ArcGIS API for JavaScript QueryTask for user's own map

Question

I am using ArcGIS online to create a web map and then I want to query this web map using ArcGIS API for JavaScript. In the tutorials I read I see

var queryTask = new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/5");

But I want to use my own web map which is "http://pawebgate.maps.arcgis.com/home/webmap/viewer.html?webmap=a0c647159b46456b963d8b180e062b57"

I have tried using the whole http://... it did not work. I have tried using only a0c647159b46456b963d8b180e062b57 it did not work.

Has anyone got any idea about how to use my web map instead of the http://samplserver1 ...

Answer 1

Webmaps are not synonymous with ArcGIS Server (or even ArcGIS Online) feature services because a webmap is typically composed of a collection/mashup of a variety of different data sources.

this doesn't mean you can't query layers from a webmap. it just means that as a developer you have to get a reference to the particular layer of interest out of the JSAPI map object itself instead of writing in your own hardcoded urls.

one way of doing this is to make a call to map.getLayer('yourlayerid'); https://developers.arcgis.com/javascript/jsapi/map-amd.html#getlayer