如何在按钮单击时显示隐藏的div并隐藏Angular 2中单击的按钮？

Question

I'm facing difficulties in Angular UI development. Here I'm having a requirement that:

• on click of Add Button it should show a hidden form:
• on click of Add Button -> Add Button should hide
• in hidden form there will be a button Cancel-
• if I click on cancel the form should hide and add button should return

I have tried this using Angular 2 template syntax and by declaring nested boolean values, but I'm not getting the perfect answer.

How to do this in Angular 2 or 4? Do I have to use any host Listener or event emitter for this? I'm sharing my sample code and plunker:

template.html

<button(click)="addParameter=addParameter==true?false:true">
              Add</button>

            <div class="Parameters" *ngIf="addParameter==true">

            <input name="hello">

            <button (click)="hideForm();">Cancel</button>
            </div>

test.ts

export class App {

  private addParameter:boolean=false;

}

https://plnkr.co/edit/fa3Pdea1mB4RztAgOAW2?p=preview

Answer 1

You can do this in a couple of ways. Depending on if you want to handle it in component or in template. I personally prefer to keep template clean and do the "work" in component. So in that case your code would simply look like this:

<button *ngIf="!addParameter" (click)="toggleForm()">Add</button>
<div class="Parameters" *ngIf="addParameter">
  <input name="hello">
  <button (click)="toggleForm()">Cancel</button>
</div>

and TS:

toggleForm() {
  this.addParameter = !this.addParameter
}

DEMO: http://plnkr.co/edit/y3bDxsXMTYLtf8HI2PlA?p=preview

---

and as said, if you want to do this in template, it would look like this:

<button *ngIf="!addParameter" (click)="addParameter = !addParameter">Add</button>
<div class="Parameters" *ngIf="addParameter">
  <input name="hello">
  <button (click)="addParameter = !addParameter">Cancel</button>
</div>

DEMO: https://plnkr.co/edit/xcSzXGWOMNIhuZ83OXbs?p=preview

Answer 2

I think what you're looking for is something like:

<div>
      <form>
        <input name="hello">
        <button *ngIf="addingForm===false" (click)="addingForm = true">Add</button>
        <button *ngIf="addingForm===true" (click)="addingForm = false">Cancel</button>
      </form>
      <form *ngIf="addingForm===true">
        <input name="hidden">
      </form>
    </div>

In TS:

addingForm = false;

Like here: https://plnkr.co/edit/uXztfHwdWxuTVNIg6sxA?p=preview