Enable Trix to upload files to S3

app/assets/javascripts/bongo/attachments.js.erb

@@ -0,0 +1,51 @@
+(function() {
+  var HOST = "<%= Bongo::Engine.routes.url_helpers.files_path %>"
+
+  addEventListener("trix-attachment-add", function(event) {
+    if (event.attachment.file) {
+      uploadFileAttachment(event.attachment)
+    }
+  })
+
+  function uploadFileAttachment(attachment) {
+    uploadFile(attachment.file, setProgress, setAttributes)
+
+    function setProgress(progress) {
+      attachment.setUploadProgress(progress)
+    }
+
+    function setAttributes(attributes) {
+      attachment.setAttributes(attributes)
+    }
+  }
+
+  function uploadFile(file, progressCallback, successCallback) {
+    var formData = createFormData(file)
+    var xhr = new XMLHttpRequest()
+
+    xhr.open("POST", HOST, true)
+
+    xhr.upload.addEventListener("progress", function(event) {
+      var progress = event.loaded / event.total * 100
+      progressCallback(progress)
+    })
+
+    xhr.addEventListener("load", function(event) {
+      if (xhr.status == 200) {
+        var attributes = {
+          url: xhr.response
+        }
+        successCallback(attributes)
+      }
+    })
+
+    xhr.send(formData)
+  }
+
+  function createFormData(file) {
+    var data = new FormData()
+    data.append("Content-Type", file.type)
+    data.append("file", file)
+    return data
+  }
+})();

app/controllers/bongo/files_controller.rb

@@ -0,0 +1,22 @@
+require_dependency "bongo/application_controller"
+
+require "aws-sdk-s3"
+
+module Bongo
+  class FilesController < ApplicationController
+    before_action :authenticate_user!
+
+    skip_before_action :verify_authenticity_token
+
+    def create
+      extension = File.extname(params[:file].original_filename)
+      s3 = Aws::S3::Resource.new
+      obj = s3.bucket(ENV["AWS_S3_BUCKET"]).object(SecureRandom.uuid + extension)
+      obj.upload_file(params[:file])
+
+      respond_to do |format|
+        format.json { render json: obj.public_url }
+      end
+    end
+  end
+end

bongo.gemspec

@@ -18,4 +18,5 @@ Gem::Specification.new do |spec|
 
   spec.add_runtime_dependency "rails", "~> 6.0.3"
   spec.add_runtime_dependency "mongoid", "~> 7.0.5"
+  spec.add_runtime_dependency "aws-sdk-s3", "~> 1"
 end

config/routes.rb

@@ -1,4 +1,5 @@
 Bongo::Engine.routes.draw do
   root to: "articles#index"
   resources :articles
+  resources :files, only: :create
 end

lib/bongo/version.rb

@@ -1,3 +1,3 @@
 module Bongo
-  VERSION = '0.0.3'
+  VERSION = '0.0.4'
 end