Module: Miasma::Utils::Lazy::ClassMethods

Defined in:
lib/miasma/utils/lazy.rb

Overview

Class methods for laziness

Instance Method Summary collapse

Instance Method Details

#attribute(name, type, options = {}) ⇒ nil

Add new attributes to class

Parameters:

  • name (String)
  • type (Class, Array<Class>)
  • options (Hash) (defaults to: {})

Options Hash (options):

  • :required (TrueClass, FalseClass) —

    must be provided on initialization

  • :default (Object, Proc) —

    default value

  • :coerce (Proc)

Returns:

  • (nil) 


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# File 'lib/miasma/utils/lazy.rb', line 110

def attribute(name, type, options={})
  name = name.to_sym
  options = options.to_smash
  attributes[name] = Smash.new(:type => type).merge(options)
  coerce = attributes[name][:coerce]
  valid_types = [attributes[name][:type], NilClass].flatten.compact
  allowed_values = attributes[name][:allowed]
  multiple_values = attributes[name][:multiple]
  depends_on = attributes[name][:depends]
  define_method(name) do
    send(depends_on) if depends_on
    self.class.on_missing(self) unless data.has_key?(name) || dirty.has_key?(name)
    dirty[name] || data[name]
  end
  define_method("#{name}=") do |val|
    values = multiple_values && val.is_a?(Array) ? val : [val]
    values.map! do |item|
      valid_type = valid_types.detect do |klass|
        item.is_a?(klass)
      end
      if(coerce && !valid_type)
        item = coerce.arity == 2 ? coerce.call(item, self) : coerce.call(item)
      end
      valid_type = valid_types.detect do |klass|
        item.is_a?(klass)
      end
      unless(valid_type)
        raise TypeError.new("Invalid type for `#{name}` (#{item} <#{item.class}>). Valid - #{valid_types.map(&:to_s).join(',')}")
      end
      if(allowed_values)
        unless(allowed_values.include?(item))
          raise ArgumentError.new("Invalid value provided for `#{name}` (#{item.inspect}). Allowed - #{allowed_values.map(&:inspect).join(', ')}")
        end
      end
      item
    end
    if(!multiple_values && !val.is_a?(Array))
      dirty[name] = values.first
    else
      dirty[name] = values
    end
  end
  define_method("#{name}?") do
    send(depends_on) if depends_on
    self.class.on_missing(self) unless data.has_key?(name)
    !!data[name]
  end
  nil
end

#attributes(*args) ⇒ Array<Hash>

Return attributes

Parameters:

  • args (Symbol) —

    :required or :optional

Returns:



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# File 'lib/miasma/utils/lazy.rb', line 164

def attributes(*args)
  @attributes ||= Smash.new
  if(args.include?(:required))
    Smash[@attributes.find_all{|k,v| v[:required]}]
  elsif(args.include?(:optional))
    Smash[@attributes.find_all{|k,v| !v[:required]}]
  else
    @attributes
  end
end

#on_missing(param = nil) ⇒ Symbol

Instance method to call on missing attribute or object to call method on if set

Parameters:

  • param (Symbol, Object) (defaults to: nil)

Returns:

  • (Symbol) 


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# File 'lib/miasma/utils/lazy.rb', line 180

def on_missing(param=nil)
  if(param)
    if(param.is_a?(Symbol))
      @missing_method = param
    else
      if(@missing_method && !@calling_on_missing)
        @calling_on_missing = true
        begin
          param.send(@missing_method)
        ensure
          @calling_on_missing = false
        end
      end
      @missing_method
    end
  else
    @missing_method
  end
end

#set_attributes(attrs) ⇒ TrueClass

TODO:

need deep dup here

Directly set attribute hash

Parameters:

Returns:

  • (TrueClass) 


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# File 'lib/miasma/utils/lazy.rb', line 205

def set_attributes(attrs)
  @attributes = attrs.to_smash
  true
end