caboose

Do you have a massive list of items in a scaffold-type arrangement (e.g. in a typo-style admin)? Here's a way to quickly and easily filter and sort your big-assed list. Note: this requires the Hash#to_sql function posted here a few weeks ago .. told you it was useful! More after the jump.. First, we're going to tackle filtering; if y'all want sorting or ajax, too, please leave some comments to motivate me to write the second half. Just so I know you care :) Like any good web coder (har, har) let's start with the view. We have articles, they're organized into simple categories (Category model), written by authors (Author.find(:all) is stored in @authors)

...


Now, that's the header.. it looks something like this:




  
Post title
  

  Main Category
  <%= options_from_collection_for_select(Category.find(:all), 'permalink', 'category_name', params[:category].to_i)%>
  
  

  
  Author
  <%= options_from_collection_for_select(Author.find(:all), 'id', 'nickname', params[:author].to_i )%>
  






  
Post title
  

  Main Category
  Monkeys
  Elephants
  
  

  
  Author
  Joe
  Fred
  



The giant monkey returns
Monkeys
Joe
Who's the biggest, grayest mofo?
Elephants
Fred





Finally, some pagination:




  <% @pagination_params = { 
      :category => params[:category],
      :author   => params[:author],
      :action   => :list,
      :controller => 'article'
    }
    -%>
  <%= pagination_links( 
    @content_pages, :window_size => 15,
    :link_to_current_page => false,
    :params => @pagination_params
  )%>





Now, you may notice there's some javascript in those Select boxes: onchange='filtering();'.  Here's that function. 





Hopefully that's fairly self-explanatory; it builds a query string from the values of the two select boxes.  Next: onto the controller.




class ArticleController < ApplicationController
  def list
    # create a conditions hash from our params, if they exist
    @conditions[:main_category_id] = Category.find_by_permalink(params[:category]).id if params[:category] and !params[:category].empty?
    @conditions[:user_id] = params[:author] if params[:author] and !params[:author].empty?

    @content_pages = Paginator.new self, Article.count, 10, @params['page'].to_i
    @contents = Article.find(:all, :conditions => @conditions.to_sql, :order => 'published_at desc', :offset => @params['page'].to_i, :limit => 10)

    @authors = Author.find_by_sql("SELECT DISTINCT(content.user_id), users.* FROM #{Article.table_name} LEFT JOIN users ON content.user_id = users.id WHERE content.type = 'Article' ORDER BY users.nickname ASC")
    # this is our fairly specific sql, yours is probably much different.

    @categories = Category.find(:all)
    @authors = Author.find(:all)
  end

end


Voila! We now have dropdown filtering.