Question

Wanting to play with jQuery, Orbited, and FasterCSV, I made a Rails chat application.

You can browse to a URL and there is a chat window that is similar to IRC. You can also export the contents of the chat window by visiting the same URL but adding a “.csv” extension to the URL.

HTML version: http://host.name/channel/sweetchatroom

CSV version: http://host.name/channel/sweetchatroom.csv

In Firefox, Safari, and Chrome it works normal. In IE, If I visit the “HTML” URL, I get the CSV version of the page. I have to manually add “.html” to the URL like so:

http://host.name/channel/sweetchatroom.html

My route currently looks like this:

map.chat '/channel/:name.:format', :controller => 'channels', :action => 'show'

I Googled a bit and tried the following suggestions:

map.slug '/channel/:slug.:format', :controller => 'channels', :action => 'show', :defaults => {:format => 'html'}

— and —

map.slug '/channel/:slug.:format', :controller => 'channels', :action => 'show', :format => 'html'

Neither of them worked. Apparently, if you visit a URL without specifying the format, Rails does not set params[:format] to anything. Which in principle I prefer, but the docs are pretty clear that you can set a default format and I’m not sure why it doesn’t honor this. The “:defaults => …” suggestion is what is in the Rails docs.

In order to get it to work I had to change this part of my channels controller:

respond_to do |format|
  format.csv { 
    send_data channel_to_csv(@channel),
      :type => "text/plain",
      :filename => "#{@channel.slug}.csv",
      :disposition => 'inline'
  } 
  format.html # show.html.erb
  format.xml  { render :xml => @channel }
end

To this:

respond_to do |format|
  format.csv { 
    send_data channel_to_csv(@channel),
      :type => "text/plain",
      :filename => "#{@channel.slug}.csv",
      :disposition => 'inline'
  } if params[:format] == 'csv' # <-- Here is the change
  format.html # show.html.erb
  format.xml  { render :xml => @channel }
end

It works perfectly but seems really hackish. There has to be a better, more “Ruby” way. Do I have the syntax wrong on my routes entry? It seems like routes is where this should be.

I know I have to be missing something. I couldn’t find good information on this problem on Google or on StackOverflow. That generally means I’m way out in the weeds.

Answer 1

I usually just put the format.html first. That way, when IE sends a weird accepts header (like */*), it doesn’t get fouled up. Basically, if IE says it accepts everything (like when there is no extension on the URL) Rails will send it the first thing that matches.