Class: Lafcadio::LinkField

Inherits:
ObjectField show all
Defined in:
lib/lafcadio/objectField/LinkField.rb

Overview

A LinkField is used to link from one domain class to another.

Direct Known Subclasses

SubsetLinkField

Instance Attribute Summary collapse

Attributes inherited from ObjectField

#dbFieldName, #default, #defaultFieldName, #hideDisplay, #hideLabel, #name, #notNull, #notUniqueMsg, #objectType, #unique, #writeOnce

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ObjectField

#<=>, #bind_write?, #dbWillAutomaticallyWrite, #db_table_and_field_name, #englishName, #firstTime, instantiateFromXml, #nameForSQL, #nullErrorMsg, #prevValue, #processBeforeVerify, valueType, #verifyUniqueness

Constructor Details

#initialize(objectType, linkedType, name = nil, englishName = nil, deleteCascade = false) ⇒ LinkField

objectType

The domain class that this field belongs to.

linkedType

The domain class that this field points to.

name

The name of this field.

englishName

The English name of this field. (Deprecated)

deleteCascade

If this is true, deleting the domain object that is linked to will cause this domain object to be deleted as well.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 37

def initialize( objectType, linkedType, name = nil, englishName = nil,
                deleteCascade = false )
	unless name
		linkedType.name =~ /::/
		name = $' || linkedType.name
		name = name.decapitalize
	end
	super(objectType, name, englishName)
	( @linkedType, @deleteCascade ) = linkedType, deleteCascade
	@listener = nil
	@newDuringEdit = true
end

Instance Attribute Details

#deleteCascade ⇒ Object

Returns the value of attribute deleteCascade.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 28

def deleteCascade
  @deleteCascade
end

#linkedType ⇒ Object (readonly)

Returns the value of attribute linkedType.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 27

def linkedType
  @linkedType
end

#listener ⇒ Object

Returns the value of attribute listener.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 28

def listener
  @listener
end

#newDuringEdit ⇒ Object

Returns the value of attribute newDuringEdit.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 28

def newDuringEdit
  @newDuringEdit
end

#objectStore ⇒ Object

Returns the value of attribute objectStore.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 28

def objectStore
  @objectStore
end

#sortField ⇒ Object

Returns the value of attribute sortField.



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# File 'lib/lafcadio/objectField/LinkField.rb', line 28

def sortField
  @sortField
end

Class Method Details

.instantiateWithParameters(domainClass, parameters) ⇒ Object

:nodoc:



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# File 'lib/lafcadio/objectField/LinkField.rb', line 16

def LinkField.instantiateWithParameters( domainClass, parameters ) #:nodoc:
	instance = self.new(
		domainClass, parameters['linkedType'], parameters['name'],
		parameters['englishName'], parameters['deleteCascade']
	)
	if parameters['dbFieldName']
		instance.dbFieldName = parameters['dbFieldName']
	end
	instance
end

.instantiationParameters(fieldElt) ⇒ Object

:nodoc:



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# File 'lib/lafcadio/objectField/LinkField.rb', line 7

def LinkField.instantiationParameters( fieldElt ) #:nodoc:
	parameters = super( fieldElt )
	linkedTypeStr = fieldElt.attributes['linkedType']
	linkedType = DomainObject.getObjectTypeFromString( linkedTypeStr )
	parameters['linkedType'] = linkedType
	parameters['deleteCascade'] = fieldElt.attributes['deleteCascade'] == 'y'
	parameters
end

Instance Method Details

#valueForSQL(value) ⇒ Object

:nodoc:



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# File 'lib/lafcadio/objectField/LinkField.rb', line 50

def valueForSQL(value) #:nodoc:
	require 'lafcadio/objectStore/DomainObjectInitError'
	if !value
		"null"
	elsif value.pkId
		value.pkId
	else
		raise( DomainObjectInitError, "Can't commit #{name} without pkId", 
		       caller )
	end
end

#valueFromSQL(string) ⇒ Object

:nodoc:



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# File 'lib/lafcadio/objectField/LinkField.rb', line 62

def valueFromSQL(string) #:nodoc:
	require 'lafcadio/objectStore/DomainObjectProxy'
	string != nil ? DomainObjectProxy.new(@linkedType, string.to_i) : nil
end

#verify(value, pkId) ⇒ Object

:nodoc:



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# File 'lib/lafcadio/objectField/LinkField.rb', line 67

def verify(value, pkId) #:nodoc:
	super
	if @linkedType != @objectType && pkId
		subsetLinkField = nil
		@linkedType.classFields.each { |field|
			if field.class == SubsetLinkField && field.subsetField == @name
				subsetLinkField = field
			end
		}
		if subsetLinkField
			begin
				prevObj = ObjectStore.getObjectStore.get(objectType, pkId)
				prevObjLinkedTo = prevObj.send(name)
				possiblyMyObj = prevObjLinkedTo.send(subsetLinkField.name)
				if possiblyMyObj && possiblyMyObj.pkId == pkId
					cantChangeMsg = "You can't change that."
					raise FieldValueError, cantChangeMsg, caller
				end
			rescue DomainObjectNotFoundError
				# no previous value, so nothing to check for
			end
		end
	end
end