Class ModelElement

Acts as the base class for metadata elements in the Time Cockpit data model.

Inheritance

System.Object

DynamicObject

NamedDynamicObject

ModelElement

ModelAction

Culture

EntityView

Model

ModelEntityBase

ModelEntityInterface

ModelProperty

NamedSetDefinition

RelationBase

Trigger

ValidationRule

Permission

Implements

System.Dynamic.IDynamicMetaObjectProvider

System.ComponentModel.INotifyPropertyChanged

System.ComponentModel.IDataErrorInfo

Inherited Members

NamedDynamicObject.OnPropertyChanged(String)

NamedDynamicObject.PropertyChanged

DynamicObject.GetMember(String)

DynamicObject.SetMember(String, Object)

DynamicObject.GetMetaObject(Expression)

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: TimeCockpit.Data.DataModel

Assembly: TimeCockpit.Data.dll

Syntax

public abstract class ModelElement : NamedDynamicObject, IDynamicMetaObjectProvider, INotifyPropertyChanged, IDataErrorInfo

Remarks

Time Cockpit supports a flexible data model that can be customized and extended by users. The metadata about the data model is represented as a tree data structure. The type of every object in this tree must be derived from ModelElement.

Every element in the model element tree is identified using a universal unique identifier (see ElementGuid. Additionally every element has a name. This name needs not to be globally unique (e.g. two different entites can include properties with the same name). However, it has to be unique in the corresponding collection of model elements (e.g. element names of properties inside a single dimension must be unique inside that dimension).

Beside acting as the base class for model elements, ModelElement also contains various static helper functions and properties that can be used to check conventions (e.g. IsValidIdentifier(String), etc.).

Important note to implementers: Note that ModelElement instances can be created through deserialization. Therefore make sure your fields are properly initialized. You cannot rely on your constructor being called neither can you rely on fields initializers. If you have fields and/or properties that must be initialized you have to use the System.Runtime.Serialization.OnDeserializingAttribute!

Constructors

ModelElement()

Initializes a new instance of the ModelElement class

Declaration

protected ModelElement()

ModelElement(IEnumerable<KeyValuePair<Object, Object>>)

Initializes a new instance of the ModelElement class.

Declaration

protected ModelElement(IEnumerable<KeyValuePair<object, object>> properties)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<System.Object, System.Object>>	properties	Collection of properties.

Remarks

You can use this constructor to initialize a new instance of the ModelElement class by specifying its properties in a list of key/value pairs. This is especially useful for dynamic languages like python.

ModelElement(ModelElement)

Initializes a new instance of the ModelElement class.

Declaration

protected ModelElement(ModelElement element)

Parameters

Type	Name	Description
ModelElement	element	The element to copy.

Remarks

Copy constructor for copying values of an instance of ModelElement.

Properties

Children

Gets the children of the ModelElement.

Declaration

public IEnumerable<ModelElement> Children { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<ModelElement>

Remarks

When Attach(ModelElement) is called on a ModelElement, the modelelement that is to be attatched is added to the Children collection of Parent. Detach() removes modelelement from the Children collection of the Parent modelelement.

CreationVersion

Gets the creation version of the entity object

Declaration

public ulong CreationVersion { get; }

Property Value

Type	Description
System.UInt64

ElementGuid

Gets or sets the unique identifier for the model element.

Declaration

public Guid ElementGuid { get; set; }

Property Value

Type	Description
System.Guid

Error

Gets an error message indicating why validation fails for this object.

Declaration

public string Error { get; }

Property Value

Type	Description
System.String

ErrorSummary

Gets a summary of all validation errors that occurred in the ModelElement and its children model elements

Declaration

public IEnumerable<PropertyValidationMessage> ErrorSummary { get; }

Property Value

Type	Description
System.Collections.Generic.IEnumerable<PropertyValidationMessage>

InvariantFriendlyName

Gets or sets a language invariant friendly name of the ModelElement

Declaration

public string InvariantFriendlyName { get; set; }

Property Value

Type	Description
System.String

IsApplicationSpecificElement

Gets a value indicating whether the element is a application specific element.

Declaration

public bool IsApplicationSpecificElement { get; }

Property Value

Type	Description
System.Boolean

IsFullPersistBehavior

Gets a value indicating whether the modelelement is persisted fully or not.

Declaration

public bool IsFullPersistBehavior { get; }

Property Value

Type	Description
System.Boolean

IsNonePersistBehavior

Gets a value indicating whether the modelelement is PersistBehavior.None.

Declaration

public bool IsNonePersistBehavior { get; }

Property Value

Type	Description
System.Boolean

Remarks

This property should be only user for string templating

IsSystemElement

Gets a value indicating whether the element is a system element.

Declaration

public bool IsSystemElement { get; }

Property Value

Type	Description
System.Boolean

IsSystemOrApplicationSpecificElement

Gets a value indicating whether the element is a application specific or system element.

Declaration

public bool IsSystemOrApplicationSpecificElement { get; }

Property Value

Type	Description
System.Boolean

IsUserElement

Gets a value indicating whether the element is a application specific element.

Declaration

public bool IsUserElement { get; }

Property Value

Type	Description
System.Boolean

IsValid

Gets a value indicating whether the ModelElement is valid or not

Declaration

public bool IsValid { get; }

Property Value

Type	Description
System.Boolean

LastUpdateVersion

Gets the update version of the entity object

Declaration

public ulong LastUpdateVersion { get; }

Property Value

Type	Description
System.UInt64

Name

Gets or sets the name of the model element.

Declaration

public override string Name { get; set; }

Property Value

Type	Description
System.String

Overrides

NamedDynamicObject.Name

Remarks

Note that once the model element has been added to a tree (e.g. by adding it to a parent object's collection) the name cannot be changed any more.

When the name is set and the name contains USR, SYS or APP, the ownership is set to the according value.

Exceptions

Type	Condition
System.InvalidOperationException	You tried to change the name once it has been set on a persisted model element.
System.ArgumentException	Specified name is not a valid identifier.

NonPrefixedName

Gets the name of the model element without its prefix.

Declaration

public string NonPrefixedName { get; }

Property Value

Type	Description
System.String

Ownership

Gets or sets the ownership type of a model element.

Declaration

public Ownership Ownership { get; set; }

Property Value

Type	Description
Ownership

Remarks

If the ownership for the current model element is Ownership.None, this property returns Ownership.User, as this ownership type is the specified default value for the ownership property.

The ownership property should be set before any properties, relations, validationrules or modelentityinterfaces are added to a modelentity. This is because, to a certain extent, the latter elements derive the ownership from their parent element. That is, if properties, relations etc. are added to a modelentity which is either System or User, properties, relations, etc. inherit the ownership from their parent.

When the ownership property is not set explicitely by the user, the system sets the ownership automatically to user. This behavior is especially important when using application specific elements. In contrast to system and user model entities which force their children to be of the same ownership as themselves, application specific entites can contain both, user and appspecific children. That is, they do not change the ownership of their children. When adding a property or relation to an applicationspecific entity without specifying the ownership of the property/relation, the property/relation will keep user as default ownership!

OwnershipPrefix

Gets the database prefix of the element

Declaration

public string OwnershipPrefix { get; }

Property Value

Type	Description
System.String

Parent

Gets the parent element.

Declaration

public ModelElement Parent { get; }

Property Value

Type	Description
ModelElement

Remarks

To set the parent of a given model element you have to use the function Attach(ModelElement). To remove the parent use Detach(). Parent is always null for detached model elements.

PersistBehavior

Gets or sets a value indicating whether the ModelElement instance should be persisted in the database.

Declaration

public virtual PersistBehavior PersistBehavior { get; set; }

Property Value

Type	Description
PersistBehavior

Remarks

The default value for this property is langword_csharp_True.

You should use this property if you need to create temporary model elements. These objects should not result in changes in the database. Therefore they are marked as non-persistent.

Note that you have to set this property to false immediately after object creation if you do not want it to be stored in the database. Changing the property value to false at a later point in time only prevents further changes to the object to be written to the database. However, changing the value to false does never remove anything from the database that has been written before!

Methods

Accept(ModelElementVisitor)

Accepts a visitor dispatching the corresponding operation to the concrete type.

Declaration

public abstract void Accept(ModelElementVisitor visitor)

Parameters

Type	Name	Description
ModelElementVisitor	visitor	the visitor to accept.

Attach(ModelElement)

Attaches a model element to a parent model element.

Declaration

protected virtual void Attach(ModelElement newParent)

Parameters

Type	Name	Description
ModelElement	newParent	Parent model element.

Remarks

Note to implementers: If your model element has sub-elements, your implementation of Attach should call the base class' implementation and afterwards attach all sub-elements.

Exceptions

Type	Condition
System.ArgumentNullException	newParent is null.
System.ArgumentException	Thrown in case of a recursion in the model element tree.

Detach()

Detaches a model element from a parent model element.

Declaration

protected virtual void Detach()

Remarks

Note to implementers: If your model element has sub-elements your implementation of Detach should detach all sub-elements and afterwards call the base class' implementation.

If you call Detach for a model element that has no parent the call is ignored. No exception is thrown in this case.

IsValidIdentifier(String)

Can be used to check if an identifier is valid.

Declaration

public static bool IsValidIdentifier(string identifier)

Parameters

Type	Name	Description
System.String	identifier	Identifier to check.

Returns

Type	Description
System.Boolean	langword_csharp_True indicates that the identifier is valid. langword_csharp_False means that the provided string value cannot be used as an identifier.

Remarks

Identifiers in Time Cockpit must comply with the following rules:

• Must not be null or empty.
• Must start with an uppercase letter followed by a combination of upper/lowercase letters, digits or underscores.
• Must not be a reserved word.
• Must not start with a reserved identifier prefix.
• Length must be <= 64 characters.

OnDeserializing(StreamingContext)

Called whenever deserialization of the model element is happening

Declaration

[OnDeserializing]
public void OnDeserializing(StreamingContext context)

Parameters

Type	Name	Description
System.Runtime.Serialization.StreamingContext	context	Stream context used for deserialization.

Remarks

This method is part of the internal infrastructure of the TimeCockpit.Data and must not be called from outside.

SetName(String)

Sets the name of an instance of ModelElement.

Declaration

protected void SetName(string value)

Parameters

Type	Name	Description
System.String	value	The value to set the name of a ModelElement to.

SetOwnership(Ownership)

Sets the ownership of an instance of ModelElement.

Declaration

protected void SetOwnership(Ownership value)

Parameters

Type	Name	Description
Ownership	value	The value to set the ownership of a ModelElement to.

SetOwnershipPrefix(String)

Sets the ownership of a model element according to a certain string prefix.

Declaration

protected void SetOwnershipPrefix(string prefix)

Parameters

Type	Name	Description
System.String	prefix	A string prefix to derive the ownership from.

SetPersistBehavior(PersistBehavior)

Sets the persist behavior of the current ModelElement.

Declaration

protected virtual void SetPersistBehavior(PersistBehavior persistBehavior)

Parameters

Type	Name	Description
PersistBehavior	persistBehavior	The new persist behavior of the ModelElement.

Remarks

This method's only purpose is to make it possible to override a ModelElement's persist behavior in the context of a memberwise clone

UpdateChildren(NotifyCollectionChangedEventArgs)

Attaches or detaches added or removed collection items.

Declaration

protected void UpdateChildren(NotifyCollectionChangedEventArgs e)

Parameters

Type	Name	Description
System.Collections.Specialized.NotifyCollectionChangedEventArgs	e	Provides data for the CollectionChanged event.

Remarks

Quite frequently descendant classes will contain collections of child items (ModelCollection<T>). These child items descend from ModelElement, too. UpdateChildren is typically used in descendant classes to attach/detach ModelElement instances that have been added/removed from such collections.

Validate(ref IList<PropertyValidationMessage>, Boolean)

Validates a ModelElement according to certain rules.

Declaration

protected virtual void Validate(ref IList<PropertyValidationMessage> messages, bool validateRecursively)

Parameters

Type	Name	Description
System.Collections.Generic.IList<PropertyValidationMessage>	messages	An list of strings that stores that picks up the validation errors of a model element.
System.Boolean	validateRecursively	Indicates wheter to validate only the current model element or all its children (recursively) as well.

Remarks

The rules the ModelElement is validated against are dependent on the type of ModelElement that is validated. This method can be overridden to provide custom validation behavior for subclasses of ModelElement

When Validate(ref IList<PropertyValidationMessage>, Boolean) is called on a modelelement, the Validate(ref IList<PropertyValidationMessage>, Boolean) method of all children attatched to the modelelemnt are validated recursivly.