Available as of Fuse Mediation Router 2.3

The scalate: component allows you to process a message using Scalate template, which supports either SSP or Scaml format templates. 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.fusesource.scalate</groupId>
    <artifactId>scalate-camel</artifactId>
    <version>1.0</version>
</dependency>

scalate:templateName[?options]

Where templateName is the classpath-local URI of the template to invoke; or the complete URL of the remote template (eg: file://folder/myfile.ssp).

You can append query options to the URI in the following format, ?option=value&option=value&...

The scalate component sets a couple headers on the message (you can't set these yourself and from Fuse Mediation Router 2.1 scalate component will not set these headers which will cause some side effect on the dynamic template support):

Headers set during the Scalate evaluation are returned to the message and added as headers. Then its kinda possible to return values from Scalate to the Message.

For example, to set the header value of fruit in the Scalate template .tm:

<% in.setHeader('fruit', 'Apple') %>

The fruit header is now accessible from the message.out.headers.

Fuse Mediation Router will provide exchange information in the Scalate context (just a Map). The Exchange is transfered as:

The Scalate template resource is, by default, hot reloadable for both file and classpath resources (expanded jar).

Fuse Mediation Router 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 Fuse Mediation Router uses this over the endpoint configured resource. This allows you to provide a dynamic template at runtime.

For example you could use something like

from("activemq:My.Queue").
  to("scalate:com/acme/MyResponse.ssp");

To use a Scalate template to formulate a response to 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 the following route:

from("activemq:My.Queue").
  to("scalate:com/acme/MyResponse.scaml").
  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("CamelScalateResourceUri").constant("path/to/my/template.scaml").
  to("scalate:dummy");

It's possible to specify a template directly as a header the component should use dynamically via a header, so for example:

from("direct:in").
  setHeader("CamelScalateTemplate").constant("<%@ attribute body: Object %>\nHi this is a scalate template that can do templating ${body}").
  to("scalate:dummy");

In this sample we want to use Scalate templating for an order confirmation email. The email template is laid out in Scalate as:

<%@ attribute in: org.apache.camel.scala.RichMessage %>
Dear ${in("lastName"}, ${in("firstName")}

Thanks for the order of ${in("item")}.

Regards Camel Riders Bookstore
${in.body}