[[mustache-component]]
== Mustache Component

*Available as of Camel version 2.12*

The *mustache:* component allows for processing a message using a
http://mustache.github.io/[Mustache] 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:

[source,xml]
---------------------------------------------------------------------------------
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-mustache</artifactId>
<version>x.x.x</version> <!-- use the same version as your Camel core version -->
</dependency>
---------------------------------------------------------------------------------

### URI format

[source,java]
-------------------------------
mustache: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.mustache[file://folder/myfile.mustache]).

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

### Options


// component options: START
The Mustache component supports 2 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *mustacheFactory* (advanced) | To use a custom MustacheFactory |  | MustacheFactory
| *resolveProperty Placeholders* (advanced) | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | boolean
|===
// component options: END








// endpoint options: START
The Mustache endpoint is configured using URI syntax:

----
mustache:resourceUri
----

with the following path and query parameters:

==== Path Parameters (1 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| 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
|===


==== Query Parameters (5 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *contentCache* (producer) | Sets whether to use resource content cache or not | false | boolean
| *encoding* (producer) | Character encoding of the resource content. |  | String
| *endDelimiter* (producer) | Characters used to mark template code end. | }} | String
| *startDelimiter* (producer) | Characters used to mark template code beginning. | {{ | String
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
|===
// endpoint options: END
// spring-boot-auto-configure options: START
=== Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

[source,xml]
----
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-mustache-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>
----


The component supports 3 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *camel.component.mustache.enabled* | Enable mustache component | true | Boolean
| *camel.component.mustache.mustache-factory* | To use a custom MustacheFactory. The option is a com.github.mustachejava.MustacheFactory type. |  | String
| *camel.component.mustache.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
|===
// spring-boot-auto-configure options: END



### Mustache Context

Camel will provide exchange information in the Mustache context (just a
`Map`). The `Exchange` is transferred as:

[width="100%",cols="10%,90%",options="header",]
|=======================================================================
|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).
|=======================================================================

### 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.

[width="100%",cols="10%,10%,10%,70%",options="header",]
|=======================================================================
|Header |Type |Description |Support Version

|MustacheConstants.MUSTACHE_RESOURCE_URI |String |A URI for the template resource to use instead of the endpoint
configured. | 

|MustacheConstants.MUSTACHE_TEMPLATE |String |The template to use instead of the endpoint configured. |
|=======================================================================

### Samples

For example you could use something like:

[source,java]
--------------------------------------------
from("activemq:My.Queue").
to("mustache:com/acme/MyResponse.mustache");
--------------------------------------------

To use a Mustache 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:

[source,java]
--------------------------------------------
from("activemq:My.Queue").
to("mustache:com/acme/MyResponse.mustache").
to("activemq:Another.Queue");
--------------------------------------------

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

[source,java]
--------------------------------------------------------------------------------------------
from("direct:in").
setHeader(MustacheConstants.MUSTACHE_RESOURCE_URI).constant("path/to/my/template.mustache").
to("mustache:dummy");
--------------------------------------------------------------------------------------------

### The Email Sample

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

[source,java]
-------------------------------------------------
Dear {{headers.lastName}}}, {{headers.firstName}}

Thanks for the order of {{headers.item}}.

Regards Camel Riders Bookstore
{{body}}
-------------------------------------------------

### See Also

* Configuring Camel
* Component
* Endpoint
* Getting Started
