file-choice

Helper library for dragging and dropping files.

This library allows you to do the following:

• Files can be obtained by drag and drop
• Click on the link to browse local files
• You can paste the image data on the clipboard and get it as a file

Demo

https://riversun.github.io/file-choice

Install

• NPM

npm install file-choice

or

• use <script> tag from CDN

<script src="https://cdn.jsdelivr.net/npm/file-choice@1.1.1/lib/file-choice.js"></script>

Usage

HTML

Here is the typical html for file-choice

'file-choice' enables file drag & drop function for an element with 'fc-drop-area' specified as CSS class name.

If there are multiple elements with fc-drop-area in the dom tree, all of them will be drag-drop enabled.

<div id="file-drop-area" class="fc-drop-area">
   <div class="fc-drop-area-inside">
       <div class="fc-disp-default">
           <p>You can paste an image from the clipboard as well as dropping a file.</p>
       </div>
       <div class="fc-disp-drag">
           <p>Drop here to add the file</p>
       </div>
       <div class="fc-disp-drag-not-allow">
           <p>The object cannot be dropped</p>
       </div>
       <p class="fc-visible-default">OR</p>
       <div class="fc-file-ref">
           <span>Select file</span>
       </div>
   </div>
</div>

Code

By creating a FileChoice object and setting an event handler by fileChoice.events().on('filedrop', (data) => {});, you can get the file that was dropped or picked up from the dialog.

import FileChoice from 'file-choice';// for npm environment

   const fileChoice = new FileChoice();

   //set 'filedrop' event of file-choice
   fileChoice.events().on('filedrop', (data) => {

       //data.target is the element with class="fc-drop-area".
       const target = data.target;
       const files = data.files;

       const droppedFileInfo = [];

       for (const file of files) {

           droppedFileInfo.push(
               {
                   name: file.name,
                   size: file.size,
                   type: file.type
               }
           );
       }

       alert(JSON.stringify(droppedFileInfo));
   });

Enable "paste" from Clipboard

• pasete "image" Create FileChoice object with option like below.

You can paste "image" data as a file by "ctrl+V" from clipboard.

const fileChoice = new FileChoice({
  pasteEnabled: true
});
const files = data.files;

for (const file of files) {

  if (file.type.startsWith('image/')) {
    const image = await fileChoice.getImageFromFileAsync(file, image => {
      // to do handling image
    });
  }
}

• paste "string" like a text/plain , text/html

const fileChoice = new FileChoice({
  pasteEnabled: true
});

fileChoice.events().on('paste', async (data) => {
  const clipboardItems = data.itemMap;

  const previewArea = document.querySelector('#image-preview');
  previewArea.innerHTML = '';

  let item = clipboardItems.get('text/html');
  if (!item) {
    // get the first item of the map
    item = clipboardItems.values().next().value;
  }

  const clipboardText = await fileChoice.getStringFromClipboardItemAsync(item);
  console.log('clipboardText', clipboardText);
});

styling

/* Entire file drop area */
.fc-drop-area {
    border: solid 1px #ccc;
    background: #eee;
    padding: 0px;
    text-align: center;
}

.fc-drop-area p {
    color: #666666;
}

/* Default file-drop-area-view style before dragging files */

.fc-drop-area-inside {
    color: #333;
    padding: 6px;
    margin: 6px;
    border: 5px solid transparent;
}

.fc-drop-area-inside div.fc-disp-default, .fc-drop-area-inside div.fc-disp-drag, .fc-drop-area-inside div.fc-disp-drag-not-allow {
    font-weight: bold;
}


.fc-disp-default {
    display: block;
}

.fc-visible-default {
    visibility: visible;
}

.fc-disp-drag {
    display: none;

}

.fc-disp-drag-not-allow {
    display: none;

}

.fc-disp-drag-not-allow > p {
    color: red;
}

.fc-file-ref {
    visibility: visible;

}

/* /Default file-drop-area-view style before dragging files */


/* When an allowed object is being dragged */
.fc-drop-area.dragover .fc-drop-area-inside {
    border: 5px dashed #ddd;
}

.fc-drop-area.dragover .fc-disp-drag {
    display: block;
}

.fc-drop-area.dragover .fc-disp-drag-not-allow {
    display: none;
}

.fc-drop-area.dragover .fc-disp-default {
    display: none;
}

.fc-drop-area.dragover .fc-visible-default {
    visibility: hidden;
}

.fc-drop-area.dragover .fc-file-ref {
    visibility: hidden;
}

/* /When an allowed object is being dragged */

/* When a not-allowed object is being dragged */
.fc-drop-area.dragover-not-allowed .fc-drop-area-inside {
    border: 5px dashed #ddd;
}

.fc-drop-area.dragover-not-allowed .fc-disp-drag {
    display: none;
}

.fc-drop-area.dragover-not-allowed .fc-disp-drag-not-allow {
    display: block;
}

.fc-drop-area.dragover-not-allowed .fc-disp-default {
    display: none;
}

.fc-drop-area.dragover-not-allowed .fc-visible-default {
    visibility: hidden;
}

.fc-drop-area.dragover-not-allowed .fc-file-ref {
    visibility: hidden;
}

/* /When a not-allowed object is being dragged */

/* style around file chooser */
.fc-file-ref a, .fc-file-ref a:visited {
    color: dodgerblue;
}

.fc-input {
    visibility: hidden;
    width: 0px;
    height: 0px;
}

/* /style around file chooser */

/* /Entire file drop area */