ValueExpressionParserTApplyDefaultsTExpressionScope(IEnumerablePropertyInfo, TypeRegistry) Method

Generates a delegate that will update an instance of type T accepting a contextual IValueExpressionScopeT object parameter applying any specified DefaultValueAttribute or DefaultValueExpressionAttribute instances that are declared on the type T properties. Target T instance needs to be assigned to the Instance property prior to call.

Namespace: GSF.ComponentModel
Assembly: GSF.Core (in GSF.Core.dll) Version: 2.4.218-beta+101eee949414e414795e55a6e73d88938f0177b8

Syntax

C++

JavaScript

Copy

public static Action<TExpressionScope> ApplyDefaults<TExpressionScope>(
	IEnumerable<PropertyInfo> properties = null,
	TypeRegistry typeRegistry = null
)
where TExpressionScope : Object, IValueExpressionScope<T>

Public Shared Function ApplyDefaults(Of TExpressionScope As {Object, IValueExpressionScope(Of T)}) ( 
	Optional properties As IEnumerable(Of PropertyInfo) = Nothing,
	Optional typeRegistry As TypeRegistry = Nothing
) As Action(Of TExpressionScope)

public:
generic<typename TExpressionScope>
where TExpressionScope : Object, IValueExpressionScope<T>
static Action<TExpressionScope>^ ApplyDefaults(
	IEnumerable<PropertyInfo^>^ properties = nullptr, 
	TypeRegistry^ typeRegistry = nullptr
)

static member ApplyDefaults : 
        ?properties : IEnumerable<PropertyInfo> * 
        ?typeRegistry : TypeRegistry 
(* Defaults:
        let _properties = defaultArg properties null
        let _typeRegistry = defaultArg typeRegistry null
*)
-> Action<'TExpressionScope>  when 'TExpressionScope : Object and IValueExpressionScope<'T>

JavaScript does not support generic types or methods.

View Source

Parameters

properties IEnumerablePropertyInfo (Optional): Specific properties to target, or null to target all properties.
typeRegistry TypeRegistry (Optional): Type registry to use when parsing DefaultValueExpressionAttribute instances, or null to use DefaultTypeRegistry.

Type Parameters

TExpressionScope: IValueExpressionScopeT parameter type.

Return Value

ActionTExpressionScope
Generated delegate that will update T instances with expression values applied.

Remarks

This function is useful for generating a delegate to a compiled function that will update objects of type T where properties of the type of have been decorated with DefaultValueAttribute or DefaultValueExpressionAttribute attributes. The updated object will automatically have applied any defined default values as specified by the encountered attributes. The generated delegate takes a parameter to a contextual object useful for providing extra runtime data to DefaultValueExpressionAttribute attributes; the parameter must be derived from IValueExpressionScopeT. Any public fields, methods or properties defined in the derived class will be automatically accessible from the expressions declared in the DefaultValueExpressionAttribute attributes. By default, the expressions will have access to the current T instance by referencing the this keyword, which is an alias to Instance.

Note
This function will assign evaluated expression values to properties in an existing model.

Reference

ValueExpressionParserT Class

ApplyDefaults Overload

GSF.ComponentModel Namespace