http status codes for rails

the restful scaffolding generator for rails uses various http status codes when sending results back to the client.

i was adding some additional methods and wanted to use status codes myself, so i went looking for a list of them. i didn’t readily find it in the docs and ended up looking through the source to action controller.

they’re stored in this array:

ActionController::StatusCodes::SYMBOL_TO_STATUS_CODE

type (or paste) that into script/console and you’ll have the full list (which is quite long).

reading sessions in rails

in ruby’s CGI::Session module, sessions are stored as a block of seeming junk, like this: “BMZWRlcm1hbiBCb25kaW5nIENvb”. it’s actually an encoded format which is all well and fine until you need to read something out of it for debugging purposes.

if you are using rails’ ActiveRecordStore, the contents of a session can be read fairly simply. since this relies on an AR model called Session, which your app most likely doesn’t have, we’ll create that too.

so, fire up 1script/console and input the following:

1class Session < ActiveRecord::Base ; end
2CGI::Session::ActiveRecordStore::Session.unmarshal(Session.find(:first).data)

that will dump the contents of the first session. :first can be replaced with any valid option to AR’s #find method.

dump all of the sessions with something like:

1Session.find(:all).collect {|s| CGI::Session::ActiveRecordStore::Session.unmarshal(s.data)}

announcing db_log_cleaner rails plugin

my first public rails plugin is ready to go. called db_log_cleaner, it’s a more complete version of another plugin called postgre_log_cleaner.

it filters out selected log messages from both postgres and mysql to help keep development.log cleaner.

details are on the project page.

uploading multiple files with attachment_fu

i was recently sharing with someone how to make multiple uploads work with the attachment_fu plugin. as an aside, attachment_fu is the successor to acts_as_attachment. if you were planning to use acts_as_attachment, upgrade your plans and use attachment_fu instead.

multiple file uploads are actually fairly straight forward.

first, in the view:

1<%= file_field_tag 'attachment_data[]' %>

put as many of these in the view as desired. it’s also easy to cause an arbitrary number of them to be added via javascript by the user’s browser.

then, in the controller:

1@attachment = Attachment.new
2params[:attachment_data] ||= []
3params[:attachment_data].each do |file|
4  @attachment = Attachment.create({:uploaded_data => file}) unless file == ""
5end

Attachment is my model for uploaded file—substitute as appropriate. as this isn’t a complete how-to for attachment_fu, i won’t get into configuring attachment_fu or the model here.

that’s it. that wasn’t so painful, eh?

syntax highlighting for rails

i’ve been rewriting the software backend for this site. it has been my intention, once that was partly done, to begin to discuss more technical stuff here, including code samples—most likely for rails stuff.

that’s all fine and well, but you can’t just post code snippets in black and white. no, this is a technicolor world now and that would never do. so i’ve been on a quest to figure how how to make my shiny, new rails backend parse the code blocks and introduce them to my box of 64 (!) crayolas. (as an aside, i’m pretty sure i wasn’t the only one at age 7 who thought his world would be complete if only i could get a 64-color crayola set — much better than my set of 16.)

anyway, i won’t get into lots of details at this point (although i can if somebody wants me to), but in case you need to do the same thing, here are a few jumping off points.

the most common solution seems to be to use the syntax gem. you’ll need to roll your own interface between it and rails, although rails weenie can offer some help.

syntax will recognize ruby, yaml, and xml by default. if you need something more robust, UltraViolet looks interesting although it would certainly have a heavier memory footprint. it leverages textmate bundles so it should be able to interpret/colorize nearly anything that is even semi-common, and then some.

i’m sure there are more options—add them to the comments if you know of something.