topic Re: cancel query task in flex in ArcGIS API for Flex Questions

cancel query task in flex

ReenaSingh — Wed, 05 Jan 2011 07:08:20 GMT

How to cancel the querying task of query task in the middle of query process and stop all query process.

Re: cancel query task in flex

ReenaSingh — Thu, 06 Jan 2011 10:44:18 GMT

Please help me, i need it urgently ... 😞

Re: cancel query task in flex

RobertScheitlin__GISP — Fri, 10 Dec 2021 20:45:41 GMT

Reena,

Just remove the event listener form the query task. So if you are doing some code like this:

queryTask.execute(query, new AsyncResponder(onResult, onFault));
//you need to change it to
queryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
queryTask.execute(query);
//That way you can use remove listener
queryTask.removeEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);

Re: cancel query task in flex

DasaPaddock — Thu, 06 Jan 2011 17:49:31 GMT

Here's another thread on this topic:
http://forums.arcgis.com/threads/19168-Canceling-an-Asynchronous-call?p=61887

Re: cancel query task in flex

ReenaSingh — Fri, 10 Dec 2021 20:45:44 GMT

Reena,

Just remove the event listener form the query task. So if you are doing some code like this:

queryTask.execute(query, new AsyncResponder(onResult, onFault));
//you need to change it to
queryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
queryTask.execute(query);
//That way you can use remove listener
queryTask.removeEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);

hello,
But I am not using queryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
My code is :
queryTask.executeForIds(query,new AsyncResponder(onResult,onFault,token))
Now I want to stop this task in between.

Re: cancel query task in flex

RobertScheitlin__GISP — Sun, 12 Dec 2021 15:55:14 GMT

Reena,

queryTask.executeForIds(query,new AsyncResponder(onResult,onFault,token))
//you need to change it to
queryTask.addEventListener(QueryEvent.EXECUTE_FOR_IDS_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
queryTask.executeForIds(query);
//That way you can use remove listener
queryTask.removeEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);

Re: cancel query task in flex

ReenaSingh — Fri, 10 Dec 2021 20:45:47 GMT

Reena,

queryTask.executeForIds(query,new AsyncResponder(onResult,onFault,token))
//you need to change it to
queryTask.addEventListener(QueryEvent.EXECUTE_FOR_IDS_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
queryTask.executeForIds(query);
//That way you can use remove listener
queryTask.removeEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);

Hello,

Then how to pass token as object through this.

Re: cancel query task in flex

RobertScheitlin__GISP — Tue, 11 Jan 2011 13:32:28 GMT

Reena,

The only way that I know of to pass a token object to an event listener is to create an inline function and that defeats the ability to remove the event listener. If you really need that token you need to find away to create a var that can hold the object that you can access from the onResult function.

Re: cancel query task in flex

DasaPaddock — Tue, 11 Jan 2011 15:37:43 GMT

Another approach could be to keep using responders but create a class member like "private var requestCancelled:Boolean" that you check in your onResult().

Re: cancel query task in flex

ReenaSingh — Wed, 12 Jan 2011 08:31:56 GMT

Reena,

The only way that I know of to pass a token object to an event listener is to create an inline function and that defeats the ability to remove the event listener. If you really need that token you need to find away to create a var that can hold the object that you can access from the onResult function.

Hi,

Actually i have some set of queries which run in loops, after execution of these queries, there are some other queries which needs to be fired.
Then I want to stop all these queries, for which I have used removeEventlisteners but I am not able to stop those which are already got excuted in loop.
For this i have even used even Boolean to check the condition for stopping, but the queries which are already excuted; am not able to stop them. Is there any property in the GIS Flex api to stop executions of all queries at a time.

Re: cancel query task in flex

ShannonMartel — Fri, 10 Dec 2021 20:45:49 GMT

Reena,

queryTask.executeForIds(query,new AsyncResponder(onResult,onFault,token))
//you need to change it to
queryTask.addEventListener(QueryEvent.EXECUTE_FOR_IDS_COMPLETE, onResult);
queryTask.addEventListener(FaultEvent.FAULT, onFault);
queryTask.executeForIds(query);
//That way you can use remove listener
queryTask.removeEventListener(QueryEvent.EXECUTE_COMPLETE, onResult);

I work for a town that sits in two countys. Each county's parcels are in a seperate layer. I am using a point locater to find the address. Then I use that graphic to query the parcels. I am trying to tell it if you get a value in the FeatureSet for the parcels in County A FeatureSet then proceed to query function A. If it gets a null try County B parcel layer. I have tried to so many different ways, but it always runs both queries. This is what I have tried:

1 - Made seperate query functions for both parcel layers.
2 - Created two FeatureSets (one for each County).
3 - Wrote functions to do additional queries if the featureSet is greater than zero.

It still runs both counties... Does anyone know what I am missing? Do I need eventlisteners, and how would I do it.

thanks!

Re: cancel query task in flex

ShannonMartel — Tue, 15 Mar 2011 14:13:20 GMT

Please, does anyone have any ideas?

Re: cancel query task in flex

RobertScheitlin__GISP — Tue, 15 Mar 2011 14:26:38 GMT

Shannon,

This sounds pretty straight forward... So you take the locator result geometry (MapPoint) and do a spatial query against County A and in the results function if the FeatureSet.Length == 0 then fire off the query for County B.

Or you could executeForIds on both counties and the one that returns results then fires a true query to the layer.

Re: cancel query task in flex

ShannonMartel — Tue, 15 Mar 2011 14:55:39 GMT

Here is the query function for the two parcel layers. For some reason, it gets stuck in a loop.... I don't know why. I have this query function, and then two additional functions, one for each County. It keeps looping through the two additional functions (each County's fire, school etc) and putting them in the datagrid. I have Fiddler, and it does not show the repeating queries.

Re: cancel query task in flex

RobertScheitlin__GISP — Sun, 12 Dec 2021 15:55:16 GMT

Shannon,

The first thing I would do is bracket your if statement here:

       if (featureSet.features.length == 0){
        meckParcels = new Array();
        meckParQuery.outSpatialReference = map.spatialReference;
        meckParQuery.geometry = lastAddressGraphic.geometry;
        meckParQueryTask.execute(meckParQuery, new AsyncResponder(onMeckParQResult, onMeckParQFault, tpoints));
        
        function onMeckParQResult(featureSet:FeatureSet, token:Object = null):void
        {
         meckParcels = featureSet.features;
         if (featureSet.features.length > 0){       
          meckSearch();
         }  
         
        }
        function onMeckParQFault(info:Object, token:Object = null):void 
        {
         trace(info.toString());
        }
                                                      }

Re: cancel query task in flex

ShannonMartel — Tue, 15 Mar 2011 16:17:59 GMT

Got it! I found in my code were I told it to run the meckSearch() inside the meckSearch() function. I think I have been staring at it too long... not sure how I missed that.

Thank you so much for your help.
Shannon