You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@tapestry.apache.org by bu...@apache.org on 2018/02/25 23:20:06 UTC
svn commit: r1025970 [4/5] - in /websites/production/tapestry/content: ./
cache/
Modified: websites/production/tapestry/content/page-life-cycle.html
==============================================================================
--- websites/production/tapestry/content/page-life-cycle.html (original)
+++ websites/production/tapestry/content/page-life-cycle.html Sun Feb 25 23:20:05 2018
@@ -67,7 +67,7 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><div class="aui-label" style="float:right" title="Related Articles">
+ <div id="ConfluenceContent"><div class="confluence-information-macro confluence-information-macro-note"><span class="aui-icon aui-icon-small aui-iconfont-warning confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>This is an advanced topic. Most users won't ever need to know anything about the page life cycle.</p></div></div><p>In Tapestry, you are free to develop your presentation objects, page and components classes, as ordinary objects, complete with instance variables and so forth.</p><p>This is somewhat revolutionary in terms of web development in Java. By comparison, using traditional servlets, or Struts, your presentation objects (Servlets, or Struts Actions, or the equivalent in other frameworks) are <em>stateless singletons</em>. That is, a <em>single</em> instance is created, and all incoming requests are threaded through that single instance. Because multiple requests are handled by many different threads, this means
that the singleton's instance variables are useless ... any value written into an instance variable would immediately be overwritten by a different thread. Thus, it is necessary to use the Servlet API's HttpServletRequest object to store per-request data, and the HttpSession object to store data between requests.</p><div class="aui-label" style="float:right" title="Related Articles">
@@ -136,7 +136,7 @@
</div>
-<div class="confluence-information-macro confluence-information-macro-note"><span class="aui-icon aui-icon-small aui-iconfont-warning confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>This is an advanced topic. Most users won't ever need to know anything about the page life cycle.</p></div></div><p> </p><p>In Tapestry, you are free to develop your presentation objects, page and components classes, as ordinary objects, complete with instance variables and so forth.</p><p>This is somewhat revolutionary in terms of web development in Java. By comparison, using traditional servlets, or Struts, your presentation objects (Servlets, or Struts Actions, or the equivalent in other frameworks) are <em>stateless singletons</em>. That is, a <em>single</em> instance is created, and all incoming requests are threaded through that single instance. Because multiple requests are handled by many different threads, this means that the singleton's instance
variables are useless ... any value written into an instance variable would immediately be overwritten by a different thread. Thus, it is necessary to use the Servlet API's HttpServletRequest object to store per-request data, and the HttpSession object to store data between requests.</p><p>Tapestry takes a very different approach.</p><p>In Tapestry, each page is a singleton, but with a <em>per thread</em> map of field names & values that Tapestry invisibly manages for you.</p><p>With this approach, all the difficult, ugly issues related to multi-threading go by the wayside. Instead, familiar, simple coding practices (using ordinary methods and fields) can be used.</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>Tapestry 5.0 and 5.1 used page pooling, rather than a singleton page with a per-thread
map, to achieve the same effect.</p></div></div><p>The page life cycle is quite simple:</p><ol><li>When first needed, a page is loaded. Loading a page involves instantiating the components of the page and connecting them together.</li><li>Once a page is loaded, it is <em>attached</em> to the current request. Remember that there will be many threads, each handling its own request to the same page.</li><li>At the end of a request, after a response has been sent to the client, the page is <em>detached</em> from the request. This is a chance to perform any cleanup needed for the page.</li></ol><h2 id="PageLifeCycle-PageLifeCycleMethods">Page Life Cycle Methods</h2><p>There are rare occasions where it is useful for a component to perform some operations, usually some kind of initialization or caching, based on the life cycle of the page.</p><p>As with <a href="component-rendering.html">component rendering</a>, you have the ability to make your components "aware" of these events by telli
ng Tapestry what methods to invoke for each.</p><p>Page life cycle methods should take no parameters and return void.</p><p>You have the choice of attaching an annotation to a method, or simply using the method naming conventions:</p><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Annotation</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>When Called</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageLoaded.html">PageLoaded</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageLoaded()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>After the page is fully loaded</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestr
y.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageAttached.html">PageAttached</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageAttached()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>After the page is attached to the request.</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd">@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageReset.html">PageReset</a></td><td colspan="1" rowspan="1" class="confluenceTd">pageReset()</td><td colspan="1" rowspan="1" class="confluenceTd">After the page is <em>activated</em>, except when requesting the same page</td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageDetached.html">PageDetached</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageDetached()</p></td><td colspan="1" rowspan="1" cl
ass="confluenceTd"><p>AFter the page is detached from the request.</p></td></tr></tbody></table></div><p>The @PageReset life cycle (only for Tapestry 5.2 and later) is invoked on a page render request when the page is linked to from some <em>other</em> page of the application (but <em>not</em> on a link to the same page), or upon a reload of the page in the browser. This is to allow the page to reset its state, if any, when a user returns to the page from some other part of the application.</p><h2 id="PageLifeCycle-ComparisontoJavaServerPages">Comparison to JavaServer Pages</h2><p>JSPs also act as singletons. However, the individual JSP tags are pooled.</p><p>This is one of the areas where Tapestry can significantly outperform JSPs. Much of the code inside a compiled JSP class concerns getting tags from a tag pool, configuring the properties of the tag instance, using the tag instance, then cleaning up the tag instance and putting it back in the pool.</p><p>The operations Tapestry d
oes once per request are instead executed dozens or potentially hundreds of times (depending the complexity of the page, and if any nested loops occur).</p><p>Pooling JSP tags is simply the wrong granularity.</p><p>Tapestry can also take advantage of its more coarse grained caching to optimize how data moves, via parameters, between components. This means that Tapestry pages will actually speed up after they render the first time.</p><h2 id="PageLifeCycle-PagePoolConfiguration">Page Pool Configuration</h2><div class="confluence-information-macro confluence-information-macro-note"><span class="aui-icon aui-icon-small aui-iconfont-warning confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>This section is related to versions of Tapestry prior to 5.2. Modern Tapestry uses an alternate approach that allows a single page instance to be shared across many request processing threads.</p></div></div><p>In Tapestry 5.0 and 5.1, a page pool is used to s
tore page instances. The pool is "keyed" on the name of the page (such as "start") and the <em>locale</em> for the page (such as "en" or "fr").</p><p>Within each key, Tapestry tracks the number of page instances that have been created, as well as the number that are in use (currently attached to a request).</p><p>When a page is first accessed in a request, it is taken from the pool. Tapestry has some <a href="configuration.html">configuration values</a> that control the details of how and when page instances are created.</p><ul><li>If a free page instance is available, the page is marked in use and attached to the request.</li><li>If there are fewer page instances than the <em>soft limit</em>, then a new page instance is simply created and attached to the request.</li><li>If the soft limit has been reached, Tapestry will wait for a short period of time for a page instance to become available before creating a new page instance.</li><li>If the hard limit has been reached, Tapestry w
ill throw an exception rather than create a new page instance.</li><li>Otherwise, Tapestry will create a new page instance.<br clear="none"> Thus a busy application will initially create pages up-to the soft limit (which defaults to five page instances). If the application continues to be pounded with requests, it will slow its request processing, using the soft wait time in an attempt to reuse an existing page instance.</li></ul><p>A truly busy application will continue to create new page instances as needed until the hard limit is reached.</p><p>Remember that all these configuration values are per key: the combination of page name and locale. Thus even with a hard limit of 20, you may eventually find that Tapestry has created 20 start page instances for locale "en" <em>and</em> 20 start page instances for locale "fr" (if your application is configured to support both English and French). Likewise, you may have 20 instances for the start page, and 20 instances for the newaccount pa
ge.</p><p>Tapestry periodically checks its cache for page instances that have not been used recently (within a configurable window). Unused page instances are release to the garbage collector.</p><p>The end result is that you have quite a degree of tuning control over the process. If memory is a limitation and throughput can be sacrificed, try lowering the soft and hard limit and increasing the soft wait.</p><p>If performance is absolute and you have lots of memory, then increase the soft and hard limit and reduce the soft wait. This encourages Tapestry to create more page instances and not wait as long to re-use existing instances.</p></div>
+<p>Tapestry takes a very different approach.</p><p>In Tapestry, each page is a singleton, but with a <em>per thread</em> map of field names & values that Tapestry invisibly manages for you.</p><p>With this approach, all the difficult, ugly issues related to multi-threading go by the wayside. Instead, familiar, simple coding practices (using ordinary methods and fields) can be used.</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>Tapestry 5.0 and 5.1 used page pooling, rather than a singleton page with a per-thread map, to achieve the same effect.</p></div></div><p>The page life cycle is quite simple:</p><ol><li>When first needed, a page is loaded. Loading a page involves instantiating the components of the page and connecting them together.</li><li>Once a page is loaded, it is <em>attached</em> to
the current request. Remember that there will be many threads, each handling its own request to the same page.</li><li>At the end of a request, after a response has been sent to the client, the page is <em>detached</em> from the request. This is a chance to perform any cleanup needed for the page.</li></ol><h2 id="PageLifeCycle-PageLifeCycleMethods">Page Life Cycle Methods</h2><p>There are rare occasions where it is useful for a component to perform some operations, usually some kind of initialization or caching, based on the life cycle of the page.</p><p>As with <a href="component-rendering.html">component rendering</a>, you have the ability to make your components "aware" of these events by telling Tapestry what methods to invoke for each.</p><p>Page life cycle methods should take no parameters and return void.</p><p>You have the choice of attaching an annotation to a method, or simply using the method naming conventions:</p><div class="table-wrap"><table class="confluenceTable"
><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Annotation</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Name</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>When Called</p></th></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageLoaded.html">PageLoaded</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageLoaded()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>After the page is fully loaded</p></td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageAttached.html">PageAttached</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageAttached()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>After the page is attached to the request.</p></td></tr
><tr><td colspan="1" rowspan="1" class="confluenceTd">@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageReset.html">PageReset</a></td><td colspan="1" rowspan="1" class="confluenceTd">pageReset()</td><td colspan="1" rowspan="1" class="confluenceTd">After the page is <em>activated</em>, except when requesting the same page</td></tr><tr><td colspan="1" rowspan="1" class="confluenceTd"><p>@<a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/annotations/PageDetached.html">PageDetached</a></p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>pageDetached()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>AFter the page is detached from the request.</p></td></tr></tbody></table></div><p>The @PageReset life cycle (only for Tapestry 5.2 and later) is invoked on a page render request when the page is linked to from some <em>other</em> page of the application (but <em>no
t</em> on a link to the same page), or upon a reload of the page in the browser. This is to allow the page to reset its state, if any, when a user returns to the page from some other part of the application.</p><h2 id="PageLifeCycle-ComparisontoJavaServerPages">Comparison to JavaServer Pages</h2><p>JSPs also act as singletons. However, the individual JSP tags are pooled.</p><p>This is one of the areas where Tapestry can significantly outperform JSPs. Much of the code inside a compiled JSP class concerns getting tags from a tag pool, configuring the properties of the tag instance, using the tag instance, then cleaning up the tag instance and putting it back in the pool.</p><p>The operations Tapestry does once per request are instead executed dozens or potentially hundreds of times (depending the complexity of the page, and if any nested loops occur).</p><p>Pooling JSP tags is simply the wrong granularity.</p><p>Tapestry can also take advantage of its more coarse grained caching to op
timize how data moves, via parameters, between components. This means that Tapestry pages will actually speed up after they render the first time.</p><h2 id="PageLifeCycle-PagePoolConfiguration">Page Pool Configuration</h2><div class="confluence-information-macro confluence-information-macro-note"><span class="aui-icon aui-icon-small aui-iconfont-warning confluence-information-macro-icon"></span><div class="confluence-information-macro-body"><p>This section is related to versions of Tapestry prior to 5.2. Modern Tapestry uses an alternate approach that allows a single page instance to be shared across many request processing threads.</p></div></div><p>In Tapestry 5.0 and 5.1, a page pool is used to store page instances. The pool is "keyed" on the name of the page (such as "start") and the <em>locale</em> for the page (such as "en" or "fr").</p><p>Within each key, Tapestry tracks the number of page instances that have been created, as well as the number that are in use (currently att
ached to a request).</p><p>When a page is first accessed in a request, it is taken from the pool. Tapestry has some <a href="configuration.html">configuration values</a> that control the details of how and when page instances are created.</p><ul><li>If a free page instance is available, the page is marked in use and attached to the request.</li><li>If there are fewer page instances than the <em>soft limit</em>, then a new page instance is simply created and attached to the request.</li><li>If the soft limit has been reached, Tapestry will wait for a short period of time for a page instance to become available before creating a new page instance.</li><li>If the hard limit has been reached, Tapestry will throw an exception rather than create a new page instance.</li><li>Otherwise, Tapestry will create a new page instance.<br clear="none"> Thus a busy application will initially create pages up-to the soft limit (which defaults to five page instances). If the application continues to b
e pounded with requests, it will slow its request processing, using the soft wait time in an attempt to reuse an existing page instance.</li></ul><p>A truly busy application will continue to create new page instances as needed until the hard limit is reached.</p><p>Remember that all these configuration values are per key: the combination of page name and locale. Thus even with a hard limit of 20, you may eventually find that Tapestry has created 20 start page instances for locale "en" <em>and</em> 20 start page instances for locale "fr" (if your application is configured to support both English and French). Likewise, you may have 20 instances for the start page, and 20 instances for the newaccount page.</p><p>Tapestry periodically checks its cache for page instances that have not been used recently (within a configurable window). Unused page instances are release to the garbage collector.</p><p>The end result is that you have quite a degree of tuning control over the process. If mem
ory is a limitation and throughput can be sacrificed, try lowering the soft and hard limit and increasing the soft wait.</p><p>If performance is absolute and you have lots of memory, then increase the soft and hard limit and reduce the soft wait. This encourages Tapestry to create more page instances and not wait as long to re-use existing instances.</p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/page-navigation.html
==============================================================================
--- websites/production/tapestry/content/page-navigation.html (original)
+++ websites/production/tapestry/content/page-navigation.html Sun Feb 25 23:20:05 2018
@@ -156,11 +156,11 @@
<p>In essence, a Tapestry application is a number of related pages, working together. To some degree, each page is like an application unto itself.</p><p>Any individual request will be targeted at a single page. Requests come in two forms: </p><ul><li><em>component event</em> requests target a specific component on a specific page, triggering an event within that component</li><li><em>render</em> requests target a specific page, and stream the HTML markup for that page back to the client</li></ul><p>This dichotomy between component event requests and render requests alleviates a number of problems in traditional web applications related to the browser back button, or to the user hitting the refresh button in their browser.</p><h3 id="PageNavigation-Contents">Contents</h3><h2 id="PageNavigation-Contents|RelatedArticlesLogicalPageNameShortening"><style type="text/css">/*<![CDATA[*/
-div.rbtoc1519597210782 {padding: 0px;}
-div.rbtoc1519597210782 ul {list-style: disc;margin-left: 0px;}
-div.rbtoc1519597210782 li {margin-left: 0px;padding-left: 0px;}
+div.rbtoc1519600774367 {padding: 0px;}
+div.rbtoc1519600774367 ul {list-style: disc;margin-left: 0px;}
+div.rbtoc1519600774367 li {margin-left: 0px;padding-left: 0px;}
-/*]]>*/</style></h2><div class="toc-macro rbtoc1519597210782">
+/*]]>*/</style></h2><div class="toc-macro rbtoc1519600774367">
<ul class="toc-indentation"><li><a href="#PageNavigation-Contents|RelatedArticlesLogicalPageNameShortening">Logical Page Name Shortening</a></li><li><a href="#PageNavigation-ComponentEventRequests&Responses">Component Event Requests & Responses</a>
<ul class="toc-indentation"><li><a href="#PageNavigation-1.Nullresponse">1. Null response</a></li><li><a href="#PageNavigation-2.Stringresponse">2. String response</a></li><li><a href="#PageNavigation-3.Classresponse">3. Class response</a></li><li><a href="#PageNavigation-4.Pageresponse">4. Page response</a></li><li><a href="#PageNavigation-5.HttpError">5. HttpError</a></li><li><a href="#PageNavigation-6.Linkresponse">6. Link response</a></li><li><a href="#PageNavigation-7.Streamresponse">7. Stream response</a></li><li><a href="#PageNavigation-8.URLresponse">8. URL response</a></li><li><a href="#PageNavigation-9.Objectresponse">9. Object response</a></li></ul>
</li><li><a href="#PageNavigation-PageRenderRequests">Page Render Requests</a></li><li><a href="#PageNavigation-PageActivation">Page Activation</a></li><li><a href="#PageNavigation-PageNavigationPatterns">Page Navigation Patterns</a>
@@ -323,7 +323,7 @@ public Object onAction(){
long onPassivate() { return productId; }
</pre>
-</div></div><p>The setProductId() method is no longer needed.</p><h3 id="PageNavigation-Limitations">Limitations</h3><p>As your application's workflow expands, you may find that there is not a reasonable way to avoid storing some data persistently between requests, outside of the page activation context. For example, if from the ProductDetails page, the user is allowed to navigate to related pages and then back to ProductDetails, it starts to become necessary to keep passing that product id around from page to page to page.</p><p>At some point, persistent values make more sense. Tapestry has several persistence strategies available, including one that stores data in URL query parameters. See <a href="persistent-page-data.html">Persistent Page Data</a> for details.</p></div>
+</div></div><p>The setProductId() method is no longer needed.</p><h3 id="PageNavigation-Limitations">Limitations</h3><p>As your application's workflow expands, you may find that there is not a reasonable way to avoid storing some data persistently between requests, outside of the page activation context. For example, if from the ProductDetails page, the user is allowed to navigate to related pages and then back to ProductDetails, it starts to become necessary to keep passing that product id around from page to page to page.</p><p>At some point, persistent values make more sense. Tapestry has several persistence strategies available, including one that stores data in URL query parameters. See <a href="persistent-page-data.html">Persistent Page Data</a> for details.</p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/parameter-type-coercion.html
==============================================================================
--- websites/production/tapestry/content/parameter-type-coercion.html (original)
+++ websites/production/tapestry/content/parameter-type-coercion.html Sun Feb 25 23:20:05 2018
@@ -161,7 +161,7 @@
</div></div><p> </p><p>Here, the type of all three parameters is <code>int</code>.</p><p>However, it is likely that the component will be used as so:</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;"> Merry Christmas: <t:count end="3"> Ho! </t:count>
</pre>
-</div></div><p>A bare whole number is interpreted by the prop binding prefix as a <code>long</code>. So this is the <em>long</em> value 3.</p><p>Tapestry will automatically coerce the bound value, a <code>long</code>, to the parameter's type, <code>int</code>. This may be a lossy coercion (if the <code>long</code> represents a number larger than can be stored in an <code>int</code>).</p><h2 id="ParameterTypeCoercion-TypeCoercerService">TypeCoercer Service</h2><p>Main Article: <a href="type-coercion.html">Type Coercion</a></p><p>The TypeCoercer service is responsible for this type coercion. This service is part of the <a href="ioc.html">tapestry-ioc</a> module. The service is quite extensible, allowing for new types and coercions to be added easily. The TapestryModule contributes a few additional coercions into the TypeCoercer service.</p></div>
+</div></div><p>A bare whole number is interpreted by the prop binding prefix as a <code>long</code>. So this is the <em>long</em> value 3.</p><p>Tapestry will automatically coerce the bound value, a <code>long</code>, to the parameter's type, <code>int</code>. This may be a lossy coercion (if the <code>long</code> represents a number larger than can be stored in an <code>int</code>).</p><h2 id="ParameterTypeCoercion-TypeCoercerService">TypeCoercer Service</h2><p>Main Article: <a href="type-coercion.html">Type Coercion</a></p><p>The TypeCoercer service is responsible for this type coercion. This service is part of the <a href="ioc.html">tapestry-ioc</a> module. The service is quite extensible, allowing for new types and coercions to be added easily. The TapestryModule contributes a few additional coercions into the TypeCoercer service.</p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/project-layout.html
==============================================================================
--- websites/production/tapestry/content/project-layout.html (original)
+++ websites/production/tapestry/content/project-layout.html Sun Feb 25 23:20:05 2018
@@ -67,7 +67,7 @@
</div>
<div id="content">
- <div id="ConfluenceContent"><h1 id="ProjectLayout-ProjectLayout">Project Layout</h1><p>This is the <em>suggested</em> layout for your Tapestry project; it is the layout of folders and files created by the <a href="getting-started.html">Tapestry Quickstart Archetype</a>. If you are creating your own build using Ant, you may use whatever conventions work for you ... as long as everything gets packaged up into the right place in the target WAR.</p><p>Parts of this project layout mimics the format of an <em>exploded WAR</em> (a WAR file unpackaged onto the file system). This will often enable you to run your application directly from your workspace, without any special build or packaging process, while developing. Each of the major IDEs has plugins to allow you to accomplish this task ... and it's one of the factors (combined with <a href="class-reloading.html">live class reloading</a>) that makes working with Tapestry a breeze.</p><p>Below is a sample project, whose r
oot package is <code>com.example.myapp</code>:</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image" src="project-layout.data/projectlayout.png"></span></p><h2 id="ProjectLayout-Mainsourcefiles-src/main/java">Main source files - src/main/java</h2><p>Main Java source files, the files that will be compiled into the WAR file, are in <code>src/main/java</code>. This is <em>only</em> Java source files. You can see the <code>Index.java</code> source file inside the <code>pages</code> subpackage, and the <code>Layout.java</code> source file inside the <code>components</code> subpackage. The package names demonstrated here are required, dictated by the rules for <a href="component-classes.html">component classes</a></p><p>.</p><p>Compiled Java classes will ultimately be packaged in the WAR inside the <code>WEB-INF/classes</code> folder.</p><h2 id="ProjectLayout-ClasspathResources-src/main/resources">Classpath Resources - src/main/resources</h2><p>Resou
rce files are under <code>src/main/resources</code>. This includes the <a href="localization.html">message catalog</a> for the Index page (<code>Index.properties</code>), as well as the message catalog and <a href="component-templates.html">component template</a> for the Layout component (<code>Layout.tml</code>). These files will also be packaged into the <code>WEB-INF/classes</code> folder of the WAR.</p><p>Component templates will always be stored in the resources folder. Templates for pages may be packaged in the WAR proper instead.</p><h2 id="ProjectLayout-ContextResources-src/main/webapp">Context Resources - src/main/webapp</h2><p>The WAR is built primarily from the <code>src/main/webapp</code> folder; this is where ordinary files are stored (such as images and stylesheets). Page templates may also be stored here (<code>Index.tml</code>). The file <code>src/main/webapp/WEB-INF/web.xml</code> is the servlet container deployment descriptor, which has a very specific <a href="
configuration.html">configuration</a> for Tapestry.</p><p>The build tool (usually Maven) will be responsible for putting compiled classes and resources into the <code>WEB-INF/classes</code> folder of the WAR, and for putting the Tapestry library, and its dependencies (as well as any additional libraries defined by your application) into the <code>WEB-INF/lib</code> folder.</p><h2 id="ProjectLayout-Testing-src/test">Testing - src/test</h2><p>The folders <code>src/test/java</code> and <code>src/test/resources</code> are used when compiling and executing tests. Files in these folders are <em>not</em> packaged into the final WAR.</p></div>
+ <div id="ConfluenceContent"><h1 id="ProjectLayout-ProjectLayout">Project Layout</h1><p>This is the <em>suggested</em> layout for your Tapestry project; it is the layout of folders and files created by the <a href="getting-started.html">Tapestry Quickstart Archetype</a>. If you are creating your own build using Ant, you may use whatever conventions work for you ... as long as everything gets packaged up into the right place in the target WAR.</p><p>Parts of this project layout mimics the format of an <em>exploded WAR</em> (a WAR file unpackaged onto the file system). This will often enable you to run your application directly from your workspace, without any special build or packaging process, while developing. Each of the major IDEs has plugins to allow you to accomplish this task ... and it's one of the factors (combined with <a href="class-reloading.html">live class reloading</a>) that makes working with Tapestry a breeze.</p><p>Below is a sample project, whose r
oot package is <code>com.example.myapp</code>:</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image" src="project-layout.data/projectlayout.png"></span></p><h2 id="ProjectLayout-Mainsourcefiles-src/main/java">Main source files - src/main/java</h2><p>Main Java source files, the files that will be compiled into the WAR file, are in <code>src/main/java</code>. This is <em>only</em> Java source files. You can see the <code>Index.java</code> source file inside the <code>pages</code> subpackage, and the <code>Layout.java</code> source file inside the <code>components</code> subpackage. The package names demonstrated here are required, dictated by the rules for <a href="component-classes.html">component classes</a></p><p>.</p><p>Compiled Java classes will ultimately be packaged in the WAR inside the <code>WEB-INF/classes</code> folder.</p><h2 id="ProjectLayout-ClasspathResources-src/main/resources">Classpath Resources - src/main/resources</h2><p>Resou
rce files are under <code>src/main/resources</code>. This includes the <a href="localization.html">message catalog</a> for the Index page (<code>Index.properties</code>), as well as the message catalog and <a href="component-templates.html">component template</a> for the Layout component (<code>Layout.tml</code>). These files will also be packaged into the <code>WEB-INF/classes</code> folder of the WAR.</p><p>Component templates will always be stored in the resources folder. Templates for pages may be packaged in the WAR proper instead.</p><h2 id="ProjectLayout-ContextResources-src/main/webapp">Context Resources - src/main/webapp</h2><p>The WAR is built primarily from the <code>src/main/webapp</code> folder; this is where ordinary files are stored (such as images and stylesheets). Page templates may also be stored here (<code>Index.tml</code>). The file <code>src/main/webapp/WEB-INF/web.xml</code> is the servlet container deployment descriptor, which has a very specific <a href="
configuration.html">configuration</a> for Tapestry.</p><p>The build tool (usually Maven) will be responsible for putting compiled classes and resources into the <code>WEB-INF/classes</code> folder of the WAR, and for putting the Tapestry library, and its dependencies (as well as any additional libraries defined by your application) into the <code>WEB-INF/lib</code> folder.</p><h2 id="ProjectLayout-Testing-src/test">Testing - src/test</h2><p>The folders <code>src/test/java</code> and <code>src/test/resources</code> are used when compiling and executing tests. Files in these folders are <em>not</em> packaged into the final WAR.</p><p> </p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/property-expressions.html
==============================================================================
--- websites/production/tapestry/content/property-expressions.html (original)
+++ websites/production/tapestry/content/property-expressions.html Sun Feb 25 23:20:05 2018
@@ -140,7 +140,7 @@ mapKey : keyword | constant | propertyCh
<div class="param-body">Support for map literals was added in Tapestry 5.3.</div>
-</div>Notes:<ul><li>Whitespace is ignored.</li><li>Integers and decimals may have a leading sign ('+' or '-').</li><li>Constants are in base 10 (octal and hex notation is not yet supported). Decimals may contain a decimal point (exponent notation not yet supported).</li><li>Literal strings are enclosed in single quotes.</li><li>The <code>rangeOp</code> creates a range object that will iterate between the two values. The upper and lower bounds may be literal integers, or property expressions.</li><li>An identifier by itself is a property name. An identifier with parenthesis is a method invocation.</li><li>Property names, method names, and keywords are case-insensitive.</li><li>'this' is the root object (i.e., the containing component).</li><li>The <code>not</code> operator coerces the expression to a <code>boolean</code> (so it can be used on strings, numbers, etc.).</li><li>Method matching is based on method name and number of parameters, but not parameter types. The <a href="type-
coercion.html">TypeCoercer</a> service is used to convert parameters to the correct type to be passed into the method.</li></ul><h2 id="PropertyExpressions-Examples">Examples</h2><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p> </p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Example</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Notes</p></th></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Keyword</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>this</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Keyword</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>null</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Name</p></th><td colspan="1" rowspan="1" class="confluenceTd"><
p>userName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUserName() or setUserName, depending on context</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Chain</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>user.address.city</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUser().getAddress().getCity() or getUser().getAddress().setCity(), depending on context</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Chain</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>user?.name</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUser() and, if the result is not null, calls getName() on the result</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Invocation</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>groupList.size()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>calls getGroupList().size()</p></
td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Invocation</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>members.findById(user.id)?.name</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getMembers().findById(getUser().getId()).getName() (unless findById returns null)</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Range</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>1..10</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Iterates between integers 1 and 10</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Range</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>1..myList.size()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Iterates between 1 and the result of getMyList().size()</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Literal String</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>'Beer is proof that God lov
es us and wants us to be happy.'</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Use single quotes</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>List</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>[user.name, user.email, user.phone]</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Not Operator</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>! user.deleted</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>the boolean negation of getUser().getDeleted()</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Not, Coerced</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>! user.middleName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>true only if getUser.getMiddleName() returns null or an empty string</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Map</p></th><td colspan="1"
rowspan="1" class="confluenceTd"><p>{ 'framework' : 'Tapestry', 'version' : version }</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Keys are string literals (in single quotes), but could be properties as well</p></td></tr></tbody></table></div></div>
+</div>Notes:<ul><li>Whitespace is ignored.</li><li>Integers and decimals may have a leading sign ('+' or '-').</li><li>Constants are in base 10 (octal and hex notation is not yet supported). Decimals may contain a decimal point (exponent notation not yet supported).</li><li>Literal strings are enclosed in single quotes.</li><li>The <code>rangeOp</code> creates a range object that will iterate between the two values. The upper and lower bounds may be literal integers, or property expressions.</li><li>An identifier by itself is a property name. An identifier with parenthesis is a method invocation.</li><li>Property names, method names, and keywords are case-insensitive.</li><li>'this' is the root object (i.e., the containing component).</li><li>The <code>not</code> operator coerces the expression to a <code>boolean</code> (so it can be used on strings, numbers, etc.).</li><li>Method matching is based on method name and number of parameters, but not parameter types. The <a href="type-
coercion.html">TypeCoercer</a> service is used to convert parameters to the correct type to be passed into the method.</li></ul><h2 id="PropertyExpressions-Examples">Examples</h2><div class="table-wrap"><table class="confluenceTable"><tbody><tr><th colspan="1" rowspan="1" class="confluenceTh"><p> </p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Example</p></th><th colspan="1" rowspan="1" class="confluenceTh"><p>Notes</p></th></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Keyword</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>this</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Keyword</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>null</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Name</p></th><td colspan="1" rowspan="1" class="confluenceTd"><
p>userName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUserName() or setUserName, depending on context</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Chain</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>user.address.city</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUser().getAddress().getCity() or getUser().getAddress().setCity(), depending on context</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Property Chain</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>user?.name</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getUser() and, if the result is not null, calls getName() on the result</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Invocation</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>groupList.size()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>calls getGroupList().size()</p></
td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Method Invocation</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>members.findById(user.id)?.name</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Calls getMembers().findById(getUser().getId()).getName() (unless findById returns null)</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Range</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>1..10</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Iterates between integers 1 and 10</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Range</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>1..myList.size()</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Iterates between 1 and the result of getMyList().size()</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Literal String</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>'Beer is proof that God lov
es us and wants us to be happy.'</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Use single quotes</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>List</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>[user.name, user.email, user.phone]</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p> </p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Not Operator</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>! user.deleted</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>the boolean negation of getUser().getDeleted()</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Not, Coerced</p></th><td colspan="1" rowspan="1" class="confluenceTd"><p>! user.middleName</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>true only if getUser.getMiddleName() returns null or an empty string</p></td></tr><tr><th colspan="1" rowspan="1" class="confluenceTh"><p>Map</p></th><td colspan="1"
rowspan="1" class="confluenceTd"><p>{ 'framework' : 'Tapestry', 'version' : version }</p></td><td colspan="1" rowspan="1" class="confluenceTd"><p>Keys are string literals (in single quotes), but could be properties as well</p></td></tr></tbody></table></div><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/request-processing.html
==============================================================================
--- websites/production/tapestry/content/request-processing.html (original)
+++ websites/production/tapestry/content/request-processing.html Sun Feb 25 23:20:05 2018
@@ -136,7 +136,7 @@
</div>
-<p><strong>Request Processing</strong> involves a sequence of steps that Tapestry performs when every HTTP request comes in. You <em>don't need</em> to know these steps to use Tapestry productively, but understanding the request processing pipeline is helpful if you want to understand Tapestry deeply.</p><p>Much of the early stages of processing are in the form of extensible <a href="pipelinebuilder-service.html">pipelines</a>.</p><h2 id="RequestProcessing-TapestryFilter">Tapestry Filter</h2><p>All incoming requests originate with the TapestryFilter, which is a servlet filter configured inside your application's <a href="configuration.html">web.xml</a>.</p><p>The TapestryFilter is responsible for a number of startup and initialization functions.</p><p>When it receives a request, the TapestryFilter obtains the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/HttpServletRequestHandler.html">HttpServletRequestHandler</a> service
, and invokes its service() method.</p><h2 id="RequestProcessing-HttpServletRequestHandlerPipeline">HttpServletRequestHandler Pipeline</h2><p>This pipeline performs initial processing of the request. It can be extended by contributing a <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/HttpServletRequestFilter.html">HttpServletRequestFilter</a> into the HttpServletRequestHandler service's configuration.</p><p>Tapestry does not contribute any filters into this pipeline of its own.</p><p>The terminator for the pipeline does two things:</p><ul><li>It stores the request and response into the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestGlobals.html">RequestGlobals</a> service. This is a per-thread scoped service that stores per-thread/per-request information.</li><li>It wraps the request and response as a <a class="external-link" href="http://tapestry.apache.org/cur
rent/apidocs/org/apache/tapestry5/services/Request.html">Request</a> and <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/Response.html">Response</a>, and passes them into the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestHandler.html">RequestHandler</a> pipeline.</li></ul><h2 id="RequestProcessing-RequestHandlerPipeline">RequestHandler Pipeline</h2><p>This pipeline is where most extensions related to requests take place. Request represents an abstraction on top of HttpServletRequest. (Primarily, this exists to bridge from the Servlet API objects to the corresponding Tapestry objects. This is to allow for a possible portlet integration for Tapestry.) Where other code and services within Tapestry require access to information in the request, such as query parameters, that information is obtained from the Request (or Response) objects.</p><p>The RequestHandler pipe
line includes a number of built-in filters:</p><ul><li>CheckForUpdates is responsible for <a href="class-reloading.html">class and template reloading</a>.</li><li>Localization identifies the <a href="localization.html">locale for the user</a>.</li><li>StaticFiles checks for URLs that are for static files (files that exist inside the web context) and aborts the request, so that the servlet container can handle the request normally.</li><li>ErrorFilter catches uncaught exceptions from the lower levels of Tapestry and presents the exception report page. This involves the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestExceptionHandler.html">RequestExceptionHandler</a> service, which is responsible for initializing and rendering the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/pages/ExceptionReport.html">core/ExceptionReport</a> page.</li></ul><p>The terminator fo
r this pipeline stores the Request and the Response into RequestGlobals, then requests that the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/Dispatcher.html">MasterDispatcher</a> service figure out how to handle the request (if it is, indeed, a Tapestry request).</p><h2 id="RequestProcessing-MasterDispatcherService">Master Dispatcher Service</h2><p>The MasterDispatcher service is a chain-of-command, aggregating together (in a specific order), several Dispatcher objects. Each Dispatcher is built to recognize and process a particular kind of URL.</p><h3 id="RequestProcessing-RootPathDispatcher">RootPath Dispatcher</h3><p>The RootPath Dispatcher recognizes a request for the application root (i.e., "/") and handles this the same as a render request for the "Start" page. Support for the Start page is kept for legacy purposes. Index pages are the correct approach.</p><h3 id="RequestProcessing-AssetDispatcher">Asset Dispatcher</h3
><p>Requests that begin with "/assets/" are references to <a href="assets.html">asset resources</a> that are stored on the classpath, inside the Tapestry JARs (or perhaps inside the JAR for a component library). The contents of the file will be delivered to the client browser as a byte stream. This dispatcher also handles requests that are simply polling for a change to the file.</p><h3 id="RequestProcessing-PageRenderDispatcher">PageRender Dispatcher</h3><p>Page render requests are requests to render a particular page. Such requests may include additional elements on the path, which will be treated as activation context (see ComponentEvent Dispatcher below). Generally speaking, the activation context is the primary key of some related entity object. This allows the page to reconstruct the state it will need to successfully render itself.</p><p>The event handler method for the activate event may return a value; this is treated the same as the return value from a component action re
quest; typically this will result in a redirect to another page. In this way, the activate event can perform simple validation at the page level ("can the user see this page?").</p><p>Page render URLs consist of the logical name of the page plus additional path elements for the activation context. The dispatcher here strips terms off of the path until it finds a known page name. Thus, "/mypage/27" would look first for a page whose name was "mypage/27", then look for a page name "mypage". Assuming the second search was successful, the page would be activated with the context "27". If no logical page name can be identified, control passes to the next dispatcher.</p><h3 id="RequestProcessing-ComponentEventDispatcher">ComponentEvent Dispatcher</h3><p>The ComponentEvent dispatcher is used to trigger events in components.</p><p>The URL identifies the name of the page, then a series of component ids (the path from the page down to the specific component), then the name of the event to be t
riggered on the component. The remaining path elements are used as the context for the <em>event</em> (not for the page activation, which does not currently apply). For example, "/griddemo.FOO.BAR/3" would locate page "griddemo", then component "FOO.BAR", and trigger an event named "action" (the default event type, which is omitted from the URL), with the context "3".</p><p>If the page in question has an activation context, it is supplied as an additional query parameter on the link.</p><p>In cases where the event type is not the default, "action", it will appear between the nested component id and the event context, preceded by a colon. Example: "/example/foo.bar:magic/99" would trigger an event of type "magic". This is not common in the vanilla Tapestry framework, but will likely be more common as Ajax features (which would not use the normal request logic) are implemented.</p><p>The response from a component action request is typically, but not universally, used to send a redirec
t to the client; the redirect URL is a page render URL to display the response to the event. This is detailed under <a href="page-navigation.html">Request Processing</a>.</p><h2 id="RequestProcessing-RequestGlobalsService">RequestGlobals Service</h2><p>The RequestGlobals service has a life cycle of per-thread; this means that a separate instance exists for every thread, and therefore, for every request. The terminators of the two handler pipelines store the request/response pairs into the RequestGlobals service.</p><h2 id="RequestProcessing-RequestService">Request Service</h2><p>The Request service is a <a href="shadowbuilder-service.html">shadow</a> of the RequestGlobals services' request property. That is, any methods invoked on this service are delegated to the request object stored inside the RequestGlobals.</p><h2 id="RequestProcessing-Overview">Overview</h2><p>The following diagram provides an overview of how the different pipelines, filters and dispatchers interact when pro
cessing an incoming request.</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource confluence-content-image-border" alt="Request Processing" src="https://cwiki-test.apache.org/confluence/download/attachments/22872133/tapestry_request_processing_800.png?version=1&modificationDate=1299128361000&api=v2" data-image-src="https://cwiki-test.apache.org/confluence/download/attachments/22872133/tapestry_request_processing_800.png?version=1&modificationDate=1299128361000&api=v2"></span></p></div>
+<p><strong>Request Processing</strong> involves a sequence of steps that Tapestry performs when every HTTP request comes in. You <em>don't need</em> to know these steps to use Tapestry productively, but understanding the request processing pipeline is helpful if you want to understand Tapestry deeply.</p><p>Much of the early stages of processing are in the form of extensible <a href="pipelinebuilder-service.html">pipelines</a>.</p><h2 id="RequestProcessing-TapestryFilter">Tapestry Filter</h2><p>All incoming requests originate with the TapestryFilter, which is a servlet filter configured inside your application's <a href="configuration.html">web.xml</a>.</p><p>The TapestryFilter is responsible for a number of startup and initialization functions.</p><p>When it receives a request, the TapestryFilter obtains the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/HttpServletRequestHandler.html">HttpServletRequestHandler</a> service
, and invokes its service() method.</p><h2 id="RequestProcessing-HttpServletRequestHandlerPipeline">HttpServletRequestHandler Pipeline</h2><p>This pipeline performs initial processing of the request. It can be extended by contributing a <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/HttpServletRequestFilter.html">HttpServletRequestFilter</a> into the HttpServletRequestHandler service's configuration.</p><p>Tapestry does not contribute any filters into this pipeline of its own.</p><p>The terminator for the pipeline does two things:</p><ul><li>It stores the request and response into the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestGlobals.html">RequestGlobals</a> service. This is a per-thread scoped service that stores per-thread/per-request information.</li><li>It wraps the request and response as a <a class="external-link" href="http://tapestry.apache.org/cur
rent/apidocs/org/apache/tapestry5/services/Request.html">Request</a> and <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/Response.html">Response</a>, and passes them into the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestHandler.html">RequestHandler</a> pipeline.</li></ul><h2 id="RequestProcessing-RequestHandlerPipeline">RequestHandler Pipeline</h2><p>This pipeline is where most extensions related to requests take place. Request represents an abstraction on top of HttpServletRequest. (Primarily, this exists to bridge from the Servlet API objects to the corresponding Tapestry objects. This is to allow for a possible portlet integration for Tapestry.) Where other code and services within Tapestry require access to information in the request, such as query parameters, that information is obtained from the Request (or Response) objects.</p><p>The RequestHandler pipe
line includes a number of built-in filters:</p><ul><li>CheckForUpdates is responsible for <a href="class-reloading.html">class and template reloading</a>.</li><li>Localization identifies the <a href="localization.html">locale for the user</a>.</li><li>StaticFiles checks for URLs that are for static files (files that exist inside the web context) and aborts the request, so that the servlet container can handle the request normally.</li><li>ErrorFilter catches uncaught exceptions from the lower levels of Tapestry and presents the exception report page. This involves the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/RequestExceptionHandler.html">RequestExceptionHandler</a> service, which is responsible for initializing and rendering the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/corelib/pages/ExceptionReport.html">core/ExceptionReport</a> page.</li></ul><p>The terminator fo
r this pipeline stores the Request and the Response into RequestGlobals, then requests that the <a class="external-link" href="http://tapestry.apache.org/current/apidocs/org/apache/tapestry5/services/Dispatcher.html">MasterDispatcher</a> service figure out how to handle the request (if it is, indeed, a Tapestry request).</p><h2 id="RequestProcessing-MasterDispatcherService">Master Dispatcher Service</h2><p>The MasterDispatcher service is a chain-of-command, aggregating together (in a specific order), several Dispatcher objects. Each Dispatcher is built to recognize and process a particular kind of URL.</p><h3 id="RequestProcessing-RootPathDispatcher">RootPath Dispatcher</h3><p>The RootPath Dispatcher recognizes a request for the application root (i.e., "/") and handles this the same as a render request for the "Start" page. Support for the Start page is kept for legacy purposes. Index pages are the correct approach.</p><h3 id="RequestProcessing-AssetDispatcher">Asset Dispatcher</h3
><p>Requests that begin with "/assets/" are references to <a href="assets.html">asset resources</a> that are stored on the classpath, inside the Tapestry JARs (or perhaps inside the JAR for a component library). The contents of the file will be delivered to the client browser as a byte stream. This dispatcher also handles requests that are simply polling for a change to the file.</p><h3 id="RequestProcessing-PageRenderDispatcher">PageRender Dispatcher</h3><p>Page render requests are requests to render a particular page. Such requests may include additional elements on the path, which will be treated as activation context (see ComponentEvent Dispatcher below). Generally speaking, the activation context is the primary key of some related entity object. This allows the page to reconstruct the state it will need to successfully render itself.</p><p>The event handler method for the activate event may return a value; this is treated the same as the return value from a component action re
quest; typically this will result in a redirect to another page. In this way, the activate event can perform simple validation at the page level ("can the user see this page?").</p><p>Page render URLs consist of the logical name of the page plus additional path elements for the activation context. The dispatcher here strips terms off of the path until it finds a known page name. Thus, "/mypage/27" would look first for a page whose name was "mypage/27", then look for a page name "mypage". Assuming the second search was successful, the page would be activated with the context "27". If no logical page name can be identified, control passes to the next dispatcher.</p><h3 id="RequestProcessing-ComponentEventDispatcher">ComponentEvent Dispatcher</h3><p>The ComponentEvent dispatcher is used to trigger events in components.</p><p>The URL identifies the name of the page, then a series of component ids (the path from the page down to the specific component), then the name of the event to be t
riggered on the component. The remaining path elements are used as the context for the <em>event</em> (not for the page activation, which does not currently apply). For example, "/griddemo.FOO.BAR/3" would locate page "griddemo", then component "FOO.BAR", and trigger an event named "action" (the default event type, which is omitted from the URL), with the context "3".</p><p>If the page in question has an activation context, it is supplied as an additional query parameter on the link.</p><p>In cases where the event type is not the default, "action", it will appear between the nested component id and the event context, preceded by a colon. Example: "/example/foo.bar:magic/99" would trigger an event of type "magic". This is not common in the vanilla Tapestry framework, but will likely be more common as Ajax features (which would not use the normal request logic) are implemented.</p><p>The response from a component action request is typically, but not universally, used to send a redirec
t to the client; the redirect URL is a page render URL to display the response to the event. This is detailed under <a href="page-navigation.html">Request Processing</a>.</p><h2 id="RequestProcessing-RequestGlobalsService">RequestGlobals Service</h2><p>The RequestGlobals service has a life cycle of per-thread; this means that a separate instance exists for every thread, and therefore, for every request. The terminators of the two handler pipelines store the request/response pairs into the RequestGlobals service.</p><h2 id="RequestProcessing-RequestService">Request Service</h2><p>The Request service is a <a href="shadowbuilder-service.html">shadow</a> of the RequestGlobals services' request property. That is, any methods invoked on this service are delegated to the request object stored inside the RequestGlobals.</p><h2 id="RequestProcessing-Overview">Overview</h2><p>The following diagram provides an overview of how the different pipelines, filters and dispatchers interact when pro
cessing an incoming request.</p><p><span class="confluence-embedded-file-wrapper"><img class="confluence-embedded-image confluence-external-resource confluence-content-image-border" alt="Request Processing" src="https://cwiki-test.apache.org/confluence/download/attachments/22872133/tapestry_request_processing_800.png?version=1&modificationDate=1299128361000&api=v2" data-image-src="https://cwiki-test.apache.org/confluence/download/attachments/22872133/tapestry_request_processing_800.png?version=1&modificationDate=1299128361000&api=v2"></span></p><p></p></div>
</div>
<div class="clearer"></div>
Modified: websites/production/tapestry/content/runtime-exceptions.html
==============================================================================
--- websites/production/tapestry/content/runtime-exceptions.html (original)
+++ websites/production/tapestry/content/runtime-exceptions.html Sun Feb 25 23:20:05 2018
@@ -111,7 +111,7 @@ operationQueue, MappedConfiguration<C
return context;
}
}</pre>
-</div></div><p>The contributed exception handling mechanism can easily be overused. Typically, if you can handle the exception locally, you should. Likewise, you shouldn't blindly wrap any checked exceptions inside runtime exceptions just to avoid writing try-catch blocks in higher layers. The mechanism for contributed exception types is best used for handling serious but rarely occurring exceptions happening in the action request cycle that you cannot otherwise cope with.</p></div>
+</div></div><p>The contributed exception handling mechanism can easily be overused. Typically, if you can handle the exception locally, you should. Likewise, you shouldn't blindly wrap any checked exceptions inside runtime exceptions just to avoid writing try-catch blocks in higher layers. The mechanism for contributed exception types is best used for handling serious but rarely occurring exceptions happening in the action request cycle that you cannot otherwise cope with.</p><p></p></div>
</div>
<div class="clearer"></div>