ProjectionLambdaTransformer Class

Visitor, which transforms a passed in lambda into a proper projector lambda for WithProjector and extracts the elements to pass to Select(params object[]). Uses a caching mechanism which caches the compiled result of a lambda based on the string representation of the lambda. This can increase performance. The caching is tweakable and can be switched off. (See static members of this class). If a lambda contains a constant expression, the lambda isn't cached to avoid caching a lambda referencing a local variable and keeping the object containing the local variable into memory.

Inheritance Hierarchy

SystemObject
SD.LLBLGen.Pro.QuerySpecGenericExpressionHandler
SD.LLBLGen.Pro.QuerySpecProjectionLambdaTransformer

Namespace: SD.LLBLGen.Pro.QuerySpec
Assembly: SD.LLBLGen.Pro.ORMSupportClasses (in SD.LLBLGen.Pro.ORMSupportClasses.dll) Version: 5.4.0.0 (5.4.0)

Syntax

Copy

public class ProjectionLambdaTransformer : GenericExpressionHandler

Public Class ProjectionLambdaTransformer
	Inherits GenericExpressionHandler

The ProjectionLambdaTransformer type exposes the following members.

Constructors

	Name	Description
	ProjectionLambdaTransformer	Initializes a new instance of the ProjectionLambdaTransformer class.

Top

Methods

	Name	Description
	ConvertToProjectorLambdaT	Converts the specified expression to a projector lambda. The expression is first handled, which converts elements properly and then converted into a lambda, where the passed in, altered expression is used as the body.
	CreateDataReaderProjectorFuncT	Creates the projector func which can be used to instantiate a new instance of T from a ProjectionRow instance.
	CreateProjectorFuncT	Creates the projector func which can be used to instantiate a new instance of T from a ProjectionRow instance.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	HandleBinaryExpression	Handles the binary expression. (Inherited from GenericExpressionHandler.)
	HandleBinaryExpressionArithmeticOrBitOperator	Handles the binary expression with arithmetic or bit operator. (Inherited from GenericExpressionHandler.)
	HandleBinaryExpressionBooleanOperator	Handles the binary expression with a boolean operator. (Inherited from GenericExpressionHandler.)
	HandleConditionalExpression	Handles the conditional expression. (Inherited from GenericExpressionHandler.)
	HandleConstantExpression	Handles the constant expression. (Overrides GenericExpressionHandlerHandleConstantExpression(ConstantExpression).)
	HandleElementInitializer	Handles the element initializer. (Inherited from GenericExpressionHandler.)
	HandleElementInitializerList	Handles the element initializer list. (Inherited from GenericExpressionHandler.)
	HandleExpression	Handles the expression. (Inherited from GenericExpressionHandler.)
	HandleExpressionList	Handles the expression list. (Inherited from GenericExpressionHandler.)
	HandleInvocationExpression	Handles the invocation expression. (Inherited from GenericExpressionHandler.)
	HandleLambdaExpression	Handles the lambda expression. (Inherited from GenericExpressionHandler.)
	HandleListInitExpression	Handles the list init expression. (Inherited from GenericExpressionHandler.)
	HandleMemberAssignment	Handles the member assignment. (Inherited from GenericExpressionHandler.)
	HandleMemberBinding	Handles the member binding. (Inherited from GenericExpressionHandler.)
	HandleMemberBindingList	Handles the member binding list. (Inherited from GenericExpressionHandler.)
	HandleMemberExpression	Handles the member expression. (Inherited from GenericExpressionHandler.)
	HandleMemberInitExpression	Handles the member init expression. (Inherited from GenericExpressionHandler.)
	HandleMemberListBinding	Handles the member list binding. (Inherited from GenericExpressionHandler.)
	HandleMemberMemberBinding	Handles the member member binding. (Inherited from GenericExpressionHandler.)
	HandleMethodCallExpression	Handles the method call expression. (Overrides GenericExpressionHandlerHandleMethodCallExpression(MethodCallExpression).)
	HandleNewArrayExpression	Handles the new array expression. (Inherited from GenericExpressionHandler.)
	HandleNewExpression	Handles the NewExpression expression (Inherited from GenericExpressionHandler.)
	HandleParameterExpression	Handles the parameter expression. (Inherited from GenericExpressionHandler.)
	HandleTypeBinaryExpression	Handles the type binary expression. (Inherited from GenericExpressionHandler.)
	HandleUnaryArrayLength	Handles the length of the unary array. (Inherited from GenericExpressionHandler.)
	HandleUnaryConvertExpression	Handles the unary convert expression. (Inherited from GenericExpressionHandler.)
	HandleUnaryExpression	Handles the unary expression. (Inherited from GenericExpressionHandler.)
	HandleUnaryNotExpression	Handles the unary expression of type 'Not'. (Inherited from GenericExpressionHandler.)
	HandleUnaryTypeAsExpression	Handles the unary type as expression. (Inherited from GenericExpressionHandler.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

Top

Fields

	Name	Description
	CacheCompiledLamdbas	Flag which signals whether compiled lambda's should be cached (true) or that they have to be compiled every time (false). Switch to false if caching gives memory problems or otherwise odd results.
	CacheMaxEntriesPerThread	Static value which has appdomain scope, and which controls the cache size for the compiled lambdas per thread. Every time the cache hits the set limit, it's cleared. Compiling lambda's is done in Select(lambda) calls to create typed projections.

Top

Reference

SD.LLBLGen.Pro.QuerySpec Namespace