Choosing message assembly components to include in a message map
You can add the message tree components, that is, the Properties tree, the headers, and the message body into a message map. You can also add the local environment tree into a message map, and the Environment tree.
About this task
- Message tree: This tree includes the Properties folder, the message body, and headers.
- Environment tree
- Local environment tree: This tree includes multiple destination folders, and a variables folder.
- Exception list tree
When you create a message map, the Properties folder and the message body are automatically included in your Graphical Data Mapping editor.
You cannot add the exception list tree to the message map. The exception list is included automatically, and the entire contents of the input exception list is retained in the output.
Choose one or more message assembly components to include in a message map:
- Header folders: You can add one
or more headers to a message map,
in addition to the Properties folder and the message body.
When an input message is received by an input node, the input node invokes the correct parser for each header, and includes in the message tree the corresponding headers. You can then access these headers by using message maps.The message tree always includes the following components:
- All the headers that are present in the message.
- The message body.
- The Properties folder. The Properties folder (sometimes referred as the Properties tree) is the first element of the message tree and holds information about the characteristics of the message. When the input node receives the input message, it creates and completes the Properties folder.
If you need to access information available in an element of a header or if you need to modify it, then you must add the header to the message map. For more information, see Mapping transport headers.
- Local environment tree: You can
add the local environment tree to the message map. The local environment is
divided into two parts:
- Standard folders that are automatically defined for each of the destination folders available in IBM Integration Bus.
- A variables folder that is added automatically. You can use the Cast function to include a variable into your message map. You can add variables by using the Add User Defined function.
The local environment tree stores variables that can be referred to and updated by message processing nodes that occur later in the message flow.
You can also use the local environment tree to define where a message is sent. The destination can be internal or external to the message flow.
IBM Integration Bus also stores information in the local environment tree in some circumstances, and references it to access destination values that you might have set.
If you need to access information available in an element of the variables folder or if you need to modify a variable, then you must add each individual variable to the message map. For more information, see Configuring a generic type in the local environment tree by using the Cast function.
- You can add the environment tree to the
input message assembly of the message map.
If you do not include the environment tree in the input message assembly, the entire contents of the environment tree are retained in the output.
If you add the environment tree, you can define both its content and structure by using the Add User Defined function.Note: The environment tree differs from the local environment tree in that a single instance of it is maintained throughout the message flow.
|Message assembly trees||Folders in a message assembly tree||Can be configured in a message map as an input to the map and as an output to the map?||Status in a message map|
|Message tree||Properties folder||Yes||Required|
|Message tree||Header folders||Yes||Optional|
|Message tree||Message body||Yes
Note: You must cast parts of the SOAP message body to be able to define transforms between its input and output elements.
|Local environment tree||Variables folder||Yes (You must cast a variable to define transforms between its input and output elements.)||Optional|
|Local environment tree||Destination folders||Yes||Optional|
|Exception list tree||No|
What to do next
Identify the configuration of the different message assembly components. For more information, see Choosing a mapping action.