Chapter 62. Chunk Component Available as of Camel version 2.15 The chunk: component allows for processing a message using a Chunk template. This can be ideal when using Templating to generate responses for requests. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-chunk</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> 62.1. URI format chunk:templateName[?options] Where templateName is the classpath-local URI of the template to invoke. You can append query options to the URI in the following format, ?option=value&option=value&... 62.2. Options The Chunk component supports 2 options, which are listed below. Name Description Default Type allowContextMapAll (producer) Sets whether the context map should allow access to all details. By default only the message body and headers can be accessed. This option can be enabled for full access to the current Exchange and CamelContext. Doing so imposes a potential security risk as this opens access to the full power of CamelContext API. false boolean allowTemplateFromHeader (producer) Whether to allow to use resource template from header or not (default false). Enabling this option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution. false boolean The Chunk endpoint is configured using URI syntax: with the following path and query parameters: 62.2.1. Path Parameters (1 parameters): Name Description Default Type resourceUri Required Path to the resource. You can prefix with: classpath, file, http, ref, or bean. classpath, file and http loads the resource using these protocols (classpath is default). ref will lookup the resource in the registry. bean will call a method on a bean to be used as the resource. For bean you can specify the method name after dot, eg bean:myBean.myMethod. String 62.2.2. Query Parameters (9 parameters): Name Description Default Type allowContextMapAll (producer) Sets whether the context map should allow access to all details. By default only the message body and headers can be accessed. This option can be enabled for full access to the current Exchange and CamelContext. Doing so imposes a potential security risk as this opens access to the full power of CamelContext API. false boolean allowTemplateFromHeader (producer) Whether to allow to use resource template from header or not (default false). Enabling this option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution. false boolean contentCache (producer) Sets whether to use resource content cache or not false boolean encoding (producer) Define the encoding of the body String extension (producer) Define the file extension of the template String themeFolder (producer) Define the themes folder to scan String themeLayer (producer) Define the theme layer to elaborate String themeSubfolder (producer) Define the themes subfolder to scan String synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean 62.3. Spring Boot Auto-Configuration The component supports 2 options, which are listed below. Name Description Default Type camel.component.chunk.enabled Enable chunk component true Boolean camel.component.chunk.resolve-property-placeholders Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. true Boolean Chunk component will look for a specific template in themes folder with extensions .chtml or _.cxml. _If you need to specify a different folder or extensions, you will need to use the specific options listed above. 62.4. Chunk Context Camel will provide exchange information in the Chunk context (just a Map ). The Exchange is transferred as: key value exchange The Exchange itself. exchange.properties The Exchange properties. headers The headers of the In message. camelContext The Camel Context. request The In message. body The In message body. response The Out message (only for InOut message exchange pattern). 62.5. Dynamic templates Camel provides two headers by which you can define a different resource location for a template or the template content itself. If any of these headers is set then Camel uses this over the endpoint configured resource. This allows you to provide a dynamic template at runtime. Header Type Description Support Version ChunkConstants.CHUNK_RESOURCE_URI String A URI for the template resource to use instead of the endpoint configured. ChunkConstants.CHUNK_TEMPLATE String The template to use instead of the endpoint configured. 62.6. Samples For example you could use something like: from("activemq:My.Queue"). to("chunk:template"); To use a Chunk template to formulate a response for a message for InOut message exchanges (where there is a JMSReplyTo header). If you want to use InOnly and consume the message and send it to another destination you could use: from("activemq:My.Queue"). to("chunk:template"). to("activemq:Another.Queue"); It's possible to specify what template the component should use dynamically via a header, so for example: from("direct:in"). setHeader(ChunkConstants.CHUNK_RESOURCE_URI).constant("template"). to("chunk:dummy?allowTemplateFromHeader=true"); Warning Enabling the allowTemplateFromHeader option has security ramifications. For example, if the header contains untrusted or user derived content, this can ultimately impact on the confidentility and integrity of your end application, so use this option with caution. An example of Chunk component options use: from("direct:in"). to("chunk:file_example?themeFolder=template&themeSubfolder=subfolder&extension=chunk"); In this example Chunk component will look for the file file_example.chunk in the folder template/subfolder. 62.7. The Email Sample In this sample we want to use Chunk templating for an order confirmation email. The email template is laid out in Chunk as: Dear {USDheaders.lastName}, {USDheaders.firstName} Thanks for the order of {USDheaders.item}. Regards Camel Riders Bookstore {USDbody} 62.8. See Also Configuring Camel Component Endpoint Getting Started

Commands:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-chunk</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency>
chunk:templateName[?options]
chunk:resourceUri
from("activemq:My.Queue"). to("chunk:template");
from("activemq:My.Queue"). to("chunk:template"). to("activemq:Another.Queue");
from("direct:in"). setHeader(ChunkConstants.CHUNK_RESOURCE_URI).constant("template"). to("chunk:dummy?allowTemplateFromHeader=true");
from("direct:in"). to("chunk:file_example?themeFolder=template&themeSubfolder=subfolder&extension=chunk");
Dear {USDheaders.lastName}, {USDheaders.firstName} Thanks for the order of {USDheaders.item}. Regards Camel Riders Bookstore {USDbody}