File Storage

About assets

You can make use of Asset to store file references such as images and videos on the database. An asset can only be saved with a record but not as a standalone upload. Skygear automatically uploads the files to a S3 bucket assigned to your app. You can also use your own file storage bucket. More settings can be found at the Developer Portal.

Creating an asset

The common use case is to create an asset using the File API using an HTML form with a file input field.

First you need to create a file upload input field:

<input type="file" id="picture" accept="image/*">

Once the user has selected the image to upload, you can create an Asset object by:

const picture = new skygear.Asset({
  name: 'your-asset-name',
  file: document.getElementById('picture').files[0],
});

After creating an Asset, you need to attach it to a record. Skygear will upload the asset when the record is saved.

For example, you want to allow users to upload an image as an attachment to his note:

const Note = skygear.Record.extend('note');

const note = new Note({ attachment: picture });
skygear.publicDB.save(note) // automatically upload the picture
.then((record) => {
  console.log(record.attachment.url);
  // if configured properly, the url should look like the following
  // <ASSET_STORE_URL_PREFIX>/<asset-id>-<your-asset-name>
}, (error) => {
  console.error(error)
})

Creating an Asset with a base64 string

Apart from creating an Asset through the File API, you can also create one using a base64 string.

const picture = new skygear.Asset({
  name: 'hello.png',            // filename of your asset
  base64: 'iVBORw0KGgoAAAA...', // base64 of the file, no mime
  contentType: 'image/png'      // mime of the file
});

Frequently Asked Questions

Is there limit to file upload on Skygear Cloud?

Currently, It is possible to upload file to Skygear Cloud with a maximum size of 50MB.

Is it possible to add CORS settings to file upload?

If you use Skygear Cloud, a CORS settings of * (any origin) is added to all files, so you can fetch your assets using scripts from any origin. If you have your own S3 bucket, follow the Cross-Origin Resource Sharing guide. when downloading files