Simple upload adapter

The simple upload adapter lets you upload images to your server using the XMLHttpRequest API with a minimal editor configuration. See the Server-side configuration section to learn about the requirements for your server-side application.

# Installation

First, install the @ckeditor/ckeditor5-upload package:

npm install --save @ckeditor/ckeditor5-upload

Add the SimpleUploadAdapter to your plugin list and configure the feature. For instance:

import { SimpleUploadAdapter } from '@ckeditor/ckeditor5-upload';

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ SimpleUploadAdapter, /* ... */ ],
        toolbar: [ /* ... */ ],
        simpleUpload: {
            // Feature configuration.
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

# Configuration

The client side of this feature is configurable using the config.simpleUpload object.

import { SimpleUploadAdapter } from '@ckeditor/ckeditor5-upload';

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        plugins: [ SimpleUploadAdapter, /* ... */ ],
        toolbar: [ /* ... */ ],
        simpleUpload: {
            // The URL that the images are uploaded to.
            uploadUrl: 'http://example.com',

            // Enable the XMLHttpRequest.withCredentials property.
            withCredentials: true,

            // Headers sent along with the XMLHttpRequest to the upload server.
            headers: {
                'X-CSRF-TOKEN': 'CSRF-Token',
                Authorization: 'Bearer <JSON Web Token>'
            }
        }
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

# Configuring allowed file types

The allowed file types that can be uploaded should be configured in two places:

• On the client side, in CKEditor 5, restricting image upload through the CKEditor 5 UI and commands.
• On the server side, in your server-side application configuration.

# Client-side configuration

Use the image.upload.types configuration option to define the allowed image MIME types that can be uploaded to CKEditor 5.

By default, users are allowed to upload jpeg, png, gif, bmp, webp, and tiff files, but you can customize this behavior to accept, for example, SVG files.

# Server-side configuration

It is up to you to implement any filtering mechanisms on your server to restrict the types of images that are allowed to be uploaded.

# Server-side configuration

To use this upload adapter, you must provide a server-side application that will handle the uploads and communicate with the editor, as described in the following sections.

# Communication protocol

When the image upload process is initiated, the adapter sends a POST request under config.simpleUpload.uploadUrl.

You can send additional headers along with the XMLHttpRequest to the upload server, for example, to authenticate the user, using the config.simpleUpload.headers object.

If you use the config.simpleUpload.withCredentials configuration, you may need some extra HTTP headers for the cross-site request to work.

The responseType of the request is always json. See the Successful upload and Error handling sections to learn more.

# Successful upload

If the upload is successful, the server should return:

• An object containing the url property which points to the uploaded image on the server:

  {
      "url": "https://example.com/images/foo.jpg"
  }
  

• Or an object with the urls property, if you want to use responsive images and the server supports it:

  {
      "urls": {
          "default": "https://example.com/images/foo.jpg",
          "800": "https://example.com/images/foo-800.jpg",
          "1024": "https://example.com/images/foo-1024.jpg",
          "1920": "https://example.com/images/foo-1920.jpg"
      }
  }
  

  The "default" URL will be used in the src attribute of the image in the rich-text editor content. Other URLs will be used in the srcset attribute, allowing the web browser to select the best one for the geometry of the viewport.

The URL(s) in the server response are used:

• To display the image during the editing (as seen by the user in the editor).
• In the editor content saved to the database.

# Error handling

If something went wrong, the server must return an object that contains the error property. This will cancel the upload in the editor, for example, allowing the user to select another image if the previous one was too big or did not meet some other validation criteria.

If the error object contains a message, it will be passed to the editor notification system and displayed to the user. For the convenience of the users, use clear and possibly specific error messages.

{
    "error": {
        "message": "The image upload failed because the image was too big (max 1.5MB)."
    }
}

If the message property is missing in the error object, the editor notification system will display the default “Could not upload file: [filename].” message.

# Upload progress

This upload adapter will notify users about the file upload progress out–of–the–box.

# What’s next

Check out the comprehensive Image upload overview to learn more about different ways of uploading images in CKEditor 5.

See the Image feature guide to find out more about handling images in CKEditor 5 WYSIWYG editor.

# Contribute

The source code of the feature is available on GitHub at https://github.com/ckeditor/ckeditor5/tree/master/packages/ckeditor5-upload.