dotnet-dynamic-linq/PoweredSoft.DynamicLinq/Helpers/QueryableHelpers.cs
2019-03-19 17:01:51 -05:00

615 lines
32 KiB
C#

using PoweredSoft.DynamicLinq.DynamicType;
using PoweredSoft.DynamicLinq.Parser;
using PoweredSoft.DynamicLinq.Resolver;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
namespace PoweredSoft.DynamicLinq.Helpers
{
public static class QueryableHelpers
{
public static Expression GetConditionExpressionForMember(ParameterExpression parameter, Expression member, ConditionOperators conditionOperator, ConstantExpression constant, StringComparison? stringComparision, bool negate)
{
if (parameter == null)
throw new ArgumentNullException("parameter");
if (member == null)
throw new ArgumentNullException("member");
if (constant == null)
throw new ArgumentNullException("constant");
Type stringType = typeof(string);
Expression ret = null;
if (conditionOperator == ConditionOperators.Equal)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.Call(member, Constants.StringEqualWithComparisation, constant, Expression.Constant(stringComparision.Value));
else
ret = Expression.Equal(member, constant);
}
else if (conditionOperator == ConditionOperators.NotEqual)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.Not(Expression.Call(member, Constants.StringEqualWithComparisation, constant, Expression.Constant(stringComparision.Value)));
else
ret = Expression.NotEqual(member, constant);
}
else if (conditionOperator == ConditionOperators.GreaterThan)
ret = Expression.GreaterThan(member, constant);
else if (conditionOperator == ConditionOperators.GreaterThanOrEqual)
ret = Expression.GreaterThanOrEqual(member, constant);
else if (conditionOperator == ConditionOperators.LessThan)
ret = Expression.LessThan(member, constant);
else if (conditionOperator == ConditionOperators.LessThanOrEqual)
ret = Expression.LessThanOrEqual(member, constant);
else if (conditionOperator == ConditionOperators.Contains)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.GreaterThan(Expression.Call(member, Constants.IndexOfMethod, constant, Expression.Constant(stringComparision.Value)), Expression.Constant(-1));
else
ret = Expression.Call(member, Constants.ContainsMethod, constant);
}
else if (conditionOperator == ConditionOperators.NotContains)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.GreaterThan(Expression.Not(Expression.Call(member, Constants.IndexOfMethod, constant, Expression.Constant(stringComparision.Value))), Expression.Constant(-1));
else
ret = Expression.Not(Expression.Call(member, Constants.ContainsMethod, constant));
}
else if (conditionOperator == ConditionOperators.StartsWith)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.Call(member, Constants.StartsWithMethodWithComparisation, constant, Expression.Constant(stringComparision.Value));
else
ret = Expression.Call(member, Constants.StartsWithMethod, constant);
}
else if (conditionOperator == ConditionOperators.EndsWith)
{
if (member.Type == stringType && stringComparision.HasValue)
ret = Expression.Call(member, Constants.EndsWithMethodWithComparisation, constant, Expression.Constant(stringComparision.Value));
else
ret = Expression.Call(member, Constants.EndsWithMethod, constant);
}
else
throw new ArgumentException("conditionOperator", "Must supply a known condition operator");
if (negate)
ret = Expression.Not(ret);
return ret;
}
public static IQueryable GroupBy(IQueryable query, Type type, List<(string path, string propertyName)> parts, Type groupToType = null, Type equalityCompareType = null, bool nullChecking = false)
{
// EXPRESSION
var parameter = Expression.Parameter(type, "t");
var partExpressions = new List<(Expression expression, string propertyName)>();
var fields = new List<(Type type, string propertyName)>();
// resolve part expression and create the fields inside the anonymous type.
parts.ForEach(part =>
{
var partExpression = CreateSelectExpression(query, parameter, SelectTypes.Path, part.path, SelectCollectionHandling.LeaveAsIs, nullChecking: nullChecking);
fields.Add((partExpression.Type, part.propertyName));
partExpressions.Add((partExpression, part.propertyName));
});
var keyType = groupToType ?? DynamicClassFactory.CreateType(fields);
var ctor = Expression.New(keyType);
var bindings = partExpressions.Select(partExpression => Expression.Bind(keyType.GetProperty(partExpression.propertyName), partExpression.expression)).ToArray();
var mi = Expression.MemberInit(ctor, bindings);
var lambda = Expression.Lambda(mi, parameter);
var genericMethod = equalityCompareType == null ? Constants.GroupByMethod.MakeGenericMethod(type, keyType) : Constants.GroupByMethodWithEqualityComparer.MakeGenericMethod(type, keyType); //, Activator.CreateInstance(equalityCompareType));
var groupByExpression = equalityCompareType == null ? Expression.Call(genericMethod, query.Expression, lambda) : Expression.Call(genericMethod, query.Expression, lambda, Expression.New(equalityCompareType));
var result = query.Provider.CreateQuery(groupByExpression);
return result;
}
public static IQueryable Select(IQueryable query, List<(SelectTypes selectType, string propertyName, string path, SelectCollectionHandling selectCollectionHandling)> parts, Type destinationType = null, bool nullChecking = false)
{
// create parameter.
var queryType = query.ElementType;
var parameter = Expression.Parameter(queryType, "t");
// establish which anynomous types we might need to create.
var fields = new List<(Type type, string propertyName)>();
var partExpressions = new List<(Expression expression, string propertyName)>();
parts.ForEach(part =>
{
var partBodyExpression = CreateSelectExpression(query, parameter, part.selectType, part.path, part.selectCollectionHandling, nullChecking);
fields.Add((partBodyExpression.Type, part.propertyName));
partExpressions.Add((partBodyExpression, part.propertyName));
});
// type to use.
var typeToCreate = destinationType ?? DynamicClassFactory.CreateType(fields);
var ctor = Expression.New(typeToCreate);
var bindings = partExpressions.Select(t => Expression.Bind(typeToCreate.GetProperty(t.propertyName), t.expression)).ToArray();
var mi = Expression.MemberInit(ctor, bindings);
var lambda = Expression.Lambda(mi, parameter);
var selectExpr = Expression.Call(typeof(Queryable), "Select", new[] { query.ElementType, typeToCreate }, query.Expression, lambda);
var result = query.Provider.CreateQuery(selectExpr);
return result;
}
private static Expression CreateSelectExpressionForGrouping(IQueryable query, ParameterExpression parameter, SelectTypes selectType, string path, SelectCollectionHandling selectCollectionHandling, bool nullChecking)
{
if (selectType == SelectTypes.Key)
{
var parser = new ExpressionParser(parameter, path);
var resolver = new PathExpressionResolver(parser);
resolver.NullChecking = nullChecking;
resolver.Resolve();
return resolver.GetResultBodyExpression();
}
else if (selectType == SelectTypes.Count)
{
var notGroupedType = parameter.Type.GenericTypeArguments[1];
var body = Expression.Call(typeof(Enumerable), "Count", new[] { notGroupedType }, parameter);
return body;
}
else if (selectType == SelectTypes.LongCount)
{
var notGroupedType = parameter.Type.GenericTypeArguments[1];
var body = Expression.Call(typeof(Enumerable), "LongCount", new[] { notGroupedType }, parameter);
return body;
}
else if (selectType == SelectTypes.Average)
return CreateGroupedAggregateExpression(parameter, path, "Average");
else if (selectType == SelectTypes.Sum)
return CreateGroupedAggregateExpression(parameter, path, "Sum");
else if (selectType == SelectTypes.Min)
return CreateGroupedAggregateExpression(parameter, path, "Min");
else if (selectType == SelectTypes.Max)
return CreateGroupedAggregateExpression(parameter, path, "Max");
else if (selectType == SelectTypes.ToList)
return CreateGroupedPathExpressionWithMethod(parameter, path, selectCollectionHandling, nullChecking, "ToList");
else if (selectType == SelectTypes.First)
return CreateGroupedPathExpressionWithMethod(parameter, path, selectCollectionHandling, nullChecking, "First");
else if (selectType == SelectTypes.Last)
return CreateGroupedPathExpressionWithMethod(parameter, path, selectCollectionHandling, nullChecking, "Last");
else if (selectType == SelectTypes.FirstOrDefault)
return CreateGroupedPathExpressionWithMethod(parameter, path, selectCollectionHandling, nullChecking, "FirstOrDefault");
else if (selectType == SelectTypes.LastOrDefault)
return CreateGroupedPathExpressionWithMethod(parameter, path, selectCollectionHandling, nullChecking, "LastOrDefault");
throw new NotSupportedException($"unkown select type {selectType}");
}
private static Expression CreateGroupedAggregateExpression(ParameterExpression parameter, string path, string methodName)
{
/// https://stackoverflow.com/questions/25482097/call-enumerable-average-via-expression
var notGroupedType = parameter.Type.GenericTypeArguments[1];
var innerParameter = Expression.Parameter(notGroupedType);
var innerMemberExpression = ResolvePathForExpression(innerParameter, path);
var innerMemberLambda = Expression.Lambda(innerMemberExpression, innerParameter);
var body = Expression.Call(typeof(Enumerable), methodName, new[] { notGroupedType }, parameter, innerMemberLambda);
return body;
}
private static Expression CreateGroupedPathExpressionWithMethod(ParameterExpression parameter, string path, SelectCollectionHandling selectCollectionHandling, bool nullChecking, string methodName)
{
if (string.IsNullOrWhiteSpace(path))
{
var notGroupedType = parameter.Type.GenericTypeArguments[1];
var body = Expression.Call(typeof(Enumerable), methodName, new[] { notGroupedType }, parameter);
return body;
}
else
{
var notGroupedType = parameter.Type.GenericTypeArguments[1];
var innerParameter = Expression.Parameter(notGroupedType);
var parser = new ExpressionParser(innerParameter, path);
var resolver = new PathExpressionResolver(parser);
resolver.NullChecking = nullChecking;
resolver.Resolve();
var expression = resolver.Result;
var selectExpression = WrapIntoSelectFromGrouping(parameter, expression, selectCollectionHandling);
var body = CallMethodOnSelectExpression(methodName, selectExpression);
return body;
}
}
private static Expression WrapIntoSelectFromGrouping(ParameterExpression parameter, Expression innerLambdaExpression, SelectCollectionHandling selectCollectionHandling)
{
var selectType = parameter.Type.GenericTypeArguments.Skip(1).First();
var innerSelectType = ((LambdaExpression)innerLambdaExpression).ReturnType;
Expression selectExpression;
if (QueryableHelpers.IsGenericEnumerable(innerSelectType) && selectCollectionHandling == SelectCollectionHandling.Flatten)
selectExpression = Expression.Call(typeof(Enumerable), "SelectMany", new Type[] { selectType, innerSelectType.GenericTypeArguments.First() }, parameter, innerLambdaExpression);
else
selectExpression = Expression.Call(typeof(Enumerable), "Select", new Type[] { selectType, innerSelectType }, parameter, innerLambdaExpression);
return selectExpression;
}
private static Expression CreateSelectExpression(IQueryable query, ParameterExpression parameter, SelectTypes selectType, string path, SelectCollectionHandling selectCollectionHandling, bool nullChecking)
{
if (!IsGrouping(query))
return CreateSelectExpressionRegular(query, parameter, selectType, path, selectCollectionHandling, nullChecking);
return CreateSelectExpressionForGrouping(query, parameter, selectType, path, selectCollectionHandling, nullChecking);
}
private static Expression CreateSelectExpressionRegular(IQueryable query, ParameterExpression parameter, SelectTypes selectType, string path
, SelectCollectionHandling selectCollectionHandling, bool nullChecking)
{
if (selectType == SelectTypes.Path)
{
var parser = new ExpressionParser(parameter, path);
var resolver = new PathExpressionResolver(parser);
resolver.NullChecking = nullChecking;
resolver.Resolve();
return resolver.GetResultBodyExpression();
}
else if (selectType == SelectTypes.ToList)
return CreateSelectExpressionPathWithMethodName(parameter, path, selectCollectionHandling, nullChecking, "ToList");
else if (selectType == SelectTypes.First)
return CreateSelectExpressionPathWithMethodName(parameter, path, selectCollectionHandling, nullChecking, "First");
else if (selectType == SelectTypes.FirstOrDefault)
return CreateSelectExpressionPathWithMethodName(parameter, path, selectCollectionHandling, nullChecking, "FirstOrDefault");
else if (selectType == SelectTypes.Last)
return CreateSelectExpressionPathWithMethodName(parameter, path, selectCollectionHandling, nullChecking, "Last");
else if (selectType == SelectTypes.LastOrDefault)
return CreateSelectExpressionPathWithMethodName(parameter, path, selectCollectionHandling, nullChecking, "LastOrDefault");
throw new NotSupportedException($"unkown select type {selectType}");
}
private static Expression CreateSelectExpressionPathWithMethodName(ParameterExpression parameter, string path, SelectCollectionHandling selectCollectionHandling, bool nullChecking, string methodName)
{
var parser = new ExpressionParser(parameter, path);
var resolver = new PathExpressionResolver(parser);
resolver.NullChecking = nullChecking;
resolver.CollectionHandling = selectCollectionHandling;
resolver.Resolve();
var expr = (resolver.Result as LambdaExpression).Body;
var notGroupedType = expr.Type.GenericTypeArguments.FirstOrDefault();
if (notGroupedType == null)
throw new Exception($"Path must be a Enumerable<T> but its a {expr.Type}");
var body = Expression.Call(typeof(Enumerable), methodName, new[] { notGroupedType }, expr) as Expression;
return body;
}
private static Expression CallMethodOnSelectExpression(string methodName, Expression selectExpression)
{
var notGroupedType = selectExpression.Type.GenericTypeArguments.First();
var body = Expression.Call(typeof(Enumerable), methodName, new[] { notGroupedType }, selectExpression) as Expression;
return body;
}
private static bool IsGrouping(IQueryable query)
{
// TODO needs to be alot better than this, but it will do for now.
if (query.ElementType.Name.Contains("IGrouping"))
return true;
return false;
}
public static IQueryable GroupBy(IQueryable query, Type type, string path)
{
var parameter = Expression.Parameter(type, "t");
var field = QueryableHelpers.ResolvePathForExpression(parameter, path);
var lambda = Expression.Lambda(field, parameter);
var genericMethod = Constants.GroupByMethod.MakeGenericMethod(type, field.Type);
var groupByEpression = Expression.Call(genericMethod, query.Expression, lambda);
var result = query.Provider.CreateQuery(groupByEpression);
return result;
}
internal static Expression InternalResolvePathExpression(int step, Expression param, List<string> parts, SelectCollectionHandling selectCollectionHandling, bool nullChecking, Type nullCheckingType = null)
{
var isLast = parts.Count == 1;
var currentPart = parts.First();
var memberExpression = Expression.PropertyOrField(param, currentPart);
if (isLast)
return memberExpression;
Expression ret = null;
if (!IsGenericEnumerable(memberExpression))
{
// TODO: null checking here too.
// should be easier then collection :=|
ret = InternalResolvePathExpression(step + 1, memberExpression, parts.Skip(1).ToList(), selectCollectionHandling, nullChecking, nullCheckingType: nullCheckingType);
}
else
{
// enumerable.
var listGenericArgumentType = memberExpression.Type.GetGenericArguments().First();
// sub param.
var innerParam = Expression.Parameter(listGenericArgumentType);
var innerExpression = InternalResolvePathExpression(step + 1, innerParam, parts.Skip(1).ToList(), selectCollectionHandling, nullChecking);
var lambda = Expression.Lambda(innerExpression, innerParam);
if (selectCollectionHandling == SelectCollectionHandling.LeaveAsIs)
ret = Expression.Call(typeof(Enumerable), "Select", new Type[] { listGenericArgumentType, innerExpression.Type }, memberExpression, lambda);
else
ret = Expression.Call(typeof(Enumerable), "SelectMany", new Type[] { listGenericArgumentType, innerExpression.Type.GenericTypeArguments.First() }, memberExpression, lambda);
}
if (step == 1 && nullChecking)
{
ret = Expression.Condition(
Expression.Equal(memberExpression, Expression.Constant(null)),
Expression.New(nullCheckingType),
ret
);
}
return ret;
}
/// <summary>
/// Returns the right expression for a path supplied.
/// </summary>
/// <param name="param">Expression.Parameter(typeOfClassOrInterface)</param>
/// <param name="path">the path you wish to resolve example Contact.Profile.FirstName</param>
/// <returns></returns>
public static Expression ResolvePathForExpression(ParameterExpression param, string path, bool throwIfHasEnumerable = true)
{
var expressionParser = new ExpressionParser(param, path);
expressionParser.Parse();
if (throwIfHasEnumerable && expressionParser.Pieces.Any(t2 => t2.IsGenericEnumerable))
throw new Exception("Path contains an enumerable, and this feature does not support it.");
var expressionResolver = new PathExpressionResolver(expressionParser);
expressionResolver.Resolve();
return expressionResolver.GetResultBodyExpression();
}
public static ConstantExpression GetConstantSameAsLeftOperator(Expression member, object value)
{
if (member == null)
throw new ArgumentNullException("member");
if (value == null)
return Expression.Constant(null);
var convertedValue = PoweredSoft.Types.Converter.To(value, member.Type);
return Expression.Constant(convertedValue, member.Type);
}
public static ConstantExpression ResolveConstant(Expression member, object value, QueryConvertStrategy convertStrategy)
{
if (convertStrategy == QueryConvertStrategy.LeaveAsIs)
return Expression.Constant(value);
if (convertStrategy == QueryConvertStrategy.SpecifyType)
return Expression.Constant(value, member.Type);
if (convertStrategy == QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)
return QueryableHelpers.GetConstantSameAsLeftOperator(member, value);
throw new NotSupportedException($"{convertStrategy} supplied is not recognized");
}
public static IQueryable CreateOrderByExpression(IQueryable query, string path, QueryOrderByDirection direction, bool append = true)
{
var parameter = Expression.Parameter(query.ElementType, "t");
var member = QueryableHelpers.ResolvePathForExpression(parameter, path);
string sortCommand = null;
if (direction == QueryOrderByDirection.Descending)
sortCommand = append == false ? "OrderByDescending" : "ThenByDescending";
else
sortCommand = append == false ? "OrderBy" : "ThenBy";
var expression = Expression.Lambda(member, parameter);
var resultExpression = Expression.Call
(typeof(Queryable),
sortCommand,
new Type[] { query.ElementType, member.Type },
query.Expression,
Expression.Quote(expression)
);
query = query.Provider.CreateQuery(resultExpression);
return query;
}
/*
* var methodInfo = typeof(List<Guid>).GetMethod("Contains", new Type[] { typeof(Guid) });
var list = Expression.Constant(ids);
var param = Expression.Parameter(typeof(T), "t");
var value = Expression.PropertyOrField(param, idField);
var body = Expression.Call(list, methodInfo, value);
var lambda = Expression.Lambda<Func<T, bool>>(body, param);
query = query.Where(lambda);
*/
internal static Expression InternalCreateConditionExpression(int recursionStep, Type type, ParameterExpression parameter, Expression current, List<string> parts,
ConditionOperators condition, object value, QueryConvertStrategy convertStrategy, QueryCollectionHandling collectionHandling, bool nullChecking, StringComparison? stringComparison, bool negate)
{
var partStr = parts.First();
var isLast = parts.Count == 1;
// the member expression.
var memberExpression = Expression.PropertyOrField(current, partStr);
// TODO : maybe support that last part is collection but what do we do?
// not supported yet.
if (isLast && IsGenericEnumerable(memberExpression) && value != null)
throw new NotSupportedException("Can only compare collection to null");
// create the expression and return it.
if (isLast)
{
if (condition == ConditionOperators.In || condition == ConditionOperators.NotIn)
{
return InAndNotIn(parameter, condition, value, convertStrategy, memberExpression);
}
else
{
var constant = QueryableHelpers.ResolveConstant(memberExpression, value, convertStrategy);
var filterExpression = QueryableHelpers.GetConditionExpressionForMember(parameter, memberExpression, condition, constant, stringComparison, negate);
var lambda = Expression.Lambda(filterExpression, parameter);
return lambda;
}
}
// null check.
Expression nullCheckExpression = null;
if (nullChecking)
nullCheckExpression = Expression.NotEqual(memberExpression, Expression.Constant(null));
if (IsGenericEnumerable(memberExpression))
{
var listGenericArgumentType = memberExpression.Type.GetGenericArguments().First();
var innerParameter = Expression.Parameter(listGenericArgumentType, $"t{++recursionStep}");
var innerLambda = InternalCreateConditionExpression(recursionStep, listGenericArgumentType, innerParameter, innerParameter, parts.Skip(1).ToList(), condition, value, convertStrategy, collectionHandling, nullChecking, stringComparison, negate);
// the collection method.
var collectionMethod = GetCollectionMethod(collectionHandling);
var genericMethod = collectionMethod.MakeGenericMethod(listGenericArgumentType);
var callResult = Expression.Call(genericMethod, memberExpression, innerLambda);
if (nullCheckExpression != null)
{
var nullCheckResult = Expression.AndAlso(nullCheckExpression, callResult);
return Expression.Lambda(nullCheckResult, parameter);
}
return Expression.Lambda(callResult, parameter);
}
else
{
if (nullCheckExpression != null)
{
var pathExpr = InternalCreateConditionExpression(recursionStep, type, parameter, memberExpression, parts.Skip(1).ToList(), condition, value, convertStrategy, collectionHandling, nullChecking, stringComparison, negate);
var nullCheckResult = Expression.AndAlso(nullCheckExpression, (pathExpr as LambdaExpression).Body);
var nullCheckResultLambda = Expression.Lambda((Expression)nullCheckResult, parameter);
return nullCheckResultLambda;
}
return InternalCreateConditionExpression(recursionStep, type, parameter, memberExpression, parts.Skip(1).ToList(), condition, value, convertStrategy, collectionHandling, nullChecking, stringComparison, negate);
}
}
public static Expression InAndNotIn(ParameterExpression parameter, ConditionOperators condition, object value, QueryConvertStrategy convertStrategy, MemberExpression memberExpression)
{
var enumerableValue = value as IEnumerable;
if (enumerableValue == null)
throw new Exception($"to use {ConditionOperators.In} your value must at least be IEnumerable");
var enumerableType = GetEnumerableType(enumerableValue);
var finalType = convertStrategy == QueryConvertStrategy.ConvertConstantToComparedPropertyOrField ? memberExpression.Type : enumerableType;
var genericListOfEnumerableType = typeof(List<>).MakeGenericType(memberExpression.Type);
var containsMethod = genericListOfEnumerableType.GetMethod("Contains", new Type[] { finalType });
var list = Activator.CreateInstance(genericListOfEnumerableType) as IList;
foreach (var o in enumerableValue)
{
if (convertStrategy == QueryConvertStrategy.ConvertConstantToComparedPropertyOrField)
list.Add(PoweredSoft.Types.Converter.To(o, memberExpression.Type));
else
list.Add(o);
}
var body = Expression.Call(Expression.Constant(list), containsMethod, memberExpression) as Expression;
if (condition == ConditionOperators.NotIn)
body = Expression.Not(body);
var lambda = Expression.Lambda(body, parameter);
return lambda;
}
private static Type GetEnumerableType(IEnumerable enumerableValue)
{
foreach (var o in enumerableValue)
return o.GetType();
return null;
}
public static MethodInfo GetCollectionMethod(QueryCollectionHandling collectionHandling)
{
if (collectionHandling == QueryCollectionHandling.All)
return Constants.AllMethod;
else if (collectionHandling == QueryCollectionHandling.Any)
return Constants.AnyMethod;
throw new NotSupportedException($"{collectionHandling} is not supported");
}
public static Expression<Func<T, bool>> CreateConditionExpression<T>(
string path,
ConditionOperators condition,
object value,
QueryConvertStrategy convertStrategy,
QueryCollectionHandling collectionHandling = QueryCollectionHandling.Any,
ParameterExpression parameter = null,
bool nullChecking = false,
StringComparison? stringComparision = null, bool negate = false)
{
var ret = CreateConditionExpression(typeof(T), path, condition, value, convertStrategy,
collectionHandling: collectionHandling,
parameter: parameter,
nullChecking: nullChecking,
stringComparision: stringComparision,
negate: negate) as Expression<Func<T, bool>>;
return ret;
}
public static Expression CreateConditionExpression(Type type,
string path,
ConditionOperators condition,
object value,
QueryConvertStrategy convertStrategy,
QueryCollectionHandling collectionHandling = QueryCollectionHandling.Any,
ParameterExpression parameter = null,
bool nullChecking = false,
StringComparison? stringComparision = null,
bool negate = false)
{
if (parameter == null)
parameter = Expression.Parameter(type, "t");
var parts = path.Split('.').ToList();
var result = InternalCreateConditionExpression(1, type, parameter, parameter, parts, condition, value, convertStrategy, collectionHandling, nullChecking, stringComparision, negate);
return result;
}
public static bool IsGenericEnumerable(Expression member) => IsGenericEnumerable(member.Type);
public static bool IsGenericEnumerable(Type type)
{
if (!type.IsGenericType)
return false;
var genericArgumentType = type.GenericTypeArguments.First();
var ret = typeof(IEnumerable<>).MakeGenericType(genericArgumentType).IsAssignableFrom(type);
return ret;
}
}
}