Parse an HTTP JSON message in a Rails 3 application?

Question

I have a simple Rails 3 application that I am trying to figure out how to parse JSON POST and insert data into my application database.

I have a main controller and an action model, the controller looks like this:

class ActivitiesController < ApplicationController # GET /activities # GET /activities.json def index @activities = Activity.order('created_at DESC').limit(10) respond_to do |format| format.html # index.html.erb format.json { render json: @activities } end end # GET /activities/1 # GET /activities/1.json def show @activity = Activity.find(params[:id]) respond_to do |format| format.html # show.html.erb format.json { render json: @activity } end end # GET /activities/new # GET /activities/new.json def new @activity = Activity.new respond_to do |format| format.html # new.html.erb format.json { render json: @activity } end end # GET /activities/1/edit def edit @activity = Activity.find(params[:id]) end # POST /activities # POST /activities.json def create @activity = Activity.new(params[:activity]) respond_to do |format| if @activity.save format.html { redirect_to @activity, notice: 'Activity was successfully created.' } format.json { render json: @activity, status: :created, location: @activity } else format.html { render action: "new" } format.json { render json: @activity.errors, status: :unprocessable_entity } end end end # PUT /activities/1 # PUT /activities/1.json def update @activity = Activity.find(params[:id]) respond_to do |format| if @activity.update_attributes(params[:activity]) format.html { redirect_to @activity, notice: 'Activity was successfully updated.' } format.json { head :no_content } else format.html { render action: "edit" } format.json { render json: @activity.errors, status: :unprocessable_entity } end end end # DELETE /activities/1 # DELETE /activities/1.json def destroy @activity = Activity.find(params[:id]) @activity.destroy respond_to do |format| format.html { redirect_to activities_url } format.json { head :no_content } end end end 

I also have an example JSON payload from an application that I am trying to get POST:

 payload {"files":{"changed":[],"removed":[".gitmodules","extensions","extensions/markdown"]},"project":{"permalink":"dans-stuff-2","public_key":"ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCuB80S+kMN1266LvCEXoU5hmjugcuXko61Hl7uD9VVgMgEOrLSkeYktOPshgCOwjQgGhSMVEHWrSuOddOi+V3rOu3v91jiU3vycRM3nK9GMaOFf+tTn0/4ReUvGOFHeir1vluHCmOAmpqsVhGWkCJY6eJE37muvGdTG4nW/VnpWYCTLfSOeaq5MVx5LU+zYLntvB5PXd7h1k5ROO8lW+5QzGVyHHEvilzJOqESIAWpNtcXGBt7clWpFH4lg2AT7JebYFuHl8Sl4LYzIRegcpg718CWJjrck9/xV6CBTGP520ifU6K0x4JOn/qFzVlqwnxmrPXwawptmCiYiJt3X8Oz DeployHQ.com Key for dans-stuff-2","name":"Dans Stuff","repository":{"port":null,"username":null,"branch":"master","url":" [e-mail] :atech/deploytest/test1.git","scm_type":"git","cached":true,"hosting_service":{"name":"Codebase","url":"http://www.codebasehq.com","commits_url":"http://atech.codebasehq.com/projects/deploytest/repositories/test1/commits/master","tree_url":"http://atech.codebasehq.com/projects/deploytest/repositories/test1/tree/master"}}},"server":{"name":"cybele","server_path":"/home/dan/deploytest","port":22,"username":"dan","use_ssh_keys":true,"last_revision":"2ad223b9dd6d006d69909407ac7df322e35b009b","hostname":"cybele.phoenixdev.co.uk","identifier":"de99437e-da4a-0986-a7ab-e55805261a96","protocol_type":"ssh"},"start_revision":{"timestamp":"2011-11-30T13:48:22+00:00","author":"Dan Wentworth","ref":"a1c1073b85d1662c075d77f5d88be3fd291abd12","message":"nested markdown pathg","email":" [e-mail] "},"identifier":"9d0f9c21-f242-3966-fcd3-e821a65acd45","end_revision":{"timestamp":"2011-08-30T16:41:32+01:00","author":"Dan Wentworth","ref":"2ad223b9dd6d006d69909407ac7df322e35b009b","message":"arses","email":" [e-mail] "},"configuration":{"email_notify":true,"notification_addresses":" [e-mail] ","copy_config_files":true},"timestamps":{"completed_at":"2012-01-17T09:22:15Z","duration":null,"queued_at":"2012-01-17T09:22:07Z","started_at":"2012-01-17T09:22:10Z"},"status":"completed"} -------------------------------------------------------------------------------- signature TMjVYhk/+lQigy3hdkgTZjAaaroxAi126XaDzrQ1xWGyMji9oR0F5nfE73Mo kNs7Hk7aY1GQgtDRdBjgPE+C/6etF9nPFXPacWobaxSP35TGOrpoSACNQDAQ Q0wvn0Bm/jMvhBKoQ6YYUSx8KP8nd7VkgQmv4S0cakgixA4LHfg= 

Since POST will need to be added to the url, I would suggest that I need to define a new method:

 def deploy_receive data = JSON.parse(request.body) end 

I'm not sure where to go. How would I cherry pick attributes from JSON and put them in various attributes in the Activities table?

Something like that?

 def deploy_receive data = JSON.parse(request.body) @activity = Activity.new(params[:fault]) @activity.who = data.author end 

Any pointers would be appreciated!

Answer 1

If I understand correctly, I think you are looking for something like the following:

Route File

 match '/api/activity/new' => 'activity#deploy_receive', :via => [:post] 

Activity controller (provided that the POSTed data is in the correct format)

 def deploy_receive @activity = Activity.new(params[:fault]) if @activity.save render json: @activity else @activity = "error" render json: @activity end end 

Answer 2

If I understand this correctly; Rails will already do this for you if the correct headers are set. Checkout: POST json to rails server