Data source binding and custom menu items in Angular Menu component

4 Apr 202319 minutes to read

Data binding

The Menu supports data source bindings such as array of JavaScript objects
that can be structured as either hierarchical or self-referential data.

Hierarchical data

The Menu can be populated with hierarchical data source by assigning it to the items property, and the fields with corresponding keys can be mapped to the fields property.

JSON data

The Menu can generate its menu items through an array of complex data source by mapping fields from the fields property.

import { Component } from '@angular/core';
import { enableRipple } from '@syncfusion/ej2-base';
import { FieldSettingsModel } from '@syncfusion/ej2-angular-navigations';

// Import an array of JSON data from datasource.ts
import { dataSource } from './datasource';

enableRipple(true);

@Component({
    selector: 'app-root',
    template: `<ejs-menu [items]="data" [fields]='menuFields'></ejs-menu>`
})

export class AppComponent {
    private menuFields: FieldSettingsModel = {
        text: ['continent', 'country', 'language'],
        children: ['countries', 'languages']
    };

    private data: { [key: string]: Object }[] = dataSource;
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { MenuModule } from '@syncfusion/ej2-angular-navigations';

import { AppComponent } from './app.component';

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

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Data Service

In application level, remote data binding can be achieved using DataManager.
To create Menu, assign items property with resultant data from callback function.

The following example displays five employees’ FirstName from Employees table and ShipName details from Orders table of the Northwind Data Service.

import { Component, OnInit } from '@angular/core';
import { enableRipple } from '@syncfusion/ej2-base';
import { DataManager, Query, ODataAdaptor, ReturnOption } from '@syncfusion/ej2-data';
import { FieldSettingsModel } from '@syncfusion/ej2-angular-navigations';

enableRipple(true);

@Component({
    selector: 'app-root',
    template: `<ejs-menu *ngIf='menuItems' [items]='menuItems' [fields]='menuFields'></ejs-menu>`
})

export class AppComponent implements OnInit {

    private SERVICE_URI: string = 'https://js.syncfusion.com/ejServices/Wcf/Northwind.svc/';

    // Menu fields definition.
    private menuFields: FieldSettingsModel = {
        text: ['FirstName', 'ShipName'],
        children: ['Orders']
    };

    private menuItems: { [key: string]: Object }[];

    public ngOnInit(): void {
        // Getting remote data using DataManager.
        new DataManager({ url: this.SERVICE_URI, adaptor: new ODataAdaptor, crossDomain: true })
            .executeQuery(
                new Query().from('Employees').take(5).hierarchy(
                    new Query()
                        .foreignKey('EmployeeID')
                        .from('Orders').take(13),
                    function () {
                        return [1, 2, 3, 4, 5]
                    }
                ))
            .then((e: ReturnOption) => {
                //Assign result data to menu items
                this.menuItems = e.result as { [key: string]: Object }[];
                document.getElementById('loader').style.display = "none";
            });
    }
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { MenuModule } from '@syncfusion/ej2-angular-navigations';

import { AppComponent } from './app.component';

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

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Self-referential data

Menu can be populated from self-referential data structure that contains array of JSON objects with parentId mapping.

You can directly assign self-referential data to the items property, and map all the field members with corresponding keys from self-referential data to fields property.

To render the root level nodes, specify the parentId as null or no need to specify the parentId in data source.

In the following example, the id, pId, and text columns from self-referential data have been mapped to the itemId, parentId, and text fields, respectively.

import { Component } from '@angular/core';
import { enableRipple } from '@syncfusion/ej2-base';
import { FieldSettingsModel } from '@syncfusion/ej2-angular-navigations';

enableRipple(true);

@Component({
    selector: 'app-root',
    template: `<ejs-menu [items]='data' [fields]='menuFields'></ejs-menu>`
})

export class AppComponent {
    //Menu datasource
    private data: { [key: string]: Object }[] = [
        { id: 'parent1', text: 'Events' },
        { id: 'parent2', text: 'Movies' },
        { id: 'parent3', text: 'Directory' },
        { id: 'parent4', text: 'Queries', pId: null },
        { id: 'parent5', text: 'Services', pId: null },

        { id: 'parent6', text: 'Conferences', pId: 'parent1' },
        { id: 'parent7', text: 'Music', pId: 'parent1' },
        { id: 'parent8', text: 'Workshops', pId: 'parent1' },

        { id: 'parent9', text: 'Now Showing', pId: 'parent2' },
        { id: 'parent10', text: 'Coming Soon', pId: 'parent2' },

        { id: 'parent10', text: 'Media Gallery', pId: 'parent3' },
        { id: 'parent11', text: 'Newsletters', pId: 'parent3' },

        { id: 'parent12', text: 'Our Policy', pId: 'parent4' },
        { id: 'parent13', text: 'Site Map', pId: 'parent4' },
        { id: 'parent14', text: 'Pop', pId: 'parent7' },
        { id: 'parent15', text: 'Folk', pId: 'parent7' },
        { id: 'parent16', text: 'Classical', pId: 'parent7' }
    ];

    //Menu fields definition
    private menuFields: FieldSettingsModel = {
        itemId: 'id',
        text: 'text',
        parentId: 'pId'
    };
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { MenuModule } from '@syncfusion/ej2-angular-navigations';

import { AppComponent } from './app.component';

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

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

Custom menu items

The Menu can be customized using Essential JS2 Template engine to render the elements.

To customize menu items in your application, set your customized template string to the template property.
In the following example, the menu has been rendered with customized menu items.

import { Component, Inject } from '@angular/core';
import { FieldSettingsModel } from '@syncfusion/ej2-angular-navigations';
import { enableRipple } from '@syncfusion/ej2-base';

enableRipple(false);

@Component({
    selector: 'app-root',
    styleUrls: ['template.css'],
    template: `
    <div id="menuTemplate" class="menu-section">
    <div class="menu-control">
        <ejs-menu [items]='dataSource' [fields]='menuFields' [animationSettings]="animation" cssClass="e-template-menu">
            <ng-template #template let-dataSource="">
                
                <div *ngIf="dataSource.value" style="width:100%;display:flex;justify-content:space-between;">
                    <img *ngIf="dataSource.url" class="e-avatar e-avatar-small"
                        src="src/images/platforms/.png" />
                    <span style="width:100%;"></span>
                    <span *ngIf="dataSource.count" class='e-badge e-badge-success'></span>
                </div>
                <div *ngIf="dataSource.about" tabindex="0" class="e-card">
                    <div class="e-card-header">
                        <div class="e-card-header-caption">
                            <div class="e-card-header-title">About Us</div>
                        </div>
                    </div>
                    <div class="e-card-content">
                        
                    </div>
                    <div class="e-card-actions">
                        <button class="e-btn e-outline" style="pointer-events: auto;">
                            Read More
                        </button>
                    </div>
                </div>
            </ng-template>
        </ejs-menu>
    </div>
</div>
    `
})

export class AppComponent {
      constructor(@Inject('sourceFiles') private sourceFiles: any) {
        sourceFiles.files = ['template.css'];
    }
    //Template datasource
    private dataSource: { [key: string]: Object }[] = [
     {
            category: 'Products',
            options: [
                { value: 'JavaScript', url: 'https://ej2.syncfusion.com/angular/documentation/../../../../../menu/images/javascript' },
                { value: 'Angular', url: '../../../../../../menu/images/angular' },
                { value: 'ASP.NET Core', url: '../../../../../../menu/images/core' },
                { value: 'ASP.NET MVC', url: '../../../../../../menu/images/mvc' }
            ]
        },
        {
            category: 'Services',
            options: [
                { value: 'Application Development', count: '1200+' },
                { value: 'Maintenance & Support', count: '3700+' },
                { value: 'Quality Assurance' },
                { value: 'Cloud Integration', count: '900+' }
            ]
        },
        {
            category: 'About Us',
            options: [
                {
                    id: 'about',
                    about: {
                        value: "We are on a mission to provide world-class best software solutions for web, mobile and desktop platforms. Around 900+ applications are desgined and delivered to our customers to make digital & strengthen their businesses."
                    }
                }
            ]
        },
        { category: 'Careers' },
        { category: 'Sign In' }
    ];

    // Menu fields definition
    private menuFields: object = {
        text: ['category', 'value'],
        children: ['options']
    };
}
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

import { MenuModule } from '@syncfusion/ej2-angular-navigations';
import { ButtonModule } from '@syncfusion/ej2-angular-buttons';

import { AppComponent } from './app.component';

@NgModule({
    imports: [BrowserModule, MenuModule, ButtonModule],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [
    { provide: 'sourceFiles', useValue: {files: []} }]
})
export class AppModule { }
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);

To prevent sub menu closing, set args.cancel to true in beforeClose event.

See Also