[4/6] camel git commit: Added Ruby language to Gitbook

[ac...@apache.org]

Added Ruby language to Gitbook


Project: http://git-wip-us.apache.org/repos/asf/camel/repo
Commit: http://git-wip-us.apache.org/repos/asf/camel/commit/358ba4ff
Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/358ba4ff
Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/358ba4ff

Branch: refs/heads/master
Commit: 358ba4ff52697303b8c2f797789090b82e9ca11f
Parents: f1af3ad
Author: Andrea Cosentino <an...@gmail.com>
Authored: Thu Aug 25 12:15:28 2016 +0200
Committer: Andrea Cosentino <an...@gmail.com>
Committed: Thu Aug 25 12:15:28 2016 +0200

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 .../src/main/docs/ruby-language.adoc            | 198 +++++++++++++++++++
 1 file changed, 198 insertions(+)
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http://git-wip-us.apache.org/repos/asf/camel/blob/358ba4ff/components/camel-script/src/main/docs/ruby-language.adoc
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diff --git a/components/camel-script/src/main/docs/ruby-language.adoc b/components/camel-script/src/main/docs/ruby-language.adoc
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+[[Ruby-Ruby]]
+Ruby
+~~~~
+
+Camel supports http://www.ruby-lang.org/en/[Ruby] among other
+link:scripting-languages.html[Scripting Languages] to allow an
+link:expression.html[Expression] or link:predicate.html[Predicate] to be
+used in the link:dsl.html[DSL] or link:xml-configuration.html[Xml
+Configuration].
+
+To use a Ruby expression use the following Java code
+
+[source,java]
+-----------------------------------
+... ruby("someRubyExpression") ... 
+-----------------------------------
+
+For example you could use the *ruby* function to create an
+link:predicate.html[Predicate] in a link:message-filter.html[Message
+Filter] or as an link:expression.html[Expression] for a
+link:recipient-list.html[Recipient List]
+
+[[Ruby-Language-options]]
+Ruby Language Options
+^^^^^^^^^^^^^^^^^^^^^
+
+// language options: START
+The Ruby language supports 1 options which are listed below.
+
+
+
+{% raw %}
+[width="100%",cols="2,1m,1m,6",options="header"]
+|=======================================================================
+| Name | Default | Java Type | Description
+| trim | true | Boolean | Whether to trim the value to remove leading and trailing whitespaces and line breaks
+|=======================================================================
+{% endraw %}
+// language options: END
+
+[[Ruby-Example]]
+Example
+^^^^^^^
+
+In the sample below we use Ruby to create a
+link:predicate.html[Predicate] use in the route path, to route exchanges
+from admin users to a special queue.
+
+[source,java]
+-------------------------------------------------------------------------------------
+    from("direct:start")
+        .choice()
+            .when().ruby("$request.headers['user'] == 'admin'").to("seda:adminQueue")
+        .otherwise()
+            .to("seda:regularQueue");
+-------------------------------------------------------------------------------------
+
+And a Spring DSL sample as well:
+
+[source,xml]
+----------------------------------------------------------------
+    <route>
+        <from uri="direct:start"/>
+        <choice>
+            <when>
+                <ruby>$request.headers['user'] == 'admin'</ruby>
+                <to uri="seda:adminQueue"/>
+            </when>
+            <otherwise>
+                <to uri="seda:regularQueue"/>
+            </otherwise>
+        </choice>
+    </route>
+----------------------------------------------------------------
+
+[[Ruby-ScriptContext]]
+ScriptContext
+^^^^^^^^^^^^^
+
+The JSR-223 scripting languages ScriptContext is pre configured with the
+following attributes all set at `ENGINE_SCOPE`:
+
+[width="100%",cols="10%,10%,80%",options="header",]
+|=======================================================================
+|Attribute |Type |Value
+
+|context |`org.apache.camel.CamelContext` |The Camel Context ( It cannot be used in groovy)
+
+|camelContext |`org.apache.camel.CamelContext` |The Camel Context
+
+|exchange |`org.apache.camel.Exchange` |The current Exchange
+
+|request |`org.apache.camel.Message` |The message (IN message)
+
+|response |`org.apache.camel.Message` |*Deprecated*: The OUT message. The OUT message if null by default. Use
+IN message instead.
+
+|properties |`org.apache.camel.builder.script.PropertiesFunction` |*Camel 2.9:* Function with a `resolve` method to make it easier to use
+Camels link:properties.html[Properties] component from scripts. See
+further below for example.
+|=======================================================================
+
+See link:scripting-languages.html[Scripting Languages] for the list of
+languages with explicit DSL support.
+
+[[Ruby-AdditionalargumentstoScriptingEngine]]
+Additional arguments to ScriptingEngine
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+*Available as of Camel 2.8*
+
+You can provide additional arguments to the `ScriptingEngine` using a
+header on the Camel message with the key `CamelScriptArguments`. +
+ See this example:
+
+[[Ruby-Usingpropertiesfunction]]
+Using properties function
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+*Available as of Camel 2.9*
+
+If you need to use the link:properties.html[Properties] component from a
+script to lookup property placeholders, then its a bit cumbersome to do
+so. +
+ For example to set a header name myHeader with a value from a property
+placeholder, which key is provided in a header named "foo".
+
+[source,java]
+--------------------------------------------------------------------------------------------------------------
+.setHeader("myHeader").groovy("context.resolvePropertyPlaceholders('{{' + request.headers.get('foo') + '}}')")
+--------------------------------------------------------------------------------------------------------------
+
+From Camel 2.9 onwards you can now use the properties function and the
+same example is simpler:
+
+[source,java]
+-------------------------------------------------------------------------------
+.setHeader("myHeader").groovy("properties.resolve(request.headers.get('foo'))")
+-------------------------------------------------------------------------------
+
+[[Ruby-Loadingscriptfromexternalresource]]
+Loading script from external resource
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+*Available as of Camel 2.11*
+
+You can externalize the script and have Camel load it from a resource
+such as `"classpath:"`, `"file:"`, or `"http:"`. +
+ This is done using the following syntax: `"resource:scheme:location"`,
+eg to refer to a file on the classpath you can do:
+
+[source,java]
+-------------------------------------------------------------------
+.setHeader("myHeader").groovy("resource:classpath:mygroovy.groovy")
+-------------------------------------------------------------------
+
+[[Ruby-Howtogettheresultfrommultiplestatementsscript]]
+How to get the result from multiple statements script
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+*Available as of Camel 2.14*
+
+As the scripteengine evale method just return a Null if it runs a
+multiple statments script. Camel now look up the value of script result
+by using the key of "result" from the value set. If you have multiple
+statements script, you need to make sure you set the value of result
+variable as the script return value.
+
+[source,text]
+-------------------------------------------------------------
+bar = "baz";
+# some other statements ... 
+# camel take the result value as the script evaluation result
+result = body * 2 + 1
+-------------------------------------------------------------
+
+�
+
+[[Ruby-Dependencies]]
+Dependencies
+^^^^^^^^^^^^
+
+To use scripting languages in your camel routes you need to add the a
+dependency on *camel-script* which integrates the JSR-223 scripting
+engine.
+
+If you use maven you could just add the following to your pom.xml,
+substituting the version number for the latest & greatest release (see
+link:download.html[the download page for the latest versions]).
+
+[source,xml]
+---------------------------------------
+<dependency>
+  <groupId>org.apache.camel</groupId>
+  <artifactId>camel-script</artifactId>
+  <version>x.x.x</version>
+</dependency>
+---------------------------------------