public static Expression <Func <T, bool> > AppendOr <T>(Expression <Func <T, bool> > it, params Expression <Func <T, bool> >[] expressions)
{
LambdaExpression itLambda = it as LambdaExpression;
Expression exp = itLambda.Body;
ParameterExpression parameter = itLambda.Parameters[0];
foreach (Expression expression in expressions)
{
LambdaExpression expressionLambda = expression as LambdaExpression;
Expression convertedExpression = LinqRebinder.RebindExpression(expressionLambda.Body, expressionLambda.Parameters[0], parameter);
exp = Expression.AndAlso(exp, convertedExpression);
}
return(Expression.Lambda <Func <T, bool> >(exp, itLambda.Parameters));
}
private Expression Rebind(Expression <Func <TModel, bool> > expression, ParameterExpression parameter)
{
return(LinqRebinder.RebindExpression(expression.Body, expression.Parameters.First(), parameter));
}
public static Expression <Func <T, bool> > AppendExpressionOnMember <T>(Expression <Func <T, bool> > it, MemberInfo member, params Expression[] expressions)
{
PropertyInfo propertyInfo = null;
FieldInfo fieldInfo = null;
Type type;
if (member.MemberType == MemberTypes.Property)
{
propertyInfo = (PropertyInfo)member;
type = propertyInfo.PropertyType;
}
else if (member.MemberType == MemberTypes.Field)
{
fieldInfo = (FieldInfo)member;
type = fieldInfo.FieldType;
}
else
{
throw new ArgumentException("Member is not a property or a field");
}
LambdaExpression itLambda = (LambdaExpression)it;
Expression exp = itLambda.Body;
ParameterExpression parameter = itLambda.Parameters[0];
foreach (Expression expression in expressions)
{
LambdaExpression expressionLambda = expression as LambdaExpression;
var typeDetails = TypeAnalyzer.GetTypeDetail(type);
Type elementType = null;
if (type.IsArray)
{
elementType = typeDetails.InnerTypes[0];
}
else
{
if (typeDetails.InnerTypes.Count == 1)
{
elementType = typeDetails.InnerTypes[0];
}
}
if (elementType != null && typeDetails.IsIEnumerable)
{
Expression memberExpression = member.MemberType == MemberTypes.Property ?
Expression.Property(parameter, propertyInfo) :
Expression.Field(parameter, fieldInfo);
MethodInfo anyMethod2Generic = TypeAnalyzer.GetGenericMethodDetail(anyMethod2, elementType).MethodInfo;
MethodCallExpression callAny2 = Expression.Call(anyMethod2Generic, memberExpression, expressionLambda);
MethodInfo anyMethod1Generic = TypeAnalyzer.GetGenericMethodDetail(anyMethod1, elementType).MethodInfo;
MethodCallExpression callAny1 = Expression.Call(anyMethod1Generic, memberExpression);
Expression emptyCheckExpression = Expression.OrElse(Expression.Not(callAny1), callAny2);
if (exp.NodeType == ExpressionType.Constant && ((ConstantExpression)exp).Value?.ToString().ToBoolean() == true)
{
exp = emptyCheckExpression;
}
else
{
exp = Expression.AndAlso(exp, emptyCheckExpression);
}
}
else
{
Expression memberExpression = member.MemberType == MemberTypes.Property ?
Expression.Property(parameter, propertyInfo) :
Expression.Field(parameter, fieldInfo);
LambdaExpression convertedExpressionLambda = (LambdaExpression)LinqRebinder.RebindExpression(expressionLambda, expressionLambda.Parameters[0], memberExpression);
Expression nullCheckExpression = Expression.OrElse(Expression.Equal(memberExpression, Expression.Constant(null)), convertedExpressionLambda.Body);
if (exp.NodeType == ExpressionType.Constant && ((ConstantExpression)exp).Value?.ToString().ToBoolean() == true)
{
exp = nullCheckExpression;
}
else
{
exp = Expression.AndAlso(exp, nullCheckExpression);
}
}
}
return(Expression.Lambda <Func <T, bool> >(exp, itLambda.Parameters));
}