Validator
Validator is a simple ruby validation class. You don’t use it directly inside your classes like just about every other ruby validation class out there. I chose to implement it in this way so I didn’t automatically pollute the namespace of the objects I wanted to validate.
This also solves the problem of validating forms very nicely. Frequently you will have a form that represents many different data objects in your system, and you can pre-validate everything before doing any saving.
Usage
Validator is useful for validating the state of any existing ruby object.
```ruby object = OpenStruct.new(:email => ‘[email protected]’, :password => ‘foobar’) validator = Validation::Validator.new(object) validator.rule(:email, [:email, :not_empty]) # multiple rules in one line validator.rule(:password, :not_empty) # a single rule on a line validator.rule(:password, :length => => 3) # a rule that takes parameters
if validator.valid? # save the data somewhere else @errors = validator.errors end ```
The first paramater can be any message that the object responds to.
Writing your own rules
If you have a custom rule you need to write, just put it inside the Validation::Rule
namespace:
```ruby module Validation module Rule class MyCustomRule def error_key :my_custom_rule end
def valid_value?(value)
# Logic for determining the validity of the value
end
def params
{}
end
end
end end ```
A rule class should have the following methods on it:
error_key
a symbol to represent the error. This shows up in the errors hashvalid_values?(value)
the beef of the rule. This is where you determine if the value is valid or notparams
the params hash that was passed into the constructor
Writing self-contained validators
You can also create self-contained validation classes if you don’t like the dynamic creation approach:
```ruby require ‘validation’ require ‘validation/rule/not_empty’
class MyFormValidator < Validation::Validator include Validation
rule :email, :not_empty end ```
Now you can use this anywhere in your code:
ruby
form_validator = MyFormValidator.new(OpenStruct.new(params))
form_validator.valid?
Contributing
Have an improvement? Have an awesome rule you want included? Simple!
- Fork the repository
- Write specs for the change
- Add your change
- Submit a pull request
Don’t change any version files or gemspec files in your change.