Configuring the message map to include message assembly components
In IBM® Integration Bus, the
message assembly is the internal representation of a message. When
you transform a message, you might need access to elements in a message
assembly component or you might need to modify some of these elements
in your message map. You can configure a message map to include the
following message assembly components: the Environment
tree, the message tree Properties tree, message tree headers,
the message tree body, and the local environment tree.
About this task
When a message arrives to an application or to an
integration service, it is
received by an input node that you have configured in a message flow. Before the message can
be processed by the message flow,
the message must be interpreted by one or more parsers that create
a logical tree representation from the bit stream of the message data.
The logical tree is also known as the message assembly. The tree format
contains identical content to the bit stream from which it is created,
but it is easier to manipulate in the message flow.
Procedure
To include message assembly components into your message map, complete the following
steps:
- Identify the message assembly components that you need
to add to your message map. For
more information, see Choosing message assembly components to include in a message map.
You may need to include the local environment tree to use
information provided in a variable or you may need to add a header
to access transport specific information.
You
can store information in the environment tree while the message passes
through the message flow. You might
need to use data passed in the environment tree to calculate the value
of output elements in a message map.
You might need to use data from the environment tree to determine
whether a transform should be applied.
- Identify whether you need to initialize, delete, or transform
elements in components of the message tree or in the local environment
tree. For more information, see Choosing a mapping action.
You can add different parts of the message tree to the map
input, to the map output, or to both. You can also add the local environment
tree. Depending on how you add a message assembly component, this
component can be deleted, initialized, or transformed.
- Configure the message map to
include a message assembly component. For more information, see Customizing a message map to include a message assembly component.
To customize
your message map to include more message assembly components, you
must add message assembly components to the input message and to the
output message, and then define transforms between them.
- Configure the message map to include the environment
tree.
For more information about mapping the environment
tree, see Mapping the environment tree.
Results
You now have a message map that includes the message assembly
components that you need to complete your message transformation.
What to do next
Define transforms between other message assembly components
that you have included. For more information, see Specifying a transform (mapping operation).