I am able to resolve this issue and can see the value in an image request now. eVar value was getting overridden with the one already defined in doPlugins function.
But now, the other problem I see that even though the value is getting populated in am image request but the report is not getting populated with the data. I waited for 2-3 hours but still can not see the data in report.
Kindly note that I am just trying to see Conversion Variable 'eVar' report which contains the 'search terms'. Is there any other metrics that I need to select and apply to process the meaningful report data?
If you're not seeing the search term in the image request under the eVar you're expecting, you're not going to see it in reporting. The only disconnect I see above is that the page load rule is not properly taking the data element and assigning it to the eVar.
I would double check your DTM rule and make sure that the eVar assignment is set to the data element you're expecting. I would also check that there aren't any other rules firing that also involve that eVar, potentially clearing the variable out before the image request is sent.
To recap, you are seeing the value being set to the correct variable in the image request? If that's correct, we may need to check with the Analytics folks. I'll copy our Analytics community manager here to see if he has some input.
A few basic things to check:
Ensure you are looking at the same report suite in Analytics that is included in the image request
Ensure the variable you're using has been enabled within Analytics
Gigazelle - Do you have anything to add? If the value set to the correct variable in the image request, DTM has done its job. Is there something else we should be looking for inside Analytics?