private Expression Prepare(Expression cachedExpression, ParameterBag parameters)
{
Expression result;
if (parameters.Any())
{
var visitor = new ConstantExpressionReplacementVisitor(parameters);
result = visitor.Visit(cachedExpression);
}
else
{
result = cachedExpression;
}
// perform null-propagation if this feature is enabled.
if (_configurationProvider.EnableNullPropagationForQueryMapping)
{
var nullVisitor = new NullsafeQueryRewriter();
return(nullVisitor.Visit(result));
}
return(result);
}
public Expression CreateMapExpression(Type sourceType, Type destinationType, IDictionary <string, object> parameters = null, params MemberInfo[] membersToExpand)
{
parameters = parameters ?? new Dictionary <string, object>();
var cachedExpression = _expressionCache.GetOrAdd(new ExpressionRequest(sourceType, destinationType, membersToExpand, null));
Expression x = cachedExpression;
if (parameters.Any())
{
var visitor = new ConstantExpressionReplacementVisitor(parameters);
x = visitor.Visit(cachedExpression);
}
// perform null-propagation if this feature is enabled.
if (_configurationProvider.EnableNullPropagationForQueryMapping)
{
var nullVisitor = new NullsafeQueryRewriter();
return(nullVisitor.Visit(x));
}
return(x);
}
/// <summary>
/// Create an expression tree representing a mapping from the source type to destination type
/// Includes flattening and expressions inside MapFrom member configuration
/// </summary>
/// <param name="mappingEngine">Mapping engine instance</param>
/// <param name="sourceType">Source Type</param>
/// <param name="destinationType">Destination Type</param>
/// <param name="parameters">Optional parameter object for parameterized mapping expressions</param>
/// <param name="membersToExpand">Expand members explicitly previously marked as members to explicitly expand</param>
/// <returns>Expression tree mapping source to destination type</returns>
public static Expression CreateMapExpression(this IMappingEngine mappingEngine,
Type sourceType, Type destinationType,
System.Collections.Generic.IDictionary <string, object> parameters = null, params string[] membersToExpand)
{
//Expression.const
parameters = parameters ?? new Dictionary <string, object>();
var cachedExpression =
_expressionCache.GetOrAdd(new ExpressionRequest(sourceType, destinationType, membersToExpand),
tp =>
CreateMapExpression(mappingEngine, tp,
DictionaryFactory.CreateDictionary <ExpressionRequest, int>()));
if (!parameters.Any())
{
return(cachedExpression);
}
var visitor = new ConstantExpressionReplacementVisitor(parameters);
return(visitor.Visit(cachedExpression));
}