Getting started with Angular Linear gauge component

28 Sep 202315 minutes to read

This section explains the steps required to create a simple Linear Gauge and demonstrate the basic usage of the Linear Gauge component.

Dependencies

Below is the list of minimum dependencies required to use the Linear Gauge component.

|-- @syncfusion/ej2-angular-lineargauge
    |-- @syncfusion/ej2-angular-base
    |-- @syncfusion/ej2-angular-lineargauge
    |-- @syncfusion/ej2-lineargauge
    |-- @syncfusion/ej2-base
    |-- @syncfusion/ej2-svg-base

Setup Angular Environment

Angular CLI can be used to setup the Angular applications. To install Angular CLI use the following command.

npm install -g @angular/cli

Create an Angular Application

Start a new Angular application using below Angular CLI command.

ng new my-app
cd my-app

Installing Syncfusion Linear Gauge package

Syncfusion packages are distributed in npm as @syncfusion scoped packages. You can get all the Angular Syncfusion package from npm link.

Currently, Syncfusion provides two types of package structures for Angular components,

Ivy library distribution package format
Angular compatibility compiler(Angular’s legacy compilation and rendering pipeline) package.

Ivy library distribution package

Syncfusion Angular packages(>=20.2.36) has been moved to the Ivy distribution to support the Angular Ivy rendering engine and the package are compatible with Angular version 12 and above. To download the package use the below command.

Add @syncfusion/ej2-angular-lineargauge package to the application.

npm install @syncfusion/ej2-angular-lineargauge --save

Angular compatibility compiled package(ngcc)

For Angular version below 12, you can use the legacy (ngcc) package of the Syncfusion Angular components. To download the ngcc package use the below.

Add @syncfusion/ej2-angular-lineargauge@ngcc package to the application.

npm install @syncfusion/ej2-angular-lineargauge@ngcc --save

To mention the ngcc package in the package.json file, add the suffix -ngcc with the package version as below.

@syncfusion/ej2-angular-lineargauge:"20.2.38-ngcc"

Note: If the ngcc tag is not specified while installing the package, the Ivy Library Package will be installed and this package will throw a warning.

Registering LinearGauge Module

Import LinearGaugeModule into Angular application in the src/app/app.module.ts file from the package @syncfusion/ej2-angular-lineargauge.

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
// import the LinearGaugeModule for the LinearGauge component
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { AppComponent }  from './app.component';

@NgModule({
  //declaration of Linear Gauge module in NgModule
  imports:      [ BrowserModule, LinearGaugeModule ],
  declarations: [ AppComponent ],
  bootstrap:    [ AppComponent ]
})
export class AppModule { }

Modify the template in app.component.ts file to render the Linear Gauge component.
[src/app/app.component.ts].

  import { Component, ViewEncapsulation } from '@angular/core';

  @Component({
   selector: 'app-container',
   // specifies the template string for the LinearGauge component
    template: `<ejs-lineargauge id='linear-container'></ejs-lineargauge>`,
    encapsulation: ViewEncapsulation.None
  })
  export class AppComponent  { }

Now use the <code>app-container</code> in the index.html instead of default one.

  <app-container></app-container>

Now run the application in the browser using the below command.
```
  npm start
```

The below example shows a basic Linear Gauge.

app.component.ts
app.module.ts
main.ts
import { Component } from '@angular/core';

@Component({
    selector: 'app-container',
    // specifies the template string for the linear gauge component
    template: `<ejs-lineargauge id="gauge-container"></ejs-lineargauge>`
})
export class AppComponent {

}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { GaugeTooltipService } from '@syncfusion/ej2-angular-lineargauge';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, LinearGaugeModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ GaugeTooltipService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Module Injection

LinearGauge component is segregated into the individual feature-wise modules. In order to use a particular feature, inject its feature module using the providers: {}. Please find the feature module name and description as follows.

AnnotationsService - Inject this provider to use Annotation feature.
GaugeTooltipService - Inject this provider to use Tooltip feature.

These modules should be injected in the providers section of the app.module.ts file as follows,

    import { NgModule } from '@angular/core';
    import { BrowserModule } from '@angular/platform-browser';
    import { AppComponent } from './app.component';
    import { LinearGaugeComponent } from '@syncfusion/ej2-angular-lineargauge';
    import { AnnotationsService, GaugeTooltipService} from '@syncfusion/ej2-angular-lineargauge';

    @NgModule({
        imports: [
            BrowserModule,
        ],
        declarations: [AppComponent, LinearGaugeComponent],
        bootstrap: [AppComponent],
        providers: [ AnnotationsService, GaugeTooltipService ]
    })

Add Gauge Title

The title can be added to the Linear Gauge component using the title property in the Linear Gauge.

app.component.ts
app.module.ts
main.ts
import { Component, OnInit } from '@angular/core';

@Component({
    selector: 'app-container',
    template:
    `<ejs-lineargauge id="gauge-container" [title]='Title'>
    </ejs-lineargauge>`
})
export class AppComponent implements OnInit {
    public Title?: string;
    ngOnInit(): void {
        // Title for linear gauge
        this.Title = 'linear gauge';
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { GaugeTooltipService } from '@syncfusion/ej2-angular-lineargauge';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, LinearGaugeModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ GaugeTooltipService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Axis Range

The range of the axis can be set using the minimum and maximum properties in the Linear Gauge.

app.component.ts
app.module.ts
main.ts
import { Component, OnInit } from '@angular/core';

@Component({
    selector: 'app-container',
    template:
    `<ejs-lineargauge id="gauge-container">
      <e-axes>
         <e-axis [minimum]='Minimum' [maximum]='Maximum'>
         </e-axis>
      </e-axes>
    </ejs-lineargauge>`
})
export class AppComponent implements OnInit {
    public Minimum?: number;
    public Maximum?: number;
    ngOnInit(): void {
       this.Minimum = 0,
       this.Maximum = 200
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { GaugeTooltipService } from '@syncfusion/ej2-angular-lineargauge';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, LinearGaugeModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ GaugeTooltipService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

To denote the axis labels with temperature units, add the °C as suffix to each label. This can be achieved by setting the {value}°C to the format property in the labelStyle object of the axis. Here, {value} acts as a placeholder for each axis label.

To change the pointer value from the default value of the gauge, set the value property in pointers object of the axis.

app.component.ts
app.module.ts
main.ts
import { Component, OnInit } from '@angular/core';

@Component({
    selector: 'app-container',
    template:
    `<ejs-lineargauge id="gauge-container">
      <e-axes>
         <e-axis minimum=0 maximum=200>
           <e-pointers>
             <e-pointer value=140></e-pointer>
           </e-pointers>
           <e-ranges>
             <e-range start=0 end=80 startWidth=15 endWidth=15></e-range>
             <e-range start=80 end=120 startWidth=15 endWidth=15></e-range>
             <e-range start=120 end=140 startWidth=15 endWidth=15></e-range>
             <e-range start=140 end=200 startWidth=15 endWidth=15></e-range>
           </e-ranges>
         </e-axis>
      </e-axes>
    </ejs-lineargauge>`
})
export class AppComponent implements OnInit {
    public Label?: Object;
    ngOnInit(): void {
      this.Label = {
           format: '{value}°C'
      };
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { GaugeTooltipService } from '@syncfusion/ej2-angular-lineargauge';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, LinearGaugeModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ GaugeTooltipService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Setting the value of pointer

The pointer value is changed in the below sample using the value property in pointers object of the axis.

app.component.ts
app.module.ts
main.ts
import { Component, OnInit } from '@angular/core';

@Component({
    selector: 'app-container',
    template:
    `<ejs-lineargauge id="gauge-container">
      <e-axes>
         <e-axis minimum=0 maximum=200>
           <e-pointers>
             <e-pointer value=40 color='green'></e-pointer>
           </e-pointers>
         </e-axis>
      </e-axes>
    </ejs-lineargauge>`
})
export class AppComponent implements OnInit {
    ngOnInit(): void {
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { LinearGaugeModule } from '@syncfusion/ej2-angular-lineargauge';
import { GaugeTooltipService } from '@syncfusion/ej2-angular-lineargauge';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, LinearGaugeModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [ GaugeTooltipService ]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);