HTML 5 Drag & Drop with Angular 4

Question

I am trying to get the native HTML 5 drag & drop working in my angular app. I got the drag, fire the drag & the dragOver events, but the drop unfortunately doesn't fire anything. Here I have the HTML and drag events code below.

<ul *ngFor="let channel of channelList" >
      <li class="list-group-item" *ngIf="channel.channel.substr(0, 1) === head" 
      style="float:left; margin:0.5px" draggable="true" (dragstart)="drag(channel)">
        <ng-container *ngIf="channel.compChannel.compChannelLogo.length !== 0; else noCompChannel">
          <img class="img-rounded" src="{{ channel.logo }}" alt="{{ channel.channel }}" width="100" height="100">
          <img class="img-rounded" src="{{ channel.compChannel.compChannelLogo }}" alt="{{ channel.channel.compChannelName }}" width="100" height="100">
        </ng-container>
        <ng-template #noCompChannel>
          <img class="img-rounded" src="{{ channel.logo }}" alt="{{ channel.channel }}" 
          width="100" height="100" >
        </ng-template>
      </li>
    </ul>
<ul class="list-group" *ngFor="let channels of currentPickSelection" dropzone="copy">
  <li class="list-group-item" style="float:Left; margin-left:0.5px" (dragover)="dragOver(channels[0])" (dragend)="drop(event)">
    <ng-container *ngIf="channels[0].compChannel.compChannelLogo.length !== 0; else noCompChannel">
      <img class="img-rounded" src="{{ channels[0].logo }}" alt="{{ channels[0].channel }}" width="70" height="70">
      <img class="img-rounded" src="{{ channels[0].compChannel.compChannelLogo }}" alt="{{ channels[0].compChannel.compChannelName }}"
        width="70" height="70">
    </ng-container>
    <ng-template #noCompChannel>
      <img class="img-rounded" src="{{ channels[0].logo }}" alt="{{ channels[0].channel }}" width="70" height="70">
    </ng-template>
    <br>
    <strong>
      <font size="2">{{ channels[0].pickCode }}</font>
    </strong>
  </li>
</ul>



drag(channel) {
    console.log(channel);
  }
  dragOver(channel) {
    this.draggedChannel = channel;
    // console.log(this.draggedChannel);
  }

  drop(e) {
    console.log(e);
  }

Answer 1

Simple but most powerful package

supports angular version >= 4.x

for documentation

for demo

How to use it?

Install

// if you use npm
npm install angular2-draggable

// or if you use yarn
yarn add angular2-draggable

Import

import { AngularDraggableModule } from 'angular2-draggable';

@NgModule({
  imports: [
    ...,
    AngularDraggableModule
  ],
})
export class AppModule { }

and finally use

// Basic Usage
<div ngDraggable>Drag Me!</div>

Answer 2

<div (dragover)="onDragOver($event)" 
     (dragleave)="onDragLeave($event)" (drop)="onDrop($event)">
</div>

In your Component:

onDrop(event: any) {
    event.preventDefault();
    event.stopPropagation();
    // your code goes here after droping files or any
}

onDragOver(evt) {
    evt.preventDefault();
    evt.stopPropagation();
}

onDragLeave(evt) {
    evt.preventDefault();
    evt.stopPropagation();
}

Answer 3

I made it without any other module in Angular 2/4/5/6, You can also make it by using below code:

drag.component.html:

<h2>Drag and Drop demo</h2>
<div  id="div1" 
      (drop)="drop($event)" 
      (dragover)="allowDrop($event)">

      <img 
      src="https://images.pexels.com/photos/658687/pexels-photo-658687.jpeg?auto=compress&cs=tinysrgb&h=350" 
      draggable="true" 
      (dragstart)="drag($event)" 
      id="drag1"
      width="88" 
      height="31">
</div>

<div id="div2" 
  (drop)="drop($event)" 
  (dragover)="allowDrop($event)">
</div>

drag.component.ts:

import { Component } from '@angular/core';

@Component({
  selector: 'drag-root',
  templateUrl: './drag.component.html',
  styleUrls: ['./drag.component.css']
})
export class AppComponent {

  drop(ev) {
    ev.preventDefault();
    var data = ev.dataTransfer.getData("text");
    ev.target.appendChild(document.getElementById(data));
  }

  allowDrop(ev) {
    ev.preventDefault();
  }

  drag(ev) {
    ev.dataTransfer.setData("text", ev.target.id);
  }
}

drag.component.css:

#div1, #div2 {
    float: left;
    width: 100px;
    height: 35px;
    margin: 10px;
    padding: 10px;
    border: 1px solid black;
}

Stackblitz example

Answer 4

Here is a solution on Angular 7:

Material (https://material.angular.io/) explains it perfectly (you have to take version >= 7.1). Here is a link to API.

First, import "DragAndDrop" module in your modules:

import {DragDropModule} from '@angular/cdk/drag-drop';

Then you just have to add "cdkDrag" directive to your HTML element:

<div class="example-box" cdkDrag>
  Drag me around
</div>

Stackblitz (from material): here

It's really easy to use and there are interesting options if you need to do a more specific drag and drop (for example with a position locking) !

Answer 5

To use drag and drop in angular 4 application you can use npm module "ngx-uploader".

You will find the integration step from below link:

https://www.npmjs.com/package/ngx-uploader

All the imports parameter and classes you can take from the above link.

Here is my code for angular:

if (output.type === 'allAddedToQueue') { // when all files added in queue
  // uncomment this if you want to auto upload files when added
  const event: UploadInput = {
    type: 'uploadAll',
    url: API_BASE +'/api/uploads',

    method: 'POST',
    data:{total_files: this.files.length.toString()}
  };
  this.uploadInput.emit(event);
} else if (output.type === 'addedToQueue'  && typeof output.file !== 'undefined') { // add file to array when added
  this.files.push(output.file);
} else if (output.type === 'uploading' && typeof output.file !== 'undefined') {
  // update current data in files array for uploading file
  const index = this.files.findIndex(file => typeof output.file !== 'undefined' && file.id === output.file.id);
  this.files[index] = output.file;

} else if (output.type === 'removed') {
  // remove file from array when removed
  this.files = this.files.filter((file: UploadFile) => file !== output.file);
} else if (output.type === 'dragOver') {
  this.dragOver = true;
} else if (output.type === 'dragOut') {
  this.dragOver = false;
} else if (output.type === 'drop') {
  this.dragOver = false;
}else if (output.type === 'done') { 

  if (output.file.response.status == 200) { 
    var uploaded_files = output.file.response.data;
    this.propertyImage.push(uploaded_files);
  } 
  else { 
    this.msgs = [];
    this.msgs.push({ severity: 'error', summary: 'Error Message', detail: 'unable to upload images' });
  }

In the above code for output === done, you will get response from server side (In my case nodejs)

Below you can find the code for backend:

var formidable = require('formidable'),
    http = require('http'),
    util = require('util');

var form = new formidable.IncomingForm();

var src = './public/images/properties';
var dst_small = './public/images/properties/small'
var dst_medium = './public/images/properties/medium'
var validImage = false;
form.keepExtensions = true; //keep file extension
form.uploadDir = src;
form.onPart = function (part) {
    if (!part.filename || part.filename.match(/\.(jpg|jpeg|png)$/i)) {
        validImage = true;
        this.handlePart(part);
    }

    else {
        validImage = false;
        return res.json({ status: 404, msg: part.filename + ' is not allowed.' });

    }
}
form.parse(req, function (err, fields, files) {
    if (validImage) {

        var image = files.file.path.split("/")[3];
        var name = files.file.path.split("/")[3];


        easyimg.rescrop({
            src: files.file.path, dst: dst_small + '/' + files.file.path.split('/')[3],
            width: 100, height: 100,
            cropwidth: 100, cropheight: 100,
            x: 0, y: 0
        }).then(
            function (image) {
                //  console.log('Resized and cropped: ' + image.width + ' x ' + image.height);
            },
            function (err) {
                //  console.log(err);
            }
            );


        // for largeImage
        easyimg.rescrop({
            src: files.file.path, dst: dst_medium + '/' + files.file.path.split('/')[3],
            width: 300, height: 300,
            cropwidth: 300, cropheight: 300,
            x: 0, y: 0
        }).then(
            function (image) {
                //  console.log('Resized and cropped: ' + image.width + ' x ' + image.height);
                return res.json({ status: 200, msg: 'Uploaded images', data: image });

            },
            function (err) {
                console.log(err);
            }
            );
    } else {
        return res.json({ status: 500, msg: constant.message.error_profile_pic_type });
    }
});

Please change your image path according to your file path. I have used this code and it worked for me.

Hope the above code will help for you.

Thanks !!

Answer 6

This is this the way I got it working. preventDefault() functions throws error, changed it for return false which worked fine. Thanks guys for the prompt responses.

 drag(channel) {
    console.log(channel);
  }
  onDragOver(channel: any) {
    console.log("Drag Over");
    return false;
  }
  onDrop(e:any) {
    console.log("Drop");
  }

Answer 7

Use drop event. This will fire only when you drop a file.