JavaScript ArcGIS Maps – Identify All Layers Without Pre-Designing InfoWindow

arcgis-javascript-apijavascript

This applies to the ArcGIS Server JavaScript API 2.4.

The Identify Task sample shows how IdentifyTask can be used to find features in multiple layers, as specified in the IdentifyParameters:

identifyParams.layerIds = [0,2];

In this sample, the infoWindow already contains elements for the expected layers, which are used to display multiple features in separate tabs of the infoWindow:

<!-- info window tabs -->
<div id="tabs" dojoType="dijit.layout.TabContainer" style="width:385px;height:150px;">
  <div id="bldgTab" dojoType="dijit.layout.ContentPane" title="Buildings"></div>
  <div id="parcelTab" dojoType="dijit.layout.ContentPane" title="Tax Parcels"></div>
</div>

//In the JavaScript:
dijit.byId("bldgTab").setContent(layerTabContent(bldgResults,"bldgResults"));
dijit.byId("parcelTab").setContent(layerTabContent(parcelResults,"parcelResults"));

Is there a way to handle this dynamically, and create the required tabs at run-time?

For example, I wish to run IdentifyTask on all visible layers, and return the results in a separate tab of the infoWindow. How can I create the tabs dynamically?

Best Answer

Yes, this is possible. To create your tabs dynamically, look at creating dojo dijits programmatically vs. declaratively. When your visible layers change, modify your tab container to remove or add the appropriate tabs.

Edit: here's a proof of concept on JS Fiddle: http://jsfiddle.net/swingley/wKue4/ It doesn't really handle attributes but lets you select which layers to identify and builds the info window content dynamically.

Related Solutions

[GIS] How to query all points within the current map extent

When you create map object, you can specify the extends as below:

 map = new esri.Map("map", {
          extent: esri.geometry.geographicToWebMercator(new esri.geometry.Extent(-125.90, 44.60, -114.65, 50.22, new esri.SpatialReference({wkid:4326}))),
          showInfoWindowOnClick:false
        });

Then latter you can change the map extends values as below:

http://help.arcgis.com/en/webapi/javascript/arcgis/help/jsapi_start.htm#jsapi/map.htm#setExtent

map.setExtent(taxLotExtent);

ArcGIS Server – Identify Layers from Multiple Instances

First, here is a simplified JavaScript API example to show the concept of using DeferredList to process multiple identify tasks:

//Assume that map is your map object
var idTask1, idTask2, idParams = new esri.tasks.IdentifyParameters();
var url1 = "<server1 url>", var url2 = "<server2 url>";
dojo.connect(map, "onLoad", initIdentifies);
function initIdentifies(map) { //map.onLoad passes in the map object
    idTask1 = new esri.tasks.IdentifyTask(url1);
    idTask2 = new esri.tasks.IdentifyTask(url2);
    //A few sample constant parameters. Set more or less as you need
    idParams.tolerance = 12;
    idParams.returnGeometry = true;
    idParams.layerOption = esri.tasks.IdentifyParameters.LAYER_OPTION_ALL;
    dojo.connect(map, "onClick", runIdentifies);
}
function runIdentifies(evt) {
    var defTask1 = new dojo.Deferred(), defTask2 = new dojo.Deferred;
    var dlTasks = new dojo.DeferredList([defTask1, defTask2]);
    dlTasks.then(showResults); //defTasks will fire after defTask1 and defTask2 have completed
    //These parameters change with each request
    idParams.width = map.width;
    idParams.height = map.height;
    idParams.geometry = evt.mapPoint;
    idParams.mapExtent = map.extent;
    try {
        idTask1.execute(idParams, defTask1.callback, defTask1.errback); //Pass the response into the callback on defTask1
    } catch (e) {
        console.log("Error caught");
        console.log(e);
        defTask1.errback(e); //If you get an error, execute the errback
    }
    try {
        idTask2.execute(idParams, defTask2.callback, defTask2.errback); //Pass the response into the callback on defTask2
    } catch (e) {
        console.log("Error caught");
        console.log(e);
        defTask2.errback(e); //If you get an error, execute the errback
    }
}
function showResults(r) {
    //The format of 'r' is [[Boolean task 1 success, [task 1 results]],[Boolean task 2 success, [task 2 results]]]
    //using the array 'r', build and show your infoWindow as normal
}

Then here is an example in jsFiddle that I think does what you want, runs using all visible layers in all visible dynamic map layers in the map.

http://jsfiddle.net/blordcastillo/mULcz/

All typos are fixed now :)

The basic idea is that whenever the map is clicked or visibility is toggled, the identify is rerun. When the identify is run, the number of identity tasks fired depends on the number of layers visible, and it waits until all layers return to display its results.

Related Question

[GIS] How to handle time-based raster data in the ArcGIS Server JS API