static OperatorComparisonAttribute()
{
Equal = new OperatorComparisonAttribute(OperatorType.Equal);
NotEqual = new OperatorComparisonAttribute(OperatorType.NotEqual);
GreaterThan = new OperatorComparisonAttribute(OperatorType.GreaterThan);
GreaterThanOrEqual = new OperatorComparisonAttribute(OperatorType.GreaterThanOrEqual);
LessThan = new OperatorComparisonAttribute(OperatorType.LessThan);
LessThanOrEqual = new OperatorComparisonAttribute(OperatorType.LessThanOrEqual);
}
public Expression BuildExpression(Type entityType, Expression body)
{
Expression finalExpression = body;
foreach (var key in this.Keys)
{
var filterValue = new DynamicFilter(this[key]);
if (IsPrimitive(key))
{
var targetProperty = entityType.GetProperty(key);
var value = Convert.ChangeType((string)filterValue, targetProperty.PropertyType);
var exp = new OperatorComparisonAttribute(OperatorType.Equal).BuildExpression(body, targetProperty, filterProperty: null, value);
var combined = finalExpression.Combine(exp, CombineWith);
finalExpression = body.Combine(combined, CombineWith);
}
else
{
var splitted = key.Split('.');
if (IsNotInnerObject(splitted))
{
var propName = splitted[0];
var targetProperty = entityType.GetProperty(propName);
var value = Convert.ChangeType((string)filterValue, targetProperty.PropertyType);
var comparisonKeyword = splitted[1];
if (specialKeywords.TryGetValue(comparisonKeyword, out IFilterableType filterable))
{
var exp = filterable.BuildExpression(body, targetProperty, filterProperty: null, value);
var combined = finalExpression.Combine(exp, CombineWith);
finalExpression = body.Combine(combined, CombineWith);
}
}
else
{
throw new NotImplementedException("Inner objects are not supported yet!");
}
}
}
return(finalExpression);
bool IsNotInnerObject(string[] splitted) => splitted.Length == 2;
}
