Rails Debug Toolkit
===================
Introduction
------------
`rails_dt` gem gives you `DT.p()` method you can use anywhere in your project to print your debug messages.
It's somewhat similar to Ruby's native `p()` with output being sent to log, console and web.
For example, `DT.p "Hello, world!"` invoked in `RootController` will give you a:
[DT app/controllers/root_controller.rb:3] Hello, world!
The Ideas Behind It
-------------------
* Debug message printer must **not require initialization**.
* Debug message printer must be **nothing else**, but a debug message printer.
* Debug message printer must be simple and invoked **always the same way** regardless of where you call it from.
* Debug message printer calls must be **clearly visible** in the code.
* Debug message printer must **print its location in code** so you can find and modify/remove it as easy as possible.
Express Setup (Rails 3)
-----------------------
In your `Gemfile`, add:
gem "rails_dt"
Then do a `bundle install`.
This gives you an express (zero-conf) setup, which outputs messages to log, `log/dt.log` and console.
Express Setup (Rails 2)
-----------------------
$ gem sources --add http://rubygems.org
$ gem install rails_dt
In your `config/environment.rb`, add:
config.gem "rails_dt"
Setting Up Web Output (Both Rails 3 and Rails 2)
------------------------------------------------
In your application root, do a:
$ rails generate rails_dt # Rails 3
$ script/generate rails_dt # Rails 2
Follow the instructions the generator gives you then. They are listed below.
Inside your `ApplicationController` class, add:
handles_dt
Inside your `app/views/layouts/application.html.erb` `` section, add:
<%= stylesheet_link_tag "dt" %>
Inside your `app/views/layouts/application.html.erb` `` section, add:
<%= DT.web_messages_as_html %>
Checking Setup
--------------
Somewhere in your `app/views/layouts/application.html.erb`, add:
<% DT.p "hello, world!" %>
Refresh the page. You should see "hello, world!":
* In your application log.
* In `log/dt.log`.
* On the web page, if you've set it up (see above).
Debugging...
------------
### ...Models ###
def before_save
DT.p "in before_save"
end
### ...Controllers ###
def action
DT.p "hi, I'm #{action_name}"
end
### ...Views ###
<% DT.p "@users", @users %>
### ...Filters ###
Insert debugging code:
before_filter do
DT.p "in before_filter xyz"
end
after_filter do
DT.p "in after_filter xyz"
end
See it in action:
$ tail -f log/dt.log
### ...Anything! ###
Just use `DT.p` anywhere you want.
Customizing Output Format
-------------------------
Create a sample initializer, by doing a:
$ rails generate rails_dt # Rails 3
$ script/generate rails_dt # Rails 2
In `config/initializers/dt.rb` you'll see something like:
# Customize your DT output.
#DT.log_prefix = "[DT <%= file_rel %>:<%= line %>] "
#DT.console_prefix = "[DT <%= file_rel %>:<%= line %>] "
#DT.web_prefix = '<%= file_rel %>:<%= line %> '
Uncomment and edit lines appropriately. Restart server for changes to take effect.
Values are in ERB format. The following macros are available:
* `file` -- full path to file.
* `file_base` -- file base name.
* `file_rel` -- file name relative to Rails application root.
* `line` -- line number.
You can also disable particular output target by setting its prefix to `nil`:
DT.console_prefix = nil # Disable console output.
Feedback
--------
Send bug reports, suggestions and criticisms through [project's page on GitHub](http://github.com/dadooda/rails_dt).