Qute

JVM since1.0.0 Native since1.0.0

Transform messages using Quarkus Qute templating engine

Maven coordinates

Create a new project with this extension on code.quarkus.io

Or add the coordinates to your existing project:

<dependency>
    <groupId>org.apache.camel.quarkus</groupId>
    <artifactId>camel-quarkus-qute</artifactId>
</dependency>

Check the User guide for more information about writing Camel Quarkus applications.

Usage

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The Qute component supports 4 options, which are listed below.

Name Description Default Type

allowTemplateFromHeader (producer)

Whether to allow to use resource template from header or not (default false). Enabling this allows to specify dynamic templates via message header. However this can be seen as a potential security vulnerability if the header is coming from a malicious user, so use this with care.

false

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

quteEngine (advanced)

To use the Engine otherwise a new engine is created.

Engine

Endpoint Options

The Qute endpoint is configured using URI syntax:

qute:resourceUri

with the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

resourceUri (producer)

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)

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 impose 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 allows to specify dynamic templates via message header. However this can be seen as a potential security vulnerability if the header is coming from a malicious user, so use this with care.

false

boolean

contentCache (producer)

Sets whether to use resource content cache or not.

false

boolean

encoding (producer)

Character encoding of the resource content.

String

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

Message Headers

The Qute component supports 4 message header(s), which is/are listed below:

Name Description Default Type

CamelQuteResourceUri (producer)

Constant: QUTE_RESOURCE_URI

A URI for the template resource to use instead of the endpoint configured one.

String

CamelQuteTemplate (producer)

Constant: QUTE_TEMPLATE

The template to use instead of the endpoint configured one.

String

CamelQuteTemplateInstance (producer)

Constant: QUTE_TEMPLATE_INSTANCE

The template instance to use instead of the endpoint configured one.

TemplateInstance

CamelQuteTemplateData (producer)

Constant: QUTE_TEMPLATE_DATA

The template model data.

Map

Qute template data

Camel will populate the Qute TemplateInstance data model with exchange information. The following options are available within Qute templates as variables:

key value

exchange

The Exchange itself.

exchange.properties

The Exchange properties.

variables

The exchange variables

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).

You can configure your own template data with the message header CamelQuteTemplateData like this.

Map<String, Object> variableMap = new HashMap<String, Object>();
variableMap.put("headers", headersMap);
variableMap.put("body", "Monday");
variableMap.put("exchange", exchange);
exchange.getMessage().setHeader("CamelQuteTemplateData", variableMap);

Dynamic templates

Camel provides headers CamelQuteResourceUri, CamelQuteTemplate and CamelQuteTemplateInstance which can be used to define a different resource location for a template, or provide the template instance 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.

Examples

Processing an exchange with a Qute template read from the classpath.

from("direct:start")
    .to("qute:org/acme/myTemplate.txt");

Processing an exchange with a Qute template read from a file-based resource.

from("direct:start")
    .to("qute:file://path/to/myTemplate.txt");

Dynamic template path URI.

from("direct:start")
    .setHeader(QuteConstants.QUTE_RESOURCE_URI).constant("org/acme/template.txt")
    .to("qute:dynamic?allowTemplateFromHeader=true");

Dynamic template content.

from("direct:start")
    .setHeader(QuteConstants.QUTE_TEMPLATE).constant("<hello>{headers.greeting}</hello>")
    .to("qute:dynamic?allowTemplateFromHeader=true");

Dynamic template instance.

from("direct:start")
    .setHeader(QuteConstants.QUTE_TEMPLATE_INSTANCE).constant(myTemplateInstance)
    .to("qute:dynamic?allowTemplateFromHeader=true");

Qute template example.

Dear {headers.lastName}, {headers.firstName}

Thanks for the order of {headers.item}.

Regards Camel Riders Bookstore
{body}

Quarkus Qute documentation

For more information about Qute, please refer to the Quarkus Qute documentation.

Camel Quarkus limitations

allowContextMapAll option in native mode

The allowContextMapAll option is not supported in native mode as it requires reflective access to security sensitive camel core classes such as CamelContext & Exchange. This is considered a security risk and thus access to the feature is not provided by default.

Additional Camel Quarkus configuration

By default, all files located in the src/main/resources/templates directory and its subdirectories are registered as templates. Templates are validated during startup and watched for changes in the development mode.

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