How to toggle mat-expansion-panel with button click? - html

Question

Is there any way in which I can expand a particular mat-expansion-panel by clicking an external button?
I have tried linking to the ID of the panel, but with no success...
<mat-expansion-panel id="panel1"> ... </>
...
<button (click)="document.getElementById('panel1').toggle()>Click me</button>
Here is my stackblitz code for example
My eventual plan is to use this method to open different panels within a list generated from an array: <mat-expansion-panel *ngFor="let d of data"> ...

Answer 1

In your html file:
<mat-expansion-panel [expanded]="panelOpenState">
<mat-expansion-panel-header>
<mat-panel-title>
TITLE
</mat-panel-title>
</mat-expansion-panel-header>
<p>BODY</p>
</mat-expansion-panel>
<button mat-raised-button (click)="togglePanel">TOGGLE</button>
In your TS file:
panelOpenState: boolean = false;
togglePanel() {
this.panelOpenState = !this.panelOpenState
}
If you use *ngFor to generate the expansion panels:
<mat-expansion-panel [expanded]="isOpen" *ngFor="let d of data">
<mat-expansion-panel-header>
{{ d.header }}
</mat-expansion-panel-header>
<p>{{ d.content }}</p>
</mat-expansion-panel>
<button mat-raised-button (click)="togglePanel">TOGGLE</button>
If you press the button all of the expanded panels opens
simultaneously.
To open only one panel with one button, add a "expanded" property to the data array for each element like this:
data = [
{id:1, header:'HEADER 1', content:'CONTENT 1', expanded: false},
{id:2, header:'HEADER 2', content:'CONTENT 2', expanded: false},
{id:3, header:'HEADER 3', content:'CONTENT 3', expanded: false},
{id:4, header:'HEADER 4', content:'CONTENT 4', expanded: false},
]
Then in your template:
<mat-expansion-panel [(ngModel)]="d.expanded"
[expanded]="d.expanded" *ngFor="let d of data" ngDefaultControl>
<mat-expansion-panel-header>
<button (click)="toggle(d.expanded)">TOGGLE</button>
{{ d.header }}
</mat-expansion-panel-header>
<p>{{ d.content }}</p>
</mat-expansion-panel>
And the method raised by the button click:
toggle(expanded) {
expanded = !expanded;
}

Answer 2

<mat-expansion-panel [disabled]="true"
#mep="matExpansionPanel"
*ngFor="let foo of list">
<mat-expansion-panel-header>
<button (click)="mep.expanded = !mep.expanded">Toggle</button>
</mat-expansion-panel-header>
<p>Text</p>
</mat-expansion-panel>

Answer 3

Use two-way binding on the expanded attribute of mat-expansion-panel. Here is an example live in StackBlitz:
https://stackblitz.com/edit/angular-gtsqg8
<button (click)='xpandStatus=xpandStatus?false:true'>Toggle it</button>
<p>
<mat-expansion-panel [(expanded)]="xpandStatus">
<mat-expansion-panel-header>
<mat-panel-title>This an expansion panel</mat-panel-title>
<mat-panel-description>xpandStatus is {{xpandStatus}}</mat-panel-description>
</mat-expansion-panel-header>
Two-way binding on the expanded attribute gives us a way to store and manipulate the expansion status.
</mat-expansion-panel>
</p>

Answer 4

You can use the method toggle().
First give the element an id.
<mat-expansion-panel #matExpansionPanel>
Next, access the element from javascript. Import necessary libraries (MatExpansionPanel, ViewChild)
#ViewChild(MatExpansionPanel, {static: true}) matExpansionPanelElement: MatExpansionPanel;
Lastly, call the toggle function
this.matExpansionPanelElement.toggle(); //open(), close()

Answer 5

<mat-nav-list>
<mat-expansion-panel *ngFor="let row of rows" #mep="matExpansionPanel">
<mat-expansion-panel-header>
{{row}}
</mat-expansion-panel-header>
<h2>Test</h2>
<button (click)="mep.toggle()">Toggle</button>
</mat-expansion-panel>
</mat-nav-list>
Working Example:
https://stackblitz.com/edit/mat-expansion-panel-vymjsq?file=app%2Fexpansion-overview-example.html

Answer 6

<link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
<mat-accordion displayMode="flat" multi class="mat-table">
<section matSort class="mat-elevation-z8 mat-header-row">
<span class="mat-header-cell" mat-sort-header="vesselName"></span>
<span class="mat-header-cell" mat-sort-header="vesselName">d</span>
</section>
<mat-expansion-panel [disabled]="true" #mep="matExpansionPanel"
*ngFor="let d of data">
<mat-expansion-panel-header>
<span class="mat-cell" (click)="mep.expanded = !mep.expanded">
<mat-icon class="icon" *ngIf="!mep.expanded">expand_more</mat-icon>
<mat-icon class="icon" *ngIf="mep.expanded">expand_less</mat-icon>
</span>
<span (click)="dClicked(d)" class="mat-cell">{{d.dataSet}}</span>
</mat-expansion-panel-header>
<div><pre>{{d | json}}</pre></div>
</mat-expansion-panel>
<div class="well" *ngIf="!d || d.length == 0">
<p>There are no d for this.</p>
</div>
</mat-accordion>

Answer 7

html:
<mat-accordion >
<mat-expansion-panel #first="matExpansionPanel">
<mat-expansion-panel-header>
<mat-panel-title>...</mat-panel-title>
</mat-expansion-panel-header>
...
</mat-expansion-panel>
<mat-expansion-panel #second="matExpansionPanel" expanded="true">
<mat-expansion-panel-header>
<mat-panel-title>...</mat-panel-title>
</mat-expansion-panel-header>
...
</mat-expansion-panel>
</mat-accordion>
<button (click)="doSomething(first, second)">Click</button>
ts:
import { Component } from '#angular/core';
import { MatExpansionPanel } from '#angular/material';
#Component({
selector: 'app-home',
templateUrl: './home.component.html'
})
export class HomeComponent {
doSomething(first: MatExpansionPanel, second: MatExpansionPanel) {
if (first.expanded ) { // check if first panel is expanded
first.close(); // close first panel
second.open(); // open second panel
// ...
}
}
}
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