How to Hide/Show Drop Down Angular2 Material?

How to Hide/Show Drop Down Angular2 Material?

To hide or show a dropdown (mat-select) in Angular with Angular Material, you can control its visibility using a boolean variable bound to *ngIf or [hidden] directive. Here's how you can do it:

Using *ngIf Directive

  1. HTML Template

    <button (click)="toggleDropdown()">Toggle Dropdown</button> <!-- Dropdown to show/hide --> <mat-form-field *ngIf="isDropdownVisible"> <mat-label>Select an option</mat-label> <mat-select> <mat-option value="option1">Option 1</mat-option> <mat-option value="option2">Option 2</mat-option> <mat-option value="option3">Option 3</mat-option> </mat-select> </mat-form-field>
    • Use a button or any other trigger element ((click)="toggleDropdown()") to toggle the visibility of the dropdown.
    • Use *ngIf="isDropdownVisible" to conditionally render the dropdown based on the value of isDropdownVisible.

  2. Component Class

    import { Component } from '@angular/core'; @Component({ selector: 'app-your-component', templateUrl: './your-component.component.html', styleUrls: ['./your-component.component.css'] }) export class YourComponent { isDropdownVisible = false; toggleDropdown() { this.isDropdownVisible = !this.isDropdownVisible; } }
    • Initialize isDropdownVisible to false in your component.
    • Implement toggleDropdown() method to toggle the value of isDropdownVisible between true and false.

Using [hidden] Directive

Alternatively, you can use [hidden] directive to control visibility without removing the element from the DOM:

<button (click)="toggleDropdown()">Toggle Dropdown</button> <!-- Dropdown to show/hide --> <mat-form-field [hidden]="!isDropdownVisible"> <mat-label>Select an option</mat-label> <mat-select> <mat-option value="option1">Option 1</mat-option> <mat-option value="option2">Option 2</mat-option> <mat-option value="option3">Option 3</mat-option> </mat-select> </mat-form-field>
  • [hidden]="!isDropdownVisible" will hide the dropdown when isDropdownVisible is false and show it when isDropdownVisible is true.

Summary

  • *ngIf vs [hidden]: Use *ngIf if you want to completely remove the element from the DOM when hidden. Use [hidden] if you want to keep the element in the DOM but make it invisible.
  • Control Variable: Use a boolean variable (isDropdownVisible in this case) in your component to control the visibility of the dropdown.
  • Toggle Method: Implement a method (toggleDropdown() here) to toggle the boolean variable's value to show or hide the dropdown.

Choose the approach (*ngIf or [hidden]) based on your specific use case and how you want to manage DOM elements in your Angular application using Angular Material.

Examples

  1. How to programmatically show a MatMenu in Angular Material?

    • Description: Use Angular Material's MatMenuTrigger directive to programmatically show a menu.

    • Code:

      <button mat-button [matMenuTriggerFor]="menu">Open Menu</button> <mat-menu #menu="matMenu"> <button mat-menu-item>Item 1</button> <button mat-menu-item>Item 2</button> </mat-menu> <button (click)="openMenu()">Open Menu Programmatically</button> 
      import { Component, ViewChild } from '@angular/core'; import { MatMenuTrigger } from '@angular/material/menu'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatMenuTrigger) menuTrigger: MatMenuTrigger; openMenu() { this.menuTrigger.openMenu(); } }

  2. How to hide a MatSelect dropdown in Angular Material?

    • Description: Use Angular Material's MatSelect API to programmatically hide the dropdown.

    • Code:

      <mat-form-field> <mat-label>Choose an option</mat-label> <mat-select #select> <mat-option *ngFor="let option of options" [value]="option">{{option}}</mat-option> </mat-select> </mat-form-field> <button (click)="closeSelect()">Close Select</button> 
      import { Component, ViewChild } from '@angular/core'; import { MatSelect } from '@angular/material/select'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatSelect) matSelect: MatSelect; options = ['Option 1', 'Option 2', 'Option 3']; closeSelect() { this.matSelect.close(); } }

  3. How to toggle visibility of a MatAutocomplete dropdown in Angular Material?

    • Description: Use the MatAutocompleteTrigger to toggle the visibility of the autocomplete dropdown.

    • Code:

      <mat-form-field> <input matInput [matAutocomplete]="auto" #autoCompleteTrigger> <mat-autocomplete #auto="matAutocomplete"> <mat-option *ngFor="let option of options" [value]="option">{{option}}</mat-option> </mat-autocomplete> </mat-form-field> <button (click)="toggleAutocomplete()">Toggle Autocomplete</button> 
      import { Component, ViewChild } from '@angular/core'; import { MatAutocompleteTrigger } from '@angular/material/autocomplete'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatAutocompleteTrigger) autoCompleteTrigger: MatAutocompleteTrigger; options = ['Option 1', 'Option 2', 'Option 3']; toggleAutocomplete() { if (this.autoCompleteTrigger.panelOpen) { this.autoCompleteTrigger.closePanel(); } else { this.autoCompleteTrigger.openPanel(); } } }

  4. How to show and hide a MatDatepicker dropdown in Angular Material?

    • Description: Use Angular Material's MatDatepicker API to programmatically show or hide the datepicker.

    • Code:

      <mat-form-field> <input matInput [matDatepicker]="picker" placeholder="Choose a date"> <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle> <mat-datepicker #picker></mat-datepicker> </mat-form-field> <button (click)="toggleDatepicker()">Toggle Datepicker</button> 
      import { Component, ViewChild } from '@angular/core'; import { MatDatepicker } from '@angular/material/datepicker'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatDatepicker) datepicker: MatDatepicker<any>; toggleDatepicker() { if (this.datepicker._opened) { this.datepicker.close(); } else { this.datepicker.open(); } } }

  5. How to hide MatMenu on click outside in Angular Material?

    • Description: Automatically close the MatMenu when clicking outside using Angular Material's built-in functionality.

    • Code:

      <button mat-button [matMenuTriggerFor]="menu">Open Menu</button> <mat-menu #menu="matMenu"> <button mat-menu-item>Item 1</button> <button mat-menu-item>Item 2</button> </mat-menu> 
      import { Component } from '@angular/core'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { // MatMenu will automatically close when clicking outside. }

  6. How to programmatically open a MatSidenav in Angular Material?

    • Description: Use Angular Material's MatSidenav API to programmatically open and close a sidenav.

    • Code:

      <mat-sidenav-container> <mat-sidenav #sidenav mode="side" [(opened)]="opened"> <p>Sidenav content</p> </mat-sidenav> <mat-sidenav-content> <button (click)="toggleSidenav()">Toggle Sidenav</button> </mat-sidenav-content> </mat-sidenav-container> 
      import { Component, ViewChild } from '@angular/core'; import { MatSidenav } from '@angular/material/sidenav'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatSidenav) sidenav: MatSidenav; toggleSidenav() { this.sidenav.toggle(); } }

  7. How to disable MatSelect dropdown in Angular Material?

    • Description: Disable the MatSelect component so that it cannot be interacted with.

    • Code:

      <mat-form-field> <mat-label>Choose an option</mat-label> <mat-select [disabled]="isDisabled"> <mat-option *ngFor="let option of options" [value]="option">{{option}}</mat-option> </mat-select> </mat-form-field> <button (click)="toggleDisable()">Toggle Disable</button> 
      import { Component } from '@angular/core'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { options = ['Option 1', 'Option 2', 'Option 3']; isDisabled = false; toggleDisable() { this.isDisabled = !this.isDisabled; } }

  8. How to hide MatAutocomplete suggestions based on user input in Angular Material?

    • Description: Filter and hide suggestions in MatAutocomplete based on user input.

    • Code:

      <mat-form-field> <input matInput [matAutocomplete]="auto" (input)="filterOptions($event.target.value)"> <mat-autocomplete #auto="matAutocomplete"> <mat-option *ngFor="let option of filteredOptions" [value]="option">{{option}}</mat-option> </mat-autocomplete> </mat-form-field> 
      import { Component } from '@angular/core'; import { FormControl } from '@angular/forms'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { options = ['Option 1', 'Option 2', 'Option 3']; filteredOptions = this.options; filterOptions(value: string) { this.filteredOptions = this.options.filter(option => option.toLowerCase().includes(value.toLowerCase()) ); } }

  9. How to control MatDatepicker visibility using a button in Angular Material?

    • Description: Show or hide MatDatepicker based on a button click.

    • Code:

      <mat-form-field> <input matInput [matDatepicker]="picker" placeholder="Choose a date"> <mat-datepicker-toggle matSuffix [for]="picker"></mat-datepicker-toggle> <mat-datepicker #picker></mat-datepicker> </mat-form-field> <button (click)="toggleDatepicker()">Toggle Datepicker</button> 
      import { Component, ViewChild } from '@angular/core'; import { MatDatepicker } from '@angular/material/datepicker'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { @ViewChild(MatDatepicker) datepicker: MatDatepicker<any>; toggleDatepicker() { if (this.datepicker._opened) { this.datepicker.close(); } else { this.datepicker.open(); } } }

  10. How to dynamically show/hide a MatMenu based on a condition in Angular Material?

    • Description: Use Angular Material's MatMenu API to conditionally show or hide a menu based on a boolean variable.

    • Code:

      <button mat-button [matMenuTriggerFor]="menu" *ngIf="showMenu">Open Menu</button> <mat-menu #menu="matMenu"> <button mat-menu-item>Item 1</button> <button mat-menu-item>Item 2</button> </mat-menu> <button (click)="toggleMenu()">Toggle Menu Visibility</button> 
      import { Component } from '@angular/core'; @Component({ selector: 'app-root', templateUrl: './app.component.html', }) export class AppComponent { showMenu = true; toggleMenu() { this.showMenu = !this.showMenu; } }

More Tags

gnuplot kvm ora-00904 gridlayoutmanager hibernate-mapping polish flutter-provider deviceid poker spring-4

More Programming Questions

More General chemistry Calculators

More Genetics Calculators

More Chemistry Calculators

More Financial Calculators