ModelBase Class

Provides a base object for model classes or business objects, which can validate their state, have undo/redo capability and can support committable/revertible editing.

Definition

Namespace: KGySoft.ComponentModel
Assembly: KGySoft.CoreLibraries (in KGySoft.CoreLibraries.dll) Version: 8.1.0

C#

[SerializableAttribute]
public abstract class ModelBase : ValidatingObjectBase, 
	ICanUndoRedo, ICanUndo, IRevertibleChangeTracking, IChangeTracking, ICanEdit, 
	IEditableObject

VB

<SerializableAttribute>
Public MustInherit Class ModelBase
	Inherits ValidatingObjectBase
	Implements ICanUndoRedo, ICanUndo, IRevertibleChangeTracking, IChangeTracking, 
	ICanEdit, IEditableObject

C++

[SerializableAttribute]
public ref class ModelBase abstract : public ValidatingObjectBase, 
	ICanUndoRedo, ICanUndo, IRevertibleChangeTracking, IChangeTracking, ICanEdit, 
	IEditableObject

F#

[<AbstractClassAttribute>]
[<SerializableAttribute>]
type ModelBase = 
    class
        inherit ValidatingObjectBase
        interface ICanUndoRedo
        interface ICanUndo
        interface IRevertibleChangeTracking
        interface IChangeTracking
        interface ICanEdit
        interface IEditableObject
    end

Inheritance: Object ObservableObjectBase PersistableObjectBase ValidatingObjectBase ModelBase

Implements: ICanEdit, ICanUndo, ICanUndoRedo, IChangeTracking, IEditableObject, IRevertibleChangeTracking

Remarks

Note

This class unifies the capabilities of ValidatingObjectBase, EditableObjectBase and UndoableObjectBase classes. If you don't need all of these features you can pick one of these classes as a base class for your business objects. If you need none of these features but only raising events about property changes you can use the ObservableObjectBase or PersistableObjectBase classes. See also the class diagram of the business object base classes of the KGySoft.CoreLibraries assembly:

Class diagram of business object base classes

Differences from ValidatingObjectBase:

When deriving from ModelBase, overriding DoValidation method is not mandatory. By default, DoValidation returns an empty ValidationResultsCollection instance.
See the Remarks section of the ValidatingObjectBase class for an example about how to validate properties by overriding the DoValidation method.
The ModelBase implements the ICanUndo and IRevertibleChangeTracking interfaces to support undo/redo functionality.
See the Remarks section of the UndoableObjectBase class for details about the undo/redo feature. The same applies also for the ModelBase class.
The ModelBase implements the ICanEdit and IEditableObject interfaces to support object editing.
See the Remarks section of the EditableObjectBase class for details about object editing. The same applies also for the ModelBase class.

Though undo/redo and object editing are independent features, the undo history is cleared when an editing session is reverted by the RevertLastEdit or TryRevertAllEdits methods to avoid confusion.

Notes to Implementers

See the Remarks section of the ObservableObjectBase class for an example about how to define properties in a derived class.

See the Remarks section of the ValidatingObjectBase class for an example about how to validate properties in a derived class.

Constructors

ModelBase

Initializes a new instance of the ModelBase class

Properties

AllowReadingDisposedObject	Gets whether the Get<T> method (and the observable properties using it) throw an ObjectDisposedException when the IsDisposed property returns . In a derived class this property can be overridden to return , in which case the Get<T> method returns the default value of T after the object is disposed. The base implementation returns . (Inherited from ObservableObjectBase)
CanRedo	Gets whether there are changes to redo.
CanUndo	Gets whether there are changes to undo.
EditableObjectBehavior	Gets how the object should behave if treated as an IEditableObject. The base implementation returns DisableNesting.
EditLevel	Gets the editing level. That is, the number of BeginNewEdit calls without corresponding CommitLastEdit or RevertLastEdit calls.
IsDisposed	Gets whether this instance has already been disposed. (Inherited from ObservableObjectBase)
IsModified	Gets whether this instance has been modified. Modified state can be set by the SetModified method. (Inherited from ObservableObjectBase)
IsValid	Gets whether this instance is valid. That is, if ValidationResults property does not return any entries where the value of Severity is Error. (Inherited from ValidatingObjectBase)
UndoCapacity	Gets or sets the undo capacity. Default value: 20.
ValidationResults	Gets the validation results for this instance. (Inherited from ValidatingObjectBase)

Methods

AffectsModifiedState	Gets whether the change of the specified propertyName affects the IsModified property. The ModelBase implementation excludes the IsModified, EditLevel, IsValid, UndoCapacity, CanUndo and CanRedo properties. (Overrides ValidatingObjectBaseAffectsModifiedState(String))
BeginNewEdit	Begins a new level of committable/revertible editing session on the object.
CanGetProperty	Gets whether the specified property can be retrieved. The base implementation allows to get the actual instance properties in this instance. (Inherited from ObservableObjectBase)
CanSetProperty	Gets whether the specified property can be set. The base implementation allows to set the actual instance properties in this instance if the specified value is compatible with the property type. (Inherited from ObservableObjectBase)
ClearUndoHistory	Clears the undo/redo history without performing any undo.
Clone	Creates a new object that is a copy of the current instance. The base implementation clones the internal property storage, the IsModified property and if clonePropertyChanged is , then also the subscribers of the PropertyChanged event. It respects the implementations with some special handling for arrays so arrays can be deep-cloned as well. (Inherited from ObservableObjectBase)
CommitLastEdit	Commits all changes since the last BeginNewEdit call.
Dispose	Releases the resources held by this instance. (Inherited from ObservableObjectBase)
Dispose(Boolean)	Releases the resources held by this instance. The base implementation removes the subscribers of the PropertyChanged event and clears the property storage. If the overridden method disposes properties accessed by the Get<T> and Set methods, then check the IsDisposed property first and call the base method as the last step to prevent ObjectDisposedException. (Inherited from ObservableObjectBase)
DoValidation	Performs the validation on this instance and returns the validation results. Must not return . (Overrides ValidatingObjectBaseDoValidation)
GetT(FuncT, String)	Gets the value of a property, or - if it was not set before -, then creates its initial value. The created initial value will be stored in the internal property storage without triggering the PropertyChanged event. For constant or simple expressions, or to return a default value for a non-existing property without storing it internally use the other Get overload. For an example, see the Remarks section of the ObservableObjectBase class. (Inherited from ObservableObjectBase)
GetT(T, String)	Gets the value of a property or defaultValue if no value is stored for it. No new value will be stored if the property does not exist. If the default initial value is too complex and should not be evaluated every time when the property is get, or to throw an exception for an uninitialized property use the other Get overload. For an example, see the Remarks section of the ObservableObjectBase class. (Inherited from ObservableObjectBase)
OnPropertyChanged	Raises the PropertyChanged event. (Overrides ValidatingObjectBaseOnPropertyChanged(PropertyChangedExtendedEventArgs))
RedoAll	Redoes all possible redo steps.
ResetProperty	Resets the property of the specified name, meaning, it will be removed from the underlying storage so the getter methods will return the default value again. (Inherited from ObservableObjectBase)
ResumeChangedEvent	Resumes the raising of the PropertyChanged event suspended by the SuspendChangeEvents method. (Inherited from ObservableObjectBase)
RevertLastEdit	Discards all changes since the last BeginNewEdit call.
Set	Sets the value of a property. For an example, see the Remarks section of the ObservableObjectBase class. (Inherited from ObservableObjectBase)
SetModified	Sets the modified state of this ObservableObjectBase instance represented by the IsModified property. (Inherited from ObservableObjectBase)
SuspendChangedEvent	Suspends the raising of the PropertyChanged event until ResumeChangeEvents method is called. Supports nested calls. (Inherited from ObservableObjectBase)
TryCommitAllEdits	Commits all changes of all editing levels.
TryRedo	Tries to perform one redo step.
TryRevertAllEdits	Reverts all changes of all editing levels.
TryUndo	Tries to perform one undo step.
UndoAll	Undoes all possible undo steps.
Validate	Forces calling the DoValidation method and updates the ValidationResults and IsValid properties. (Inherited from ValidatingObjectBase)

Events

PropertyChanged

Occurs when a property value changed. The actual type of the event argument is PropertyChangedExtendedEventArgs.
(Inherited from ObservableObjectBase)

Extension Methods

Convert	Converts an Object specified in the obj parameter to the desired targetType. See the Examples section of the generic ConvertTTarget(Object, CultureInfo) overload for an example. (Defined by ObjectExtensions)
ConvertTTarget	Converts an Object specified in the obj parameter to the desired TTarget. (Defined by ObjectExtensions)
In	Gets whether item is among the elements of set. See the Examples section of the generic InT(T, T) overload for an example. (Defined by ObjectExtensions)
TryConvert	Tries to convert an Object specified in the obj parameter to the desired targetType. See the Examples section of the ConvertTTarget(Object, CultureInfo) method for a related example. (Defined by ObjectExtensions)
TryConvert	Tries to convert an Object specified in the obj parameter to the desired targetType. See the Examples section of the ConvertTTarget(Object, CultureInfo) method for a related example. (Defined by ObjectExtensions)
TryConvertTTarget	Tries to convert an Object specified in the obj parameter to the desired TTarget. See the Examples section of the ConvertTTarget(Object, CultureInfo) method for a related example. (Defined by ObjectExtensions)
TryConvertTTarget	Tries to convert an Object specified in the obj parameter to the desired TTarget. See the Examples section of the ConvertTTarget(Object, CultureInfo) method for a related example. (Defined by ObjectExtensions)