Apigee Caching - How to check if the flowvariable is null or has data?

Google Cloud Apigee
1

Iam trying to host a WCF REST service in apigee. I want to cache few master datas-mediocre JSON objects. All i understand from Apigee docs is , i can define Flows and configure policies in my proxy to lookup a cached item and then decide whether to make REST call or not. I specify the variable in my LookUpPolicy. How do i check whether this variable has data or not and then proceed with the REST call? Sorry if its a simple question, i am confused and dont find a simple way to get this done

2

Hello @Swarna,

You can use the Javascript policy. And in the javascript logic you can do a check like this

var myLookUpData = "";

myLookUpData = context.getVariable("myCachedData"); //Assuming the lookup cache policy storing the fetched data in myCachedData

if (!myLookUpData) {

	//Implies data is null
} else {

	//Implies data is not null
}
3

You can check for the lookupcache.{policy-name}.cachehit (=false|true) variable to detect if the object was found in cache or not. Use that variable inside of to conditionally execute that step(s) if the variable evaluates to true. Alternatively, you can also use the variable set in the element of the lookupcache policy and evaluate that for null in the step condition.

4

Hi,

You can check variable === undefined or variable === null. Using this condition you can identify variable is null or not