#07 - Create Polygon With Esri ArcGIS JS Api

In the last post, we created polyline geometry using polyline library. Today in this post, i will describe how to create polygon using "polygon library" with Esri ArcGIS JS API. And we will add this polygon to map graphically.

What Will I Learn?

We will learn how to create polylgon using ArcGIS JS API "polygon library".

• How to create polygon.
• How to create simple fill symbol.
• How to create graphic.
• How to add graphic to map.

Requirements

You can use any operating system and any ide or editor. I will use "Windows PC" and "Visual Studio Code". And i will use ESRI ArcGIS JS Library from web. But you can install library using bower from github repository.

• Windows 10 Operating System
• Visual Studio Code Editor
• ESRI ArcGIS JS API version 3.23
• Basic knowledge of HTML
• Basic knowledge of JS
• Basic knowledge of CSS
• Basic knowledge of Dojo Toolkit

Difficulty

• Basic

Contents

1. File Schema

| -- ESRI ArcGIS JS API 3.23
| -- | -- js
| -- | -- | -- main.js
| -- | -- css
| -- | -- | -- main.css
| -- | -- fonts
| -- | -- | -- font-awesome-4.7.0
| -- | -- | -- | -- css
| -- | -- | -- | -- |-- font-awesome.min.css
| -- | -- | -- | -- fonts
| -- | -- | -- | -- less
| -- | -- | -- | -- scss
| -- | -- index.html

*Only used files in project has been shown. There are other files for dependency.

2. Create Polygon

Firstly we will create polygon using ESRI ArcGIS JS API "Polygon" library. We will work in "main.js" file.

2.1 Add Polygon Library

We will add polygon library using require method.

require([
   "esri/geometry/Polygon"
], function (
    Polygon
){...});

2.2 Create Polygon Instance

Now, we can create polygon instance. We will not use any parameters. We will use addRing method to add points that creating our polyline in next step.

var polygon = new Polygon();

2.3 Add Ring To Polygon

We will add points to polygon using "addRing" method. This method has take one parameter that is an array veriable consist of points. We already learned how to create point. I will create polygon that has rectangle shape.

polygon.addRing([
            new Point(28.991808, 41.014267),
            new Point(28.991808, 41.004267),
            new Point(29.001808, 41.004267),
            new Point(29.001808, 41.014267),
            new Point(28.991808, 41.014267)
        ]);

3. Create Simple Symbol

We will create simple fill symbol to show our polygon on map.

3.1 Add Simple Fill Symbol Library

We will add simple fill symbol library using require method.

require([
  "esri/symbols/SimpleFillSymbol"
], function (
    SimpleFillSymbol
){...});

3.2 Create Simple Fill Symbol Instance

We will create new symbol instance. We will not use any parameters for now. But we will learn how to create special symbol in future posts.

var simpleFillSymbol = new SimpleFillSymbol();

4. Create Graphic Instance And Add To Map

We learned how to create graphic previous post. We will create new graphic instance using two parameters. First parameter is geometry for this example it will be our polygon. And second parameter is symbol for this example it will be our simple fill symbol.

var polygonGraphic = new Graphic(polygon, simpleFillSymbol);

Now, we can add polygon graphic to graphics layer using add method.

graphicsLayer.add(polygonGraphic);

5. Result

We can see the result by running the "index.html" file.

We learned how to create polygon geometry and add to map using ArcGIS JS API and Dojo in web.

Thank you for your attention and see you next time!

Curriculum

You can view old post below links.

• #01 - Create Map With Esri ArcGIS JS Api
• #02 - Add Basemap Gallery on Map With Esri ArcGIS JS Api
• #03 - Change Basemap Gallery Style on Map With Dojo Toolkit
• #04 - Add Graphics on Map With Esri ArcGIS JS Api
• #05 - Create Point With Esri ArcGIS JS Api
• #06 - Create Polyline With Esri ArcGIS JS Api

Source

• GitHub
• ArcGIS JS API 3.23
• Dojo Toolkit

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Posted on Utopian.io - Rewarding Open Source Contributors

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