Skip to content
This repository
tag: v3.0.14
Fetching contributors…

Cannot retrieve contributors at this time

file 301 lines (269 sloc) 11.666 kb
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301
module ActiveRecord
  # = Active Record Persistence
  module Persistence
    # Returns true if this object hasn't been saved yet -- that is, a record
    # for the object doesn't exist in the data store yet; otherwise, returns false.
    def new_record?
      @new_record
    end

    # Returns true if this object has been destroyed, otherwise returns false.
    def destroyed?
      @destroyed
    end

    # Returns if the record is persisted, i.e. it's not a new record and it was
    # not destroyed.
    def persisted?
      !(new_record? || destroyed?)
    end

    # :call-seq:
    # save(options)
    #
    # Saves the model.
    #
    # If the model is new a record gets created in the database, otherwise
    # the existing record gets updated.
    #
    # By default, save always run validations. If any of them fail the action
    # is cancelled and +save+ returns +false+. However, if you supply
    # :validate => false, validations are bypassed altogether. See
    # ActiveRecord::Validations for more information.
    #
    # There's a series of callbacks associated with +save+. If any of the
    # <tt>before_*</tt> callbacks return +false+ the action is cancelled and
    # +save+ returns +false+. See ActiveRecord::Callbacks for further
    # details.
    def save(*)
      begin
        create_or_update
      rescue ActiveRecord::RecordInvalid
        false
      end
    end

    # Saves the model.
    #
    # If the model is new a record gets created in the database, otherwise
    # the existing record gets updated.
    #
    # With <tt>save!</tt> validations always run. If any of them fail
    # ActiveRecord::RecordInvalid gets raised. See ActiveRecord::Validations
    # for more information.
    #
    # There's a series of callbacks associated with <tt>save!</tt>. If any of
    # the <tt>before_*</tt> callbacks return +false+ the action is cancelled
    # and <tt>save!</tt> raises ActiveRecord::RecordNotSaved. See
    # ActiveRecord::Callbacks for further details.
    def save!(*)
      create_or_update || raise(RecordNotSaved)
    end

    # Deletes the record in the database and freezes this instance to
    # reflect that no changes should be made (since they can't be
    # persisted). Returns the frozen instance.
    #
    # The row is simply removed with an SQL +DELETE+ statement on the
    # record's primary key, and no callbacks are executed.
    #
    # To enforce the object's +before_destroy+ and +after_destroy+
    # callbacks, Observer methods, or any <tt>:dependent</tt> association
    # options, use <tt>#destroy</tt>.
    def delete
      self.class.delete(id) if persisted?
      @destroyed = true
      freeze
    end

    # Deletes the record in the database and freezes this instance to reflect
    # that no changes should be made (since they can't be persisted).
    def destroy
      destroy_associations

      if persisted?
        self.class.unscoped.where(self.class.arel_table[self.class.primary_key].eq(id)).delete_all
      end

      @destroyed = true
      freeze
    end

    # Returns an instance of the specified +klass+ with the attributes of the
    # current record. This is mostly useful in relation to single-table
    # inheritance structures where you want a subclass to appear as the
    # superclass. This can be used along with record identification in
    # Action Pack to allow, say, <tt>Client < Company</tt> to do something
    # like render <tt>:partial => @client.becomes(Company)</tt> to render that
    # instance using the companies/company partial instead of clients/client.
    #
    # Note: The new instance will share a link to the same attributes as the original class.
    # So any change to the attributes in either instance will affect the other.
    def becomes(klass)
      became = klass.new
      became.instance_variable_set("@attributes", @attributes)
      became.instance_variable_set("@attributes_cache", @attributes_cache)
      became.instance_variable_set("@new_record", new_record?)
      became.instance_variable_set("@destroyed", destroyed?)
      became
    end

    # Updates a single attribute and saves the record.
    # This is especially useful for boolean flags on existing records. Also note that
    #
    # * Validation is skipped.
    # * Callbacks are invoked.
    # * updated_at/updated_on column is updated if that column is available.
    # * Updates all the attributes that are dirty in this object.
    #
    def update_attribute(name, value)
      name = name.to_s
      raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name)
      send("#{name}=", value)
      save(:validate => false)
    end

    # Updates the attributes of the model from the passed-in hash and saves the
    # record, all wrapped in a transaction. If the object is invalid, the saving
    # will fail and false will be returned.
    def update_attributes(attributes)
      # The following transaction covers any possible database side-effects of the
      # attributes assignment. For example, setting the IDs of a child collection.
      with_transaction_returning_status do
        self.attributes = attributes
        save
      end
    end

    # Updates its receiver just like +update_attributes+ but calls <tt>save!</tt> instead
    # of +save+, so an exception is raised if the record is invalid.
    def update_attributes!(attributes)
      # The following transaction covers any possible database side-effects of the
      # attributes assignment. For example, setting the IDs of a child collection.
      with_transaction_returning_status do
        self.attributes = attributes
        save!
      end
    end

    # Initializes +attribute+ to zero if +nil+ and adds the value passed as +by+ (default is 1).
    # The increment is performed directly on the underlying attribute, no setter is invoked.
    # Only makes sense for number-based attributes. Returns +self+.
    def increment(attribute, by = 1)
      self[attribute] ||= 0
      self[attribute] += by
      self
    end

    # Wrapper around +increment+ that saves the record. This method differs from
    # its non-bang version in that it passes through the attribute setter.
    # Saving is not subjected to validation checks. Returns +true+ if the
    # record could be saved.
    def increment!(attribute, by = 1)
      increment(attribute, by).update_attribute(attribute, self[attribute])
    end

    # Initializes +attribute+ to zero if +nil+ and subtracts the value passed as +by+ (default is 1).
    # The decrement is performed directly on the underlying attribute, no setter is invoked.
    # Only makes sense for number-based attributes. Returns +self+.
    def decrement(attribute, by = 1)
      self[attribute] ||= 0
      self[attribute] -= by
      self
    end

    # Wrapper around +decrement+ that saves the record. This method differs from
    # its non-bang version in that it passes through the attribute setter.
    # Saving is not subjected to validation checks. Returns +true+ if the
    # record could be saved.
    def decrement!(attribute, by = 1)
      decrement(attribute, by).update_attribute(attribute, self[attribute])
    end

    # Assigns to +attribute+ the boolean opposite of <tt>attribute?</tt>. So
    # if the predicate returns +true+ the attribute will become +false+. This
    # method toggles directly the underlying value without calling any setter.
    # Returns +self+.
    def toggle(attribute)
      self[attribute] = !send("#{attribute}?")
      self
    end

    # Wrapper around +toggle+ that saves the record. This method differs from
    # its non-bang version in that it passes through the attribute setter.
    # Saving is not subjected to validation checks. Returns +true+ if the
    # record could be saved.
    def toggle!(attribute)
      toggle(attribute).update_attribute(attribute, self[attribute])
    end

    # Reloads the attributes of this object from the database.
    # The optional options argument is passed to find when reloading so you
    # may do e.g. record.reload(:lock => true) to reload the same record with
    # an exclusive row lock.
    def reload(options = nil)
      clear_aggregation_cache
      clear_association_cache
      @attributes.update(self.class.unscoped { self.class.find(self.id, options) }.instance_variable_get('@attributes'))
      @attributes_cache = {}
      self
    end

    # Saves the record with the updated_at/on attributes set to the current time.
    # Please note that no validation is performed and no callbacks are executed.
    # If an attribute name is passed, that attribute is updated along with
    # updated_at/on attributes.
    #
    # product.touch # updates updated_at/on
    # product.touch(:designed_at) # updates the designed_at attribute and updated_at/on
    #
    # If used along with +belongs_to+ then +touch+ will invoke +touch+ method on associated object.
    #
    # class Brake < ActiveRecord::Base
    # belongs_to :car, :touch => true
    # end
    #
    # class Car < ActiveRecord::Base
    # belongs_to :corporation, :touch => true
    # end
    #
    # # triggers @brake.car.touch and @brake.car.corporation.touch
    # @brake.touch
    def touch(name = nil)
      attributes = timestamp_attributes_for_update_in_model
      attributes << name if name
      unless attributes.empty?
        current_time = current_time_from_proper_timezone
        changes = {}

        attributes.each do |column|
          changes[column.to_s] = write_attribute(column.to_s, current_time)
        end

        @changed_attributes.except!(*changes.keys)
        primary_key = self.class.primary_key
        self.class.unscoped.update_all(changes, { primary_key => self[primary_key] }) == 1
      end
    end

  private

    # A hook to be overriden by association modules.
    def destroy_associations
    end

    def create_or_update
      raise ReadOnlyRecord if readonly?
      result = new_record? ? create : update
      result != false
    end

    # Updates the associated record with values matching those of the instance attributes.
    # Returns the number of affected rows.
    def update(attribute_names = @attributes.keys)
      attributes_with_values = arel_attributes_values(false, false, attribute_names)
      return 0 if attributes_with_values.empty?
      self.class.unscoped.where(self.class.arel_table[self.class.primary_key].eq(id)).arel.update(attributes_with_values)
    end

    # Creates a record with values matching those of the instance attributes
    # and returns its id.
    def create
      if self.id.nil? && connection.prefetch_primary_key?(self.class.table_name)
        self.id = connection.next_sequence_value(self.class.sequence_name)
      end

      attributes_values = arel_attributes_values

      new_id = if attributes_values.empty?
        self.class.unscoped.insert connection.empty_insert_statement_value
      else
        self.class.unscoped.insert attributes_values
      end

      self.id ||= new_id

      @new_record = false
      id
    end

    # Initializes the attributes array with keys matching the columns from the linked table and
    # the values matching the corresponding default value of that column, so
    # that a new instance, or one populated from a passed-in Hash, still has all the attributes
    # that instances loaded from the database would.
    def attributes_from_column_definition
      self.class.columns.inject({}) do |attributes, column|
        attributes[column.name] = column.default unless column.name == self.class.primary_key
        attributes
      end
    end
  end
end
Something went wrong with that request. Please try again.