Is there a way to cancel actionFunctions?

Question

With standard AJAX, I can cancel a request-in-progress by using xhr.abort():

var xhr = new XMLHttpRequest();
// set up my xhr
// etc...
xhr.send();

// Later: realize I don't want the response after all...
xhr.abort();

Is there any way to do this with actionFunctions?

My use case is a complex search interface where the request-response-rerender circuit can take several seconds. We've decided not to disable the search interface during the query, so it's possible for a user to realize they want to refine their criteria and requery. So in the query function, I want to check whether there's already a request in process, cancel it if there is, and send a new one. Here's the simplified concept:

<apex:actionFunction name="doSearch" value="{!doSearch}">
    <apex:param name="myParams" assignTo="{!queryParams}" value=""/>
</apex:actionFunction>

<script>
function prepareQuery() {
     // grab values from the search form, client-side validation, etc.
     // if we're going to query:
     someWayToCancelPreviousQuery();
     doSearch(myParams);
}
</script>

Thanks!

Answer 1

I would try with timeout param of actionFunction:

<apex:actionFunction timeout="500" />

After 30 secs the actionFunction will be cancelled (timeouted) automatically.

The amount of time (in milliseconds) before an AJAX update request should time out.

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