Legend in EJ2 TypeScript Treemap control

19 Apr 202324 minutes to read

Legend is used to provide valuable information for interpreting what the TreeMap displays. The legends can be represented in various colors, shapes or other identifiers based on the data.

Position and alignment

Legend position is used to place legend in various positions. Based on the legend position, the legend item will be aligned. For example, if the position is top or bottom, the legend items are placed by rows. If the position is left or right, the legend items are placed by columns.

The following options are available to customize the legend position:

  • Top
  • Bottom
  • Left
  • Right
  • Float
let fruits:Object[] = [{ fruit:'Apple', count:5000 },
                       { fruit:'Mango', count:3000 },
                       { fruit:'Orange', count:2300 },
                       { fruit:'Banana', count:500 },
                       { fruit:'Grape', count:4300 },
                       { fruit:'Papaya', count:1200 },
                       { fruit:'Melon', count:4500 }
                     ];

import { TreeMap, TreeMapLegend } from '@syncfusion/ej2-treemap';
TreeMap.Inject(TreeMapLegend);
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    rangeColorValuePath:'count',
    legendSettings: {
        visible: true,
        position: 'Top'
    },
    leafItemSettings: {
        labelPath: 'fruit',
        colorMapping:[
            {
               from:500,
               to:3000,
               color:'orange'
           },
           {
               from:3000,
               to:5000,
               color:'green'
           }
        ]
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Legend Alignment is used to align the legend items in specific location. The following options are available to customize the legend alignment:

  • Near
  • Center
  • Far
let fruits:Object[] = [{ fruit:'Apple', count:5000 },
                       { fruit:'Mango', count:3000 },
                       { fruit:'Orange', count:2300 },
                       { fruit:'Banana', count:500 },
                       { fruit:'Grape', count:4300 },
                       { fruit:'Papaya', count:1200 },
                       { fruit:'Melon', count:4500 }
                     ];

import { TreeMap, TreeMapLegend } from '@syncfusion/ej2-treemap';
TreeMap.Inject(TreeMapLegend);
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    rangeColorValuePath:'count',
    legendSettings: {
        visible: true,
        alignment:'Far',
    },
    leafItemSettings: {
        labelPath: 'fruit',
        colorMapping:[
            {
               from:500,
               to:3000,
               color:'orange'
           },
           {
               from:3000,
               to:5000,
               color:'green'
           }
        ]
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Legend mode

The TreeMap control supports two different types of legend rendering modes such as Default and Interactive.

Default mode

In default mode, the legends have symbols with legend labels that are used to identify the items in the TreeMap.

let CarDetails:Object[] = [{ Car:'Mustang', Brand:'Ford', count:232 },
                       { Car:'EcoSport', Brand:'Ford', count:121 },
                       { Car:'Swift', Brand:'Maruti', count:143 },
                       { Car:'Baleno', Brand:'Maruti', count:454 },
                       { Car:'Vitara Brezza', Brand:'Maruti', count:545 },
                       { Car:'A3 Cabriolet', Brand:'Audi',count:123 },
                       { car:'RS7 Sportback', Brand:'Audi', count:523 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: CarDetails ,
    weightValuePath: 'count',
    equalColorValuePath:'Brand',
    legendSettings: {
        visible: true,
        position:'Top',
        border:{color:'black',width:2}
    },
    leafItemSettings: {
        labelPath: 'Car',
        colorMapping:[
            {
               value:'Ford',
               color:'green'
           },
           {
               value:'Audi',
               color:'red'
           },
           {
               value:'Maruti',
               color:'orange'
           }
        ]
     },
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Interactive mode

The legends can be made interactive with an arrow mark that indicates exact range color in the legend when the mouse hovers on the TreeMap item. Enable this option by setting the mode property in the legendSettings to Interactive.

let CarDetails:Object[] = [{ Car:'Mustang', Brand:'Ford', count:232 },
                       { Car:'EcoSport', Brand:'Ford', count:121 },
                       { Car:'Swift', Brand:'Maruti', count:143 },
                       { Car:'Baleno', Brand:'Maruti', count:454 },
                       { Car:'Vitara Brezza', Brand:'Maruti', count:545 },
                       { Car:'A3 Cabriolet', Brand:'Audi',count:123 },
                       { car:'RS7 Sportback', Brand:'Audi', count:523 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: CarDetails ,
    weightValuePath: 'count',
    equalColorValuePath:'Brand',
    legendSettings: {
        visible: true,
        mode:'Interactive',
        position:'Top',
        border:{color:'black',width:2}
    },
    leafItemSettings: {
        labelPath: 'Car',
        colorMapping:[
            {
               value:'Ford',
               color:'green'
           },
           {
               value:'Audi',
               color:'red'
           },
           {
               value:'Maruti',
               color:'orange'
           }
        ]
     },
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Legend size

Customize the legend size by modifying the height and width properties in the legendSettings. It accepts values in both percentage and pixel.

let CarDetails:Object[] = [{ Car:'Mustang', Brand:'Ford', count:232 },
                       { Car:'EcoSport', Brand:'Ford', count:121 },
                       { Car:'Swift', Brand:'Maruti', count:143 },
                       { Car:'Baleno', Brand:'Maruti', count:454 },
                       { Car:'Vitara Brezza', Brand:'Maruti', count:545 },
                       { Car:'A3 Cabriolet', Brand:'Audi',count:123 },
                       { car:'RS7 Sportback', Brand:'Audi', count:523 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: CarDetails ,
    weightValuePath: 'count',
    equalColorValuePath:'Brand',
    legendSettings: {
        visible: true,
        height:'50px',
        width:'200px',
        position:'Top',
        border:{color:'black',width:2}
    },
    leafItemSettings: {
        labelPath: 'Car',
        colorMapping:[
            {
               value:'Ford',
               color:'green'
           },
           {
               value:'Audi',
               color:'red'
           },
           {
               value:'Maruti',
               color:'orange'
           }
        ]
     },
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Paging support

TreeMap support legend paging, if the legend items cannot be placed within the provided height and width of the legend.

let CarDetails:Object[] = [{ Car:'Mustang', Brand:'Ford', count:232 },
                       { Car:'EcoSport', Brand:'Ford', count:121 },
                       { Car:'Swift', Brand:'Maruti', count:143 },
                       { Car:'Baleno', Brand:'Maruti', count:454 },
                       { Car:'Vitara Brezza', Brand:'Maruti', count:545 },
                       { Car:'A3 Cabriolet', Brand:'Audi',count:123 },
                       { car:'RS7 Sportback', Brand:'Audi', count:523 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: CarDetails ,
    weightValuePath: 'count',
    equalColorValuePath:'Brand',
    legendSettings: {
        visible: true,
        height:'50px',
        width:'100px',
        border:{color:'black',width:2}
    },
    leafItemSettings: {
        labelPath: 'Car',
        colorMapping:[
            {
               value:'Ford',
               color:'green'
           },
           {
               value:'Audi',
               color:'red'
           },
           {
               value:'Maruti',
               color:'orange'
           }
        ]
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Legend for items excluded from color mapping

Based on the mapping ranges in the data source, get the excluded ranges from the color mapping, and show the legend with the excluded range values that are bound to the specific legend.

let fruits:Object[] = [{ fruit:'Apple', count:5000 },
                       { fruit:'Mango', count:3000 },
                       { fruit:'Orange', count:2300 },
                       { fruit:'Banana', count:500 },
                       { fruit:'Grape', count:4300 },
                       { fruit:'Papaya', count:1200 },
                       { fruit:'Melon', count:4500 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    rangeColorValuePath:'count',
    legendSettings:{
        visible:true
    },
    leafItemSettings: {
        labelPath: 'fruit',
        colorMapping:[
            {
               from:500,
               to:2500,
               minOpacity:0.2,
               maxOpacity:0.5,
               color:'orange'
           },
           {
               from:3000,
               to:4000,
               minOpacity:0.5,
               maxOpacity:0.8,
               color:'green'
           },
           {
               color:'red'
           }
        ]
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Hide desired legend items

To enable or disable the desired legend item for each color mapping, set the showLegend property to true in the colorMapping.

let fruits:Object[] = [{ fruit:'Apple', count:5000 },
                       { fruit:'Mango', count:3000 },
                       { fruit:'Orange', count:2300 },
                       { fruit:'Banana', count:500 },
                       { fruit:'Grape', count:4300 },
                       { fruit:'Papaya', count:1200 },
                       { fruit:'Melon', count:4500 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    rangeColorValuePath:'count',
    legendSettings:{
        visible:true
    },
    leafItemSettings: {
        labelPath: 'fruit',
        colorMapping:[
            {
               from:500,
               to:2500,
               color:'orange',
               showLegend: true
           },
           {
               from:3000,
               to:4000,
               color:'green',
               showLegend: false
           },
           {
               color:'red',
               showLegend: true
           }
        ]
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Hide legend items based data source value

To enable or disable the legend visibility for each item through the data source, bind the appropriate data source field name to showLegendPath property in the legendSettings.

let fruits:Object[] = [{ fruit:'Apple', count:5000, visibility: true , color: '#71B081' },
                       { fruit:'Orange', count:3000, visibility: false, color: '#5A9A77' },
                       { fruit:'Grape', count:2300, visibility: true, color: '#498770' },
                       { fruit:'Banana', count:500, visibility: false, color: '#39776C' },
                       { fruit:'Mango', count:4300, visibility: true, color: '#266665' },
                       { fruit:'Papaya', count:1200, visibility: false, color: '#124F5E' }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    colorValuePath: 'color',
    palette: [],
    legendSettings:{
        visible:true,
        showLegendPath:'visibility'
    },
    leafItemSettings: {
        labelPath: 'fruit',
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Bind legend item text from data source

To show the legend item text from the data source, bind the property name from data source to the valuePath property in the legendSettings.

let fruits:Object[] = [{ fruit:'Apple', count:5000, visibility: true , color: '#71B081' },
                       { fruit:'Orange', count:3000, visibility: false, color: '#5A9A77' },
                       { fruit:'Grape', count:2300, visibility: true, color: '#498770' },
                       { fruit:'Banana', count:500, visibility: false, color: '#39776C' },
                       { fruit:'Mango', count:4300, visibility: true, color: '#266665' },
                       { fruit:'Papaya', count:1200, visibility: false, color: '#124F5E' }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    colorValuePath: 'color',
    palette: [],
    legendSettings:{
        visible:true,
        valuePath:'fruit'
    },
    leafItemSettings: {
        labelPath: 'fruit',
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Hide duplicate legend items

To enable or disable the duplicate legend items, set the removeDuplicateLegend property to true in the legendSettings.

let fruits:Object[] = [{ fruit:'Apple', count:5000, visibility: true , color: '#71B081' },
                       { fruit:'Grape', count:3000, visibility: false, color: '#5A9A77' },
                       { fruit:'Apple', count:2300, visibility: true, color: '#498770' },
                       { fruit:'Banana', count:500, visibility: false, color: '#39776C' },
                       { fruit:'Grape', count:4300, visibility: true, color: '#266665' },
                       { fruit:'Papaya', count:1200, visibility: false, color: '#124F5E' }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    colorValuePath:'color',
    palette: [],
    legendSettings:{
        visible:true,
        valuePath:'fruit',
        removeDuplicateLegend: true
    },
    leafItemSettings: {
        labelPath: 'fruit',
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>

Legend Responsiveness

Use a responsive legend that switches positions between the right and the bottom based on the available height and width. To enable the responsive legend, set the position property to Auto in the legendSettings and the legend position is changed based on the available height and width.

let fruits:Object[] = [{ fruit:'Apple', count:5000 },
                       { fruit:'Grape', count:3000 },
                       { fruit:'Apple', count:2300 },
                       { fruit:'Banana', count:500 },
                       { fruit:'Grape', count:4300 },
                       { fruit:'Papaya', count:1200 }
                     ];

import { TreeMap } from '@syncfusion/ej2-treemap';
let treemap: TreeMap = new TreeMap({
    dataSource: fruits ,
    weightValuePath: 'count',
    palette:['#71B081','#5A9A77', '#498770', '#39776C', '#266665','#124F5E'],
    width: '700px',
    height: '500px',
    legendSettings:{
        visible:true,
        position:'Auto'
    },
    leafItemSettings: {
        labelPath: 'fruit',
     }
}, '#container');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for Treemap </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for treemap UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
    </div>
</body>

</html>