A legend is a key used on a map that contains swatches of symbols with descriptions. It provides valuable information for interpreting what the map is displaying and can be represented in various colors, shapes or other identifiers based on the data. It gives a breakdown of what each symbol represents throughout the map.
The Legends can be made visible by setting the visible property of legendSettings to true.
The legend can be positioned in two ways.
Absolute Position.
Dock Position.
Based on the margin values of X and Y-axes, the Map legends can be positioned with the support of location.x
and location.y properties available in legendSettings. For positioning the legend based on margins
corresponding to a map, position value is set as ‘Float’.
The map legends can be positioned in following locations within the container.
You can set this option by using position property in legendSettings.
1 Top
2 Left
3 Bottom
4 Rightabove four positions can be aligned combination of ‘Near’, ‘Center’ and ‘Far’ using alignment in
legendSettings. So legend can be aligned 12 positions.
Legend had two type of mode. Default mode and Interactive mode.
Default mode legends having symbols with legend labels, used to identify the shape or bubble or marker color.
The legends can be made interactive with an arrow mark indicating the exact range color in the legend when the
mouse hovers over the corresponding shapes. You can enable this option by setting mode property in
legendSettings value as “Interactive” and default value of mode property is “Default” to enable the normal legend.
The map legend size can be modified by using the height and width properties in legendSettings.
The Layer shape type legends can be generated for each color mappings in shape settings. Note: Below code snippet demonstrate the equal colormapping legends for the shapes.
Create the electiondata.ts file with following data for layer dataSource.
export var UNcountries: Object[] =
[
{ "Country": "China", "Membership": "Permanent"},
{"Country": "France","Membership": "Permanent" },
{ "Country": "Russia","Membership": "Permanent"},
{"Country": "Kazakhstan","Membership": "Non-Permanent"},
{ "Country": "Poland","Membership": "Non-Permanent"},
{"Country": "Sweden","Membership": "Non-Permanent"}
];Import the ‘electionData’ and assign for the layer dataSource. Provide the shapePropertyPath value as ‘name
and shapeDataPath value as ‘State’.
To enable the equal colormapping refer the shapeSettings.colorMapping code snippet.
Finally set legendSettings.visible as true and Inject the Legend Module into Maps using
<Inject services={[Legend]}/> tag.
import { world_map } from 'world-map.ts';
import { uncountries } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true } } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='Country' shapePropertyPath='name' dataSource={uncountries}
shapeSettings={ {
colorValuePath: 'Membership',
colorMapping: [
{
value: 'Permanent', color: '#D84444'
},
{
value: 'Non-Permanent', color: '#316DB5'
}]
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);To get the legend shape value for legendSettings by using shape property. You can customize the shape by
using the shapeWidth and shapeHeight property.
Based on the ranges in data source, get the excluded ranges from color mapping, and then show the legend with excluded range values are bound to the specific legend.
The following code example shows legends for the items excluded from color mapping.
Finally set legendSettings.visible as true and Inject the Legend Module into Maps using
<Inject services={[Legend]}/> tag.
import { world_map } from 'world-map.ts';
import { uncountries } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true } } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='Country' shapePropertyPath='name' dataSource={uncountries}
shapeSettings={ {
colorValuePath: 'Membership',
colorMapping: [
{
from: 0, to: 100, color: 'rgb(153,174,214)',
},
{
from: 101, to: 200, color: 'rgb(115,143,199)',
},
{
color: 'rgb(77,112,184)'
}]
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);To enable or disable the desired legend for each colormapping, set the showLegend property to true in colorMapping.
The following code example shows legends for the items excluded from color mapping.
Finally set legendSettings.visible as true and Inject the Legend Module into Maps using
<Inject services={[Legend]}/> tag.
import { world_map } from 'world-map.ts';
import { uncountries } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true } } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='Country' shapePropertyPath='name' dataSource={uncountries}
shapeSettings={ {
colorValuePath: 'Membership',
colorMapping: [
{
from: 0, to: 100, color: 'rgb(153,174,214)',
showLegend: true
},
{
from: 101, to: 200, color: 'rgb(115,143,199)',
showLegend: false
},
{
color: 'rgb(77,112,184)', showLegend: false
}]
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);To enable or disable the legend visibility for each item, bind the field name in the data source to the showLegendPath property in legendSettings.
The following code example shows how to hide the legend items based data source value.
import { world_map } from 'world-map.ts';
import { dafaultData } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true , showLegendPath: 'visibility'} } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='continent' shapePropertyPath='continent' dataSource={dafaultData}
shapeSettings={ {
colorValuePath: 'color',
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);To show the legend text based on binding, the field name in the datasource should be set to the valuePath property in legendSettings.
The following code example shows how to hide the legend items based data source value.
import { world_map } from 'world-map.ts';
import { dafaultData } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true , valuePath: 'continent'} } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='continent' shapePropertyPath='continent' dataSource={dafaultData}
shapeSettings={ {
colorValuePath: 'color',
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);To show the legend text based on binding, the field name in the datasource should be set to the valuePath property in legendSettings.
The following code example shows how to hide the legend items based data source value.
import { world_map } from 'world-map.ts';
import { dafaultData } from 'data.ts'
import * as React from "react";
import * as ReactDOM from "react-dom";
import { MapsComponent, LayersDirective, LayerDirective, Inject, Legend } from '@syncfusion/ej2-react-maps';
ReactDOM.render(
<MapsComponent id="maps" legendSettings={ { visible: true , valuePath: 'continent' ,
removeDuplicateLegend: true} } >
<Inject services={[Legend]} />
<LayersDirective>
<LayerDirective shapeData={world_map} shapeDataPath='continent' shapePropertyPath='continent' dataSource={dafaultData}
shapeSettings={ {
colorValuePath: 'color',
} }>
</LayerDirective>
</LayersDirective>
</MapsComponent>,
document.getElementById("maps") as HTMLElement
);Refer the API for Legend feature.