TBoldObject¶

TBoldObject is the representation of Bold objects.

Declaration¶

TBoldObject = class(TBoldDomainElement)

Hierarchy¶

TObject
TBoldMemoryManagedObject
TBoldFlaggedObject
TBoldSubscribableObject
TBoldElement
TBoldDomainElement
TBoldObject
Direct subclasses
TBusinessClassesRoot

Description¶

TBoldObject is the representation of Bold objects. The business classes in the generated code will all be subclasses of this class. The business objects in a Bold application are instances of this class, or one of its subclasses.

Properties¶

Name	Summary	Notes
AsIBoldObjectContents	This property gives the ValueSpace view of an object.	read-only
BoldClassTypeInfo	The class type info holds the model information for objects of this type.	read-only
BoldExistenceState	The existence state of a Bold object tells us if the conceptual object exists or not.	read-only
BoldMemberAssigned	If a specific member of the object has been created yet.	read-only
BoldMemberByExpressionName	The member with a given expression name.	read-only
BoldMemberCount	The total number of members of the object	read-only
BoldMemberIndexByExpressionName	The index of the member with a given expression name.	read-only
BoldMembers	The members of a Bold object are the objects that represent the attributes and roles of the object.	read-only
BoldObjectExists	If the object exists conceptually	read-only
BoldObjectIsDeleted	If the object has been deleted	read-only
BoldObjectIsNew	If the object has been created, but not yet saved.	read-only
BoldObjectLocator	The object's locator	read-only
BoldPersistenceState	Reflects the relationship between the value in memory and in persistent storage.	read-only
BoldSystem	The system the object belongs to.	read-only
BoldTime	Returns the time stamp associated with this version of the Bold object.	read-only
ObjectHasSubscribers	True if there is anything subscribing to the object.	read-only
Touched	Bold-internal	read-only

AsIBoldObjectContents¶

property AsIBoldObjectContents[Mode:TBoldDomainElementProxyMode]: IBoldObjectContents;

This property gives the ValueSpace view of an object.

BoldClassTypeInfo¶

property BoldClassTypeInfo: TBoldClassTypeInfo;

The class type info holds the model information for objects of this type.

BoldExistenceState¶

property BoldExistenceState: TBoldExistenceState;

The existence state of a Bold object tells us if the conceptual object exists or not.

If the value is besNotCreated then the object has not yet been created. An object is typically only in this state during the early phases of its creation.
The value besExisting means that the conceptual object exists.
The value besDeleted means that the object has been deleted. Thus, the object conceptually does not exist anymore. Objects with this state are kept in memory as a reminder to also delete them from the database.

When the existence state changes from besExisting to either besNotCreated or

Note

besDeleted

, the event beObjectDeleted is sent. When the state changes from either besNotCreated or besDeleted to besExisting, the event beObjectCreated is sent.

BoldMemberAssigned¶

property BoldMemberAssigned[index:Integer]: Boolean;

For reasons of conserving memory, the individual members of a Bold object (instances of TBoldMember) are not created until the first time they are needed. This property can be used to check if a specific member has been created, so as not to unnecessarily create it.

BoldMemberByExpressionName¶

property BoldMemberByExpressionName[constname:string]: TBoldMember;

The member with a given expression name.

BoldMemberCount¶

property BoldMemberCount: Integer;

The total number of members of the object. Can be used to loop over the BoldMembers property.

BoldMemberIndexByExpressionName¶

property BoldMemberIndexByExpressionName[constname:string]: Integer;

The index of the member with a given expression name. -1 if there is no member with that name.

BoldMembers¶

property BoldMembers[index:Integer]: TBoldMember;

The members of a Bold object are the objects that represent the attributes and roles of the object. This property allows access to these objects using their index.

BoldObjectExists¶

property BoldObjectExists: Boolean;

This property corresponds to testing BoldExistenceState = besExisting, and will be be true if the object conceptually exists, and false if it has been deleted (and for a short time during the creation-phase of the object).

BoldObjectIsDeleted¶

property BoldObjectIsDeleted: Boolean;

This property will be true for a Bold object after Delete has been called.

BoldObjectIsNew¶

property BoldObjectIsNew: Boolean;

If the object has been created, but not yet saved.

BoldObjectLocator¶

property BoldObjectLocator: TBoldObjectLocator;

The object's locator

BoldPersistenceState¶

property BoldPersistenceState: TBoldValuePersistenceState;

The persistence state of a Bold object reflects the relationship between its value in memory and in the persistent storage. It tells us which of the two is the most recent. The value of a Bold object is concidered to be its existence state.

If the state of an object is bvpsInvalid it means that the value in memory is not correct. This means that the object is being fetched. After the object has been fetched the state will become bvpsCurrent. If the object is deleted in memory the state will change to bvpsModified, implying that the object should be deleted from the persistent storage. When a new object is created it also receives the bvpsModified state. Finally, the bvpsTransient state tells us that the object only exists in memory.

Calling Invalidate on an object only invalidates the members of the object, and does not set the object's persistence state to invalid.

Discard makes an object 'forget' that it has been created or deleted. It changes its state from bvpsModified to bvpsInvalid. It also discards the members of the object.

Objects can change state from bvpsTransient to bvpsModified. This happens when the method BoldMakePersistent is called, assuming that the object's class is persistent.

After an object is created the virtual method CompleteCreate is called. Override this to add initialization code. The event beCompleteModify is also sent at this time.

Before an object is deleted the method CanDelete is checked. This, among other things, calls the virtual MayDelete method and the bqMayDelete query-event. If the delete operation is allowed the virtual method PrepareDelete is called before the existence state is changed. The event bePrepareModify is also sent at this time.

BoldSystem¶

property BoldSystem: TBoldSystem;

The system the object belongs to.

BoldTime¶

property BoldTime: TBoldTimestampType;

Each version of a Bold object is represented in memory by a separate instance of TBoldObject (or subclass). The BoldTime property returns the time stamp for this version.

Note

This feature is only available in the Object Versioning Extension.

ObjectHasSubscribers¶

property ObjectHasSubscribers: Boolean;

True if there is anything subscribing to the object.

See Also

Subscriptions

Touched¶

property Touched: Boolean;

Bold-internal

Methods¶

Name	Summary	Notes
AtTime
BoldMakePersistent
CanDelete	True if the object is allowed to be deleted.
CanUpdate	True if the object is allowed to be updated.
CheckLinks	Checks that there are no associations to the object.
ClearTouched	Bold-internal
CompleteCreate	Override this method to add behaviour after an object is created.	protected, virtual
CompleteUpdate	Virtual method that is called after an object has been updated in the persistent storage	protected, virtual
Create	Creates a Bold object.
DefaultSubscribe	Subscribes to the default events on the Bold object.	override
Delete	Deletes the Bold object.
Destroy	Destructor	override
Discard	Discards all changes made in memory, that have not been written to persistent storage yet.
GetAsList	Overrides TBoldElement.GetAsList	override
GetBoldDirty	Overrides TBoldDomainElement.GetBoldDirty	protected, override
GetBoldType	Overrides TBoldElement.GetBoldType.	protected, override
GetDeriveMethodForMember	Internal. Sets up derived attributes.	protected, virtual
GetDisplayName	Overrides TBoldElement.GetDisplayName.	protected, override
GetEvaluator	Overrides TBoldElement.GetEvaluator.	protected, override
GetReverseDeriveMethodForMember	Internal. Sets up derived attributes.	protected, virtual
GetStringRepresentation	Overrides TBolfElement.GetStringRepresentation	protected, override
InternalCreateNewWithClassAndSystem	Bold-internal.
Invalidate	Invalidates the members of the object.
IsEqualAs	Overrides TBoldElement.IsEqualAs	override
MarkObjectDirty	Forces the object to become dirty.
MayDelete	User overrideable function. Return false to prohibit deleting the object.	protected, virtual
MayUpdate	Override this function and return false to prohibit the update state transition.	protected, virtual
PrepareDelete	Override this method to add behaviour before an object is deleted.	protected, virtual
PrepareUpdate	Override this method to add behaviour before an object is updated.	protected, virtual
ProxyInterface	Overrides TBoldElement.ProxyInterface	override
ReceiveEventFromOwned	Overrides TBoldDomainElement.ReceiveEventFromOwned	override
ReRead	The object will be fetched even if its persistence state is current.
StateError	Overrides TBoldDomainElement.StateError.	protected, override
SubscribeToStringRepresentation	Overrides TBoldElement.SubscribeToStringRepresentation.	override
ToBeRemovedClassAccessed	Called when a class with EvolutionState ToBeRemoved is accessed.	protected, virtual
ToBeRemovedMemberAccessed	Called when a member with EvolutionState ToBeRemoved is accessed.	protected, virtual
ToBeRemovedMemberModified	Called when a member with EvolutionState ToBeRemoved is modified.	protected, virtual
UnLinkAll	Clear all associations to the object.
ValidateMember	Internal convenience method	protected

AtTime¶

function AtTime(Time: TBoldTimestampType): TBoldObject;

Returns the object as it looked at the time point identified by the Time time stamp.

Note

This feature is only available in the Object Versioning Extension to Bold for Delphi.

BoldMakePersistent¶

procedure BoldMakePersistent;

If you have created a transient instance of a persistent class, BoldMakePersistent will make that instance persistent. Note that this will not actually save the Bold object to the persistent storage, but rather mark it as a newly created instance.

Transient instances of persistent classes can be created by passing False as the second parameter to create.

CanDelete¶

function CanDelete: Boolean;

Returns True if the object is allowed to be deleted. A programmer can disallow deleting either by overriding the virtual MayDelete function or subscribing to the bqMayDelete query.

CanUpdate¶

function CanUpdate: Boolean;

Returns True if the object is allowed to be updated. A programmer can disallow updating either by overriding the virtual MayUpdate function or subscribing to the bqMayUpdate query.

CheckLinks¶

function CheckLinks(index: Integer): Boolean;

Checks that there are no associations to the object, except by the role with member index **Index**.

ClearTouched¶

procedure ClearTouched;

Bold-internal

CompleteCreate¶

procedure CompleteCreate; virtual;

Override this method to add behaviour after an object is created, such as setting default values for attributes. The default implementation is empty.

See Also

TBoldValuePersistenceState

CompleteUpdate¶

procedure CompleteUpdate; virtual;

Override this method to add behaviour after an object is updated in the persistent storage. The default implementation is empty.

Create¶

constructor Create(AOwningElement: TBoldDomainElement; Persistent: Boolean = True);

Creates a Bold object. This constructor can not be called on TBoldObject, but should be called on a subclass. The OwningElement should be a TBoldSystem. If **nil**, the object will belong to the default system.

Good practice is to specify the system explicitly.

DefaultSubscribe¶

procedure DefaultSubscribe(Subscriber: TBoldSubscriber; RequestedEvent: TBoldEvent = breReEvaluate); override; See also Ancestor Method

Subscribes to the default events on the Bold object. There are no default events for a TBoldObject, so, in reality, no subscriptions are placed.

See Also

Subscriptions

Delete¶

procedure Delete;

Deletes the Bold object. If the object is transient or has not been written to the persistent storage the Delphi object is destroyed. Otherwise, the object is marked for deletion and will be deleted from the persistent storage and memory when UpdateDatabase is called on the owning system.

Delete triggers a change in the persistence state of the object.

Before a Bold object is deleted it will try to clear all associations. The clearing of associations will depend on the setting of the DeleteAction of the association. Details can be found in the Model Information topic (Association Ends/DeleteAction).

Note

When an object is deleted, it is not always immediately destroyed. If the object is persistent, the object will be kept by the system until it the delete is saved to the database. It is however not advised to hold any pointers to a deleted objects unless for specific technical reasons. The obejct will send the event beObjectDeleted when it is being deleted, and the event beDestroying when it is destroyed

See Also

TBoldValuePersistenceState

Destroy¶

destructor Destroy; override; See also Ancestor Method

Do not call TBoldObject.Destroy directly. To delete a Bold object, call Delete. To remove the object from memory without deleting it in the persistent storage, call UnloadBoldObject on the locator of the object.

Discard¶

procedure Discard;

All changes made to the object since it was fetched from, or updated to, the persistent storage will be lost. All modified members will be discarded. If the object is a newly created object or a transient object, it will be deleted, and thus destroyed in memory. If the object is a deleted object it will be undeleted and its persistence state will change to bvpsCurrent.

GetAsList¶

procedure GetAsList(ResultList: TBoldIndirectElement); override; See also Ancestor Method

Sets ResultList to point to a TBoldObjectList containing the object.

GetBoldDirty¶

function GetBoldDirty: Boolean; override; See also Ancestor Method

A TBoldObject is considered dirty if one of its members is dirty, or if the object itself has persistence state bvpsModified. This is the case for a newly created or deleted object.

GetBoldType¶

function GetBoldType: TBoldElementTypeInfo; override; See also Ancestor Method

Overrides GetBoldType. The bold type of a TBoldObject is the same as the BoldClassTypeInfo.

GetDeriveMethodForMember¶

function GetDeriveMethodForMember(Member: TBoldMember): TBoldDeriveAndResubscribe; virtual;

The implementation of this method will be automatically generated when generating code for a class that has derived attributes.

GetDisplayName¶

function GetDisplayName: String; override; See also Ancestor Method

Overrides GetDisplayName. The display name for a Bold object is the name of the class.

GetEvaluator¶

function GetEvaluator: TBoldEvaluator; override; See also Ancestor Method

Overrides GetEvaluator.

GetReverseDeriveMethodForMember¶

function GetReverseDeriveMethodForMember(Member: TBoldMember): TBoldReverseDerive; virtual;

Overrides GetDisplayName. The display name for a Bold object is the name of the class.

GetStringRepresentation¶

function GetStringRepresentation(Representation: TBoldRepresentation): string; override; See also Ancestor Method

In the default implementation for a Bold object, the string representation is the attribute with index Representation. If that member is not an attribute the StringRepresentation is the object's id and classname.

InternalCreateNewWithClassAndSystem¶

constructor InternalCreateNewWithClassAndSystem(ClassTypeInfo: TBoldClassTypeInfo; aSystem: TBoldSystem; Persistent: Boolean);

Bold-internal constructor. Use the normal constructor Create.

Invalidate¶

procedure Invalidate;

All persistent members of the BoldObject will have their values invalidated. Thus, they will be refetched from the persistent storage the next time they are accessed. See Invalidate.

IsEqualAs¶

function IsEqualAs(CompareType: TBoldCompareType; BoldElement: TBoldElement): Boolean; override; See also Ancestor Method

Bold objects are compared with reference semantics, meaning that an object is only equal to itself. An object can also be compared to a TBoldObjectReference and they will be considered equal if the object reference refers the the object.

MarkObjectDirty¶

procedure MarkObjectDirty;

Forces the object to become dirty. This does not change the value of any of the members of the object.

MayDelete¶

function MayDelete: Boolean; virtual;

Override this function and return false to prohibit the delete state transition.

See Also

CanDelete
StartDelete

MayUpdate¶

function MayUpdate: Boolean; virtual;

Override this function and return false to prohibit the update state transition.

See Also

CanUpdate
StartUpdate

PrepareDelete¶

procedure PrepareDelete; virtual;

Override this method to add behaviour before an object is deleted. The default implementation is empty.

PrepareUpdate¶

procedure PrepareUpdate; virtual;

Override this method to add behaviour before an object is updated. The default implementation is empty.

ProxyInterface¶

function ProxyInterface(const IId: TGUID; Mode: TBoldDomainElementProxyMode; out Obj): Boolean; override; See also Ancestor Method

Overrides ProxyInterface

ReceiveEventFromOwned¶

procedure ReceiveEventFromOwned(originator: TObject; originalEvent: TBoldEvent); override; See also Ancestor Method

Override this method in one of your business classes to catch any event sent by a member. The member sending the event is the originator.

Note

Don't forget to call `inherited`.

ReRead¶

procedure ReRead;

The object will be fetched even if its persistence state is current.

StateError¶

procedure StateError(S: String); override; See also Ancestor Method

Overrides StateError.

SubscribeToStringRepresentation¶

procedure SubscribeToStringRepresentation(Representation: TBoldRepresentation; Subscriber: TBoldSubscriber; RequestedEvent: TBoldEvent = breReEvaluate); override; See also Ancestor Method

Overrides SubscribeToStringRepresentation.

See Also

Subscriptions

ToBeRemovedClassAccessed¶

procedure ToBeRemovedClassAccessed; virtual;

Called when a class with EvolutionState ToBeRemoved is accessed. See Related Topics.

It can be useful during development to place a breakpoint in the implementation of this method to pinpoint when the class is accessed. To do this, add the method to your root class, add the method as override and generate code. The implementation on TBoldObject is empty.

ToBeRemovedMemberAccessed¶

procedure ToBeRemovedMemberAccessed(MemberRTInfo: TBoldMemberRTInfo); virtual;

Called when a member with EvolutionState ToBeRemoved is accessed. See Related Topics.

It can be useful during development to place a breakpoint in the implementation of this method to pinpoint when the class is accessed. To do this, add the method to your root class, add the method as override and generate code. The implementation on TBoldObject is empty.

ToBeRemovedMemberModified¶

procedure ToBeRemovedMemberModified(MemberRTInfo: TBoldMemberRTInfo); virtual;

Called when a member with EvolutionState ToBeRemoved is accessed. See Related Topics.

It can be useful during development to place a breakpoint in the implementation of this method to pinpoint when the class is accessed. To do this, add the method to your root class, add the method as override and generate code. The implementation on TBoldObject is empty.

UnLinkAll¶

procedure UnLinkAll;

The members that correspond to roles are cleared, i.e. members of type TBoldObjectList will be emptied and members of type TBoldObjectReference will be set to **nil**. Associations with association classes will not be removed when UnlinkAll is called on a link object.

ValidateMember¶

function ValidateMember(const ObjectDelphiName, MemberDelphiName: String; GeneratedMemberIndex: integer; MemberClass: TBoldMemberClass): Boolean;

Internal convenience method, used by the generated code to verify that it is in sync with the model.

Generated from the Bold 4.0 help (Help/BfD.chm) by Tools/chm2mkdocs.py; member lists reflect Bold 4.0, see the source for members added since.