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angulardrag-and-dropangular-materialangular7angular-cdk

How to use Angular7 (angular material) drag drop between two components


As recently angular introduced drag and drop in angular material https://material.angular.io/cdk/drag-drop/overview .

All examples describes with in a single component. How to use this in two different components, Drag one component item and drop into another component.


Solution

  • You may use properties id and cdkDropListConnectedTo to link both lists:

    Component 1:

    <div cdkDropList id="list-1" cdkDropListConnectedTo="list-2" (cdkDropListDropped)="drop($event)">
        <div *ngFor="let item of list" cdkDrag>{{ item }}</div>
    </div>
    

    Component 2:

    <div cdkDropList id="list-2" cdkDropListConnectedTo="list-1" (cdkDropListDropped)="drop($event)">
      <div *ngFor="let item of list" cdkDrag>{{ item }}</div>
    </div>
    

    If you need to connect several lists to one list, you may use the following syntax: [cdkDropListConnectedTo]="['list-1', 'list-2', 'list-3', 'list-4']"

    After linking the lists, you must correctly update one or both lists depending on the actions. You may do it on the drop function like this:

    drop(event: CdkDragDrop<string[]>) {
        if (event.container.id === event.previousContainer.id) {
          // move inside same list
          moveItemInArray(this.list, event.previousIndex, event.currentIndex);
        } else {
          // move between lists
        }
    }
    

    For moving items between lists, you will possibly want to keep track of the lists centrally. You may do so by using a Service, a Store or other methods.