Examine checkbox using LayerList widget for layer visibility

[LoriEmerson_McCormack]

I want to identify only those layers that have been toggled on and ignore those layers that have been toggled off in my web app.  I am using the LayerList widget that sets up the checkboxes behind the scenes.  I have tried three different approaches.

My first two efforts (see the attached .gif documents):

1.  using jquery

2.  using the function called updateLayerVisibility(), where ".esriCheckbox" is the class name I obtained from the LayerList.css when I downloaded it from the LayerList widget web page.

3.  Lastly, I tried using the updateLayerVisibility() function, by somehow accessing:

myWidget.layers.visibility==true.  Essentially, I was trying to check the visibility option on each layer that I set up in the LayerList widget to see if it had changed after the layer was toggled on or off in my web app.

     a.  var inputs = query("#layerListDiv");

Here's my LayerList:

Here's my layerListDiv:

<div data-role="panel" id="ui-settings-panel" data-theme="a" data-position="right" data-display="overlay" data-position-fixed="true" style="overflow:scroll">

   <ul data-role="listview">

     <li id="layerListDiv"></li>

   </ul>

[LoriEmerson_McCormack · Accepted solution]

I got it to work by adding/removing the layer index values from the identifyParams.layerIds array.  The code needs to be added within the layerlist widget build (within the map.on("layers-add-result"...) and after myWidget.startup();).

By right-clicking on the layerlist and inspecting element, I was able to find the ESRI names for the layerlist items.

Because I am using the dynamic map service, my first layer in the layerlist widget is a group layer.  Therefore, I am accessing the sublayer index:

var x = $(this).attr("data-sublayer-index");

I only want to identify on certain layers (indexes = 0, 2, 3, 4).

I also want consistent "identify" behavior, so I am keeping the order of the layer indexes in my array in the same position, which is why I am using the splice command.

//*********************************************

//add the legend and layerlist

//*********************************************

map.on("layers-add-result", function (evt) {

var layerInfo = arrayUtils.map(evt.layers, function (layer, index) {

return { layer: layer.layer, title: layer.layer.name };

});

if (layerInfo.length > 0) {

var legendDijit = new Legend({

map: map,

layerInfos: layerInfo

}, "legendDiv");

legendDijit.startup();

var myWidget = new LayerList({

map: map

, layers: [

{

layer: allTravelImpactsLayer // required unless featureCollection.

, showSubLayers: true // optional, show sublayers for this layer. Defaults to the widget's 'showSubLayers' property.

, showLegend: false // optional, display a legend for the layer items.

, showOpacitySlider: false // optional, display the opacity slider for layer items.

//, visibility: false // optionally set the default visibility

,id: "All Travel Impacts" // optionally set the layer's id

}

]

}, "layerListDiv");

myWidget.startup();

//*********************************************

// Set up identify parms for checked layers

//*********************************************

var arr = [];

$('input.esriCheckbox:checkbox:checked').each(function () {

var x = $(this).attr("data-sublayer-index");

if ($(this).is(':checked') && ((x == "0") || (x == "2") || (x == "3") || (x == "4"))) {

arr.push(x);

} // end if

});

if (arr.length > 0) {

identifyParams.layerIds = arr;

}

else {

// turn on id parm for impact points if checked

}

//*********************************************

// When layer is toggled, change identify parms

//*********************************************

$(".esriCheckbox").click(function () {

var x = $(this).attr("data-sublayer-index");

if ($(this).is(':checked')) {

var z = add_item(identifyParams.layerIds, x);

identifyParams.layerIds = z;

} else {

var y = remove_item(identifyParams.layerIds, x);

identifyParams.layerIds = y;

}

});

}

});

map.addLayers([allTravelImpactsLayer]);

//*********************************************

// remove value from array

//*********************************************

remove_item = function (arr, value) {

var b = '';

for (b in arr) {

if (arr == value) {

arr.splice(b, 1);

break;

}

}

return arr;

}

//*********************************************

// add value to array in the correct position

//*********************************************

add_item = function (arr, value) {

var b = '';

var added = false;

for (b in arr) {

if (arr > value) {

arr.splice(b, 0, value);

added = true;

break;

}

}

if (!added) {

arr.push(value);

}

return arr;

}