page" of those results to present to the user, consisting of items from <code>firstIndex</code> to <code>lastIndex</code> within the overall set.</p><p>In your templates, you have to check to see if the SearchResult exists, then see if it is empty, before you can get to the part that displays the content:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default" style="font-size:12px;"><t:if test="searchResult">
<t:if test="! searchResult.empty">
. . .
</t:if>
</t:if>
-</plain-text-body><p>The first test checks to see if <code>searchResult</code> is not null (null is treated as false). The second checks to see if the search result is empty.</p><p>What we'd like is for the test to look at the <code>searchResult</code> directly and treat an empty search result as false, and a non-empty search result as true. This is similar to what Tapestry already does for Collections.</p><p>This is just a matter of extending the TypeCoercer service:</p><parameter ac:name="language">java</parameter><parameter ac:name="title">AppModule.java (partial)</parameter><plain-text-body>public static void contributeTypeCoercer(Configuration<CoercionTuple> configuration) {
+</pre>
+</div></div><p>The first test checks to see if <code>searchResult</code> is not null (null is treated as false). The second checks to see if the search result is empty.</p><p>What we'd like is for the test to look at the <code>searchResult</code> directly and treat an empty search result as false, and a non-empty search result as true. This is similar to what Tapestry already does for Collections.</p><p>This is just a matter of extending the TypeCoercer service:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>AppModule.java (partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;">public static void contributeTypeCoercer(Configuration<CoercionTuple> configuration) {
add(configuration, SearchResult.class, Boolean.class,
new Coercion<SearchResult, Boolean>() {
@@ -111,10 +126,13 @@ private static <S, T> void add(Con
configuration.add(tuple);
}
-</plain-text-body><p>Inside this thicket of generics and brackets is the code that treats a SearchResult as a boolean: <code>return !input.isEmpty();</code>.</p><p>With this in place, the previous template can be simplified:</p><parameter ac:name="language">xml</parameter><plain-text-body><t:if test="searchResult">
+</pre>
+</div></div><p>Inside this thicket of generics and brackets is the code that treats a SearchResult as a boolean: <code>return !input.isEmpty();</code>.</p><p>With this in place, the previous template can be simplified:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: xml; gutter: false; theme: Default" style="font-size:12px;"><t:if test="searchResult">
. . .
</t:if>
-</plain-text-body><p>The single test now implies that <code>searchResult</code> is not null and not empty.</p></div>
+</pre>
+</div></div><p>The single test now implies that <code>searchResult</code> is not null and not empty.</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/forms-and-form-components-faq.html
==============================================================================
--- websites/production/tapestry/content/forms-and-form-components-faq.html (original)
+++ websites/production/tapestry/content/forms-and-form-components-faq.html Sat Feb 3 18:21:36 2018
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css' rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet' type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js' type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,7 +77,8 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><plain-text-body>{scrollbar}</plain-text-body><h2 id="FormsandFormComponentsFAQ-FormsandFormComponents">Forms and Form Components</h2><p>Main article: <a href="forms-and-validation.html">Forms and Validation</a></p><h3 id="FormsandFormComponentsFAQ-Whatisthet:formdatahiddenfieldfor?">What is the <code>t:formdata</code> hidden field for?</h3><p>In Tapestry, rendering a form can be a complicated process; inside the body of the Form component are many of field components: TextField, Select, TextArea, and so forth. Each of these must pull data out of your data model and convert it to the string form used inside the client web browser. In addition, JavaScript to support client-side validation must be generated. This can be further complicated by the use of Loop and If components, or made really complicated by the use of Block (to render portions of other pages: this is what the BeanEditForm component does).</p><p>Along the way, the Form is gen
erating unique form control names for each field component, as it renders.</p><p>When the client-side Form is submitted, an event is triggered on the server-side Form component. It now needs to locate each component, in turn, inform the component of its control name, and allow the component to read the corresponding query parameter. The component then converts the client-side string back into a server-side value and performs validations before updating the data model.</p><p>That's where <code>t:formdata</code> comes in. While components are rendering, they are using the FormSupport environmental object to record callbacks:</p><parameter ac:name="controls">true</parameter><parameter ac:name="title">FormSupport.java (partial)</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body>public interface FormSupport extends ClientElement
+ <div id="ConfluenceContent"><h2 id="FormsandFormComponentsFAQ-FormsandFormComponents">Forms and Form Components</h2><p>Main article: <a href="forms-and-form-components-faq.html">Forms and Form Components FAQ</a></p><h3 id="FormsandFormComponentsFAQ-Whatisthet:formdatahiddenfieldfor?">What is the <code>t:formdata</code> hidden field for?</h3><p>In Tapestry, rendering a form can be a complicated process; inside the body of the Form component are many of field components: TextField, Select, TextArea, and so forth. Each of these must pull data out of your data model and convert it to the string form used inside the client web browser. In addition, JavaScript to support client-side validation must be generated. This can be further complicated by the use of Loop and If components, or made really complicated by the use of Block (to render portions of other pages: this is what the BeanEditForm component does).</p><p>Along the way, the Form is generating unique form control
names for each field component, as it renders.</p><p>When the client-side Form is submitted, an event is triggered on the server-side Form component. It now needs to locate each component, in turn, inform the component of its control name, and allow the component to read the corresponding query parameter. The component then converts the client-side string back into a server-side value and performs validations before updating the data model.</p><p>That's where <code>t:formdata</code> comes in. While components are rendering, they are using the FormSupport environmental object to record callbacks:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>FormSupport.java (partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;">public interface FormSupport extends ClientElement
{
/**
* Stores an action for execution during a later request. If the action contains any mutable state, it should be in
@@ -84,16 +95,25 @@
* @param action the action that will be triggered (and passed the component)
*/
<T> void storeAndExecute(T component, ComponentAction<T> action);
-</plain-text-body><p>The <code>ComponentAction</code> objects are the callbacks. <code>t:formdata</code> is simply an object stream of these callbacks, compressed and encoded in Base64. When using Ajax, you may see multiple <code>t:formdata</code> hidden fields (they are processed one after another).</p><h3 id="FormsandFormComponentsFAQ-HowdoIchangethelabelforafieldonthefly?">How do I change the label for a field on the fly?</h3><p>Tapestry tries to be smart about generating the label string for a field. It has some smart default logic, first checking for the <em>component-id</em><code>-label</code> in the container's message catalog, then ultimately converting the component's id into a user-presentable label.</p><p>You can override the label in two ways:</p><p>First, you can supply a body to the <code>Label</code> component:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> <t:label for="username">${usernameLa
bel}</t:label>
+</pre>
+</div></div><p>The <code>ComponentAction</code> objects are the callbacks. <code>t:formdata</code> is simply an object stream of these callbacks, compressed and encoded in Base64. When using Ajax, you may see multiple <code>t:formdata</code> hidden fields (they are processed one after another).</p><h3 id="FormsandFormComponentsFAQ-HowdoIchangethelabelforafieldonthefly?">How do I change the label for a field on the fly?</h3><p>Tapestry tries to be smart about generating the label string for a field. It has some smart default logic, first checking for the <em>component-id</em><code>-label</code> in the container's message catalog, then ultimately converting the component's id into a user-presentable label.</p><p>You can override the label in two ways:</p><p>First, you can supply a body to the <code>Label</code> component:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> <t:label for="username">${usernameLabel}</t:label>
<t:textfield t:id="username"/>
-</plain-text-body><p>Here, the component class must provide a <code>usernameLabel</code> property. That property becomes the text of the label. An implementation of the property might look something like:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> public String getUsernameLabel()
+</pre>
+</div></div><p>Here, the component class must provide a <code>usernameLabel</code> property. That property becomes the text of the label. An implementation of the property might look something like:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> public String getUsernameLabel()
{
return systemPreferences.useEmailAddressForUserName() ? "Email address" : "User name";
}
-</plain-text-body><p>However, if there are any validations on the field, the error message will include the default label (as discussed above).</p><p>To uniformly update the label both on the page, and in any validation messages, bind the TextField's <code>label</code> parameter:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> <t:label for="username"/>
+</pre>
+</div></div><p>However, if there are any validations on the field, the error message will include the default label (as discussed above).</p><p>To uniformly update the label both on the page, and in any validation messages, bind the TextField's <code>label</code> parameter:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> <t:label for="username"/>
<t:textfield t:id="username" label="prop:usernameLabel"/>
-</plain-text-body><p>The "prop:" prefix identifies that "usernameLabel" is to be interpreted as a property expression (normally, the binding for the <code>label</code> parameter is interpreted as a string literal). The Label component gets the text it displays from the TextField component, and the TextField component uses the same text when generating server-side and client-side validation messages.</p><h3 id="FormsandFormComponentsFAQ-Tapestryfocusesonthewrongfieldinmyform,howdoIfixthat?">Tapestry focuses on the wrong field in my form, how do I fix that?</h3><p>Tapestry normally figures out the correct field in your form to initially receive focus; this is based on assigning a <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/FieldFocusPriority.html">FieldFocusPriority</a> to each field as it renders, which works out to the following logic:</p><ul><li>The first field which has an error</li><li>Or, the first field which is required</li><
li>Or, the first field</li></ul><p>Occasionally, due a wide range of factors beyond Tapestry's control, it's selection will not be quite what you want, and it is necessary to supply an override. The information is tracked inside the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/javascript/JavaScriptSupport.html">JavaScriptSupport</a> environmental. It's just a matter of injecting the component so that you can determine its client id, then informing JavaScriptSupport about your override.</p><p>Here's an example</p><plain-text-body> <t:textfield t:id="email" t:mixins="OverrideFieldFocus" .../>
-</plain-text-body><p>The <a class="external-link" href="http://tapestry.apache.org/5.4/apidocs/org/apache/tapestry5/corelib/mixins/OverrideFieldFocus.html">OverrideFieldFocus</a> mixin forces the email field to be the focus field, regardless.</p><plain-text-body>{scrollbar}</plain-text-body></div>
+</pre>
+</div></div><p>The "prop:" prefix identifies that "usernameLabel" is to be interpreted as a property expression (normally, the binding for the <code>label</code> parameter is interpreted as a string literal). The Label component gets the text it displays from the TextField component, and the TextField component uses the same text when generating server-side and client-side validation messages.</p><h3 id="FormsandFormComponentsFAQ-Tapestryfocusesonthewrongfieldinmyform,howdoIfixthat?">Tapestry focuses on the wrong field in my form, how do I fix that?</h3><p>Tapestry normally figures out the correct field in your form to initially receive focus; this is based on assigning a <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/FieldFocusPriority.html">FieldFocusPriority</a> to each field as it renders, which works out to the following logic:</p><ul><li>The first field which has an error</li><li>Or, the first field which is required</li><li>Or,
the first field</li></ul><p>Occasionally, due a wide range of factors beyond Tapestry's control, it's selection will not be quite what you want, and it is necessary to supply an override. The information is tracked inside the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/javascript/JavaScriptSupport.html">JavaScriptSupport</a> environmental. It's just a matter of injecting the component so that you can determine its client id, then informing JavaScriptSupport about your override.</p><p>Here's an example</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;"> <t:textfield t:id="email" t:mixins="OverrideFieldFocus" .../>
+</pre>
+</div></div><p>The <a class="external-link" href="http://tapestry.apache.org/5.4/apidocs/org/apache/tapestry5/corelib/mixins/OverrideFieldFocus.html">OverrideFieldFocus</a> mixin forces the email field to be the focus field, regardless.</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/general-questions.html
==============================================================================
--- websites/production/tapestry/content/general-questions.html (original)
+++ websites/production/tapestry/content/general-questions.html Sat Feb 3 18:21:36 2018
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css' rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet' type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js' type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,7 +77,16 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><plain-text-body>{scrollbar}</plain-text-body><h2 id="GeneralQuestions-GeneralQuestions">General Questions</h2><p></p><h3 id="GeneralQuestions-HowdoIgetstartedwithTapestry?">How do I get started with Tapestry?</h3><p>The easiest way to get started is to use <a class="external-link" href="http://maven.apache.org">Apache Maven</a> to create your initial project; Maven can use an <em>archetype</em> (a kind of project template) to create a bare-bones Tapestry application for you. See the <a href="getting-started.html">Getting Started</a> page for more details.</p><p>Even without Maven, Tapestry is quite easy to set up. You just need to <a href="download.html">download</a> the binaries and setup your build to place them inside your WAR's WEB-INF/lib folder. The rest is just some one-time <a href="configuration.html">configuration of the web.xml deployment descriptor</a>.</p><h3 id="GeneralQuestions-WhydoesTapestryusePrototype?Whynotinsertfa
voriteJavaScriptlibraryhere?">Why does Tapestry use Prototype? Why not <em>insert favorite JavaScript library here</em>?</h3><p>An important goal for Tapestry is seamless DHTML and Ajax integration. To serve that goal, it was important that the built in components be capable of Ajax operations, such as dynamically re-rendering parts of the page. Because of that, it made sense to bundle a well-known JavaScript library as part of Tapestry.</p><p>At the time (this would be 2006-ish), Prototype and Scriptaculous were well known and well documented, and jQuery was just getting started.</p><p>The intent has always been to make this aspect of Tapestry pluggable. Tapestry 5.4 includes the option of either Prototype or jQuery Tapestry 5.5 will remove Prototype as an option..</p><h3 id="GeneralQuestions-WhydoesTapestryhaveitsownInversionofControlContainer?WhynotSpringorGuice?">Why does Tapestry have its own Inversion of Control Container? Why not Spring or Guice?</h3><p>An Inversion of Contro
l Container is <em>the</em> key piece of Tapestry's infrastructure. It is absolutely necessary to create software as robust, performant ,and extensible as Tapestry.</p><p>Tapestry IoC includes a number of features that distinguish itself from other containers:</p><ul><li>Configured in code, not XML</li><li>Built-in extension mechanism for services: configurations and contributions</li><li>Built-in aspect oriented programming model (service decorations and advice)</li><li>Easy modularization</li><li>Best-of-breed exception reporting</li></ul><p>Because Tapestry is implemented on top of its IoC container, and because the container makes it easy to extend or replace any service inside the container, it is possible to make the small changes to Tapestry needed to customize it to any project's needs.</p><h3 id="GeneralQuestions-HowdoIupgradefromTapestry4toTapestry5?">How do I upgrade from Tapestry 4 to Tapestry 5?</h3><p>There is no existing tool that supports upgrading from Tapestry 4 to
Tapestry 5; Tapestry 5 is a complete rewrite.</p><p>Many of the basic concepts in Tapestry 4 are still present in Tapestry 5, but refactored, improved, streamlined, and simplified. The basic concept of pages, templates and components are largely the same. Other aspects, such as server-side event handling, is markedly different.</p><h3 id="GeneralQuestions-HowdoIupgradefromoneversionofTapestry5toanother?">How do I upgrade from one version of Tapestry 5 to another?</h3><p>A lot of effort goes into making an upgrade from one Tapestry 5 release to another go smoothly. In the general case, it is just a matter of updating the version number in your Maven <code>build.xml</code> or Gradle <code>build.gradle</code> file and executing the appropriate commands (e.g., <code>gradle idea</code> or <code>mvn eclipse:eclipse</code>) to bring your local workspace up to date with the latest binaries.</p><p>After changing dependencies, you should always perform a clean recompile of your application.<
/p><p>We make every effort to ensure backwards-compatibility. Tapestry is mostly coded in terms of interfaces; those interfaces are stable to a point: interfaces your code is expected to implement are usually completely frozen; interfaces your code is expected to invoke, such as the interfaces to IoC services, are stable, but may have new methods added in a release; existing methods are not changed.</p><p>In <em>rare</em> cases a choice is necessary between fixing bugs (or adding essential functionality) and maintaining complete backwards compatibility; in those cases, an incompatible change may be introduced. These are always discussed in detail in the <a href="release-notes.html">Release Notes</a> for the specific release. You should always read the release notes before attempting an upgrade, and always (really, <em>always</em>) be prepared to retest your application afterwards.</p><p>Note that you should be careful any time you make use of <strong>internal</strong> APIs (you can
tell an API is internal by the package name, <code>org.apache.tapestry5.internal...</code>. Internal APIs may change <em>at any time</em>; there's no guarantee of backwards compatibility. Please always check on the documentation, or consult the user mailing list, to see if there's a stable, public alternative. If you do make use of internal APIs, be sure to get a discussion going so that your needs can be met in the future by a stable, public API.</p><p><span style="color: rgb(83,145,38);font-size: 16.0px;line-height: 1.5625;">Why are there both Request and HttpServletRequest?</span></p><p>Tapestry's Request interface is <em>very</em> close to the standard HttpServletRequest interface. It differs in a few ways, omitting some unneeded methods, and adding a couple of new methods (such as <code>isXHR()</code>), as well as changing how some existing methods operate. For example, <code>getParameterNames()</code> returns a sorted List of Strings; HttpServletRequest returns an Enumeration
, which is a very dated approach.</p><p>However, the stronger reason for Request (and the related interfaces Response and Session) is to enable the support for Portlets at some point in the future. By writing code in terms of Tapestry's Request, and not HttpServletRequest, you can be assured that the same code will operate in both Servlet Tapestry and Portlet Tapestry.</p><plain-text-body>{scrollbar}</plain-text-body></div>
+ <div id="ConfluenceContent"><h2 id="GeneralQuestions-GeneralQuestions">General Questions</h2><p><style type="text/css">/*<![CDATA[*/
+div.rbtoc1517682034135 {padding: 0px;}
+div.rbtoc1517682034135 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1517682034135 li {margin-left: 0px;padding-left: 0px;}
+
+/*]]>*/</style></p><div class="toc-macro rbtoc1517682034135">
+<ul class="toc-indentation"><li><a href="#GeneralQuestions-GeneralQuestions">General Questions</a>
+<ul class="toc-indentation"><li><a href="#GeneralQuestions-HowdoIgetstartedwithTapestry?">How do I get started with Tapestry?</a></li><li><a href="#GeneralQuestions-WhydoesTapestryusePrototype?WhynotinsertfavoriteJavaScriptlibraryhere?">Why does Tapestry use Prototype? Why not insert favorite JavaScript library here?</a></li><li><a href="#GeneralQuestions-WhydoesTapestryhaveitsownInversionofControlContainer?WhynotSpringorGuice?">Why does Tapestry have its own Inversion of Control Container? Why not Spring or Guice?</a></li><li><a href="#GeneralQuestions-HowdoIupgradefromTapestry4toTapestry5?">How do I upgrade from Tapestry 4 to Tapestry 5?</a></li><li><a href="#GeneralQuestions-HowdoIupgradefromoneversionofTapestry5toanother?">How do I upgrade from one version of Tapestry 5 to another?</a></li></ul>
+</li></ul>
+</div><h3 id="GeneralQuestions-HowdoIgetstartedwithTapestry?">How do I get started with Tapestry?</h3><p>The easiest way to get started is to use <a class="external-link" href="http://maven.apache.org">Apache Maven</a> to create your initial project; Maven can use an <em>archetype</em> (a kind of project template) to create a bare-bones Tapestry application for you. See the <a href="general-questions.html">General Questions</a> page for more details.</p><p>Even without Maven, Tapestry is quite easy to set up. You just need to <a href="general-questions.html">download</a> the binaries and setup your build to place them inside your WAR's WEB-INF/lib folder. The rest is just some one-time <a href="general-questions.html">configuration of the web.xml deployment descriptor</a>.</p><h3 id="GeneralQuestions-WhydoesTapestryusePrototype?WhynotinsertfavoriteJavaScriptlibraryhere?">Why does Tapestry use Prototype? Why not <em>insert favorite JavaScript library here</em>?</h3><p>An importan
t goal for Tapestry is seamless DHTML and Ajax integration. To serve that goal, it was important that the built in components be capable of Ajax operations, such as dynamically re-rendering parts of the page. Because of that, it made sense to bundle a well-known JavaScript library as part of Tapestry.</p><p>At the time (this would be 2006-ish), Prototype and Scriptaculous were well known and well documented, and jQuery was just getting started.</p><p>The intent has always been to make this aspect of Tapestry pluggable. Tapestry 5.4 includes the option of either Prototype or jQuery Tapestry 5.5 will remove Prototype as an option..</p><h3 id="GeneralQuestions-WhydoesTapestryhaveitsownInversionofControlContainer?WhynotSpringorGuice?">Why does Tapestry have its own Inversion of Control Container? Why not Spring or Guice?</h3><p>An Inversion of Control Container is <em>the</em> key piece of Tapestry's infrastructure. It is absolutely necessary to create software as robust, performant ,an
d extensible as Tapestry.</p><p>Tapestry IoC includes a number of features that distinguish itself from other containers:</p><ul><li>Configured in code, not XML</li><li>Built-in extension mechanism for services: configurations and contributions</li><li>Built-in aspect oriented programming model (service decorations and advice)</li><li>Easy modularization</li><li>Best-of-breed exception reporting</li></ul><p>Because Tapestry is implemented on top of its IoC container, and because the container makes it easy to extend or replace any service inside the container, it is possible to make the small changes to Tapestry needed to customize it to any project's needs.</p><h3 id="GeneralQuestions-HowdoIupgradefromTapestry4toTapestry5?">How do I upgrade from Tapestry 4 to Tapestry 5?</h3><p>There is no existing tool that supports upgrading from Tapestry 4 to Tapestry 5; Tapestry 5 is a complete rewrite.</p><p>Many of the basic concepts in Tapestry 4 are still present in Tapestry 5, but refactor
ed, improved, streamlined, and simplified. The basic concept of pages, templates and components are largely the same. Other aspects, such as server-side event handling, is markedly different.</p><h3 id="GeneralQuestions-HowdoIupgradefromoneversionofTapestry5toanother?">How do I upgrade from one version of Tapestry 5 to another?</h3><p>A lot of effort goes into making an upgrade from one Tapestry 5 release to another go smoothly. In the general case, it is just a matter of updating the version number in your Maven <code>build.xml</code> or Gradle <code>build.gradle</code> file and executing the appropriate commands (e.g., <code>gradle idea</code> or <code>mvn eclipse:eclipse</code>) to bring your local workspace up to date with the latest binaries.</p><p>After changing dependencies, you should always perform a clean recompile of your application.</p><p>We make every effort to ensure backwards-compatibility. Tapestry is mostly coded in terms of interfaces; those interfaces are stable
to a point: interfaces your code is expected to implement are usually completely frozen; interfaces your code is expected to invoke, such as the interfaces to IoC services, are stable, but may have new methods added in a release; existing methods are not changed.</p><p>In <em>rare</em> cases a choice is necessary between fixing bugs (or adding essential functionality) and maintaining complete backwards compatibility; in those cases, an incompatible change may be introduced. These are always discussed in detail in the <a href="general-questions.html">General Questions</a> for the specific release. You should always read the release notes before attempting an upgrade, and always (really, <em>always</em>) be prepared to retest your application afterwards.</p><p>Note that you should be careful any time you make use of <strong>internal</strong> APIs (you can tell an API is internal by the package name, <code>org.apache.tapestry5.internal...</code>. Internal APIs may change <em>at any ti
me</em>; there's no guarantee of backwards compatibility. Please always check on the documentation, or consult the user mailing list, to see if there's a stable, public alternative. If you do make use of internal APIs, be sure to get a discussion going so that your needs can be met in the future by a stable, public API.</p><p><span style="color: rgb(83,145,38);">Why are there both Request and HttpServletRequest?</span></p><p>Tapestry's Request interface is <em>very</em> close to the standard HttpServletRequest interface. It differs in a few ways, omitting some unneeded methods, and adding a couple of new methods (such as <code>isXHR()</code>), as well as changing how some existing methods operate. For example, <code>getParameterNames()</code> returns a sorted List of Strings; HttpServletRequest returns an Enumeration, which is a very dated approach.</p><p>However, the stronger reason for Request (and the related interfaces Response and Session) is to enable the support for Portlets
at some point in the future. By writing code in terms of Tapestry's Request, and not HttpServletRequest, you can be assured that the same code will operate in both Servlet Tapestry and Portlet Tapestry.</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/google-app-engine.html
==============================================================================
--- websites/production/tapestry/content/google-app-engine.html (original)
+++ websites/production/tapestry/content/google-app-engine.html Sat Feb 3 18:21:36 2018
@@ -44,13 +44,26 @@
<div class="wrapper bs">
- <div id="navigation"><div class="nav"><ul class="alternate"><li><a href="index.html">Home</a></li><li><a href="getting-started.html">Getting Started</a></li><li><a href="documentation.html">Documentation</a></li><li><a href="download.html">Download</a></li><li><a href="about.html">About</a></li><li><a class="external-link" href="http://www.apache.org/licenses/LICENSE-2.0">License</a></li><li><a href="community.html">Community</a></li><li><a class="external-link" href="http://www.apache.org/security/">Security</a></li><li><a class="external-link" href="http://www.apache.org/">Apache</a></li><li><a class="external-link" href="http://www.apache.org/foundation/sponsorship.html">Sponsorship</a></li><li><a class="external-link" href="http://www.apache.org/foundation/thanks.html">Thanks</a></li></ul></div></div>
+ <div id="navigation"><div class="nav"><ul class="alternate"><li><a href="index.html">Home</a></li><li><a href="getting-started.html">Getting Started</a></li><li><a href="documentation.html">Documentation</a></li><li><a href="download.html">Download</a></li><li><a href="about.html">About</a></li><li><a class="external-link" href="http://www.apache.org/licenses/LICENSE-2.0">License</a></li><li><a href="community.html">Community</a></li><li><a class="external-link" href="http://www.apache.org/security/">Security</a></li><li><a class="external-link" href="http://www.apache.org/">Apache</a></li><li><a class="external-link" href="http://www.apache.org/foundation/sponsorship.html">Sponsorship</a></li><li><a class="external-link" href="http://www.apache.org/foundation/thanks.html">Thanks</a></li></ul></div>
+
+</div>
<div id="top">
- <div id="smallbanner"><div class="searchbox" style="float:right;margin: .3em 1em .1em 1em"><span style="color: #999; font-size: 90%">Tapestry docs, issues, wikis & blogs:</span><form enctype="application/x-www-form-urlencoded" method="get" action="http://tapestry.apache.org/search.html">
- <input type="text" name="q">
- <input type="submit" value="Search">
-</form></div><div class="emblem" style="float:left"><p><a href="index.html"><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource" src="http://tapestry.apache.org/images/tapestry_small.png" data-image-src="http://tapestry.apache.org/images/tapestry_small.png"></span></a></p></div><div class="title" style="float:left; margin: 0 0 0 3em"><h1 id="SmallBanner-PageTitle">Google App Engine</h1></div></div>
+ <div id="smallbanner"><div class="searchbox" style="float:right;margin: .3em 1em .1em 1em"><span style="color: #999; font-size: 90%">Tapestry docs, issues, wikis & blogs:</span>
+<form enctype="application/x-www-form-urlencoded" method="get" action="http://tapestry.apache.org/search.html">
+ <input type="text" name="q">
+ <input type="submit" value="Search">
+</form>
+
+</div>
+
+
+<div class="emblem" style="float:left"><p><a href="index.html"><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource" src="http://tapestry.apache.org/images/tapestry_small.png" data-image-src="http://tapestry.apache.org/images/tapestry_small.png"></span></a></p></div>
+
+
+<div class="title" style="float:left; margin: 0 0 0 3em"><h1 id="SmallBanner-PageTitle">Google App Engine</h1></div>
+
+</div>
<div class="clearer"></div>
</div>
@@ -73,7 +86,7 @@
configuration.add(IOCSymbols.THREAD_POOL_ENABLED, "false");
...
     }</pre>
-</div></div><p>NOTE: Setting production mode to true is generally only desirable in production and QA/testing environments, but you can override that symbol with a JVM system property (<code>-Dtapestry.production-mode=false</code>) in those environments.</p><h2 id="GoogleAppEngine-SerializableObjects">Serializable Objects</h2><ul><li>Make sure all objects that you store in the servlet session -- particularly those annotated with @SessionState and @SessionAttribute – are actually serializable types. Otherwise you may see strange behavior in which objects seem to lose their session values.</li></ul><h2 id="GoogleAppEngine-FileUploads">File Uploads</h2><ul><li>If you use the Tapestry-upload module (or any file upload mechanism, for that matter), you'll need to be sure that it is configured to <em>not</em> store temporary uploaded files on the file system.  See <a href="uploading-files.html">Uploading Files</a> – particularly the <code>upload.repository-
threshold</code> symbol, which should be set to a large value.</li></ul><h2 id="GoogleAppEngine-OtherConsiderations">Other Considerations</h2><p>Other than the above settings, Tapestry should provide no impediment to running your app under Google App Engine. However, you still need to adhere to all of GAE's usual constraints (as with any app, Tapestry or otherwise). Please carefully read Google's documentation for general guidelines for creating an app that is compatible with GAE.</p></div>
+</div></div><p>NOTE: Setting production mode to true is generally only desirable in production and QA/testing environments, but you can override that symbol with a JVM system property (<code>-Dtapestry.production-mode=false</code>) in those environments.</p><h2 id="GoogleAppEngine-SerializableObjects">Serializable Objects</h2><ul><li>Make sure all objects that you store in the servlet session -- particularly those annotated with @SessionState and @SessionAttribute – are actually serializable types. Otherwise you may see strange behavior in which objects seem to lose their session values.</li></ul><h2 id="GoogleAppEngine-FileUploads">File Uploads</h2><ul><li>If you use the Tapestry-upload module (or any file upload mechanism, for that matter), you'll need to be sure that it is configured to <em>not</em> store temporary uploaded files on the file system.  See <a href="google-app-engine.html">Google App Engine</a> – particularly the <code>upload.reposit
ory-threshold</code> symbol, which should be set to a large value.</li></ul><h2 id="GoogleAppEngine-OtherConsiderations">Other Considerations</h2><p>Other than the above settings, Tapestry should provide no impediment to running your app under Google App Engine. However, you still need to adhere to all of GAE's usual constraints (as with any app, Tapestry or otherwise). Please carefully read Google's documentation for general guidelines for creating an app that is compatible with GAE.</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/hibernate-support-faq.html
==============================================================================
--- websites/production/tapestry/content/hibernate-support-faq.html (original)
+++ websites/production/tapestry/content/hibernate-support-faq.html Sat Feb 3 18:21:36 2018
@@ -77,7 +77,7 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><h2 id="HibernateSupportFAQ-HibernateSupport">Hibernate Support</h2><p>Main article: <a href="hibernate.html">Hibernate</a></p><h3 id="HibernateSupportFAQ-HowdoIgetHibernatetostartupupwhentheapplicationstartsup,ratherthanlazilywiththefirstrequestfortheapplication?">How do I get Hibernate to startup up when the application starts up, rather than lazily with the first request for the application?</h3><p>This was a minor problem in 5.0; by 5.1 it is just a matter of overriding the configuration system <code>tapestry.hibernate-early-startup</code> to "true".</p></div>
+ <div id="ConfluenceContent"><h2 id="HibernateSupportFAQ-HibernateSupport">Hibernate Support</h2><p>Main article: <a href="hibernate-support-faq.html">Hibernate Support FAQ</a></p><h3 id="HibernateSupportFAQ-HowdoIgetHibernatetostartupupwhentheapplicationstartsup,ratherthanlazilywiththefirstrequestfortheapplication?">How do I get Hibernate to startup up when the application starts up, rather than lazily with the first request for the application?</h3><p>This was a minor problem in 5.0; by 5.1 it is just a matter of overriding the configuration system <code>tapestry.hibernate-early-startup</code> to "true".</p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/how-to-upgrade.html
==============================================================================
--- websites/production/tapestry/content/how-to-upgrade.html (original)
+++ websites/production/tapestry/content/how-to-upgrade.html Sat Feb 3 18:21:36 2018
@@ -67,7 +67,7 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><p>Upgrading from one Tapestry version to the next is usually quite easy. Backward compatibility is one of Tapestry's <a href="principles.html">core principles</a>. Even so, sometimes a checklist comes in handy to be sure you consider all of the implications of an upgrade.</p><h2 id="HowtoUpgrade-BeforeYouUpgrade">Before You Upgrade</h2><ol><li>Check the <a href="supported-environments-and-versions.html"><strong>Supported Environments and Versions</strong></a> matrix for Java and app server compatibility.</li><li><strong>Check 3rd Party compatibility:</strong> Find out whether your 3rd party modules are compatible with the new version of Tapestry. Although the Tapestry developers try very hard to maintain backward compatibility across versions, sometimes an older version of a 3rd party module (particularly if it uses internal APIs) won't work with a newly-released version of Tapestry, and in that case you may have to wait until that 3rd
party module is updated by its developers.</li><li><strong>Find and replace all calls to deprecated APIs.</strong> Those are the places most likely to be broken after the upgrade. Most IDEs make it easy to find all deprecated items. In Eclipse, for example, the "Problems" view will show warnings for the use of deprecated APIs if you set it to show "All Errors/Warnings on Project".</li><li><strong>Read the Release Notes:</strong> Each Tapestry version has a <a href="release-notes.html">Release Notes</a> document that lists all of the changes, including some that may cause compatibility issues with your current code. You will save yourself a lot of frustration if you carefully read this material before proceeding.</li></ol><h2 id="HowtoUpgrade-Upgrading">Upgrading</h2><ol><li><strong>Upgrade one step at a time:</strong> It is usually best to upgrade to each intermediate version of Tapestry rather than skipping ahead multiple versions. Skipping versions (except for minor bug fix relea
ses) makes it harder to find all calls to deprecated APIs (see above).</li><li><strong>Update your POM (or download the JARs manually):</strong> If you're using Maven (or Gradle), update the version of the Tapestry dependencies in your pom.xml (or build.gradle) file. Remember to keep all of the Tapestry-supplied modules in sync. For example, don't forget to update the version of Tapestry-hibernate, Tapestry-spring, Tapestry-upload, etc.</li><li><strong>Remove old Tapestry JARs:</strong> If you're not using Maven or Gradle (e.g. if you have the Tapestry JARs in your lib directory), be sure you remove older versions of Tapestry JARs (including JARs for any Tapestry-supplied modules).</li></ol><h2 id="HowtoUpgrade-AfterYouUpgrade">After You Upgrade</h2><ol><li><strong>Remove cached JavaScript:</strong> Tapestry's internal JavaScript may change between releases, and your web browser may have cached the older version. If you have set a specific <a href="configuration.html">application v
ersion</a> in your application's module class (usually AppModule.java), you should increment it to ensure that the URLs to the JavaScript files will have a new version number in their paths. Doing so will cause the browser to download the latest versions from your server. Alternatively, you can just clear your browser's cache (and have all your developers and testers do the same). <em>This issue is usually not a problem on production servers, since you will likely increment the application version with each new production release.</em></li></ol></div>
+ <div id="ConfluenceContent"><p>Upgrading from one Tapestry version to the next is usually quite easy. Backward compatibility is one of Tapestry's <a href="how-to-upgrade.html">core principles</a>. Even so, sometimes a checklist comes in handy to be sure you consider all of the implications of an upgrade.</p><h2 id="HowtoUpgrade-BeforeYouUpgrade">Before You Upgrade</h2><ol><li><strong>Check 3rd Party compatibility:</strong> Find out whether your 3rd party modules are compatible with the new version of Tapestry. Although the Tapestry developers try very hard to maintain backward compatibility across versions, sometimes an older version of a 3rd party module (particularly if it uses internal APIs) won't work with a newly-released version of Tapestry, and in that case you may have to wait until that 3rd party module is updated by its developers.</li><li><strong>Find and replace all calls to deprecated APIs.</strong> Those are the places most likely to be broken after th
e upgrade. Most IDEs make it easy to find all deprecated items. In Eclipse, for example, the "Problems" view will show warnings for the use of deprecated APIs if you set it to show "All Errors/Warnings on Project".</li><li><strong>Read the Release Notes:</strong> Each Tapestry version has a <a href="how-to-upgrade.html">How to Upgrade</a> document that lists all of the changes, including some that may cause compatibility issues with your current code. You will save yourself a lot of frustration if you carefully read this material before proceeding.</li></ol><h2 id="HowtoUpgrade-Upgrading">Upgrading</h2><ol><li><strong>Upgrade one step at a time:</strong> It is usually best to upgrade to each intermediate version of Tapestry rather than skipping ahead multiple versions. Skipping versions (except for minor bug fix releases) makes it harder to find all calls to deprecated APIs (see above).</li><li><strong>Update your POM (or download the JARs manually):</strong> If you're using Maven
(or Gradle), update the version of the Tapestry dependencies in your pom.xml (or build.gradle) file. Remember to keep all of the Tapestry-supplied modules in sync. For example, don't forget to update the version of Tapestry-hibernate, Tapestry-spring, Tapestry-upload, etc.</li><li><strong>Remove old Tapestry JARs:</strong> If you're not using Maven or Gradle (e.g. if you have the Tapestry JARs in your lib directory), be sure you remove older versions of Tapestry JARs (including JARs for any Tapestry-supplied modules).</li></ol><h2 id="HowtoUpgrade-AfterYouUpgrade">After You Upgrade</h2><ol><li><strong>Remove cached JavaScript:</strong> Tapestry's internal JavaScript may change between releases, and your web browser may have cached the older version. If you have set a specific <a href="how-to-upgrade.html">application version</a> in your application's module class (usually AppModule.java), you should increment it to ensure that the URLs to the JavaScript files will have a new versio
n number in their paths. Doing so will cause the browser to download the latest versions from your server. Alternatively, you can just clear your browser's cache (and have all your developers and testers do the same). <em>This issue is usually not a problem on production servers, since you will likely increment the application version with each new production release.</em></li></ol><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/injection-faq.html
==============================================================================
--- websites/production/tapestry/content/injection-faq.html (original)
+++ websites/production/tapestry/content/injection-faq.html Sat Feb 3 18:21:36 2018
@@ -27,6 +27,16 @@
</title>
<link type="text/css" rel="stylesheet" href="/resources/space.css" />
+ <link href='/resources/highlighter/styles/shCoreCXF.css' rel='stylesheet' type='text/css' />
+ <link href='/resources/highlighter/styles/shThemeCXF.css' rel='stylesheet' type='text/css' />
+ <script src='/resources/highlighter/scripts/shCore.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushJava.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushXml.js' type='text/javascript'></script>
+ <script src='/resources/highlighter/scripts/shBrushPlain.js' type='text/javascript'></script>
+ <script>
+ SyntaxHighlighter.defaults['toolbar'] = false;
+ SyntaxHighlighter.all();
+ </script>
<link href="/styles/style.css" rel="stylesheet" type="text/css"/>
@@ -67,13 +77,22 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><plain-text-body>{scrollbar}</plain-text-body><h2 id="InjectionFAQ-Injection">Injection</h2><p>Main article: <a href="injection.html">Injection</a></p><h3 id="InjectionFAQ-What'sthedifferencebetweenthe@Componentand@InjectComponentannotations?">What's the difference between the <code>@Component</code> and <code>@InjectComponent</code> annotations?</h3><p>The <code>@Component</code> annotation is used to define the <em>type</em> of component, and its parameter bindings. When using <code>@Component</code>, the template must not define the type, and any parameter bindings are merged in:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> <a t:id="home" class="nav">Back to home</a>
-</plain-text-body><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @Component(parameters={ "page=index" })
+ <div id="ConfluenceContent"><h2 id="InjectionFAQ-Injection">Injection</h2><p>Main article: <a href="injection-faq.html">Injection FAQ</a></p><h3 id="InjectionFAQ-What'sthedifferencebetweenthe@Componentand@InjectComponentannotations?">What's the difference between the <code>@Component</code> and <code>@InjectComponent</code> annotations?</h3><p>The <code>@Component</code> annotation is used to define the <em>type</em> of component, and its parameter bindings. When using <code>@Component</code>, the template must not define the type, and any parameter bindings are merged in:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> <a t:id="home" class="nav">Back to home</a>
+</pre>
+</div></div><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @Component(parameters={ "page=index" })
private PageLink home;
-</plain-text-body><p>Here the type of component is defined by the field type. The field name is matched against the <code>t:id</code> in the template. The <code>page</code> parameter is set in the Java class, and the informal <code>class</code> parameter is set in the template. If the tag in the template was <code><t:pagelink></code>, or if the template tag included the attribute <code>t:type="pagelink"</code>, then you would see an exception.</p><p>By contrast, <code>@InjectComponent</code> expects the component to be already defined, and doesn't allow any configuration of it:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> <t:form t:id="login"> .... </t:form>
-</plain-text-body><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @InjectComponent
+</pre>
+</div></div><p>Here the type of component is defined by the field type. The field name is matched against the <code>t:id</code> in the template. The <code>page</code> parameter is set in the Java class, and the informal <code>class</code> parameter is set in the template. If the tag in the template was <code><t:pagelink></code>, or if the template tag included the attribute <code>t:type="pagelink"</code>, then you would see an exception.</p><p>By contrast, <code>@InjectComponent</code> expects the component to be already defined, and doesn't allow any configuration of it:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> <t:form t:id="login"> .... </t:form>
+</pre>
+</div></div><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @InjectComponent
private Form login;
-</plain-text-body><p>Again, we're matching the field name to the component id, and you would get an error if the component is not defined in the template.</p><h3 id="InjectionFAQ-What'sthedifferencebetweenthe@InjectPageand@InjectContainerannotations?">What's the difference between the <code>@InjectPage</code> and <code>@InjectContainer</code> annotations?</h3><p>The <code>@InjectPage</code> annotation is used to inject some page in the application into a field of some other page. You often see it used from event handler methods:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @InjectPage
+</pre>
+</div></div><p>Again, we're matching the field name to the component id, and you would get an error if the component is not defined in the template.</p><h3 id="InjectionFAQ-What'sthedifferencebetweenthe@InjectPageand@InjectContainerannotations?">What's the difference between the <code>@InjectPage</code> and <code>@InjectContainer</code> annotations?</h3><p>The <code>@InjectPage</code> annotation is used to inject some page in the application into a field of some other page. You often see it used from event handler methods:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @InjectPage
private ConfirmRegistration confirmRegistration;
Object onSuccessFromRegistrationForm()
@@ -83,21 +102,31 @@
return confirmRegistration;
}
-</plain-text-body><p>This code pattern is used to configure peristent properties of a page before returning it; Tapestry will send a client redirect to the page to present the data.</p><p><code>@InjectContainer</code> can be used inside a component or a mixin. In a component, it injects the immediate container of the component; this is often the top-level page object.</p><p>In a mixin, it injects the component to which the mixin is attached.</p><h3 id="InjectionFAQ-IgetanexceptionbecauseIhavetwoserviceswiththesameinterface,howdoIhandlethis?">I get an exception because I have two services with the same interface, how do I handle this?</h3><p>It's not uncommon to have two or more services that implement the exact same interface. When you inject, you might start by just identifying the type of service to inject:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @Inject
+</pre>
+</div></div><p>This code pattern is used to configure peristent properties of a page before returning it; Tapestry will send a client redirect to the page to present the data.</p><p><code>@InjectContainer</code> can be used inside a component or a mixin. In a component, it injects the immediate container of the component; this is often the top-level page object.</p><p>In a mixin, it injects the component to which the mixin is attached.</p><h3 id="InjectionFAQ-IgetanexceptionbecauseIhavetwoserviceswiththesameinterface,howdoIhandlethis?">I get an exception because I have two services with the same interface, how do I handle this?</h3><p>It's not uncommon to have two or more services that implement the exact same interface. When you inject, you might start by just identifying the type of service to inject:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @Inject
private ComponentEventResultProcessor processor;
-</plain-text-body><p>Which results in the error: <strong>Service interface org.apache.tapestry5.services.ComponentEventResultProcessor is matched by 3 services: AjaxComponentEventResultProcessor, ComponentEventResultProcessor, ComponentInstanceResultProcessor. Automatic dependency resolution requires that exactly one service implement the interface.</strong></p><p>We need more information than just the service interface type in order to identify which of the three services to inject. One possibility is to inject with the correct service id:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @InjectService("ComponentEventResultProcessor")
+</pre>
+</div></div><p>Which results in the error: <strong>Service interface org.apache.tapestry5.services.ComponentEventResultProcessor is matched by 3 services: AjaxComponentEventResultProcessor, ComponentEventResultProcessor, ComponentInstanceResultProcessor. Automatic dependency resolution requires that exactly one service implement the interface.</strong></p><p>We need more information than just the service interface type in order to identify which of the three services to inject. One possibility is to inject with the correct service id:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @InjectService("ComponentEventResultProcessor")
private ComponentEventResultProcessor processor;
-</plain-text-body><p>This works ... but it is clumsy. If the service id, "ComponentEventResultProcessor", ever changes, this code will break. It's not <em>refactoring safe</em>.</p><p>Instead, we should use marker annotations. If we look at <code>TapestryModule</code>, where the ComponentEventResultProcessor service is defined, we'll see it identifies the necessary markers:</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @Marker(
+</pre>
+</div></div><p>This works ... but it is clumsy. If the service id, "ComponentEventResultProcessor", ever changes, this code will break. It's not <em>refactoring safe</em>.</p><p>Instead, we should use marker annotations. If we look at <code>TapestryModule</code>, where the ComponentEventResultProcessor service is defined, we'll see it identifies the necessary markers:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @Marker(
{ Primary.class, Traditional.class })
public ComponentEventResultProcessor buildComponentEventResultProcessor(
Map<Class, ComponentEventResultProcessor> configuration)
{
return constructComponentEventResultProcessor(configuration);
}
-</plain-text-body><p>When a service has marker annotations, the annotations present at the <em>point of injection</em> (the field, method parameter, or constructor parameter) are used to select a matching service. The list of services that match by type is then filtered to only include services that have all of the marker annotations present at the point of injection.</p><parameter ac:name="controls">true</parameter><parameter ac:name="linenumbers">true</parameter><plain-text-body> @Inject
+</pre>
+</div></div><p>When a service has marker annotations, the annotations present at the <em>point of injection</em> (the field, method parameter, or constructor parameter) are used to select a matching service. The list of services that match by type is then filtered to only include services that have all of the marker annotations present at the point of injection.</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: true; theme: Default" style="font-size:12px;"> @Inject
@Traditional @Primary
private ComponentEventResultProcessor processor;
-</plain-text-body><p>The two marker annotations, <code>@Traditional</code> and <code>@Primary</code>, ensure that only a single service matches.</p><h3 id="InjectionFAQ-What'sthedifferencebetween@Injectand@Environmental?">What's the difference between <code>@Inject</code> and <code>@Environmental</code>?</h3><p><code>@Inject</code> is relatively general; it can be used to inject resources specific to a page or component (such as ComponentResources, Logger, or Messages), or it can inject services or other objects obtained from the Tapestry IoC container. Once the page is loaded, the values for these injections never change.</p><p><code>@Environmental</code> is different; it exposes a request-scoped, dynamically bound value:</p><ul><li>"Request scoped": different threads (processing different requests) will see different values when reading the field.</li><li>"Dynamically bound": the value is explicitly placed into the Environment, and can be overridden at any time.</li></ul><p>Enviro
nmentals are a form of loosely connected communication between an outer component (or even a service) and an inner component. Example: the Form component places a <code>FormSupport</code> object into the environment. Other components, such as TextField, use the <code>FormSupport</code> when rendering to perform functions such as allocate unique control names or register client-side validations. The TextField doesn't require that the Form component be the immediate container component, or even an ancestor: a Form on one page may, indirectly, communicate with a TextField on some entirely different page. Neither component directly links to the other, the <code>FormSupport</code> is the conduit that connects them.</p><p>The term "Environmental" was chosen as the value "comes from the environment".</p><h3 id="InjectionFAQ-Butwait...IseeIusedthe@Injectannotationanditstillworked.Whatgives?">But wait ... I see I used the <code>@Inject</code> annotation and it still worked. What gives?</h3><
p>In certain cases, Tapestry exposes a service (which can be injected) that is a proxy to the environmental; this is primarily for common environmentals, such as <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/javascript/JavaScriptSupport.html">JavaScriptSupport</a>, that may be needed outside of component classes. You can see this in TapestryModule:</p><parameter ac:name="">Java</parameter><parameter ac:name="title">TapestryModule.java (partial)</parameter><plain-text-body> /**
+</pre>
+</div></div><p>The two marker annotations, <code>@Traditional</code> and <code>@Primary</code>, ensure that only a single service matches.</p><h3 id="InjectionFAQ-What'sthedifferencebetween@Injectand@Environmental?">What's the difference between <code>@Inject</code> and <code>@Environmental</code>?</h3><p><code>@Inject</code> is relatively general; it can be used to inject resources specific to a page or component (such as ComponentResources, Logger, or Messages), or it can inject services or other objects obtained from the Tapestry IoC container. Once the page is loaded, the values for these injections never change.</p><p><code>@Environmental</code> is different; it exposes a request-scoped, dynamically bound value:</p><ul><li>"Request scoped": different threads (processing different requests) will see different values when reading the field.</li><li>"Dynamically bound": the value is explicitly placed into the Environment, and can be overridden at any time.</li></ul><p>Environmenta
ls are a form of loosely connected communication between an outer component (or even a service) and an inner component. Example: the Form component places a <code>FormSupport</code> object into the environment. Other components, such as TextField, use the <code>FormSupport</code> when rendering to perform functions such as allocate unique control names or register client-side validations. The TextField doesn't require that the Form component be the immediate container component, or even an ancestor: a Form on one page may, indirectly, communicate with a TextField on some entirely different page. Neither component directly links to the other, the <code>FormSupport</code> is the conduit that connects them.</p><p>The term "Environmental" was chosen as the value "comes from the environment".</p><h3 id="InjectionFAQ-Butwait...IseeIusedthe@Injectannotationanditstillworked.Whatgives?">But wait ... I see I used the <code>@Inject</code> annotation and it still worked. What gives?</h3><p>In c
ertain cases, Tapestry exposes a service (which can be injected) that is a proxy to the environmental; this is primarily for common environmentals, such as <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/javascript/JavaScriptSupport.html">JavaScriptSupport</a>, that may be needed outside of component classes. You can see this in TapestryModule:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>TapestryModule.java (partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;"> /**
* Builds a proxy to the current {@link JavaScriptSupport} inside this thread's {@link Environment}.
*
* @since 5.2.0
@@ -106,11 +135,14 @@
{
return environmentalBuilder.build(JavaScriptSupport.class);
}
-</plain-text-body><p>This kind of logic is based on the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/EnvironmentalShadowBuilder.html">EnvironmentalShadowBuilder</a> service.</p><h3 id="InjectionFAQ-Ok,butRequestisasingletonservice,notanenvironmental,andIcaninjectthat.IsTapestryreallythreadsafe?">Ok, but Request is a singleton service, not an environmental, and I can inject that. Is Tapestry really thread safe?</h3><p>Yes, of course Tapestry is thread safe. The Request service is another special case, as seen in TapestryModule:</p><parameter ac:name="">Java</parameter><parameter ac:name="title">TapestryModule.java (partial)</parameter><plain-text-body> public Request buildRequest()
+</pre>
+</div></div><p>This kind of logic is based on the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/EnvironmentalShadowBuilder.html">EnvironmentalShadowBuilder</a> service.</p><h3 id="InjectionFAQ-Ok,butRequestisasingletonservice,notanenvironmental,andIcaninjectthat.IsTapestryreallythreadsafe?">Ok, but Request is a singleton service, not an environmental, and I can inject that. Is Tapestry really thread safe?</h3><p>Yes, of course Tapestry is thread safe. The Request service is another special case, as seen in TapestryModule:</p><div class="code panel pdl" style="border-width: 1px;"><div class="codeHeader panelHeader pdl" style="border-bottom-width: 1px;"><b>TapestryModule.java (partial)</b></div><div class="codeContent panelContent pdl">
+<pre class="brush: java; gutter: false; theme: Default" style="font-size:12px;"> public Request buildRequest()
{
return shadowBuilder.build(requestGlobals, "request", Request.class);
}
-</plain-text-body><p><a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestGlobals.html">RequestGlobals</a> is a per-thread service. The Request service is a global singleton created by the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/ioc/services/PropertyShadowBuilder.html">PropertyShadowBuilder</a> service, but is just a proxy. It has no internal state; invoking a method on the Request service just turns around and extracts the Request object from the per-thread RequestGlobals and invokes the same method there.</p><h3 id="InjectionFAQ-Iuse@Injectonafieldtoinjectaservice,butthefieldisstillnull,whathappened?">I use <code>@Inject</code> on a field to inject a service, but the field is still null, what happened?</h3><p>This can happen when you use the wrong <code>@Inject</code> annotation; for example, com.google.inject.Inject instead of org.apache.tapestry5.ioc.annotations.Inj
ect. This can occur when you have TestNG on the classpath, for example, and your IDE is too helpful. Double check your imports when things seem weird.</p><p>Also remember that <code>@Inject</code> on fields works for components and for service implementations or other objects that Tapestry instantiates, but not on arbitrary objects (that are created via Java's new keyword).</p><plain-text-body>{scrollbar}</plain-text-body></div>
+</pre>
+</div></div><p><a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestGlobals.html">RequestGlobals</a> is a per-thread service. The Request service is a global singleton created by the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/ioc/services/PropertyShadowBuilder.html">PropertyShadowBuilder</a> service, but is just a proxy. It has no internal state; invoking a method on the Request service just turns around and extracts the Request object from the per-thread RequestGlobals and invokes the same method there.</p><h3 id="InjectionFAQ-Iuse@Injectonafieldtoinjectaservice,butthefieldisstillnull,whathappened?">I use <code>@Inject</code> on a field to inject a service, but the field is still null, what happened?</h3><p>This can happen when you use the wrong <code>@Inject</code> annotation; for example, com.google.inject.Inject instead of org.apache.tapestry5.ioc.annotations.Inject. T
his can occur when you have TestNG on the classpath, for example, and your IDE is too helpful. Double check your imports when things seem weird.</p><p>Also remember that <code>@Inject</code> on fields works for components and for service implementations or other objects that Tapestry instantiates, but not on arbitrary objects (that are created via Java's new keyword).</p></div>
</div>
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