Module: ActiveRecord::AttributeMethods

Extended by:
ActiveSupport::Autoload, ActiveSupport::Concern
Includes:
ActiveModel::AttributeMethods
Included in:
Base
Defined in:
activerecord/lib/active_record/attribute_methods.rb,
activerecord/lib/active_record.rb,
activerecord/lib/active_record/attribute_methods/read.rb,
activerecord/lib/active_record/attribute_methods/query.rb,
activerecord/lib/active_record/attribute_methods/dirty.rb,
activerecord/lib/active_record/attribute_methods/write.rb,
activerecord/lib/active_record/attribute_methods/primary_key.rb,
activerecord/lib/active_record/attribute_methods/serialization.rb,
activerecord/lib/active_record/attribute_methods/before_type_cast.rb,
activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb,
activerecord/lib/active_record/attribute_methods/deprecated_underscore_read.rb

Overview

Active Record Attribute Methods

Defined Under Namespace

Modules: BeforeTypeCast, ClassMethods, DeprecatedUnderscoreRead, Dirty, PrimaryKey, Query, Read, Serialization, TimeZoneConversion, Write

Constant Summary

Constants included from ActiveModel::AttributeMethods

ActiveModel::AttributeMethods::CALL_COMPILABLE_REGEXP, ActiveModel::AttributeMethods::NAME_COMPILABLE_REGEXP

Instance Method Summary collapse

Methods included from ActiveSupport::Concern

append_features, extended, included

Methods included from ActiveSupport::Autoload

autoload, autoload_at, autoload_under, autoloads, eager_autoload, eager_autoload!

Methods included from ActiveModel::AttributeMethods

#respond_to_without_attributes?

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

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

If we haven't generated any methods yet, generate them, then see if we've created the method we're looking for.


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 139

def method_missing(method, *args, &block)
  unless self.class.attribute_methods_generated?
    self.class.define_attribute_methods

    if respond_to_without_attributes?(method)
      send(method, *args, &block)
    else
      super
    end
  else
    super
  end
end

Instance Method Details

#attribute_for_inspect(attr_name) ⇒ Object

Returns an #inspect-like string for the value of the attribute attr_name. String attributes are truncated upto 50 characters, and Date and Time attributes are returned in the :db format. Other attributes return the value of #inspect without modification.

person = Person.create!(:name => "David Heinemeier Hansson " * 3)

person.attribute_for_inspect(:name)
# => '"David Heinemeier Hansson David Heinemeier Hansson D..."'

person.attribute_for_inspect(:created_at)
# => '"2009-01-12 04:48:57"'

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# File 'activerecord/lib/active_record/attribute_methods.rb', line 202

def attribute_for_inspect(attr_name)
  value = read_attribute(attr_name)

  if value.is_a?(String) && value.length > 50
    "#{value[0..50]}...".inspect
  elsif value.is_a?(Date) || value.is_a?(Time)
    %("#{value.to_s(:db)}")
  else
    value.inspect
  end
end

#attribute_missing(match, *args, &block) ⇒ Object


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 153

def attribute_missing(match, *args, &block)
  if self.class.columns_hash[match.attr_name]
    ActiveSupport::Deprecation.warn(
      "The method `#{match.method_name}', matching the attribute `#{match.attr_name}' has " \
      "dispatched through method_missing. This shouldn't happen, because `#{match.attr_name}' " \
      "is a column of the table. If this error has happened through normal usage of Active " \
      "Record (rather than through your own code or external libraries), please report it as " \
      "a bug."
    )
  end

  super
end

#attribute_namesObject

Returns an array of names for the attributes available on this object.


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 178

def attribute_names
  @attributes.keys
end

#attribute_present?(attribute) ⇒ Boolean

Returns true if the specified attribute has been set by the user or by a database load and is neither nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings).


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 216

def attribute_present?(attribute)
  value = read_attribute(attribute)
  !value.nil? && !(value.respond_to?(:empty?) && value.empty?)
end

#attributesObject

Returns a hash of all the attributes with their names as keys and the values of the attributes as values.


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 183

def attributes
  attrs = {}
  attribute_names.each { |name| attrs[name] = read_attribute(name) }
  attrs
end

#column_for_attribute(name) ⇒ Object

Returns the column object for the named attribute.


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 222

def column_for_attribute(name)
  self.class.columns_hash[name.to_s]
end

#has_attribute?(attr_name) ⇒ Boolean

Returns true if the given attribute is in the attributes hash


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 173

def has_attribute?(attr_name)
  @attributes.has_key?(attr_name.to_s)
end

#respond_to?(name, include_private = false) ⇒ Boolean


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# File 'activerecord/lib/active_record/attribute_methods.rb', line 167

def respond_to?(name, include_private = false)
  self.class.define_attribute_methods unless self.class.attribute_methods_generated?
  super
end