Class: ParamsValidator::Validator

Inherits:
Object
  • Object
show all
Defined in:
lib/params_validator/validator.rb

Overview

This class keeps the rulesets defined in the program and performs the validation between a specific ruleset and a set of parameters

Constant Summary collapse

ERROR_MESSAGE_NULL = 
"Parameter %s cannot be null"
ERROR_MESSAGE_TYPE = 
"Parameter %s present but invalid type %s"
ERROR_MESSAGE_BLOCK = 
"Parameter %s present but does not match the ruleset"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Validator

Returns a new instance of Validator.



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# File 'lib/params_validator/validator.rb', line 22

def initialize
  @methods_loaded = {}
end

Instance Attribute Details

#methods_loaded ⇒ Object (readonly)

Returns the value of attribute methods_loaded.



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# File 'lib/params_validator/validator.rb', line 20

def methods_loaded
  @methods_loaded
end

Class Method Details

.check_param(valid_param, param) ⇒ Object

This method validates if the specific method is valid

Parameters:

  • valid_param —

    object containing the param ruleset

  • param —

    param specified by the user in the method call



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# File 'lib/params_validator/validator.rb', line 125

def check_param(valid_param, param)
  if valid_param.optional? and param.nil? # argument optional and not present -> continue
    return nil
  end

  if param.nil? # argument mandatory and not present
    return ERROR_MESSAGE_NULL % valid_param.name
  else
    # check argument type is valid
    unless param.is_a?(valid_param.klass)
      return ERROR_MESSAGE_TYPE % [valid_param.name, param.class]
    end

    # check argument satisfies ruleset (if present)
    unless valid_param.rule.nil?
      !valid_param.rule.call(param) and return ERROR_MESSAGE_BLOCK % valid_param.name
    end
  end
  nil
end

.validate_ruleset(valid_params, params) ⇒ Object

This method validates a params hash against a specific ruleset

Parameters:

  • valid_params —

    ruleset

  • params 


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# File 'lib/params_validator/validator.rb', line 83

def validate_ruleset(valid_params, params)
  errors = []

  # if params.nil? but the ruleset defines all the parameters as optional
  # this method should return true
  if !valid_params.nil? and params.nil?
    valid_params.each{|param|
      !param.optional? and (
        errors.push "Nil parameters when #{valid_params.length} expected"
        raise ArgumentError, errors
      )
    }
    return true
  end

  # if just one param -> include as array with length 1
  if valid_params.instance_of?(Array) && valid_params.length == 1 && params.instance_of?(String)
    params = {valid_params[0].name.to_sym => params}
  end

  # Validate the params
  valid_params.each{|key|
    # get param
    param = params[key.name.to_sym]
    check_result = Validator.check_param(key, param)
    unless check_result.nil?
      errors.push check_result
    end
  }
  unless errors.empty?
    raise ArgumentError, errors
  end
  # no exception -> successfully validated
  true

end

Instance Method Details

#has_method_rule?(method_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/params_validator/validator.rb', line 48

def has_method_rule?(method_name)
  !method_name.is_a?(Symbol) and method_name = method_name.to_sym
  @methods_loaded.has_key?(method_name)
end

#load_rules(rules) ⇒ Object

This method loads new rules in memory validatation_rule method do

param1 (type) &block
param2 (type) &block

end



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# File 'lib/params_validator/validator.rb', line 33

def load_rules(rules)
  self.instance_eval(rules)
end

#validate_params(method_name, params) ⇒ Object

This method validates if the specific call to method_name is valid

Parameters:

  • method_name —

    fully qualified method name (Module::Class::method)

  • params 


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# File 'lib/params_validator/validator.rb', line 58

def validate_params(method_name, params)
  errors = []

  # fetch method rulesets
  method = @methods_loaded[method_name.to_sym]
  
  if method.nil?
    # TODO enable devel or prod mode to raise or not an exception
    errors.push "Unable to validate method #{method_name} with (#{@methods_loaded.keys.length}) keys #{@methods_loaded.keys}"
    raise ArgumentError, errors
  end

  # fetch all params (optional and mandatory)
  check_params = method.parameters

  self.class.validate_ruleset(check_params, params)

end

#validation_rule(method_name, &block) ⇒ Object

This method is part of the DSL and defines a new validator rule

Parameters:

  • method_name —

    fully qualified method name (Module::Class::method)

  • block —

    the block to be executed



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# File 'lib/params_validator/validator.rb', line 42

def validation_rule(method_name, &block)
  method = MethodValidation.new(method_name)
  block_given? and method.block &block
  @methods_loaded[:"#{method_name}"] = method
end