public bool AddLast(EFOperation operation, EFComparison comparison, object comparisonValue)
{
if (_filters.Count == 0)
{
_filters.AddLast(new EFValueFilter(comparison, comparisonValue, null));
}
else
{
_filters.AddLast(new EFValueFilter(comparison, comparisonValue, operation));
}
Filters = _filters.ToArray();
IsEmpty = false;
return(true);
}
public EFValueFilter(EFComparison comparison, object comparisonValue, EFOperation?operation)
{
Comparison = comparison;
ComparisonValue = comparisonValue;
Operation = operation;
}
private Linq.Expressions.Expression GetExpression(ParameterExpression modelExp, Type propertyType, string propertyName, EFComparison comparison, object comparisonValue)
{
var propertyExp = Linq.Expressions.Expression.Property(modelExp, propertyName);
var valueExp = Linq.Expressions.Expression.Constant(comparisonValue);
var trueExp = Linq.Expressions.Expression.Constant(true);
switch (comparison)
{
case EFComparison.Equal:
if (propertyType == typeof(string) && string.IsNullOrEmpty(comparisonValue?.ToString()))
{
return(Linq.Expressions.Expression.Call(typeof(string), nameof(string.IsNullOrEmpty), null, propertyExp)); // string.IsNullOrEmpty(i.PropertyName)
}
else
{
return(Linq.Expressions.Expression.Equal(propertyExp, valueExp)); //i.PropertyName = value;
}
case EFComparison.NotEqual:
if (propertyType == typeof(string) && string.IsNullOrEmpty(comparisonValue?.ToString())) // string.IsNullOrEmpty(i.PropertyName)==false
{
var isNullExp = Linq.Expressions.Expression.Call(typeof(string), nameof(string.IsNullOrEmpty), null, propertyExp); // string.IsNullOrEmpty(i.PropertyName)
return(Linq.Expressions.Expression.NotEqual(isNullExp, trueExp)); //string.IsNullOrEmpty(i.PropertyName) != true
}
else
{
return(Linq.Expressions.Expression.NotEqual(propertyExp, valueExp)); //i.PropertyName != value;
}
case EFComparison.GreaterThan:
return(Linq.Expressions.Expression.GreaterThan(propertyExp, valueExp)); //i.PropertyName > value;
case EFComparison.GreaterThanOrEqual:
return(Linq.Expressions.Expression.GreaterThanOrEqual(propertyExp, valueExp)); //i.PropertyName >= value;
case EFComparison.LessThan:
return(Linq.Expressions.Expression.LessThan(propertyExp, valueExp)); //i.PropertyName < value;
case EFComparison.LessThanOrEqual:
return(Linq.Expressions.Expression.LessThanOrEqual(propertyExp, valueExp)); //i.PropertyName <= value;
case EFComparison.Contains:
return(Linq.Expressions.Expression.Call(propertyExp, nameof(string.Contains), null, valueExp)); // i.PropertyName.Contains(value);
case EFComparison.NotContains:
var containsExp = Linq.Expressions.Expression.Call(propertyExp, nameof(string.Contains), null, valueExp);
return(Linq.Expressions.Expression.NotEqual(containsExp, trueExp)); //i.PropertyName.Contains(value) != true
case EFComparison.StartWith:
return(Linq.Expressions.Expression.Call(propertyExp, nameof(string.StartsWith), null, valueExp)); // i.PropertyName.StartsWith(value);
case EFComparison.EndWith:
return(Linq.Expressions.Expression.Call(propertyExp, nameof(string.EndsWith), null, valueExp)); // i.PropertyName.EndsWith(value);
default:
break;
}
return(null);
}
