aboutsummaryrefslogtreecommitdiffstats
path: root/activerecord/lib/active_record/attribute_assignment.rb
blob: abc2fa546a821cc79d1e6f147d31426a831e8071 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
require 'active_support/concern'

module ActiveRecord
  module AttributeAssignment
    extend ActiveSupport::Concern
    include ActiveModel::MassAssignmentSecurity

    module ClassMethods
      private

      # The primary key and inheritance column can never be set by mass-assignment for security reasons.
      def attributes_protected_by_default
        default = [ primary_key, inheritance_column ]
        default << 'id' unless primary_key.eql? 'id'
        default
      end
    end

    # Allows you to set all the attributes at once by passing in a hash with keys
    # matching the attribute names (which again matches the column names).
    #
    # If any attributes are protected by either +attr_protected+ or
    # +attr_accessible+ then only settable attributes will be assigned.
    #
    #   class User < ActiveRecord::Base
    #     attr_protected :is_admin
    #   end
    #
    #   user = User.new
    #   user.attributes = { :username => 'Phusion', :is_admin => true }
    #   user.username   # => "Phusion"
    #   user.is_admin?  # => false
    def attributes=(new_attributes)
      return unless new_attributes.is_a?(Hash)

      assign_attributes(new_attributes)
    end

    # Allows you to set all the attributes for a particular mass-assignment
    # security role by passing in a hash of attributes with keys matching
    # the attribute names (which again matches the column names) and the role
    # name using the :as option.
    #
    # To bypass mass-assignment security you can use the :without_protection => true
    # option.
    #
    #   class User < ActiveRecord::Base
    #     attr_accessible :name
    #     attr_accessible :name, :is_admin, :as => :admin
    #   end
    #
    #   user = User.new
    #   user.assign_attributes({ :name => 'Josh', :is_admin => true })
    #   user.name       # => "Josh"
    #   user.is_admin?  # => false
    #
    #   user = User.new
    #   user.assign_attributes({ :name => 'Josh', :is_admin => true }, :as => :admin)
    #   user.name       # => "Josh"
    #   user.is_admin?  # => true
    #
    #   user = User.new
    #   user.assign_attributes({ :name => 'Josh', :is_admin => true }, :without_protection => true)
    #   user.name       # => "Josh"
    #   user.is_admin?  # => true
    def assign_attributes(new_attributes, options = {})
      return if new_attributes.blank?

      attributes = new_attributes.stringify_keys
      multi_parameter_attributes = []
      nested_parameter_attributes = []
      previous_options = @mass_assignment_options
      @mass_assignment_options = options

      unless options[:without_protection]
        attributes = sanitize_for_mass_assignment(attributes, mass_assignment_role)
      end

      attributes.each do |k, v|
        if k.include?("(")
          multi_parameter_attributes << [ k, v ]
        elsif respond_to?("#{k}=")
          if v.is_a?(Hash)
            nested_parameter_attributes << [ k, v ]
          else
            send("#{k}=", v)
          end
        else
          raise(UnknownAttributeError, "unknown attribute: #{k}")
        end
      end

      # assign any deferred nested attributes after the base attributes have been set
      nested_parameter_attributes.each do |k,v|
        send("#{k}=", v)
      end

      assign_multiparameter_attributes(multi_parameter_attributes)
    ensure
      @mass_assignment_options = previous_options
    end

    protected

    def mass_assignment_options
      @mass_assignment_options ||= {}
    end

    def mass_assignment_role
      mass_assignment_options[:as] || :default
    end

    private

    # Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done
    # by calling new on the column type or aggregation type (through composed_of) object with these parameters.
    # So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate
    # written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the
    # parentheses to have the parameters typecasted before they're used in the constructor. Use i for Fixnum,
    # f for Float, s for String, and a for Array. If all the values for a given attribute are empty, the
    # attribute will be set to nil.
    def assign_multiparameter_attributes(pairs)
      execute_callstack_for_multiparameter_attributes(
        extract_callstack_for_multiparameter_attributes(pairs)
      )
    end

    def instantiate_time_object(name, values)
      if self.class.send(:create_time_zone_conversion_attribute?, name, column_for_attribute(name))
        Time.zone.local(*values)
      else
        Time.time_with_datetime_fallback(self.class.default_timezone, *values)
      end
    end

    def execute_callstack_for_multiparameter_attributes(callstack)
      errors = []
      callstack.each do |name, values_with_empty_parameters|
        begin
          send(name + "=", read_value_from_parameter(name, values_with_empty_parameters))
        rescue => ex
          errors << AttributeAssignmentError.new("error on assignment #{values_with_empty_parameters.values.inspect} to #{name}", ex, name)
        end
      end
      unless errors.empty?
        raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes"
      end
    end

    def read_value_from_parameter(name, values_hash_from_param)
      klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
      if values_hash_from_param.values.all?{|v|v.nil?}
        nil
      elsif klass == Time
        read_time_parameter_value(name, values_hash_from_param)
      elsif klass == Date
        read_date_parameter_value(name, values_hash_from_param)
      else
        read_other_parameter_value(klass, name, values_hash_from_param)
      end
    end

    def read_time_parameter_value(name, values_hash_from_param)
      # If Date bits were not provided, error
      raise "Missing Parameter" if [1,2,3].any?{|position| !values_hash_from_param.has_key?(position)}
      max_position = extract_max_param_for_multiparameter_attributes(values_hash_from_param, 6)
      # If Date bits were provided but blank, then return nil
      return nil if (1..3).any? {|position| values_hash_from_param[position].blank?}

      set_values = (1..max_position).collect{|position| values_hash_from_param[position] }
      # If Time bits are not there, then default to 0
      (3..5).each {|i| set_values[i] = set_values[i].blank? ? 0 : set_values[i]}
      instantiate_time_object(name, set_values)
    end

    def read_date_parameter_value(name, values_hash_from_param)
      return nil if (1..3).any? {|position| values_hash_from_param[position].blank?}
      set_values = [values_hash_from_param[1], values_hash_from_param[2], values_hash_from_param[3]]
      begin
        Date.new(*set_values)
      rescue ArgumentError # if Date.new raises an exception on an invalid date
        instantiate_time_object(name, set_values).to_date # we instantiate Time object and convert it back to a date thus using Time's logic in handling invalid dates
      end
    end

    def read_other_parameter_value(klass, name, values_hash_from_param)
      max_position = extract_max_param_for_multiparameter_attributes(values_hash_from_param)
      values = (1..max_position).collect do |position|
        raise "Missing Parameter" if !values_hash_from_param.has_key?(position)
        values_hash_from_param[position]
      end
      klass.new(*values)
    end

    def extract_max_param_for_multiparameter_attributes(values_hash_from_param, upper_cap = 100)
      [values_hash_from_param.keys.max,upper_cap].min
    end

    def extract_callstack_for_multiparameter_attributes(pairs)
      attributes = { }

      pairs.each do |pair|
        multiparameter_name, value = pair
        attribute_name = multiparameter_name.split("(").first
        attributes[attribute_name] = {} unless attributes.include?(attribute_name)

        parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
        attributes[attribute_name][find_parameter_position(multiparameter_name)] ||= parameter_value
      end

      attributes
    end

    def type_cast_attribute_value(multiparameter_name, value)
      multiparameter_name =~ /\([0-9]*([if])\)/ ? value.send("to_" + $1) : value
    end

    def find_parameter_position(multiparameter_name)
      multiparameter_name.scan(/\(([0-9]*).*\)/).first.first.to_i
    end

  end
end