post '/layer/:layer_id' do
  @layer = PageLayer.where(id: params[:layer_id]).first
  @layer.content = params[:content]
  @layer.save
end

TestCtrl = ($scope, $routeParams, $http, $resource) ->
    $scope.layer = []

    Layer = $resource('/layer/:id', {id:'@id'})

$scope.layer = Layer.get {id: $routeParams.layerId}, ->
    console.log "Got you!"

$scope.saveContent = ->
    $scope.layer.$save()
    console.log "Saved!"

angular.module('appDirectives', []).directive "test", ->
    return (scope, element, attrs) ->
        element.bind "blur", ->
            console.log("blur!")
            scope.saveContent()

<div>Content: {{layer.content}}</div>

<div>
    <form>
        <input type="text" test ng-model="layer.content">
    </form>
</div>

g {id: 27245, page_id: 2302, external_id: 26518, original_upload: null…}
content: "dfgdfg"
external_id: 26518
id: 27245
layerNumber: 8
page_id: 2302

ng_params = JSON.parse(request.body.read)

post '/api/v1/test' do
  ng_params = JSON.parse(request.body.read)
  @foo = Foo.new(ng_params)
  if @foo.save
    puts "Page Saved"
    content_type :json
    rabl :foos, format: "json"
  end
end

// app declaration
var app = angular.module("App", ['ngResource']);

// data service
app.factory('Foo', ['$resource', function($resource) {
  return $resource('/api/v1/test/:id', {id: '@id'});
}]);

// the controller
app.controller('Controller', function($scope, Foo) {

  $scope.foos = Foo.query();

  $scope.create = function(anything) {
    Foo.save({anything: anything}, function(foo){
      $scope.foos.push(foo);
    });
  };
});

<h3>Add something new</h3>
<form ng-submit="create(anything)">
  <input ng-model="anything" type="text">
  <button type="submit">Do it</button>
</form>

<li ng-repeat="foo in foos">
  <p>{{foo.anything}}</p>
</li>

post '/layer/:layer_id' do
  @updated_layer = JSON.parse(request.body.string)
  @layer = PageLayer.where(id: params[:layer_id]).first
  @layer.content = @updated_layer['content']
  @layer.save
end

require 'rack/parser'
use Rack::Parser, content_types: {
  'application/json' => Proc.new {|body| JSON.parse body }
}