Angular Material – Prevent mat-stepper from navigating between steps

angularangular-materialangular-material-stepperangular-material2

I have a mat-horizontal-stepper where I set linear property as true. When all the steps are valid as of now I can navigate to previous steps by clicking the header or label. I don't want that property.

I need to navigate only through buttons.

I tried disabling pointer function with:

    .mat-horizontal-stepper-header{
       pointer-events: none;
     }

but it didn't worked.

I need either to stop navigating by clicking header or fire a function on clicking the stepper header.

Best Answer

What you originally posted:

.mat-horizontal-stepper-header{
    pointer-events: none;
}

does work, as long as you add ::ng-deep to the CSS class. Like this:

::ng-deep .mat-horizontal-stepper-header {
    pointer-events: none !important;
}

Also make sure you are using the horizontal stepper instead of the vertical one. This obviously matters when calling the appropriate CSS class.

Related Solutions

R – How to Verify Atomic Writes

I think that, technically, devices are not FIFOs, so it's not at all clear that the guarantees you quote are supposed to apply.

Are you concerned about partial writes and reads within a process, or are you actually reading and/or writing the same device from different processes? Assuming the latter, you might be better off implementing a proxy process of some sort. The proxy owns the device exclusively and performs all reads and writes, thus avoiding the multi-process atomicity problem entirely.

In short, I advise not attempting to verify that "reading/writing from this device is actually an atomic operation". It will be difficult to do with confidence, and leave you with an application that is subject to subtle failures if a later version of linux (or different o/s altogether) fails to implement atomicity the way you need.

Angular – programmatically move the steps of a mat-horizontal-stepper in Angular / Angular Material

Yes. It is possible to jump to a specific stepper by using selectedIndex property of the MatStepper. Also, MatStepper exposes public methods next() and previous(). You can use them to move back and forth.

In your template:

Add an id to your stepper e.g. #stepper. Then in your goBack() and goForward() methods, pass the stepper id:

<mat-horizontal-stepper #stepper>
    <!-- Steps -->
</mat-horizontal-stepper>    
<!-- second option -->
<div>
   <button (click)="goBack(stepper)" type="button">Back</button>
   <button (click)="goForward(stepper)" type="button">Next</button>
</div>

.. and in your typescript:

import { MatStepper } from '@angular/material/stepper';

goBack(stepper: MatStepper){
    stepper.previous();
}

goForward(stepper: MatStepper){
    stepper.next();
}

Link to stackblitz demo.

You can also use ViewChild to get a reference to the stepper component in your TypeScript as shown below:

@ViewChild('stepper') private myStepper: MatStepper;

goBack(){
    this.myStepper.previous();
}

goForward(){
    this.myStepper.next();
}

In this case, you don't have to pass the stepper reference in the method in your component's html. Link to Demo with ViewChild

You can enable/disable the Back and Next buttons by using the following:

<button (click)="goBack(stepper)" type="button" 
        [disabled]="stepper.selectedIndex === 0">Back</button>
<button (click)="goForward(stepper)" type="button" 
        [disabled]="stepper.selectedIndex === stepper._steps.length-1">Next</button>

Best Answer

Related Solutions

R – How to Verify Atomic Writes

Angular – programmatically move the steps of a mat-horizontal-stepper in Angular / Angular Material

Related Topic