Post#approve!: signal errors with invalid object instead of exception.

app/controllers/moderator/post/approvals_controller.rb

@@ -3,14 +3,13 @@ module Moderator
     class ApprovalsController < ApplicationController
       before_filter :approver_only
       skip_before_filter :api_check
+      respond_to :json, :xml, :js
 
       def create
         cookies.permanent[:moderated] = Time.now.to_i
-        @post = ::Post.find(params[:post_id])
-        if @post.is_deleted? || @post.is_flagged? || @post.is_pending?
-          @post.approve!
-        end
-      rescue ::Post::ApprovalError
+        post = ::Post.find(params[:post_id])
+        @approval = post.approve!
+        respond_with(@approval)
       end
     end
   end

app/models/post.rb

@@ -322,7 +322,7 @@ class Post < ActiveRecord::Base
     end
 
     def approve!(approver = CurrentUser.user)
-      approvals.create!(user: approver)
+      approvals.create(user: approver)
     end
 
     def approved_by?(user)

app/models/post_approval.rb

@@ -14,6 +14,10 @@ class PostApproval < ActiveRecord::Base
       errors.add(:post, "is locked and cannot be approved")
     end
 
+    if post.status == "active"
+      errors.add(:post, "is already active and cannot be approved")
+    end
+
     if post.uploader == user
       errors.add(:base, "You cannot approve a post you uploaded")
     end

app/views/moderator/post/approvals/create.js.erb

@@ -1,6 +1,6 @@
-<% if @post.errors.any? %>
+<% if @approval.errors.any? %>
 
-Danbooru.error("Error: " + <%= @post.errors.full_messages.join("; ").to_json.html_safe %>);
+Danbooru.error("Error: " + <%= @approval.errors.full_messages.join("; ").to_json.html_safe %>);
 
 <% else %>
 
@@ -10,7 +10,7 @@ $("#c-posts #flag").show();
 
 $("#pending-approval-notice").hide();
 
-$("#c-moderator-post-queues #post-<%= @post.id %>").hide();
+$("#c-moderator-post-queues #post-<%= @approval.post.id %>").hide();
 Danbooru.notice("Post was approved");
 
 Danbooru.ModQueue.increment_processed();