ValueExpressionParserTCreateInstanceTExpressionScope(IEnumerablePropertyInfo, TypeRegistry) Method

Generates a delegate that will create new 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.

Namespace: GSF.ComponentModel
Assembly: GSF.Core (in GSF.Core.dll) Version: 2.4.248-beta+a497a19de709fd99e2448886199a2c8824265ddf

Syntax

C++

JavaScript

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

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

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

static member CreateInstance : 
        ?properties : IEnumerable<PropertyInfo> * 
        ?typeRegistry : TypeRegistry 
(* Defaults:
        let _properties = defaultArg properties null
        let _typeRegistry = defaultArg typeRegistry null
*)
-> Func<'TExpressionScope, 'T>  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

FuncTExpressionScope, T
Generated delegate that will create new T instances with default values applied.

Remarks

This function is useful for generating a delegate to a compiled function that will create new objects of type T where properties of the type of have been decorated with DefaultValueAttribute or DefaultValueExpressionAttribute attributes. The newly created 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 a newly created model.

Reference

ValueExpressionParserT Class

CreateInstance Overload

GSF.ComponentModel Namespace