Introduction

The aim of params-validator is to allow an easy way to validate the parameters in a method call.

Install

gem install params-validator

Requirements

v0.2.0 changes

FEATURE: definition of validation rulesets inside the method, so it improves the code style including the validation as the first step in a method execution (suggested by osuka)
FIXED: If a method has a ruleset that defines all the parameters as optional, a nil argument is allowed. On previous versions an ArgumentError exception was thrown
FIXED: inheritance allowed. A method can define a more restrictive ruleset in a inherited method.
FIXED: a method validation can be redefined, the first definition will not be used.
MOVED: specs to folder ./spec

Usage

There are four ways of use:

Include validation rules inside the object:

See this example:

  require 'params-validator'
  class MockObject
    include ParamsValidator::ValidParams
    # define two useless methods 
    [:method1, :method2].each{|m|
      define_method(m) do |*args, &block|
        puts {:foo => "bar"}
        true
      end
    }
    # method1 arguments ruleset
    validate_method(:method1) do
      level(Fixnum, :optional)
    end
    # method2 arguments ruleset
    validate_method(:method2) do
      data(String) { |data| !data.nil? and data.length > 0}
      level(Fixnum, :optional) {|level| level <= 3}
    end
  end

When calling a specific method, an ArgumentError exception will be raised if at least one parameter is invalid

  obj = MockObject.new
  obj.method1({:level => "1"})  # This will raise an ArgumentError exception because :level parameter type is invalid
  obj.method1({:level => 1})  # This will execute successfully the method call
  obj.method2({:level => 1})  # This will raise an ArgumentError exception because :data parameter is missing

Include validation rules outside the object:

class MockObject
  include ParamsValidator::ValidParams
  # define two useless methods 
  [:method1, :method2].each{|m|
    define_method(m) do |*args, &block|
      true
    end
  }
  # method1 and method2 should be validated, but no ruleset is defined
  validate_method [:method1, :method2]
end

Then in a separate file, rulesets must be loaded:

  require 'params-validator'
  include ParamsValidator::ValidParams
  # define rulesets
  rules = <<EOF
    validation_rule("MockObject::method1") do
      level(Fixnum, :optional)
    end
    validation_rule("MockObject::method2") do
      data(String) { |data| !data.nil? and data.length > 0}
      level(Fixnum, :optional) {|level| level <= 3}
    end
  EOF
  # load rulesets in validation framework
  load_rules(rules)
  obj = MockObject.new
  obj.method1({:level => "1"})  # This will raise an ArgumentError exception because :level parameter type is invalid 
  obj.method1({:level => 1})  # This will execute successfully the method call
  obj.method2({:level => 1})  # This will raise an ArgumentError exception because :data parameter is missing

Implicit validation

Ruleset defined inside the method, kudos to osuka

require 'params-validator'
class MockObject
  include ParamsValidator::ValidParams

  def method1(args)
  	validate_method(args) do
    	level(Fixnum, :optional)
  	end
  end
end

Client side validation

Request validation to ensure a method call is valid in advance, kudos to drslump

obj = ParamsValidator::Request.new
obj[:data] = "this is a log"
obj[:level] = 1
ruleset = MockObject.get_rule(:method2)
obj.valid?(ruleset) # false
begin
  obj.validate(ruleset)
rescue ArgumentError => ae
  p ae.message  # array with validation errors
end

More examples can be found in test/spec folders.

juandebravo/params-validator

Introduction

Install

Requirements

v0.2.0 changes

Usage