TEC Workbook - IBM

IBM Software
3.2.11 DataPower Contexts
While configuring the various actions (sign, transform, etc.), you may have noticed that each action
declares an input and an output context. In the case of a transform action, the input context will be the
document that is fed to the transformer, and the results of the transformation will be written to the output
context.
Some actions may only have an input context. For example, the verify action has an input context, but no
output context; the signature verification either passes or fails. In contrast, some actions may only have
an output context. The fetch action can fetch an XML document from a local file or a remote server, and
the fetched document becomes the output context. Contexts are referred to by the following names:
● INPUT – represents the original message as it arrived from the client.
● OUTPUT – represents the outbound message which will be forwarded to the destination. In
the case of client-to-server processing, the OUTPUT context represents what will be sent
to the backend server. In the case of server-to-client processing, the OUTPUT context
represents what will be returned to the client.
● NULL – indicates that the output is not needed. In other words, the output from the action
is sent to the bit bucket.
● PIPE – indicates that the output of the action should be piped into the input of the next
action. In this case, the input context of the next action must also specify PIPE.
● Named context – in this case, you can assign a name to a context and use it at a later
point in the processing rule. For example, a transform action can be configured with an
input context of INPUT and an output context of newRequest. Later in the processing
rule, another action can use newRequest as the input context.
__1. Click on the magnifying glass in front of the transform action.
The XML document shown in the window shows what will be fed into the transform action as the context
document. In this case, the message with the digital signature will be the input context to the
transformation.
__2. Click on the magnifying glass after the transform action (in front of the sign action).
The input to the schema validate action is the results of the prior transform action. In the content section,
notice that the digital signature has been removed.
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