Module: CouchFoo::AttributeMethods

Defined in:
lib/couch_foo/attribute_methods.rb

Defined Under Namespace

Modules: ClassMethods

Constant Summary collapse

DEFAULT_SUFFIXES = 
%w(= ? _before_type_cast)
ATTRIBUTE_TYPES_CACHED_BY_DEFAULT = 
[Time, DateTime, Date]
JSON_DATETIME_FORMAT = 
"%Y/%m/%d %H:%M:%S +0000"

Class Method Summary collapse

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method_id, *args, &block) ⇒ Object

Allows access to the object attributes, which are held in the @attributes hash, as though they were first-class methods. So a Person class with a name attribute can use Person#name and Person#name= and never directly use the attributes hash – except for multiple assigns with CouchFoo#attributes=. A Milestone class can also ask Milestone#completed? to test that the completed attribute is not nil or 0.

It’s also possible to instantiate related objects, so a Client class belonging to the clients table with a master_id foreign key can instantiate master through Client#master.



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# File 'lib/couch_foo/attribute_methods.rb', line 165

def method_missing(method_id, *args, &block)
  method_name = method_id.to_s

  # Make sure methods are generated
  if !self.class.generated_methods?
    self.class.define_attribute_methods
    if self.class.generated_methods.include?(method_name)
      return self.send(method_id, *args, &block)
    end
  end

  # Unchangeable properties are called directly, not through generated methods
  if self.class.unchangeable_property_names.include?(method_id)
    send(method_id, *args, &block)
  elsif md = self.class.match_attribute_method?(method_name)
    attribute_name, method_type = md.pre_match, md.to_s
    if @attributes.include?(attribute_name)
      __send__("attribute#{method_type}", attribute_name, *args, &block)
    else
      super
    end
  elsif attributes.include?(method_name)
    read_attribute(method_name)
  else
    super
  end
end

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/couch_foo/attribute_methods.rb', line 7

def self.included(base)
  base.extend ClassMethods
  base.attribute_method_suffix(*DEFAULT_SUFFIXES)
  base.cattr_accessor :attribute_types_cached_by_default, :instance_writer => false
  base.attribute_types_cached_by_default = ATTRIBUTE_TYPES_CACHED_BY_DEFAULT
end

Instance Method Details

#query_attribute(attr_name) ⇒ Object 



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# File 'lib/couch_foo/attribute_methods.rb', line 211

def query_attribute(attr_name)
  unless value = read_attribute(attr_name)
    false
  else
    column_type = type_for_property(attr_name)
    if column_type.nil?
      if Numeric === value || value !~ /[^0-9]/
        !value.to_i.zero?
      else
        !value.blank?
      end
    elsif column_type == Integer || column_type == Float
      !value.zero?
    else
      !value.blank?
    end
  end
end

#read_attribute(attr_name) ⇒ Object

Returns the value of the attribute identified by attr_name after it has been typecast (for example, “2004-12-12” in a data type is cast to a date object, like Date.new(2004, 12, 12)).



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# File 'lib/couch_foo/attribute_methods.rb', line 195

def read_attribute(attr_name)
  convert_to_type(@attributes[attr_name.to_s], type_for_property(attr_name.to_sym))
end

#read_attribute_before_type_cast(attr_name) ⇒ Object 



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# File 'lib/couch_foo/attribute_methods.rb', line 199

def read_attribute_before_type_cast(attr_name)
  @attributes[attr_name]
end

#respond_to?(method, include_priv = false) ⇒ Boolean

Returns:



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# File 'lib/couch_foo/attribute_methods.rb', line 234

def respond_to?(method, include_priv = false)
  method_name = method.to_s
  if super
    return true
  elsif !self.class.generated_methods?
    self.class.define_attribute_methods
    if self.class.generated_methods.include?(method_name)
      return true
    end
  end
    
  if @attributes.nil?
    return super
  elsif @attributes.include?(method_name)
    return true
  elsif md = self.class.match_attribute_method?(method_name)
    return true if @attributes.include?(md.pre_match)
  end
  super
end

#respond_to_without_attributes? ⇒ Object

A Person object with a name attribute can ask person.respond_to?("name"), person.respond_to?("name="), and person.respond_to?("name?") which will all return true.



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# File 'lib/couch_foo/attribute_methods.rb', line 233

alias :respond_to_without_attributes? :respond_to?

#write_attribute(attr_name, value) ⇒ Object

Updates the attribute identified by attr_name with the specified value. Empty strings for fixnum and float types are turned into nil.



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# File 'lib/couch_foo/attribute_methods.rb', line 205

def write_attribute(attr_name, value)
  attr_name = attr_name.to_s
  @attributes_cache.delete(attr_name)
  @attributes[attr_name] = convert_to_json(value, type_for_property(attr_name.to_sym))
end