topic Check Topology in JavaScript? in ArcGIS JavaScript Maps SDK Questions

Check Topology in JavaScript?

ShaningYu — Mon, 05 Mar 2018 20:30:56 GMT

Does current JS API provides topology functions? Thanks.

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Mon, 05 Mar 2018 20:40:34 GMT

Shanning,

Topology is more of a desktop thing, so the best answer is no, but what exactly are you looking for as somethings can be done using the GeometryEngine.

Re: Check Topology in JavaScript?

ShaningYu — Mon, 05 Mar 2018 20:44:19 GMT

Robert: Thanks for your response. What I want to Do a topology validation and see if a point is in a polygon.

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Mon, 05 Mar 2018 20:51:14 GMT

Shaning,

Then that is definitely possible the Polygon class has a contains method.

https://developers.arcgis.com/javascript/3/jsapi/polygon-amd.html#contains

Re: Check Topology in JavaScript?

ShaningYu — Tue, 06 Mar 2018 16:16:35 GMT

Dear Robert: Thanks for your response. In order to use the contains method, I need to get the polygon feature through a URL on a map service. I tried to query a feature on a map service layer. I type attributeName like 'ABC%' in the Where Box, and then * in the Out Fields Box, and make Return Geometry checked.

The URL generated looks like:

http://myArcGISSite/rest/services/theFolder/theLayer/MapServer/1/query?where=attributeName+like%27ABC%01%25%27&text=&objectIds=&time=&geometry=&geometryType=esriGeometryEnvelope&inSR=&spatialRel=esriSpatialRelIntersects&relationParam=&outFields=*&returnGeometry=true&maxAllowableOffset=&geometryPrecision=&outSR=&returnIdsOnly=false&returnCountOnly=false&orderByFields=&groupByFieldsForStatistics=&outStatistics=&returnZ=false&returnM=false&gdbVersion=&returnDistinctValues=false&f=html

I am not sure the returned object is a feature (e.g. polygon). Could you guide me how a feature can be returned through URL? Thanks again.

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Tue, 06 Mar 2018 16:25:13 GMT

Shaning,

You are using the JS API so you would use a QueryTask and Query Class to get the feature from your map service.

QueryTask | API Reference | ArcGIS API for JavaScript 3.23

Query | API Reference | ArcGIS API for JavaScript 3.23

Re: Check Topology in JavaScript?

ShaningYu — Tue, 06 Mar 2018 19:26:02 GMT

Robert: Thanks for your response. I use a similar approach to get the polygon feature (termed selected_Poly here). Then I use

var b = selected_Poly.contains(pt);

get Object doesn't support property or method 'contains'. How can the selected feature be cast as a polygon? Thanks.

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Tue, 06 Mar 2018 19:30:53 GMT

Shaning,

Is the var selected_Poly a Graphic or a Polygon class?

If it is a Graphic which is the normal result of a QueryTask then you just need to use

selected_Poly.geometry.contains(pt);

Re: Check Topology in JavaScript?

ShaningYu — Tue, 06 Mar 2018 19:49:01 GMT

var selected_Poly = response.features.geometry.rings[0]; // e.g. i =0

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Tue, 06 Mar 2018 19:54:08 GMT

Shanning,

That means that you have an array of point and not a polygon. If you omit the rings[0] portion you then have the Polygon class.

Re: Check Topology in JavaScript?

ShaningYu — Tue, 06 Mar 2018 20:31:24 GMT

selected_Poly = response.features.geometry; //.rings[0];

var polygonSymbol = new esri.symbol.SimpleFillSymbol(

esri.symbol.SimpleFillSymbol.STYLE_SOLID, // or "solid",

new esri.symbol.SimpleLineSymbol("solid", new esri.Color([232, 104, 80]), 2),

new esri.Color([232, 104, 80, 0.25])

);

var graphic = new esri.Graphic(selected_Poly, polygonSymbol); // got attributes, geometry, and symbol null value; what is wrong here? Thanks.

graphic.setSymbol(polygonSymbol);

...

Re: Check Topology in JavaScript?

ShaningYu — Tue, 06 Mar 2018 20:40:55 GMT

also in debugging

selected_Poly.contains(new esri.geometry.Point([-76.99, 38.88]))

got Object doesn't support property or method 'contains'

where

selected_ContractSection.rings

[-8574575.3238,4706898.530699998,-8574717.6555,4706897.306000002,-8574736.575,4706897.310400002,-8575245.9761,4706912.5276999995,-8575227.622,4707114.234399997,-8575227.5562,4707119.869999997,-8575219.9439,4707238.998999998,-8574736.4339,4707222.973899998,-8574717.4695,4707222.967699997,-8574503.5524,4707224.6489999965,-8574507.9585,4707120.172899999,-8574507.9603,4707114.672899999,-8574535.2586,4706976.1853,-8574575.3238,4706898.530699998]

__proto__: []

length: 1

[0]: [...]

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Tue, 06 Mar 2018 21:35:38 GMT

Shaning,

Can you check the instance of selected_Poly using this code?

console.log(selected_Poly instanceof esri.geometry.Polygon);‍

Should come back as true.

Re: Check Topology in JavaScript?

ShaningYu — Wed, 07 Mar 2018 16:43:02 GMT

Got selected_Poly != esri.geometry.Polygon. The I tried

var ar2D = new Array();

for (var j=0; j < selected_Poly.length; j++) {

var ar1D = [ selected_Poly[0], selected_Poly[1] ];

ar2D.push(ar1D);

}

polygon = new esri.geometry.Polygon();

polygon.addRing(ar2D);

Then, I checked the polygon object:

polygon

_ring: 0

cache: undefined

rings: [-8574575.3238,4706898.530699998,-8574717.6555,4706897.306000002,......]

spatialReference: {...}

type: "polygon"

However, still get

polygon.geometry != esri.geometry.Polygon

What's wrong in my code? Thanks.

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Wed, 07 Mar 2018 17:02:26 GMT

Shaning,

What is the WKID of your data?

Re: Check Topology in JavaScript?

ShaningYu — Wed, 07 Mar 2018 17:15:59 GMT

wkid=102100

Re: Check Topology in JavaScript?

RobertScheitlin__GISP — Sat, 11 Dec 2021 16:33:37 GMT

Shaning,

You are still using Legacy style of coding verses AMD which is what you really should be using in today's day and age (Legacy style of coding is not even supported in JS 4.x api). Here is a very simple sample that shows the contains method. Also you will notice that I have used some of your polygon coordinates with wkid 102100 and they do not plot on the map. So I am not sure your data is 102100.

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="initial-scale=1, maximum-scale=1,user-scalable=no">
    <title>Polygon Contains</title>

    <link rel="stylesheet" href="https://js.arcgis.com/3.23/dijit/themes/claro/claro.css">
    <link rel="stylesheet" href="https://js.arcgis.com/3.23/esri/css/esri.css">
    <style>
      html, body, #map {
        height:100%;
        margin: 0;
        padding: 0;
        width:100%;
        overflow:hidden;
      }
    </style>

    <script src="https://js.arcgis.com/3.23/"></script>
    <script>
      var map, editToolbar, ctxMenuForGraphics, ctxMenuForMap;
      var selected, currentLocation;

      require([
        "esri/map", "esri/geometry/Point", "esri/geometry/Polygon",
        "esri/symbols/SimpleLineSymbol",
        "esri/symbols/SimpleFillSymbol",
        "esri/graphic",
        "esri/Color",
        "esri/tasks/query", "esri/tasks/QueryTask",
        "dojo/domReady!"
      ], function(
        Map, Point, Polygon,
        SimpleLineSymbol,
        SimpleFillSymbol,
        Graphic,
        Color,
        query,
        QueryTask
      ) {

        map = new Map("map", {
          basemap: "satellite",
          center: [20.039, 62.739],
          zoom: 3
        });
        map.on("load", addGraphics);

        function addGraphics() {
          // Adds pre-defined geometries to map
          var polygonSymbol = new SimpleFillSymbol(
            SimpleFillSymbol.STYLE_SOLID,
            new SimpleLineSymbol(
              SimpleLineSymbol.STYLE_DOT,
              new Color([151, 249, 0, 0.8]),
              3
            ),
            new Color([151, 249, 0, 0.45])
          );

          var polygon = new Polygon({
            "rings": [
              [
                [-4226661.916056009, 8496372.808143634],
                [-3835304.3312360067, 8731187.359035634],
                [-2269873.991956003, 9005137.668409634],
                [-1213208.5129420012, 8613780.083589634],
                [-1017529.7205320001, 8065879.464841632],
                [-1213208.5129420012, 7478843.087611631],
                [-2230738.233474003, 6891806.710381631],
                [-2935181.8861500043, 6735263.6764536295],
                [-3522218.263380006, 6891806.710381631],
                [-3952711.606682008, 7165757.01975563],
                [-4265797.674538009, 7283164.295201631],
                [-4304933.433020009, 7635386.121539632],
                [-4304933.433020009, 7674521.880021632],
                [-4226661.916056009, 8496372.808143634]
              ]
            ],
            "spatialReference": {
              "wkid": 102100
            }
          });

          var spolygon = new Polygon({
            "rings": [
              [
                [-8574575.3238, 4706898.530699998],
                [-8574717.6555, 4706897.306000002],
                [-8574736.575, 4706897.310400002],
                [-8575245.9761, 4706912.5276999995],
                [-8575227.622, 4707114.234399997],
                [-8575227.5562, 4707119.869999997],
                [-8575219.9439, 4707238.998999998],
                [-8574736.4339, 4707222.973899998],
                [-8574717.4695, 4707222.967699997],
                [-8574503.5524, 4707224.6489999965],
                [-8574507.9585, 4707120.172899999],
                [-8574507.9603, 4707114.672899999],
                [-8574535.2586, 4706976.1853],
                [-8574575.3238, 4706898.530699998]
              ]
            ],
            "spatialReference": {
              "wkid": 102100
            }
          });

          map.graphics.add(new Graphic(polygon, polygonSymbol));
          map.graphics.add(new Graphic(spolygon, polygonSymbol));
          console.info(polygon.contains(new Point([-76.99, 38.88])));
        }
      });
    </script>
  </head>
  <body class="claro">
      <div id="map"></div>
  </body>
</html>
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Re: Check Topology in JavaScript?

ShaningYu — Wed, 07 Mar 2018 19:21:14 GMT

GREAT HELP! Thanks a LOT!!!

Re: Check Topology in JavaScript?

ShaningYu — Thu, 08 Mar 2018 18:08:38 GMT

Rebert: Got an additional prob. (see my email to you). Could you take a look? Thanks.