Chapter 29. Ruby
Overview
Ruby is a dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write. The Ruby support is part of the
camel-script module.
Adding the script module
To use Ruby in your routes you need to add a dependency on
camel-script to your project as shown in Example 29.1, “Adding the camel-script dependency”.
Example 29.1. Adding the camel-script dependency
<!-- Maven POM File -->
...
<dependencies>
...
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-script</artifactId>
<version>${camel-version}</version>
</dependency>
...
</dependencies>Static import
To use the
ruby() static method in your application code, include the following import statement in your Java source files:
import static org.apache.camel.builder.camel.script.ScriptBuilder.*;
Built-in attributes
Table 29.1, “Ruby attributes” lists the built-in attributes that are accessible when using Ruby.
| Attribute | Type | Value |
|---|---|---|
context | org.apache.camel.CamelContext | The Camel Context |
exchange | org.apache.camel.Exchange | The current Exchange |
request | org.apache.camel.Message | The IN message |
response | org.apache.camel.Message | The OUT message |
properties | org.apache.camel.builder.script.PropertiesFunction | Function with a resolve method to make it easier to use the properties component inside scripts. |
The attributes all set at
ENGINE_SCOPE.
Example
Example 29.2, “Route using Ruby” shows a route that uses Ruby.
Example 29.2. Route using Ruby
<camelContext>
<route>
<from uri="direct:start"/>
<choice>
<when>
<langauge langauge="ruby">$request.headers['user'] == 'admin'</langauge>
<to uri="seda:adminQueue"/>
</when>
<otherwise>
<to uri="seda:regularQueue"/>
</otherwise>
</choice>
</route>
</camelContext>Using the properties component
To access a property value from the properties component, invoke the
resolve method on the built-in properties attribute, as follows:
.setHeader("myHeader").ruby("properties.resolve(PropKey)")
Where PropKey is the key of the property you want to resolve, where the key value is of
String type.
For more details about the properties component, see Properties in the Apache Camel Component Reference Guide.
