Good notes posted to Ruby on Rails
RSS feedList of status codes and their symbols
Note that the :status option accepts not only an HTTP status code (such as 500), but also a symbol representing that code (such as :created), if that makes more sense to you. Here’s a list of which symbols map to which numbers (derived from ActionController::StatusCodes::SYMBOL_TO_STATUS_CODE):
100 = :continue 101 = :switching_protocols 102 = :processing 200 = :ok 201 = :created 202 = :accepted 203 = :non_authoritative_information 204 = :no_content 205 = :reset_content 206 = :partial_content 207 = :multi_status 226 = :im_used 300 = :multiple_choices 301 = :moved_permanently 302 = :found 303 = :see_other 304 = :not_modified 305 = :use_proxy 307 = :temporary_redirect 400 = :bad_request 401 = :unauthorized 402 = :payment_required 403 = :forbidden 404 = :not_found 405 = :method_not_allowed 406 = :not_acceptable 407 = :proxy_authentication_required 408 = :request_timeout 409 = :conflict 410 = :gone 411 = :length_required 412 = :precondition_failed 413 = :request_entity_too_large 414 = :request_uri_too_long 415 = :unsupported_media_type 416 = :requested_range_not_satisfiable 417 = :expectation_failed 422 = :unprocessable_entity 423 = :locked 424 = :failed_dependency 426 = :upgrade_required 500 = :internal_server_error 501 = :not_implemented 502 = :bad_gateway 503 = :service_unavailable 504 = :gateway_timeout 505 = :http_version_not_supported 507 = :insufficient_storage 510 = :not_extended
Implemented in database adapters
These methods are not implemented in the abstract classes. Instead, all database adapters implement these separately, if the feature is supported.
Rendering nothing
If your controller action does not explicitly call render, Rails will, by default, attempt to locate and render the template corresponding to the action. It’s not uncommon, for example with Ajax calls, to want to render nothing. This will circumvent the default rendering and prevent errors on missing templates. To render nothing simply do the following:
render :nothing => true
Its important to note that this isn’t the same as returning no HTTP response. In fact, this results in an HTTP response with a status code of 200 OK being sent back with a blank content body. Why does it matter? Well, you can still test your controller by asserting that a :success response was returned.
Seriously! Do not forget the brackets
thank you source jamesandre.ws
the form_for([:admin, @user]) must have the [] brackets to avoid errors like “Only get requests are allowed”
<% form_for([:admin, @user]) do |f| %> <%= render :partial => 'form' %> <%= submit_tag "Create" %> <% end %>
More on deprecation
This is not deprecated. I think the docs are confused because the validate, validate_on_create, and validate_on_update methods are actually callbacks and not explicitly defined on their own. The correct usage is the same as in the docs above.
:prefix option
Be aware!
By default, if you do select_month(Date.today, :field_name => ‘start’) it will generate select tag with name “date[start]”. If you want it to be something other than date[], add :prefix option, like this:
select_month(Date.today, :field_name => 'start', :prefix => 'timer')
This will render select tag with name “timer[start]”.
Taken from sources of name_and_id_from_options method.
Link to caller URL
link_to “Back”, :back
Documentation for Associations
You are most likely looking for ActiveRecord::Associations::ClassMethods
If you're not using resource
If you don’t use resource for your remote_form_for, then :url option is necessary.
For example:
<% remote_form_for "not_resource" do |f| ... %>
won’t work. But with :url option, it will:
<% remote_form_for "not_resource", :url => { :controller => "recommend", :action => "send" } do ... %>
has_one Nesting in Rails 2.0
Routers:
map.resources :user, :has_one => [:avatar]
Views:
form_for [@user, @avatar], :url => user_avatar_url(@user) do |f| ... end
Pass the observed fields value as a parameter in the Ajax request
Use encodeURIComponent with with to pass an encoded value as a parameter (POST or GET) of the AJAX request. For example:
<%= observe_field :company_id,
:url => {:action => ‘facilities’, :only_path => false}, :with => “‘company=’ + encodeURIComponent(value)” %> Also, setting only_path => false for the URL ensures that the full URL (including host and protocol) is used for the AJAX request.
Example of composed_of composition class implementation
If we have following code in model:
composed_of :temperature, :mapping => %w(celsius)
Then our composition class can be this:
class Temperature def initialize(celsius) @celsius = celsius end # This method is called by ActiveRecord, when record is saved. # Result of this method will be stored in table in "celsius" field, # and later when the record is loaded again, this will go to # our Temperature#new constructor. def celsius @celsius end # This is example of method that we can add to make this composition useful. def farenheit @celsius * 9/5 + 32 end end
has_many :through
It’s is recommended to use has_many :through association instead of has_and_belongs_to_many. has_many :through is better supported and generally easier to work with once you grasp the idea.
Compare old and new form for
Old form for
<% form_for :user, :url => users_path do %> <%= render :partial => 'form' %> <%= submit_tag 'Create' %> <% end %>
New form for
<% form_for(@user) do |f| %> <%= render :partial => f %> <%= submit_tag 'Create' %> <% end %>
All methods
create_table :table do |t|
t.column # adds an ordinary column. Ex: t.column(:name, :string) t.index # adds a new index. t.timestamps t.change # changes the column definition. Ex: t.change(:name, :string, :limit => 80) t.change_default # changes the column default value. t.rename # changes the name of the column. t.references t.belongs_to t.string t.text t.integer t.float t.decimal t.datetime t.timestamp t.time t.date t.binary t.boolean t.remove t.remove_references t.remove_belongs_to t.remove_index t.remove_timestamps end
All methods
change_table :table do |t|
t.column # adds an ordinary column. Ex: t.column(:name, :string) t.index # adds a new index. t.timestamps t.change # changes the column definition. Ex: t.change(:name, :string, :limit => 80) t.change_default # changes the column default value. t.rename # changes the name of the column. t.references t.belongs_to t.string t.text t.integer t.float t.decimal t.datetime t.timestamp t.time t.date t.binary t.boolean t.remove t.remove_references t.remove_belongs_to t.remove_index t.remove_timestamps end
Method description from Rails 2.0
If text is longer than length, text will be truncated to the length of length (defaults to 30) and the last characters will be replaced with the truncate_string (defaults to “…”).
Examples
truncate("Once upon a time in a world far far away", 14) # => Once upon a... truncate("Once upon a time in a world far far away") # => Once upon a time in a world f... truncate("And they found that many people were sleeping better.", 25, "(clipped)") # => And they found that many (clipped) truncate("And they found that many people were sleeping better.", 15, "... (continued)") # => And they found... (continued)
:expires_in option
If you need :expires_in functionality in Rails 2.1, you can use this plugin:
http://github.com/nickpad/rails-caches-action-patch/tree/master
Turn layout off with render
Thats awkward, but the code below does not turn layout off:
render :action => "short_goal", :layout => nil
you must use false
render :action => "short_goal", :layout => false
print standard-looking messages during migration
Within a migration file you can use the say_with_time method to print out informational messages that match the style of standard migration messages. See the say method also.
say_with_time "migrate existing data" do # ... execute migration sql ... end #=> "-- migrate existing data" #=> " -> 0.0299s"
:null => false
To not allow a column to have a NULL value, pass :null => false. Seems silly, but that’s it.
Information on 'ModelName.transaction'
If you are looking for information about:
ModelName.transaction do ... end
or
transaction do ... end
Information on 'ModelName.transaction'
If you are looking for information about:
ModelName.transaction do ... end
or
transaction do ... end
Be careful with overriding dynamic attribute based finders
don’t try something like this:
class Foo < ActiveRecord::Base def self.find_by_bar(*args) foo = super(*args) raise SomeCustomException unless foo foo end end
In newer versions of rails, method_missing defines find_by_bar when you first use it. By calling super, you’re triggering method_missing and overwriting your custom definition! It will work the first time then break! Manually write the call to find!
Custom collection local variable name
Regarding the previous note from hoodow about using :variable_name to create a custom local variable name when rendering a collection with a partial, the argument should be :as instead of :variable_name, so:
render :partial => “video_listing”, :collection => @recommendations, :as => :video
This method has moved
To help anyone else looking, this method is now on the ActionView::Template class.
Testing protected controllers
When testing controllers which are protected with #authenticate_or_request_with_http_basic this is how you can supply the credentials for a successful login:
@request.env["HTTP_AUTHORIZATION"] = "Basic " + Base64::encode64("username:password")
Must be set before the request is sent through #get or whatever method.