When

Table of Contents

Usage
Properties
Related topics

Triggers a route when an expression evaluates to true

Usage

The When pattern is part of a content based router. It is used to determine if a path is to be followed by the message. The message is evaluated against the specified expression and if it evaluates to true the path is followed.

The When pattern must follow one of these patterns:

  • Choice
  • Intercept
  • Intercept Send To Endpoint

The When pattern can also be used with these patterns:

  • On Completion
  • On Exception

Properties

Table 57, “When Properties” describes the properties you can specify using the properties editor.

Table 57. When Properties

NameDescription

language

Specifies the expression language used to process the expression.

Description

Specifies a text description for the node. This description is included in the generated XML file, but it is informational only. It is not used by Apache Camel.

Id

Specifies a unique identifier for the endpoint.

The tooling automatically generates an id for a node when it is created, but you can remove that id or replace it with your own. The Camel debugger requires all nodes with a breakpoint set to have a unique id.

You can use the id to refer to endpoints in your Camel XML file.


Related topics