Entries from June 2008 ↓

I want my list of data to be paginated by letters. The will_paginate plugin certainly gives excellent pagination if all you want is “prev 1 2 3 .. 6 next” kind of pagination.

However what if you’re looking for entries that start with the letter H and you have no idea if that’s page 4 or page 42? You’re probably wanting something more like “# A B C D…” pagination.

I did some googling and found people speaking of solutions for “A B C D…” but in my case, not all of my entries start with letters! If you have something like media titles in your data set, having an entry start with a number is perfectly normal. Some might even start with special characters! Some people suggest having an ‘All’ option, but if you need pagination, it’s probably because you have enough data that showing all options at once is a very bad idea.

Here’s my solution:

First I make a helper function for my options that’ll be cached permanently.

def letter_options
  $letter_options_list ||= ['#'].concat(("A".."Z").to_a)
end

Here’s my index action in my controller:

@letter = params[:letter].blank? ? 'a' : params[:letter]
if params[:letter] == '#'
  @data = Model.find(:all, :conditions => ["title REGEXP ?", 
      "^[^a-z]"], :order => 'title', :select => "id, title")
else
  @data = Model.find(:all, :conditions => ["title LIKE ?", 
      "#{params[:letter]}%"], :order => 'title', :select => "id, title")
end

Here’s my html

<div class ="pagination">
  <% letter_options.each do |letter| %>
    <% if params[:letter] == letter %>
      <span class="current"><%= letter %></span>
    <% else %>
      <%= link_to letter, staff_games_path(:letter => letter)%>
    <% end %>
  <% end %>
</div>

There we go! Now the # will pull up all entries where the first character is not a letter.

Today I’m going to share how you can let your app accept zip files which will then be extracted into multiple attachments. If you already use Attachment Fu to manage files, this should be super easy to add.

Before my controller had something like this:

Attachment.create(:uploaded_data => params[:Filedata])

First break that up into something more like this:

attachment = Attachment.new
attachment.uploaded_data = params[:Filedata]
attachment.save

Then put in some split logic for if it’s a zip file:

attachment = Attachment.new
attachment.uploaded_data = params[:Filedata]
      
if attachment.content_type == "application/zip"
    # Unzip this and process all the inner files
    Attachment.build_from_zip(attachment)
else
    attachment.save
end

Now we’ll need the RubyZip gem and MIME Types gem, so do:

sudo gem install rubyzip
sudo gem install mime-types

Now in the Attachment class we’ll add the build_from_zip method:

def self.build_from_zip(ss)
 zipfile = Zip::ZipFile.open(ss.temp_path)
  
 zipfile.each do |entry|
   if entry.directory?
     next
   elsif entry.name.include?("/")
     next
   else
     screen = Attachment.new
     screen.filename = entry.name
     screen.temp_data = zipfile.read(entry.name)
      
     mime = MIME::Types.type_for(entry.name)[0]
     screen.content_type = mime.content_type unless mime.blank?

     screen.save
   end
 end
  
end

The only two non-obvious things to note here are:

• I skip the files with / in them because when I archive files on my machine, hidden files with / characters in them make it into the archive. I only want the real files.
• I use the MIME Types gem to decide the content type from the filename.

I hope you find this helpful, enjoy!