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, Client < Company to do something like render :partial => @client.becomes(Company) 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.
# File lib/active_record/persistence.rb, line 158 158: def becomes(klass) 159: became = klass.new 160: became.instance_variable_set("@attributes", @attributes) 161: became.instance_variable_set("@attributes_cache", @attributes_cache) 162: became.instance_variable_set("@new_record", new_record?) 163: became.instance_variable_set("@destroyed", destroyed?) 164: became.instance_variable_set("@errors", errors) 165: became.send("#{klass.inheritance_column}=", klass.name) unless self.class.descends_from_active_record? 166: became 167: 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.
# File lib/active_record/persistence.rb, line 252 252: def decrement(attribute, by = 1) 253: self[attribute] ||= 0 254: self[attribute] -= by 255: self 256: 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.
# File lib/active_record/persistence.rb, line 262 262: def decrement!(attribute, by = 1) 263: decrement(attribute, by).update_attribute(attribute, self[attribute]) 264: 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 :dependent association options, use #.
# File lib/active_record/persistence.rb, line 117 117: def delete 118: if persisted? 119: self.class.delete(id) 120: IdentityMap.remove(self) if IdentityMap.enabled? 121: end 122: @destroyed = true 123: freeze 124: 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).
# File lib/active_record/persistence.rb, line 128 128: def destroy 129: destroy_associations 130: 131: if persisted? 132: IdentityMap.remove(self) if IdentityMap.enabled? 133: pk = self.class.primary_key 134: column = self.class.columns_hash[pk] 135: substitute = connection.substitute_at(column, 0) 136: 137: relation = self.class.unscoped.where( 138: self.class.arel_table[pk].eq(substitute)) 139: 140: relation.bind_values = [[column, id]] 141: relation.delete_all 142: end 143: 144: @destroyed = true 145: freeze 146: end
Returns true if this object has been destroyed, otherwise returns false.
# File lib/active_record/persistence.rb, line 58 58: def destroyed? 59: @destroyed 60: 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.
# File lib/active_record/persistence.rb, line 235 235: def increment(attribute, by = 1) 236: self[attribute] ||= 0 237: self[attribute] += by 238: self 239: 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.
# File lib/active_record/persistence.rb, line 245 245: def increment!(attribute, by = 1) 246: increment(attribute, by).update_attribute(attribute, self[attribute]) 247: end
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.
# File lib/active_record/persistence.rb, line 53 53: def new_record? 54: @new_record 55: end
Returns if the record is persisted, i.e. it’s not a new record and it was not destroyed.
# File lib/active_record/persistence.rb, line 64 64: def persisted? 65: !(new_record? || destroyed?) 66: 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.
# File lib/active_record/persistence.rb, line 287 287: def reload(options = nil) 288: clear_aggregation_cache 289: clear_association_cache 290: 291: IdentityMap.without do 292: fresh_object = self.class.unscoped { self.class.find(self.id, options) } 293: @attributes.update(fresh_object.instance_variable_get('@attributes')) 294: end 295: 296: @attributes_cache = {} 297: self 298: end
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 before_* callbacks return false the action is cancelled and save returns false. See ActiveRecord::Callbacks for further details.
# File lib/active_record/persistence.rb, line 82 82: def save(*) 83: begin 84: create_or_update 85: rescue ActiveRecord::RecordInvalid 86: false 87: end 88: end
Saves the model.
If the model is new a record gets created in the database, otherwise the existing record gets updated.
With save! 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 save!. If any of the before_* callbacks return false the action is cancelled and save! raises ActiveRecord::RecordNotSaved. See ActiveRecord::Callbacks for further details.
# File lib/active_record/persistence.rb, line 103 103: def save!(*) 104: create_or_update || raise(RecordNotSaved) 105: end
Assigns to attribute the boolean opposite of attribute?. So if the predicate returns true the attribute will become false. This method toggles directly the underlying value without calling any setter. Returns self.
# File lib/active_record/persistence.rb, line 270 270: def toggle(attribute) 271: self[attribute] = !send("#{attribute}?") 272: self 273: 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.
# File lib/active_record/persistence.rb, line 279 279: def toggle!(attribute) 280: toggle(attribute).update_attribute(attribute, self[attribute]) 281: 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
# File lib/active_record/persistence.rb, line 320 320: def touch(name = nil) 321: attributes = timestamp_attributes_for_update_in_model 322: attributes << name if name 323: 324: unless attributes.empty? 325: current_time = current_time_from_proper_timezone 326: changes = {} 327: 328: attributes.each do |column| 329: changes[column.to_s] = write_attribute(column.to_s, current_time) 330: end 331: 332: changes[self.class.locking_column] = increment_lock if locking_enabled? 333: 334: @changed_attributes.except!(*changes.keys) 335: primary_key = self.class.primary_key 336: self.class.unscoped.update_all(changes, { primary_key => self[primary_key] }) == 1 337: end 338: 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.
# File lib/active_record/persistence.rb, line 177 177: def update_attribute(name, value) 178: name = name.to_s 179: raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name) 180: send("#{name}=", value) 181: save(:validate => false) 182: 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.
When updating model attributes, mass-assignment security protection is respected. If no :as option is supplied then the :default role will be used. If you want to bypass the protection given by attr_protected and attr_accessible then you can do so using the :without_protection option.
# File lib/active_record/persistence.rb, line 212 212: def update_attributes(attributes, options = {}) 213: # The following transaction covers any possible database side-effects of the 214: # attributes assignment. For example, setting the IDs of a child collection. 215: with_transaction_returning_status do 216: self.assign_attributes(attributes, options) 217: save 218: end 219: end
Updates its receiver just like update_attributes but calls save! instead of save, so an exception is raised if the record is invalid.
# File lib/active_record/persistence.rb, line 223 223: def update_attributes!(attributes, options = {}) 224: # The following transaction covers any possible database side-effects of the 225: # attributes assignment. For example, setting the IDs of a child collection. 226: with_transaction_returning_status do 227: self.assign_attributes(attributes, options) 228: save! 229: end 230: end
Updates a single attribute of an object, without calling save.
Validation is skipped.
Callbacks are skipped.
updated_at/updated_on column is not updated if that column is available.
Raises an ActiveRecordError when called on new objects, or when the name attribute is marked as readonly.
# File lib/active_record/persistence.rb, line 192 192: def update_column(name, value) 193: name = name.to_s 194: raise ActiveRecordError, "#{name} is marked as readonly" if self.class.readonly_attributes.include?(name) 195: raise ActiveRecordError, "can not update on a new record object" unless persisted? 196: 197: updated_count = self.class.update_all({ name => value }, self.class.primary_key => id) 198: 199: raw_write_attribute(name, value) 200: 201: updated_count == 1 202: end
Creates a record with values matching those of the instance attributes and returns its id.
# File lib/active_record/persistence.rb, line 364 364: def create 365: attributes_values = arel_attributes_values(!id.nil?) 366: 367: new_id = self.class.unscoped.insert attributes_values 368: 369: self.id ||= new_id if self.class.primary_key 370: 371: IdentityMap.add(self) if IdentityMap.enabled? 372: @new_record = false 373: id 374: end
# File lib/active_record/persistence.rb, line 346 346: def create_or_update 347: raise ReadOnlyRecord if readonly? 348: result = new_record? ? create : update 349: result != false 350: end
A hook to be overridden by association modules.
# File lib/active_record/persistence.rb, line 343 343: def destroy_associations 344: end
Updates the associated record with values matching those of the instance attributes. Returns the number of affected rows.
# File lib/active_record/persistence.rb, line 354 354: def update(attribute_names = @attributes.keys) 355: attributes_with_values = arel_attributes_values(false, false, attribute_names) 356: return 0 if attributes_with_values.empty? 357: klass = self.class 358: stmt = klass.unscoped.where(klass.arel_table[klass.primary_key].eq(id)).arel.compile_update(attributes_with_values) 359: klass.connection.update stmt 360: end
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