I have two drop down lists. Niether of them have a relation ship with each other. But I need to filter one drop down list based on the chosen value of another drop down list.
I can filter it in code. When I debug I can see the filtered results on the property. However when I run the app, it does not work. Here is my code so far:
private BindingList<Commodity> _AllocationCommodities;
[Browsable(false)]
public BindingList<Commodity> AllocationCommodities
{
get
{
if (_AllocationCommodities == null)
{
_AllocationCommodities = new BindingList<Commodity>();
ChangeCommodities();
}
return _AllocationCommodities;
}
}
private SourceEntity _SourceEntity;
[ImmediatePostData]
[Association("SourceEntity-LimitAllocations")]
[RuleRequiredField("RuleRequiredField_LimitAllocation_SourceEntity", DefaultContexts.Save)]
public SourceEntity SourceEntity
{
get
{
return _SourceEntity;
}
set
{
//New Code
if (SetPropertyValue<SourceEntity>("SourceEntity", value))
{
if (IsSaving || IsLoading) return;
ChangeCommodities();
}
}
}
private Commodity _Commodity;// This is the drop down to be filtered
[ImmediatePostData]
[DataSourceProperty("AllocationCommodities")] //// This Attribute Should filter Commodities
[RuleRequiredField("RuleRequiredField_LimitAllocation_Commodity", DefaultContexts.Save)]
public Commodity Commodity
{
get
{
return _Commodity;
}
set
{
SetPropertyValue("Commodity", ref _Commodity, value);
if (Commodity.Oid != Guid.Empty)
AllocationVolumeUnits.Reload();
}
}
private void ChangeCommodities()
{
if (!this.IsLoading && _SourceEntity != null)
{
_AllocationCommodities.RaiseListChangedEvents = false;
_AllocationCommodities.Clear();
OperandValue[] _params;
System.Collections.Generic.List<CMSBOD.SourceCommodity> _sc = new System.Collections.Generic.List<SourceCommodity>();
BindingList<Commodity> _Commodities = new BindingList<Commodity>();
foreach (SourceCommodityEntity _tempSCE in _SourceEntity.SourceCommodityEntities)
{
if (_tempSCE.SourceCommodity != null)
_sc.Add(_tempSCE.SourceCommodity);
}
foreach (SourceCommodity _tempSC in _sc)
{
if (_tempSC.Commodity != null && !_Commodities.Contains<Commodity>(_tempSC.Commodity) && _tempSC.Commodity.IsActive)
_Commodities.Add(_tempSC.Commodity);
}
_AllocationCommodities.RaiseListChangedEvents = true;
_AllocationCommodities = _Commodities;///This is where I can see the filtered list when debugging.
}
}
You can find a DataSourceCriteria useful in this scenario, instead of DataSourceProperty.
Assuming you have collection properties that associates Commodity back to SourceCommodityEntity, you can use this criteria:
[DataSourceCriteria("IsActive And SourceCommodities[SourceCommodityEntities[SourceEntity = '@SourceEntity'] ]")]
Even if its designed to be a 1x1 assocation, you can find that associations can be useful for filtering purposes.