topic Re: pulling data out of map click .run in Open Source Mapping Libraries Ques.

pulling data out of map click .run

TimLohnes — Mon, 28 Aug 2023 13:49:11 GMT

Hi all,

Just playing around with esri-leaflet to see if I can get everything done easier.

I a bit of a novice, but was able to quickly access my data attributes on map click with Tasks.identifyFeatures.

However I don't know how to get that data out of that task and into a variable so I can process the selection elsewhere.

In the console.log in run, I can get all the info I want. How do I pass it back to the parcels variable in map.on and then get access to the data?

map.on('click', function (e) {

parcels = queryOnMapClick(e);

});

function queryOnMapClick(clicked) {

var clickedParcels = L.esri.Tasks.identifyFeatures(pathtoservice)

.on(map)

.at(clicked.latlng)

.layers('visible:4')

.run(function (error, featureCollection, response) {

console.log("UTC Offset: " + featureCollection.features[0].properties.APN_PQ);

});

}

Thanks for any tips.

-Tim

Re: pulling data out of map click .run

OwenEarley — Sun, 12 Dec 2021 11:08:36 GMT

You could assign the variable in your run function:

map.on('click', function (e) {
     queryOnMapClick(e);
});

function queryOnMapClick(clicked) {
     var clickedParcels = L.esri.Tasks.identifyFeatures(pathtoservice)
          .on(map)
          .at(clicked.latlng)
          .layers('visible:4')
          .run(function (error, featureCollection, response) {
               console.log("UTC Offset: " + featureCollection.features[0].properties.APN_PQ);
               parcels = featureCollection.features;
          });
}

Re: pulling data out of map click .run

OwenEarley — Sun, 12 Dec 2021 11:08:39 GMT

Alternatively, return a value from within the run function:

map.on('click', function (e) {
  parcels = queryOnMapClick(e);
});

function queryOnMapClick(clicked) {
        var clickedParcels = L.esri.Tasks.identifyFeatures(pathtoservice)
            .on(map)
            .at(clicked.latlng)
            .layers('visible:4')
            .run(function (error, featureCollection, response) {
                console.log("UTC Offset: " + featureCollection.features[0].properties.APN_PQ);
                return featureCollection.features;
            });
}

Re: pulling data out of map click .run

TimLohnes — Thu, 26 Feb 2015 21:50:47 GMT

Thanks, Owen. I can't get access to the data anywhere outside of .run.

With your examples most of the time it would just say undefined.

if I return the main variable 'clickedParcels' at the bottom like

.run(function (error, featureCollection, response) {
console.log("UTC Offset: " + featureCollection.features[0].properties.APN_PQ);
return featureCollection.features;
});
return clickedParcels;
}

In the console I get some response from console.log(parcels):

XMLHttpRequest {statusText: "", status: 0, responseURL: "", response: "", responseType: ""…}

But I haven't been able to figure out how to retrieve the data out of that. I'm just trying to get a set of data that I can plug into other functions.

Re: pulling data out of map click .run

OwenEarley — Thu, 26 Feb 2015 21:55:27 GMT

The run function is an asynchronous task - you may be attempting to use the parcels variable before the run function has assigned anything to it.

I haven't tried leaflet yet but you should look into promises.

Re: pulling data out of map click .run

TimLohnes — Fri, 27 Feb 2015 22:15:36 GMT

Thanks, Owen. I believe that to be the problem. We'll see if I can make it through promises unscathed....