Extract a path variable for later use in target end point call

[jivanpatil]

My use case is I have a path variable someID coming in the request, for example "example/example/someID/example" , which I want to extract and use later in target endpoint as a path variable. What is the standard recommended way to do this in Apigee. As of now what I have known is to use Extract variable policy. But how it use it ?

[nagashree_b · Accepted solution]

@jivan patil

You can use the extract variable policy to capture the path parameter in the URL into a variable and use the same to set the target path.

Here is an example - extract the someID from the URIPath into a variable named id

  <URIPath>  <Pattern ignoreCase="true">/example/example/{id}/example</Pattern></URIPath>

You can then use an AssignMessage policy or JS policy to add that to your target url or use <Path> in the target endpoint to append it to the target path

<AssignVariable><Name>target.url</Name><Value>http://httpbin.org/get/{id}</Value></AssignVariable>

or add the Path in the HttpTargetConnection if you are using a LoadBalancer configuration

<Path>/get/{id}</Path>

[jivanpatil]

I tried the first part you've mentioned. Then I am using JS policy to print, this is just to confirm if it's making it through. I am getting null for someID.

[mdunker]

Sorry, missed the path variable part of the question when I answered above. Nagashree's answer is correct -- make sure the pattern only includes the parts of the path after the proxy's BasePath.

[jivanpatil]

Some how stil now working. Following is my code for ExtractPolicy.

<ExtractVariables async="false" continueOnError="false" enabled="true" name="ev-extract-some-id">
    <DisplayName>ev-extract-some-id</DisplayName>
    <Properties/>
    <URIPath>
        <Pattern ignoreCase="true">mypath/mypath/{someID}/mypath</Pattern>
    </URIPath>
    <QueryParam name="name"/>
    <Header name="name"/>
    <FormParam name="name"/>
    <Variable name="name"/>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <Source clearPayload="false">request</Source>
</ExtractVariables>

[nagashree_b]

@jivan patil

Please provide more details - what's your complete URL, basepath and pathsuffix?check the attached sample and the trace.extractpathparams-rev1-2019-03-04.ziptrace-1551727457453.txt

[jivanpatil]

Thanks for sharing sample.I found the issue. My pattern was missing "/" in the path if you see the code I have posted in the previous comment. Thanks Mike, the parts were not fully matching.

<Pattern ignoreCase="true">/mypath/mypath/{someID}/mypath</Pattern>

[nagashree_b]

Hmm, didn't notice the missing slash in your policy. Glad you figured out from the sample.