topic Identify Task-How to combine results from two deferred object? in ArcGIS JavaScript Maps SDK Questions

Identify Task-How to combine results from two deferred object?

GauriDeshmukh — Wed, 06 Aug 2014 05:14:12 GMT

I m executing identify task on multiple services,thus getting results of all services, i want to combine all results to show in a infowindow.

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

var identify_result=[];

var resultDef=[];

var callback_counter=0;

var deferred;

var counter_res=0;

map.setCursor("Default");

if(viewData_clicked){

var def = new dojo.Deferred();

dojo.forEach(layerInfo,function(id){

var url = map.getLayer(id).url;

identifyTask = new IdentifyTask(url);

identifyParams = new IdentifyParameters();

identifyParams.tolerance=10;

identifyParams.returnGeometry = true;

identifyParams.layerIds = map.getLayer(id).visibleLayers;

identifyParams.layerOption = IdentifyParameters.LAYER_OPTION_VISIBLE;

identifyParams.width = map.width;

identifyParams.height = map.height;

identifyParams.geometry = event.mapPoint;

identifyParams.mapExtent = map.extent;

deferred = identifyTask

//identifyTask

.execute(identifyParams)

.addCallback(function (response) {

console.log("response",response);

return arrayUtils.map(response, function (result) {

var feature = result.feature;

var layerName = result.layerName;

// map.infoWindow.setTitle(layerName);

var content = "<tr bgcolor='grey'><th><b>Field Name</b></th><th><b>Value</b></th></tr>";

$.each(feature.attributes,function (key,value){

content +="<tr><td>"+ key+"</td><td><b>"+value+"</b></td></tr>";

});

// map.infoWindow.setContent("<table border='1'>"+content+"</table>");

var infotemplate = new InfoTemplate(layerName,"<table border='1'>"+content+"</table>");

feature.setInfoTemplate(infotemplate);

return feature;

});

});//execute

callback_counter++;

identify_result.push(deferred);

}); //forEach

//if(layerInfo.length === callback_counter){

//var def = identifyTask.execute();

var res_features=[];

dojo.require("dojo.promise.all");

dojo.forEach(identify_result,function(i){

counter_res++;

var def = dojo.promise.all()

def.then(function(result) {

//res=result;

dojo.forEach(result,function(element){

dojo.forEach(element,function(j){

res_features.push(j);

});

if((identify_result.length === counter_res) && (res_features.length > 0) ){

console.log("identify_result.length",identify_result.length);

console.log("counter_res",counter_res);

console.log("result",result);

console.log("res_features",res_features);

var defrd = new dojo.Deferred();

defrd = deferred;

defrd.results=res_features;

console.log(defrd);

//map.infoWindow.setFeatures([defrd]);

//map.infoWindow.show(event.mapPoint);

}

});

Re: Identify Task-How to combine results from two deferred object?

KenBuja — Wed, 06 Aug 2014 12:15:07 GMT

Here's an example that uses dojo/promise/all. This also contains extra code to identify which service the results are coming from

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <!--The viewport meta tag is used to improve the presentation and behavior of the samples
      on iOS devices-->
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
    <title>Identify with Popup</title>

    <link rel="stylesheet" href="http://js.arcgis.com/3.8/js/esri/css/esri.css">
    <style>
        html, body, #map {
            height: 100%;
            width: 100%;
            margin: 0;
            padding: 0;
        }
    </style>

    <script>var dojoConfig = { parseOnLoad: true };</script>
    <script src="http://js.arcgis.com/3.8/"></script>
    <script>

        var map;
        var identifyTask, identifyParams, idPoint;
        var identifyResults;

        require([
          "esri/map", "esri/dijit/Popup", "dojo/promise/all", "dojo/domReady!"
        ], function (
          Map, Popup, All
        ) {
            var popup = new Popup({
                fillSymbol: new esri.symbol.SimpleFillSymbol(esri.symbol.SimpleFillSymbol.STYLE_SOLID, new esri.symbol.SimpleLineSymbol(esri.symbol.SimpleLineSymbol.STYLE_SOLID, new dojo.Color([255, 0, 0]), 2), new dojo.Color([255, 255, 0, 0.25]))
            }, dojo.create("div"));

            map = new Map("map", {
                basemap: "satellite",
                center: [-83.275, 42.573],
                zoom: 18,
                infoWindow: popup
            });

            dojo.connect(map, "onLoad", mapReady);

            var landBaseLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/BloomfieldHillsMichigan/Parcels/MapServer", { opacity: .55 });
            map.addLayer(landBaseLayer);

            var militaryLayer = new esri.layers.ArcGISDynamicMapServiceLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/Military/MapServer", { opacity: .55 });
            map.addLayer(militaryLayer);


            function mapReady(map) {
                dojo.connect(map, "onClick", runIdentifies);
            }

            function runIdentifies(evt) {
                identifyResults = [];
                idPoint = evt.mapPoint;
                var layers = dojo.map(map.layerIds, function (layerId) {
                    return map.getLayer(layerId);
                });
                layers = dojo.filter(layers, function (layer) {
                    if (layer.visibleLayers[0] !== -1) {
                        return layer.getImageUrl && layer.visible
                    }
                }); //Only dynamic layers have the getImageUrl function. Filter so you only query visible dynamic layers
                var tasks = dojo.map(layers, function (layer) {
                    return new esri.tasks.IdentifyTask(layer.url);
                }); //map each visible dynamic layer to a new identify task, using the layer url
                var defTasks = dojo.map(tasks, function (task) {
                    return new dojo.Deferred();
                }); //map each identify task to a new dojo.Deferred
                var params = createIdentifyParams(layers, evt);

                var promises = [];

                for (i = 0; i < tasks.length; i++) {
                    promises.push(tasks.execute(params)); //Execute each task
                }

                var allPromises = new All(promises);
                allPromises.then(function (r) { showIdentifyResults(r, tasks); });
            }

            function showIdentifyResults(r, tasks) {
                var results = [];
                var taskUrls = [];
                r = dojo.filter(r, function (result) {
                    return r[0];
                });
                for (i = 0; i < r.length; i++) {
                    results = results.concat(r);
                    for (j = 0; j < r.length; j++) {
                        taskUrls = taskUrls.concat(tasks.url);
                    }
                }
                results = dojo.map(results, function (result, index) {
                    var feature = result.feature;
                    var layerName = result.layerName;
                    var serviceUrl = taskUrls[index];
                    feature.attributes.layerName = result.layerName;

                    var template = new esri.InfoTemplate("", "Service Url: " + serviceUrl + "<br/><br/>Layer name: " + result.layerName + "<br/><br/> Object Id: ${OBJECTID}");
                    feature.setInfoTemplate(template);

                    var resultGeometry = feature.geometry;
                    var resultType = resultGeometry.type;
                    return feature;
                });

                if (results.length === 0) {
                    map.infoWindow.clearFeatures();
                } else {
                    map.infoWindow.setFeatures(results);
                }
                map.infoWindow.show(idPoint);
                return results;
            }

            function createIdentifyParams(layers, evt) {
                var identifyParamsList = [];
                identifyParamsList.length = 0;
                dojo.forEach(layers, function (layer) {
                    var idParams = new esri.tasks.IdentifyParameters();
                    idParams.width = map.width;
                    idParams.height = map.height;
                    idParams.geometry = evt.mapPoint;
                    idParams.mapExtent = map.extent;
                    idParams.layerOption = esri.tasks.IdentifyParameters.LAYER_OPTION_VISIBLE;
                    var visLayers = layer.visibleLayers;
                    if (visLayers !== -1) {
                        var subLayers = [];
                        for (var i = 0; i < layer.layerInfos.length; i++) {
                            if (layer.layerInfos.subLayerIds == null)
                                subLayers.push(layer.layerInfos.id);
                        }
                        idParams.layerIds = subLayers;
                    } else {
                        idParams.layerIds = [];
                    }
                    idParams.tolerance = 3;
                    idParams.returnGeometry = true;
                    identifyParamsList.push(idParams);
                });
                return identifyParamsList;
            }

        });
    </script>
</head>

<body>
    <div id="map"></div>
</body>

</html>

Re: Identify Task-How to combine results from two deferred object?

JoshHevenor — Thu, 07 Aug 2014 18:45:51 GMT

You can run each Identify individually and append their results to your infoWindow, so no need to synchronize. I haven't tested as a whole, key part on line 12:

function handleIdentify(/*IdentifyResult*/ results){

    var features = [];

    // deal with results, set up templates, etc.
    // . . .
    // populate features as required

    // Get the features currently in your infoWindow
    var existingFeatures = map.infoWindow.features || [];
    // Append the latest result set
    map.infoWindow.setFeatures(existingFeatures.concat(features));  // <-- key part

}

function handleErrror(err){
    // . . .
}

// Your many service URLs
var serviceUrls = [
    "http://service1/",
    "http://service2/",
    "http://service3/",
];

// for each URL
for(n in services){
    // create a new task
    var identify = new IdentifyTask(serviceUrls);
    // set the params as needed
    var identifyParams = new IdentifyParameters();
    // Execute the task    
    identify.execute(identifyParams, handleIdentify, handleError);

}

map.infoWindow.show(somePoint);