在Apigee中，如何为统计信息收集器策略要使用的Javascript中的变量分配值？

Question

While working with an Apigee API proxy, I have obtained the value of a query parameter from the URL and extracted a part of it. I need to get a message count on the extracted part of the query parameter using the Statistics Collector Policy.

An example: orgname-test.apigee.net/v0/myURL?Qparam=abc.9421.345.ghi567 is the URL with the query parameter 'Qparam' with a value of 'abc.9421.345.ghi567'.

Using the Javascript policy, I managed to obtain the query parameter value and extract the part coming after the third dot, that is; '345'. I need to use the Statistics Collector policy on this part of the query parameter value ('345') to get a count of how many times it was called. How can I do that? And is this the right approach overall?

Answer 1

1) After query parameter is parsed and the value is retrieved from the string, set a flow variable in the JavaScript policy such as:

context.setVariable('QParam.thirdElement', value)

2) Set QParam.thirdElement in Statistic Collector policy:

This value will then be available later on to be set as a reference in the statistics collector policy. And could be used as:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<StatisticsCollector async="false" continueOnError="false" enabled="true" name="statisticscollector-analyze-QParam">
    <DisplayName>StatisticsCollector-AnalyzeQParam</DisplayName>
    <FaultRules/>
    <Properties/>
    <Statistics>
        <Statistic name="thirdElement" ref="QParam.thirdElement" type="STRING">id</Statistic>
    </Statistics>
</StatisticsCollector>

Your approach should be fine, if there's no other way to get this value in a separate parameter. Perhaps using RegEx to extract the value from QParam.