topic Re: How do i remove an event listener from Identify Task in ArcGIS JavaScript Maps SDK Questions

How do i remove an event listener from Identify Task

SteffiAntony — Tue, 15 Sep 2020 06:54:55 GMT

Seems like this should be simple, but I'm stumped. i need the functionality to be done in such a a way that on button click the identify task should be run properly on every click function on map . and on the same time when i press the same button again it should stop the API calls, and the event should be removed and vice-versa. how do it can be possible?

var identifyButton = dom.byId("identify")

on(identifyButton, "click", function (evt) {

map.on("click", executeIdentifyTask);

//create identify tasks and setup parameters

identifyTask = new IdentifyTask(textbox.value);

identifyParams = new IdentifyParameters();

identifyParams.tolerance = 3;

identifyParams.returnGeometry = true;

identifyParams.layerIds = [0, 2];

identifyParams.layerOption = IdentifyParameters.LAYER_OPTION_ALL;

identifyParams.width = map.width;

identifyParams.height = map.height;

})

function executeIdentifyTask(event) {

identifyParams.geometry = event.mapPoint;

identifyParams.mapExtent = map.extent;

var deferred = identifyTask

.execute(identifyParams)

.addCallback(function (response) {

// response is an array of identify result objects

// Let's return an array of features.

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

var feature = result.feature;

var layerName = result.layerName;

feature.attributes.layerName = layerName;

var Templates = new InfoTemplate("");

feature.setInfoTemplate(Templates);

return feature;

});

// InfoWindow expects an array of features from each deferred

// object that you pass. If the response from the task execution

// above is not an array of features, then you need to add a callback

// like the one above to post-process the response and return an

// array of features.

map.infoWindow.setFeatures([deferred]);

map.infoWindow.show(event.mapPoint);

}

Re: How do i remove an event listener from Identify Task

ManishPatel — Tue, 15 Sep 2020 13:38:03 GMT

Hi Steffi Antony,

You can use the connect and disconnect to disable the events. And if I understand your requirement correctly, I have put together a sample for you. Have a look at it at Identify with Popup

The source code you can find at https://codepen.io/mrpatel/pen/OJNwMeE

Hope this helps.

Cheers!

Manish

Re: How do i remove an event listener from Identify Task

SteffiAntony — Wed, 16 Sep 2020 06:14:36 GMT

Thank you. Manish Patel‌ meanwhile i added 2 line of code.

identifyClickHandler = on(map, 'click', executeIdentifyTask);

identifyClickHandler.remove();

is this ok??

var identifyButton = dom.byId("identify")

on(identifyButton, "click", function (evt) {

identifyClickHandler = on(map, 'click', executeIdentifyTask);

identifyTask = new IdentifyTask(textbox.value);

identifyParams = new IdentifyParameters();

identifyParams.tolerance = 3;

identifyParams.returnGeometry = true;

identifyParams.layerIds = [0, 2];

identifyParams.layerOption = IdentifyParameters.LAYER_OPTION_ALL;

identifyParams.width = map.width;

identifyParams.height = map.height;

})

function executeIdentifyTask(event) {

identifyParams.geometry = event.mapPoint;

identifyParams.mapExtent = map.extent;

var deferred = identifyTask

.execute(identifyParams)

.addCallback(function (response) {

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

var feature = result.feature;

var layerName = result.layerName;

feature.attributes.layerName = layerName;

// console.log(feature.attributes);

var Templates = new InfoTemplate("");

feature.setInfoTemplate(Templates);

return feature;

});

map.infoWindow.setFeatures([deferred]);

map.infoWindow.show(event.mapPoint);

identifyClickHandler.remove();

}

Re: How do i remove an event listener from Identify Task

ManishPatel — Wed, 16 Sep 2020 09:28:53 GMT

Yes that will work too.

Re: How do i remove an event listener from Identify Task

ManishPatel — Thu, 17 Sep 2020 02:31:04 GMT

Steffi Antony‌ please dont forget to mark the question as answered if the code provided helped to answer your question. This will help others to check when they need to find any answer.

Cheers,

Manish