camel git commit: Added spel-language to Gitbook

[ac...@apache.org]

Repository: camel
Updated Branches:
  refs/heads/master 4c4f24c0f -> cdd5b735f


Added spel-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/cdd5b735
Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/cdd5b735
Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/cdd5b735

Branch: refs/heads/master
Commit: cdd5b735f4fb5ce73c77e14268ef44edbdb875a1
Parents: 4c4f24c
Author: Andrea Cosentino <an...@gmail.com>
Authored: Tue Aug 23 14:27:07 2016 +0200
Committer: Andrea Cosentino <an...@gmail.com>
Committed: Tue Aug 23 14:29:59 2016 +0200

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 .../src/main/docs/spel-language.adoc            | 182 +++++++++++++++++++
 1 file changed, 182 insertions(+)
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http://git-wip-us.apache.org/repos/asf/camel/blob/cdd5b735/components/camel-spring/src/main/docs/spel-language.adoc
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diff --git a/components/camel-spring/src/main/docs/spel-language.adoc b/components/camel-spring/src/main/docs/spel-language.adoc
new file mode 100644
index 0000000..ac64f46
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+[[SpEL-SpringExpressionLanguageSpEL]]
+Spring Expression Language (SpEL)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+*Available as of Camel 2.7*
+
+Camel allows
+http://static.springsource.org/spring/docs/current/spring-framework-reference/htmlsingle/spring-framework-reference.html#expressions[SpEL]
+to be used as an link:expression.html[Expression] or
+link:predicate.html[Predicate] in the link:dsl.html[DSL] or
+link:xml-configuration.html[Xml Configuration].
+
+[[SpEL-Variables]]
+Variables
+^^^^^^^^^
+
+The following variables are available in expressions and predicates
+written in SpEL:
+
+[width="100%",cols="10%,10%,80%",options="header",]
+|=======================================================================
+|Variable |Type |Description
+
+|*this* |Exchange |the Exchange is the root object
+
+|exchange |Exchange |the Exchange object
+
+|exception |Throwable |the Exchange exception (if any)
+
+|exchangeId |String |the exchange id
+
+|fault |Message |the Fault message (if any)
+
+|body |Object |Camel 2.11: The IN message body.
+
+|request |Message |the exchange.in message
+
+|response |Message |the exchange.out message (if any)
+
+|properties |Map |the exchange properties
+
+|property(name) |Object |the property by the given name
+
+|property(name, type) |Type |the property by the given name as the given type
+|=======================================================================
+
+[[SpEL-Options]]
+Options
+^^^^^^^
+
+// language options: START
+The SpEL 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
+
+[[SpEL-Samples]]
+Samples
+^^^^^^^
+
+[[SpEL-Expressiontemplating]]
+Expression templating
++++++++++++++++++++++
+
+SpEL expressions need to be surrounded by `#{` `}` delimiters since
+expression templating is enabled. This allows you to combine SpEL
+expressions with regular text and use this as extremely lightweight
+template language.
+
+For example if you construct the following route:
+
+[source,java]
+-----------------------------------------------------------------------------------------------------------------------------------
+from("direct:example").setBody(spel("Hello #{request.body}! What a beautiful #{request.headers['dayOrNight']}")).to("mock:result");
+-----------------------------------------------------------------------------------------------------------------------------------
+
+In the route above, notice spel is a static method which we need to
+import from `org.apache.camel.language.spel.SpelExpression.spel`, as we
+use spel as an link:expression.html[Expression] passed in as a parameter
+to the `setBody` method. Though if we use the fluent API we can do this
+instead:
+
+[source,java]
+------------------------------------------------------------------------------------------------------------------------------------
+from("direct:example").setBody().spel("Hello #{request.body}! What a beautiful #{request.headers['dayOrNight']}").to("mock:result");
+------------------------------------------------------------------------------------------------------------------------------------
+
+Notice we now use the `spel` method from the `setBody()` method. And
+this does not require us to static import the spel method from
+`org.apache.camel.language.spel.SpelExpression.spel`.
+
+And sent a message with the string "World" in the body, and a header
+"dayOrNight" with value "day":
+
+[source,java]
+---------------------------------------------------------------------------
+template.sendBodyAndHeader("direct:example", "World", "dayOrNight", "day");
+---------------------------------------------------------------------------
+
+The output on `mock:result` will be _"Hello World! What a beautiful
+day"_
+
+[[SpEL-Beanintegration]]
+Bean integration
+++++++++++++++++
+
+You can reference beans defined in the link:registry.html[Registry]
+(most likely an `ApplicationContext`) in your SpEL expressions. For
+example if you have a bean named "foo" in your `ApplicationContext` you
+can invoke the "bar" method on this bean like this:
+
+[source,java]
+--------------------
+#{@foo.bar == 'xyz'}
+--------------------
+
+[[SpEL-SpELinenterpriseintegrationpatterns]]
+SpEL in enterprise integration patterns
++++++++++++++++++++++++++++++++++++++++
+
+You can use SpEL as an expression for link:recipient-list.html[Recipient
+List] or as a predicate inside a link:message-filter.html[Message
+Filter]:
+
+[source,xml]
+---------------------------------------------------
+<route>
+  <from uri="direct:foo"/>
+  <filter>
+    <spel>#{request.headers['foo'] == 'bar'}</spel>
+    <to uri="direct:bar"/>
+  </filter>
+</route>
+---------------------------------------------------
+
+And the equivalent in Java DSL:
+
+[source,java]
+-------------------------------------------------------------------------------------------
+   from("direct:foo").filter().spel("#{request.headers['foo'] == 'bar'}").to("direct:bar");
+-------------------------------------------------------------------------------------------
+
+[[SpEL-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").spel("resource:classpath:myspel.txt")
+------------------------------------------------------------
+
+[[SpEL-Dependencies]]
+Dependencies
+^^^^^^^^^^^^
+
+You need Spring 3.0 or higher to use Spring Expression Language. If you
+use Maven you could just add the following to your `pom.xml`:
+
+[source,xml]
+----------------------------------------------------------
+<dependency>
+  <groupId>org.apache.camel</groupId>
+  <artifactId>camel-spring</artifactId>
+  <version>xxx</version>
+  <!-- use the same version as your Camel core version -->
+</dependency>
+----------------------------------------------------------