Warnable models adds warning functionality to ActiveRecord models, in a similar way as ActiveRecord::Errors does. It lets you handle non-blocking warning logic inside the model itself.
WarnableModels is supposed to be run as a Rails plugin.
script/plugin install git@github.com:freegenie/warnable_models.git
All you need to start playing with warnings is this line in your model:
acts_as_warnable
And a run_warnings method, which is where you put the logic behind you model's warnings.
It should look like this:
protected
def run_warnings
if self.balance < 0
warnings.add(:balance, BALANCE_WARNING)
end
end
Optionally you can specify two parameters:
-
store_count: a database field where to save the warnings count.
-
store_yaml: a database field where to save warnings' yaml serialization.
It's a before_save hook which executes your run_warnings method .
The first time you call .warnings on your model, the run_warnings method gets evaluated. If you don't call it, it gets evaluated on before_save anyway.
If you ever need to cleanup warnings during your program execution, just call the clear_warnings! method.
Tests are the clearest source of example. Given the following models:
class Book < ActiveRecord::Base
include Freegenie::WarnableModels
acts_as_warnable
protected
def run_warnings
if self.description.nil? || self.description.size < 10
warnings.add(:description, "Description is probably too short.")
end
if self.author.blank?
warnings.add(:author, "Did you forget the author?")
end
end
end
class Account < ActiveRecord::Base
BALANCE_WARNING = "Should warn the customer?"
include Freegenie::WarnableModels
acts_as_warnable :store_count => :warnings_count, :store_yaml => :verbose_warnings
protected
def run_warnings
if self.balance < 0
warnings.add(:balance, BALANCE_WARNING)
end
end
end
You get:
# irb
>> require 'test/warnable_models_test'
== CreateTestTable: reverting ================================================
-- drop_table(:books)
-> 0.0058s
-- drop_table(:accounts)
-> 0.0018s
== CreateTestTable: reverted (0.0079s) =======================================
== CreateTestTable: migrating ================================================
-- create_table("books", {:force=>true})
-> 0.0291s
-- create_table("accounts", {:force=>true})
-> 0.0153s
== CreateTestTable: migrated (0.0504s) =======================================
=> true
>> book = Book.new
=> #<Book id: nil, title: nil, author: nil, description: nil, warnings: nil>
>> book.warnings
=> #<Freegenie::WarnableModels::Warnings:0x102085298 @warnings={"author"=>["Did you forget the author?"], "description"=>["Description is probably too short."]}>
>> book.save!
=> true
>> book.warnings
=> #<Freegenie::WarnableModels::Warnings:0x102071dd8 @warnings={"author"=>["Did you forget the author?"], "description"=>["Description is probably too short."]}>
>> book.author = "E.A. Poe"
=> "E.A. Poe"
>> book.title = "The black cat"
=> "The black cat"
>> book.clear_warnings!
=> nil
>> book.warnings
=> #<Freegenie::WarnableModels::Warnings:0x101f6d4f0 @warnings={"description"=>["Description is probably too short."]}>
>> book.save!
=> true
>> book.warnings
=> #<Freegenie::WarnableModels::Warnings:0x101f652f0 @warnings={"description"=>["Description is probably too short."]}>
>> book.description = "The first horror book I've ever read!"
=> "The first horror book I've ever read!"
>> book.save!
=> true
>> book.warnings
=> #<Freegenie::WarnableModels::Warnings:0x101f52880 @warnings={}>
=> Account.new
=> #<Account id: nil, balance: nil, warnings_count: nil, verbose_warnings: nil>
>> account.warnings
=> #<Freegenie::WarnableModels::Warnings:0x101eeccb0 @warnings={}>
>> account.balance = -10.0
=> -10.0
>> account.warnings
=> #<Freegenie::WarnableModels::Warnings:0x101eeccb0 @warnings={}>
>> account.save!
>> account.balance = -10.0
=> -10.0
>> account.save
=> true
>> account.verbose_warnings
=> "--- \nbalance: \n- Should warn the customer?\n"
>> account.warnings_count
=> 1
>>
And so on... ..
Copyright (c) 2008 freegenie, released under the MIT license