public MemberExpression GetJoinPropertyExpression(Expression source, Expression parameter, SingleValuePropertyAccessNode propertyNode)
{
IReadOnlyList <IEdmNavigationProperty> joinPath = GetJoinPath(propertyNode);
MemberExpression propertyExpression = GetJoinPropertyExpression(source, parameter, joinPath, propertyNode.Property);
if (propertyExpression != null)
{
return(propertyExpression);
}
propertyExpression = (MemberExpression)Visitor.TranslateNode(propertyNode);
if (propertyExpression == null)
{
throw new InvalidOperationException("property " + propertyNode.Property.Name + " not found");
}
if (Visitor.Parameter == parameter)
{
return(propertyExpression);
}
var replaceParameterVisitor = new ReplaceParameterVisitor(Visitor.Parameter, parameter);
return((MemberExpression)replaceParameterVisitor.Visit(propertyExpression));
}
/// <summary>
/// Replaces the parameter of the expression with given one.
/// </summary>
/// <typeparam name="T">Type the expression is being used on.</typeparam>
/// <param name="expression">Expression to be changed.</param>
/// <param name="parameter">Parameter for the new expression.</param>
/// <returns>The expression with the new parameter.</returns>
private static Expression ReplaceParameter <T>(Expression <Func <T, bool> > expression, ParameterExpression parameter)
{
var visitor = new ReplaceParameterVisitor(expression.Parameters[0], parameter);
var newexpression = visitor.Visit(expression.Body);
return(newexpression);
}
public MethodCallExpression Build(Expression outer, Expression inner, ODataPath odataPath, OrderByClause orderBy, long?skip, long?top)
{
var segment = (NavigationPropertySegment)odataPath.LastSegment;
IEdmNavigationProperty navigationProperty = segment.NavigationProperty;
if (navigationProperty.ContainsTarget)
{
ModelBuilder.ManyToManyJoinDescription joinDescription = _edmModel.GetManyToManyJoinDescription(navigationProperty);
IEdmEntitySet joinEntitySet = OeEdmClrHelper.GetEntitySet(_edmModel, joinDescription.JoinNavigationProperty);
outer = OeEnumerableStub.CreateEnumerableStubExpression(joinDescription.JoinClassType, joinEntitySet);
navigationProperty = joinDescription.TargetNavigationProperty;
}
Type outerType = OeExpressionHelper.GetCollectionItemType(outer.Type);
ParameterExpression outerParameter = Expression.Parameter(outerType, outerType.Name);
inner = new ReplaceParameterVisitor(outerParameter).Visit(inner); //replace $it
Expression subquery = CreateWhereExpression(outerParameter, inner, navigationProperty);
subquery = _expressionBuilder.ApplyOrderBy(subquery, orderBy);
subquery = _expressionBuilder.ApplySkip(subquery, skip, odataPath);
subquery = _expressionBuilder.ApplyTake(subquery, top, odataPath);
Type innerType = OeExpressionHelper.GetCollectionItemType(inner.Type);
MethodInfo selectManyMethdoInfo = OeMethodInfoHelper.GetSelectManyMethodInfo(outerType, innerType);
return(Expression.Call(selectManyMethdoInfo, outer, Expression.Lambda(subquery, outerParameter)));
}
public static Expression <Func <T, bool> > AndAlso <T>(this Expression <Func <T, bool> > expr1, Expression <Func <T, bool> > expr2)
{
ParameterExpression parameter1 = expr1.Parameters[0];
var visitor = new ReplaceParameterVisitor(expr2.Parameters[0], parameter1);
var body2WithParam1 = visitor.Visit(expr2.Body);
return(Expression.Lambda <Func <T, bool> >(Expression.AndAlso(expr1.Body, body2WithParam1), parameter1));
}
/// <summary>
/// Returns a new expression where references to the specified parameter
/// have been replaced by references to another one.
/// </summary>
/// <param name="expression">The expression.</param>
/// <param name="original">The original parameter.</param>
/// <param name="replacement">The replacement parameter.</param>
/// <returns></returns>
public static Expression ReplaceParameter(
this Expression expression,
ParameterExpression original,
Expression replacement
)
{
var visitor = new ReplaceParameterVisitor(original, replacement);
return(visitor.Visit(expression));
}
public static Expression <Func <T, bool> > Or <T>(this Expression <Func <T, bool> > one, Expression <Func <T, bool> > another)
{
var parameter = one.Parameters[0];
var visitor = new ReplaceParameterVisitor(parameter);
another = (Expression <Func <T, bool> >)visitor.Visit(another);
var body = Expression.Or(one.Body, another.Body);
return(Expression.Lambda <Func <T, bool> >(body, parameter));
}
/// <summary>
/// An Expression<Func<T,bool>> extension method that with parameters of.
/// </summary>
/// <typeparam name="T">Generic type parameter.</typeparam>
/// <param name="left">The left.</param>
/// <param name="right">The right.</param>
/// <param name="expressionType">Type of the expression.</param>
/// <returns>An Expression<Func<T,bool>></returns>
private static Expression <Func <T, bool> > WithParametersOf <T>(this Expression <Func <T, bool> > left,
Expression <Func <T, bool> > right, ExpressionType expressionType)
{
var visitor = new ReplaceParameterVisitor {
SubstituteMapping = { [right.Parameters[0]] = left.Parameters[0] }
};
Expression body = Expression.MakeBinary(expressionType, left.Body, visitor.Visit(right.Body));
return(Expression.Lambda <Func <T, bool> >(body, left.Parameters[0]));
}
public static Expression <T> AddExpression <T>(this Expression <T> first, Expression <T> second, Func <Expression, Expression, Expression> merge)
{
var map = first.Parameters.Select((left, i) => new
{
left,
right = second.Parameters[i]
}).ToDictionary(p => p.right, p => p.left);
var rightBody = ReplaceParameterVisitor.ReplacementExpression(map, second.Body);
return(Expression.Lambda <T>(merge(first.Body, rightBody), first.Parameters));
}
public static Expression <Func <T, bool> > Combine <T>(Expression <Func <T, bool> > leftExpression, Expression <Func <T, bool> > rightExpression, Func <Expression, Expression, BinaryExpression> combineOperator)
{
var leftParameter = leftExpression.Parameters[0];
var rightParameter = rightExpression.Parameters[0];
var visitor = new ReplaceParameterVisitor(rightParameter, leftParameter);
var leftBody = leftExpression.Body;
var rightBody = visitor.Visit(rightExpression.Body);
return(Expression.Lambda <Func <T, bool> >(combineOperator(leftBody, rightBody), leftParameter));
}
/// <summary>
/// Returns a new expression where references to the specified parameter
/// have been replaced by references to another one.
/// </summary>
/// <param name="expression">The expression.</param>
/// <param name="original">The original parameter.</param>
/// <param name="replacement">The replacement parameter.</param>
/// <param name="wasReplaced">Indicates whether the <paramref name="original"/> has been replaced at least once.</param>
/// <returns></returns>
public static Expression ReplaceParameter(
this Expression expression,
ParameterExpression original,
Expression replacement,
out bool wasReplaced
)
{
var visitor = new ReplaceParameterVisitor(original, replacement);
var result = visitor.Visit(expression);
wasReplaced = visitor.WasReplaced;
return(result);
}
public static MemberExpression GetPropertyExpression(OeJoinBuilder joinBuilder, Expression source, Expression parameterExpression, SingleValueNode sortProperty)
{
if (sortProperty is SingleValuePropertyAccessNode propertyNode)
{
return(joinBuilder.GetJoinPropertyExpression(source, parameterExpression, propertyNode));
}
if (sortProperty is SingleValueOpenPropertyAccessNode openPropertyNode)
{
var propertyExpression = (MemberExpression)joinBuilder.Visitor.TranslateNode(openPropertyNode);
var replaceParameterVisitor = new ReplaceParameterVisitor(joinBuilder.Visitor.Parameter, parameterExpression);
return((MemberExpression)replaceParameterVisitor.Visit(propertyExpression));
}
throw new InvalidOperationException("Unknown type order by expression " + sortProperty.GetType().Name);
}
public static Expression <Func <TElement, bool> > ReplaceParameter <TElement>(
Expression <Func <TElement, TElement, bool> > inputExpression,
TElement element)
{
Expression body = inputExpression.Body;
ReplaceParameterVisitor visitor =
new ReplaceParameterVisitor(inputExpression.Parameters[1],
Expression.Constant(element, typeof(TElement)));
Expression newBody = visitor.Visit(body);
Expression <Func <TElement, bool> > newExpression =
Expression.Lambda <Func <TElement, Boolean> >(
newBody,
new ParameterExpression[] { inputExpression.Parameters[0] });
return(newExpression);
}
public MemberExpression GetJoinPropertyExpression(Expression source, Expression parameter, SingleValuePropertyAccessNode propertyNode)
{
IReadOnlyList <IEdmNavigationProperty> joinPath = GetJoinPath(propertyNode);
MemberExpression?joinPropertyExpression = GetJoinPropertyExpression(source, parameter, joinPath, propertyNode.Property);
if (joinPropertyExpression != null)
{
return(joinPropertyExpression);
}
var propertyExpression = (MemberExpression)Visitor.TranslateNode(propertyNode);
if (Visitor.Parameter == parameter)
{
return(propertyExpression);
}
var replaceParameterVisitor = new ReplaceParameterVisitor(Visitor.Parameter, parameter);
return((MemberExpression)replaceParameterVisitor.Visit(propertyExpression));
}
/// <summary>
/// Replace parameter <paramref name="oldExpression"/> by <paramref name="newExpression"/>.
/// </summary>
/// <param name="expression">The expression.</param>
/// <param name="oldExpression">The parameter to be replaced.</param>
/// <param name="newExpression">The expression to replace all occurrences of <paramref name="oldExpression"/>.</param>
/// <returns>New expression with applied replacement.</returns>
public static Expression ReplaceParameter(
this Expression expression,
ParameterExpression oldExpression,
Expression newExpression)
{
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
if (oldExpression == null)
{
throw new ArgumentNullException(nameof(oldExpression));
}
if (newExpression == null)
{
throw new ArgumentNullException(nameof(newExpression));
}
var visitor = new ReplaceParameterVisitor(oldExpression, newExpression);
return(visitor.Visit(expression));
}
private static Expression SelectStructuralProperties(Expression source, OeNavigationSelectItem root)
{
if (!root.HasNavigationItems())
{
return(source);
}
ParameterExpression parameter = Expression.Parameter(OeExpressionHelper.GetCollectionItemType(source.Type));
IReadOnlyList <MemberExpression> joins = OeExpressionHelper.GetPropertyExpressions(parameter);
var newJoins = new Expression[joins.Count];
List <OeNavigationSelectItem> navigationItems = FlattenNavigationItems(root, false);
bool isNavigationNullable = false;
for (int i = 0; i < navigationItems.Count; i++)
{
newJoins[i] = joins[i];
isNavigationNullable |= i > 0 && navigationItems[i].EdmProperty.Type.IsNullable;
if (!navigationItems[i].AllSelected)
{
IReadOnlyList <OeStructuralSelectItem> structuralItems = navigationItems[i].GetStructuralItemsWithNotSelected();
if (structuralItems.Count > 0)
{
var properties = new Expression[structuralItems.Count];
for (int j = 0; j < structuralItems.Count; j++)
{
if (structuralItems[j].EdmProperty is ComputeProperty computeProperty)
{
properties[j] = new ReplaceParameterVisitor(joins[i]).Visit(computeProperty.Expression);
}
else
{
PropertyInfo property = joins[i].Type.GetPropertyIgnoreCase(structuralItems[j].EdmProperty);
properties[j] = Expression.Property(joins[i], property);
}
}
Expression newTupleExpression = OeExpressionHelper.CreateTupleExpression(properties);
if (isNavigationNullable)
{
UnaryExpression nullConstant = Expression.Convert(OeConstantToVariableVisitor.NullConstantExpression, newTupleExpression.Type);
newTupleExpression = Expression.Condition(Expression.Equal(joins[i], OeConstantToVariableVisitor.NullConstantExpression), nullConstant, newTupleExpression);
}
newJoins[i] = newTupleExpression;
}
}
}
NewExpression newSelectorBody = OeExpressionHelper.CreateTupleExpression(newJoins);
MethodInfo selectMethodInfo = OeMethodInfoHelper.GetSelectMethodInfo(parameter.Type, newSelectorBody.Type);
LambdaExpression newSelector = Expression.Lambda(newSelectorBody, parameter);
//Quirk EF Core 2.1.1 bug Take/Skip must be last in expression tree
var skipTakeExpressions = new List <MethodCallExpression>();
while (source is MethodCallExpression callExpression && (callExpression.Method.Name == nameof(Enumerable.Skip) || callExpression.Method.Name == nameof(Enumerable.Take)))
{
skipTakeExpressions.Add(callExpression);
source = callExpression.Arguments[0];
}
source = Expression.Call(selectMethodInfo, source, newSelector);
for (int i = skipTakeExpressions.Count - 1; i >= 0; i--)
{
MethodInfo skipTakeMethodInfo = skipTakeExpressions[i].Method.GetGenericMethodDefinition().MakeGenericMethod(newSelector.ReturnType);
source = Expression.Call(skipTakeMethodInfo, source, skipTakeExpressions[i].Arguments[1]);
}
return(source);
}
private static Expression GetValueExpression(Expression valueExpression,
ParameterExpression parameter)
{
valueExpression = new ReplaceParameterVisitor(parameter).Visit(valueExpression);
return(valueExpression);
}
