added better error messages for search errors

app/controllers/posts_controller.rb

@@ -2,6 +2,7 @@ class PostsController < ApplicationController
   before_filter :member_only, :except => [:show, :index]
   after_filter :save_recent_tags, :only => [:update]
   respond_to :html, :xml, :json
+  rescue_from PostSets::SearchError, :with => :search_error
   
   def index
     @post_set = PostSets::Post.new(tag_query, params[:page])
@@ -38,6 +39,11 @@ class PostsController < ApplicationController
   end
 
 private
+  def search_error(exception)
+    @exception = exception
+    render :action => "error"
+  end
+  
   def tag_query
     params[:tags] || (params[:post] && params[:post][:tags])
   end

app/logical/post_sets/post.rb

@@ -1,7 +1,4 @@
 module PostSets
-  class SearchError < Exception
-  end
-  
   class Post < Base
     attr_reader :tag_array, :page
     
@@ -28,7 +25,7 @@ module PostSets
     
     def posts
       if tag_array.size > 2 && !CurrentUser.is_privileged?
-        raise SearchError
+        raise SearchError.new("Upgrade your account to search more than two tags at once")
       end
       
       @posts ||= ::Post.tag_match(tag_string).paginate(page)

app/logical/post_sets/search_error.rb

@@ -0,0 +1,4 @@
+module PostSets
+  class SearchError < Exception
+  end
+end

app/views/posts/error.html.erb

@@ -0,0 +1 @@
+<p>Error: <%= @exception.to_s %></p>

app/views/posts/error.json.erb

@@ -0,0 +1 @@
+{success: false, message: "<%= @exception.to_s %>"}

app/views/posts/error.xml.erb

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<result success="false"><%= @exception.to_s %></result>