} // func CreateSelectorAsync
/// <summary>Create a selector from a select information.</summary>
/// <param name="select"></param>
/// <param name="columns"></param>
/// <param name="filter"></param>
/// <param name="order"></param>
/// <param name="throwException"></param>
/// <returns></returns>
public async Task <PpsDataSelector> CreateSelectorAsync(string select, PpsDataColumnExpression[] columns, PpsDataFilterExpression filter = null, PpsDataOrderExpression[] order = null, bool throwException = true)
{
if (String.IsNullOrEmpty(select))
{
throw new ArgumentNullException(nameof(select));
}
// create selector
var selectorInfo = new PpsViewJoinExpression(this, select, throwException);
if (!selectorInfo.IsValid && !throwException)
{
return(null);
}
// create selector
var selector = await selectorInfo.CreateSelectorAsync();
if (selector == null)
{
return(null);
}
// column restrictions
if (!PpsDataColumnExpression.IsEmpty(columns))
{
selector = selector.ApplyColumns(columns);
}
// apply filter rules
if (!PpsDataFilterExpression.IsEmpty(filter))
{
selector = selector.ApplyFilter(filter, selectorInfo.LookupFilter);
}
// apply order
if (!PpsDataOrderExpression.IsEmpty(order))
{
selector = selector.ApplyOrder(order, selectorInfo.LookupOrder);
}
return(selector);
} // func CreateSelector
public PpsViewJoinVisitor(PpsViewJoinExpression owner)
{
this.owner = owner ?? throw new ArgumentNullException(nameof(owner));
} // ctor
