Images
We are using Reaction FileCollections for file uploading, downloading, and transformation.
The Media FileCollection
There is just one MeteorFileCollection named Media, which is defined in /imports/plugins/core/files. The related server setup is in /imports/plugins/core/files/server/fileCollections.js.
The Media FileCollection is available in both client code and server code with a similar API.
Importing in a client code file:
import { Media } from "/imports/plugins/core/files/client";
Importing in a server code file:
import { Media } from "/imports/plugins/core/files/server";
The normal Mongo.Collection that backs the Media FileCollection is imported like any other collection:
import { MediaRecords } from "/lib/collections";
Use Media when you want to work with FileRecord instances. Use MediaRecords directly if you just want to modify the collection data directly, either for performance or convenience.
Changing the Binary Data Store
By default, GridFS is used to store the actual file data (as opposed to the information about the file, which is what is stored in the MediaRecords collection). GridFS stores the binary data in MongoDB collections.
If you'd like to use a different store, such as a cloud storage service, this is relatively easy. Refer to Reaction FileCollections documentation. Then import your storage adapter and change all of the new GridFSStore in /imports/plugins/core/files/server/fileCollections.js to new YourCustomStore.
Image Transformation
The Sharp package handles resizing images when they are uploaded. Refer to the imgTransforms array and the transformWrite functions in /imports/plugins/core/files/server/fileCollections.js. For more details about transformWrite, refer to Reaction FileCollections documentation.