Solved: How can I pass parameters to a Flow Callout Policy... - Page 2

Report Inappropriate Content · 06-14-2017 01:15 AM

I want to create a Shared Flow that puts something in the cache and makes a call to slack, but depending on given parameters the text in the call to slack and the key for the cache should be different.

I've looked at http://docs.apigee.com/api-services/reference/flow-callout-policy but I haven't seen how to add a variable.

Can I use <AssignVariable> like in the Assign Message Policy?

dchiesa1

FYI,

Apigee has added an enhancement to the FlowCallout to allow explicit parameterization of the callout. The reference is b/74750586 .

Usage is like this:

<FlowCallout name="FC-MySharedFlow">
    <Parameters>
        <Parameter name="input1" value='FOO'/>
        <Parameter name="input2" ref='request.header.bar'/>
        <Parameter name="destination">FOO</Parameter>
        <Parameter name="tmplvalue">{request.header.foo}</Parameter>
    </Parameters>
    <SharedFlowBundle>MySharedFlow</SharedFlowBundle>
</FlowCallout>

The effect is that the execution of the sharedflow will begin with a new set of context variables, corresponding to the set of Parameter elements. They're just normal context variables, so within policies inside the sharedflow, you can access those context variables as you would normally. Eg., in a JavaScript policy within MySharedFlow you could

var input1 = context.getVariable("input1");
var destination = context.getVariable("destination");
var value = context.getVariable('tmplvalue');
context.setVariable(destination, value.toLowerCase());

As you can see from the sample configuration, there are a number of options for specifying the value for each Parameter.

specify the value with a value= attribute. This is a fixed value.
Specify the value with a ref= attribute, which refers to a different variable.
specify the value with a text value of the node. This is actually a Message Template, so you get curly-braced variable dereferencing and the Message Template functions too.

If you repeat a Parameter name, the behavior is not defined.

Special note: If context variables with those names already exist , they are temporarily overwritten with new values. When the SharedFlow completes, the former values of these context variables are restored.

I'll link to the official documentation when it becomes available.

This should be available in the cloud soon.

This isn't a huge new feature, but it is a nice ease-of-use thing. It will make it easier to explicitly see the intended inputs to a FlowCallout invocation.

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How can I pass parameters to a Flow Callout Policy?