Extracting Photos form Conference edit form

close #384

app/controllers/admin/photos_controller.rb

@@ -0,0 +1,65 @@
+module Admin
+  class PhotosController < ApplicationController
+    before_action :set_conference
+    before_action :set_photo, only: [:edit, :update, :destroy]
+
+# GET /admin/photos
+    def index
+      @photos = @conference.photos.all
+    end
+
+# GET /admin/photos/new
+    def new
+      @photo = @conference.photos.build
+    end
+
+# GET /admin/photos/1/edit
+    def edit
+    end
+
+# POST /admin/photos
+    def create
+      @photo = @conference.photos.build(photo_params)
+      if @photo.save
+        redirect_to admin_conference_photos_path, notice: 'Photo was successfully created.'
+      else
+        flash[:alert] = "A error prohibited this Photo from being saved: #{@photo.errors.full_messages.join('. ')}."
+        render :new
+      end
+    end
+
+# PATCH/PUT /admin/photos/1
+    def update
+      if @photo.update(photo_params)
+        redirect_to admin_conference_photos_path, notice: 'Photo was successfully updated.'
+      else
+        flash[:alert] = "A error prohibited this Photo from being saved: #{@photo.errors.full_messages.join('. ')}."
+        render :edit
+      end
+    end
+
+# DELETE /admin/photos/1
+    def destroy
+      @photo.destroy
+      redirect_to admin_conference_photos_path, notice: 'Photo was successfully destroyed.'
+    end
+
+    private
+
+# Use callbacks to share common setup or constraints between actions.
+    def set_conference
+      @conference = Conference.find_by(short_title: params[:conference_id])
+    end
+
+# Use callbacks to share common setup or constraints between actions.
+    def set_photo
+      @photo = Photo.find_by(id: params[:id])
+    end
+
+# Only allow a trusted parameter "white list" through.
+    def photo_params
+      params[:photo]
+    end
+  end
+end
+