State persistence in Angular Query builder component

15 Sep 20225 minutes to read

State persistence allows you to maintain the current state in the browser’s localStorage even if the browser is refreshed or if you move to the next page within the browser. State persistence stores the Query Builder’s rule object in the local storage when the enablePersistence is defined to true.

app.component.ts

import { Component, OnInit } from '@angular/core';
import { RuleModel } from '@syncfusion/ej2-angular-querybuilder';
import { hardwareData } from './datasource';

@Component({
    selector: 'app-root',
    template: `<!-- To render Query Builder. -->
               <ejs-querybuilder #querybuilder width="70%" [dataSource]="data" [rule]="importRules" enablePersistence="true" >
                <e-columns>
                  <e-column field="TaskID" label="Task ID" type="number"></e-column>
                  <e-column field="Name" label="Name" type="string"></e-column>
                  <e-column field="Category" label="Category" type="string"></e-column>
                  <e-column field="SerialNo" label="SerialNo" type="string"></e-column>
                  <e-column field="InvoiceNo" label="InvoiceNo" type="string"></e-column>
                  <e-column field="Status" label="Status" type="string"></e-column>
                </e-columns>
              </ejs-querybuilder>`
})

export class AppComponent implements OnInit {
    public data: Object[];
    public importRules: RuleModel;
    ngOnInit(): void {
        this.data = hardwareData;
        this.importRules = {
        'condition': 'or',
        'rules': [{
            'label': 'Category',
            'field': 'Category',
            'type': 'string',
            'operator': 'equal',
            'value': 'Laptop'
        },
        {
        'condition': 'and',
            'rules': [{
                'label': 'Status',
                'field': 'Status',
                'type': 'string',
                'operator': 'notequal',
                'value': 'Pending'
            },
            {
                'label': 'Task ID',
                'field': 'TaskID',
                'type': 'number',
                'operator': 'equal',
                'value': 5675
            }]
        }]
    };
    }
}

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { QueryBuilderModule } from '@syncfusion/ej2-angular-querybuilder';
import { AppComponent } from './app.component';
import { enableRipple } from '@syncfusion/ej2-base';

enableRipple(true);

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule,
        QueryBuilderModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule { }

main.ts

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

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