public override Expression HandleOperation(
QueryableFilterContext context,
IFilterOperationField field,
IValueNode value,
object parsedValue)
{
if (context.RuntimeTypes.Count > 0 &&
context.RuntimeTypes.Peek().TypeArguments is { Count : > 0 } args&&
parsedValue is bool parsedBool)
{
Expression?property = context.GetInstance();
Expression expression;
if (parsedBool)
{
expression = FilterExpressionBuilder.Any(args[0].Source, property);
}
else
{
expression = FilterExpressionBuilder.Not(
FilterExpressionBuilder.Any(args[0].Source, property));
}
if (context.InMemory)
{
expression = FilterExpressionBuilder.NotNullAndAlso(property, expression);
}
return(expression);
}
throw new InvalidOperationException();
}
protected object?ParseValue(
IValueNode node,
object?parsedValue,
IType type,
QueryableFilterContext context)
{
if (parsedValue is null)
{
return(parsedValue);
}
Type returnType = context.RuntimeTypes.Peek().Source;
if (type.IsListType())
{
Type elementType = type.ElementType().ToRuntimeType();
if (returnType != elementType)
{
Type listType = typeof(List <>).MakeGenericType(returnType);
parsedValue = TypeConverter.Convert(typeof(object), listType, parsedValue) ??
throw ThrowHelper.FilterConvention_CouldNotConvertValue(node);
}
return(parsedValue);
}
if (!returnType.IsInstanceOfType(parsedValue))
{
parsedValue = TypeConverter.Convert(typeof(object), returnType, parsedValue) ??
throw ThrowHelper.FilterConvention_CouldNotConvertValue(node);
}
return(parsedValue);
}
protected override Expression HandleListOperation(
QueryableFilterContext context,
IFilterField field,
ObjectFieldNode node,
Type closureType,
LambdaExpression lambda) =>
FilterExpressionBuilder.All(closureType, context.GetInstance(), lambda);
public override Expression HandleOperation(
QueryableFilterContext context,
IFilterOperationField field,
IValueNode value,
object?parsedValue)
{
Expression property = context.GetInstance();
return(FilterExpressionBuilder.Contains(property, parsedValue));
}
public override Expression HandleOperation(
QueryableFilterContext context,
IFilterOperationField field,
IValueNode value,
object?parsedValue)
{
Expression property = context.GetInstance();
parsedValue = ParseValue(value, parsedValue, field.Type, context);
return(FilterExpressionBuilder.NotEquals(property, parsedValue));
}
public override Expression HandleOperation(
QueryableFilterContext context,
IFilterOperationField field,
IValueNode value,
object parsedValue)
{
Expression property = context.GetInstance();
return(FilterExpressionBuilder.In(
property,
context.RuntimeTypes.Peek().Source,
parsedValue));
}
public static FilterScope <Expression> AddIsNullClosure(
this QueryableFilterContext context)
{
var closure = new QueryableScope(
context.RuntimeTypes.Peek(), "_s" + context.Scopes.Count, false);
context.Scopes.Push(closure);
context.GetLevel().Enqueue(
FilterExpressionBuilder.Equals(context.GetClosure().Parameter, null));
return(closure);
}
public Func <T, bool> Build <T>(IValueNode filter)
{
var visitorContext = new QueryableFilterContext(_inputType, true);
var visitor = new FilterVisitor <QueryableFilterContext, Expression>(
new QueryableCombinator());
visitor.Visit(filter, visitorContext);
if (visitorContext.TryCreateLambda(out Expression <Func <T, bool> >?where))
{
return(where.Compile());
}
throw new InvalidOperationException();
}
/// <summary>
/// Tries to build the a typed expression based on the items that are stored on the scope
/// </summary>
/// <param name="context">the context</param>
/// <param name="expression">The query that was build</param>
/// <typeparam name="T">The generic type of the expression</typeparam>
/// <returns>True in case the query has been build successfully, otherwise false</returns>
public static bool TryCreateLambda <T>(
this QueryableFilterContext context,
[NotNullWhen(true)] out Expression <T>?expression)
{
if (context.Scopes.TryPeekElement(out FilterScope <Expression>?scope) &&
scope is QueryableScope closure &&
closure.Level.TryPeekElement(out Queue <Expression>?levels) &&
levels.TryPeekElement(out Expression? level))
{
expression = Expression.Lambda <T>(level, closure.Parameter);
return(true);
}
expression = null;
return(false);
}
public override Expression HandleOperation(
QueryableFilterContext context,
IFilterOperationField field,
IValueNode value,
object?parsedValue)
{
Expression property = context.GetInstance();
parsedValue = ParseValue(value, parsedValue, field.Type, context);
if (parsedValue is null)
{
throw new InvalidOperationException();
}
return(FilterExpressionBuilder.GreaterThan(property, parsedValue));
}
public static bool TryCreateLambda(
this QueryableFilterContext context,
[NotNullWhen(true)] out LambdaExpression?expression)
{
if (context.Scopes.TryPeek(out FilterScope <Expression>?scope) &&
scope is QueryableScope closure)
{
expression = null;
if (closure.Level.Peek().Count == 0)
{
return(false);
}
expression = Expression.Lambda(closure.Level.Peek().Peek(), closure.Parameter);
return(true);
}
expression = null;
return(false);
}
/// <summary>
/// Reads the current closure from the context
/// </summary>
/// <param name="context">The context</param>
/// <returns>The current closure</returns>
public static QueryableScope GetClosure(
this QueryableFilterContext context) =>
(QueryableScope)context.GetScope();