Module: Parameters::ClassMethods

Defined in:
lib/parameters/class_methods.rb

Instance Method Summary collapse

Instance Method Details

#describe_param(name) ⇒ String

Returns the description of the class parameters with a given name.

Returns:

  • (String) —

    Description of the class parameter with the specified name.

Raises:

  • (ParamNotFound) —

    No class parameter with the specified name could be found.



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# File 'lib/parameters/class_methods.rb', line 226

def describe_param(name)
  get_param(name).description
end

#each_param {|param| ... } ⇒ Object

Iterates over the parameters of the class and it's ancestors.

Yields:

  • (param) —

    The block that will be passed each class parameter.



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# File 'lib/parameters/class_methods.rb', line 205

def each_param(&block)
  ancestors.reverse_each do |ancestor|
    if ancestor.included_modules.include?(Parameters)
      ancestor.params.each_value(&block)
    end
  end

  return self
end

#get_param(name) ⇒ ClassParam

Searches for the class parameter with the matching name.

Parameters:

  • name (Symbol, String) —

    The class parameter name to search for.

Returns:

  • (ClassParam) —

    The class parameter with the matching name.

Raises:

  • (ParamNotFound) —

    No class parameter with the specified name could be found.



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# File 'lib/parameters/class_methods.rb', line 150

def get_param(name)
  name = name.to_sym

  ancestors.each do |ancestor|
    if ancestor.included_modules.include?(Parameters)
      if ancestor.params.has_key?(name)
        return ancestor.params[name]
      end
    end
  end

  raise(Parameters::ParamNotFound,"parameter #{name.to_s.dump} was not found in class #{self}")
end

#has_param?(name) ⇒ Boolean

Determines if a class parameter exists with the given name.

Returns:

  • (Boolean) —

    Specifies whether or not there is a class parameter with the specified name.



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# File 'lib/parameters/class_methods.rb', line 124

def has_param?(name)
  name = name.to_sym

  ancestors.each do |ancestor|
    if ancestor.included_modules.include?(Parameters)
      return true if ancestor.params.has_key?(name)
    end
  end

  return false
end

#param_value(name) ⇒ Object

Returns the value of the class parameters with a given name.

Returns:

  • (Object) —

    Value of the class parameter with the specified name.

Raises:

  • (ParamNotFound) —

    No class parameter with the specified name could be found.



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# File 'lib/parameters/class_methods.rb', line 241

def param_value(name)
  get_param(name).value
end

#parameter(name, options = {}) ⇒ Object

Adds a new parameters to the class.

Examples:

parameter 'var'
parameter 'var', :default => 3, :description => 'my variable'

Parameters:

  • name (Symbol, String) —

    The name of the new parameter.

  • options (Hash) (defaults to: {}) —

    Additional options.

Options Hash (options):

  • :type (Class, Array[Class]) —

    The type to enforce the parameter values to.

  • :default (Object, Proc) —

    The default value for the new parameter.

  • :description (String) —

    The description for the new parameter.



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# File 'lib/parameters/class_methods.rb', line 69

def parameter(name,options={})
  name = name.to_sym

  # define the reader class method for the parameter
  meta_def(name) do
    get_param(name).value
  end

  # define the writer class method for the parameter
  meta_def("#{name}=") do |value|
    get_param(name).value = value
  end

  # define the ? method, to determine if the parameter is set
  meta_def("#{name}?") do
    !!get_param(name).value
  end

  # define the reader instance methods for the parameter
  define_method(name) do
    get_param(name).value
  end

  # define the writter instance methods for the parameter
  define_method("#{name}=") do |value|
    get_param(name).value = value
  end

  # define the ? method, to determine if the parameter is set
  define_method("#{name}?") do
    !!get_param(name).value
  end

  # create the new parameter
  new_param = Parameters::ClassParam.new(
    name,
    options[:type],
    options[:description],
    options[:default]
  )

  # add the parameter to the class params list
  params[name] = new_param
  return new_param
end

#params ⇒ Hash

Returns Parameters for the class.

Returns:

  • (Hash) —

    Parameters for the class.



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# File 'lib/parameters/class_methods.rb', line 13

def params
  @parameters ||= {}
end

#params=(values) ⇒ Object

Sets the values of the class parameters.

Examples:

Test.params = {:x => 5, :y => 2}
# => {:x=>5, :y=>2}

Parameters:

  • values (Hash) —

    The names and new values to set the class params to.



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# File 'lib/parameters/class_methods.rb', line 29

def params=(values)
  values.each do |name,value|
    if has_param?(name)
      get_param(name).value = case value
                              when Parameters::ClassParam,
                                   Parameters::InstanceParam
                                value.value
                              else
                                value
                              end
    end
  end
end

#set_param(name, value) ⇒ Object

Sets a class parameter.

Parameters:

  • name (Symbol, String) —

    The name of the class parameter.

  • value (Object) —

    The new value for the class parameter.

Returns:

  • (Object) —

    The new value of the class parameter.

Raises:

  • (ParamNotfound) —

    No class parameter with the specified name could be found.

Since:

  • 0.3.0



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# File 'lib/parameters/class_methods.rb', line 183

def set_param(name,value)
  name = name.to_sym

  ancestors.each do |ancestor|
    if ancestor.included_modules.include?(Parameters)
      if ancestor.params.has_key?(name)
        return ancestor.params[name].set(value)
      end
    end
  end

  raise(Parameters::ParamNotFound,"parameter #{name.to_s.dump} was not found in class #{self}")
end