To access a value in a model before it is type cast, append _before_type_cast.
self.phone_number_before_type_cast
A possible use of this is to remove characters from a string before it is cast to an integer (in a before_save method, for example):
def before_save
self['phone_number'] = phone_number_before_type_cast.gsub(/[^0-9]/,'')
end
If you’ve included fixtures in your unit test:
class UserTest
... the data will be available using:
users(:johnny)
A fixtures object behaves like a hash but is actually a method. It is a “hash with special powers”. To get Johnny’s surname you would do:
users(:johnny).surname
The YAML fixture might look something like this:
johnny:
id: 2
first_name: Johnny
surname: Smith
email_address: jsmith@jsmith.cc
Rails migrations do not seem to support decimal or float columns with a set precision and scale at the moment, e.g. float(8,2).
The accepted solution seems to be to store prices in pence (or cents) and then convert to a decimal price in pounds (or dollars) in the model. See How To Use Integer Fields As Money on the Rails wiki.
You need to escape a percentage symbol with an extra % (%%) when including a % in a SQL query. This is required because Rails uses sprintf (%) on the string.
search_conditions
Source: http://one.textdrive.com/pipermail/rails/2004-December/001330.html
When working with file uploads, I came across some unexpected behaviour in the file_column plugin. If you submit a form containing an empty file input, a StringIO object will still be created for it. The example upload is a confidentiality agreement. When you upload a file, params[:confidentiality_agreement][:file] is populated with the StringIO object for the file. Unfortunately, the same happens when the file upload field is empty!
raise params[:confidentiality_agreement][:file].inspect
… produces something like StringIO:0xb7ae3978.
So in order to check whether or not a new file has been uploaded, you need to check the size of the StringIO object as well as checking if the field is blank. For example:
# has a new confidentiality agreement been uploaded?
if params[:confidentiality_agreement][:file].blank? || params[:confidentiality_agreement][:file].size == 0
# no new file, use existing one
else
# new file has been uploaded, save it!
end
Sources: StringIO docs
To use a view helper - like a method from NumberHelper - in your model or controller, use an include line like this at the top of the class:
class Business
There is a nifty method in ActiveSupport called to_sentence:
>> fruits = ['apple','banana','peach']
=> ["apple", "banana", "peach"]
>> fruits.to_sentence
=> "apple, banana, and peach"
>> fruits.to_sentence :skip_last_comma => true
=> "apple, banana and peach"
I prefer to drop the last comma - use :skip_last_comma => true to do this.
Private methods are useful in Rails where you need to define a method inside a controller that does not map to an action.
private
def my_method
# code here
end
Unlike in other languages, in Ruby the ‘private’ keyword acts as a toggle - all methods after the ‘private’ keyword will be made private unless you call a different privacy method before them - ‘public’ for example.
In Rails it makes sense to logically group private controllers at the end of the file, under a single ‘private’ keyword.
Use the following command in your app’s top level directory to copy the structure of the development database to the test db:
rake clone_structure_to_test
