I need to drag an element from a list and drop it to another block in angular 6

Question

I am working on drag and drop functionality(using ng2-dragula).

I need to drag an element from a list and drop it to another blocks. But where I am stuck is that I need to drop only one element in the drop block at a time and if I remove firstly added element from drop block only then I can add another element. There are multiple drop blocks. But list block is one only.

Answer 1

I have created a stackblitz url: I think this is what you are looking for..

you can always catch events in ng2-dragula like this:

import { Subscription } from 'rxjs';
import { DragulaService } from 'ng2-dragula';

export class MyComponent {
  // RxJS Subscription is an excellent API for managing many unsubscribe calls.
  // See note below about unsubscribing.
  subs = new Subscription();

  constructor(private dragulaService: DragulaService) {

    // These will get events limited to the VAMPIRES group.

    this.subs.add(this.dragulaService.drag("VAMPIRES")
      .subscribe(({ name, el, source }) => {
        // ...
      })
    );
    this.subs.add(this.dragulaService.drop("VAMPIRES")
      .subscribe(({ name, el, target, source, sibling }) => {
        // ...
      })
    );
    // some events have lots of properties, just pick the ones you need
    this.subs.add(this.dragulaService.dropModel("VAMPIRES")
      // WHOA
      // .subscribe(({ name, el, target, source, sibling, sourceModel, targetModel, item }) => {
      .subscribe(({ sourceModel, targetModel, item }) => {
        // ...
      })
    );

    // You can also get all events, not limited to a particular group
    this.subs.add(this.dragulaService.drop()
      .subscribe(({ name, el, target, source, sibling }) => {
        // ...
      })
    );
  }

  ngOnDestroy() {
    // destroy all the subscriptions at once
    this.subs.unsubscribe();
  }
}

https://stackblitz.com/edit/ng2-dragula-base-jystom?file=src%2Fapp%2Fapp.component.ts

I have used an event to manipulate data like this:

import { Component } from '@angular/core';
import { DragulaService } from 'ng2-dragula';
import { Subscription } from 'rxjs';


@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  // these are some basics to get you started -- modify as you see fit.
subs = new Subscription();
  vamps = [
    { name: "Bad Vamp" },
    { name: "Petrovitch the Slain" },
    { name: "Bob of the Everglades" },
    { name: "The Optimistic Reaper" }
  ];

  vamps2 = [
    { name: "Dracula" },

  ];

  constructor(private dragulaService: DragulaService) {
    // use these if you want

    this.dragulaService.createGroup("VAMPIRES", {
      // ...
    });

    this.dragulaService.dropModel("VAMPIRES").subscribe(args => {
      console.log(args);
    });
      this.subs.add(this.dragulaService.drop("VAMPIRES")
      .subscribe(({ name, el, target, source, sibling }) => {
        this.vamps2=[{name: el.textContent}]
        // ...
              console.log( "@@@@@@@@@@@@@",name, el.textContent, target, source, sibling);

      })
    );
  }
}