Efficiently Retrieve Crop Box for Given View

Konrads Samulis shared a very nice solution to retrieve the crop box for a given view using a highly efficient parameter filter in his comment on rotating a plan view.

In his own words:

In digging up this old thread, I found something quite curious in the API in 18.1, that I’m not sure was there before.

The method of using a temporary transaction (with rollback) to find the element id of the crop box was taking a very long time on a large model, so I did a bit of digging to see how I could improve it.

I noticed that in the built-in parameter ID_PARAM of the crop box contains the element id of the view it’s in. E.g., the crop box ‘points’ to the id of the view it is in using ID_PARAM.

That got me thinking… why not use a parameter filter to retrieve it?

So… in VB.NET (because I’m an old school vber):

Public Function GetELementIDOfCropBox(activeView As View, revDoc As Document) As ElementId
  Dim provider As ParameterValueProvider = New ParameterValueProvider(New ElementId(CInt(BuiltInParameter.ID_PARAM)))
  Dim ruleID_PARAM As FilterElementIdRule = New FilterElementIdRule(provider, New FilterNumericEquals(), activeView.Id)
  Dim filter As ElementParameterFilter = New ElementParameterFilter(ruleID_PARAM)
  Dim collector = New FilteredElementCollector(revDoc).WherePasses(filter).ToElementIds().Except(New List(Of ElementId)(New ElementId() {activeView.Id}))
  Return collector.FirstOrDefault
End Function

This can all be stuffed into one single statement:

Public Function GetELementIDOfCropBoxShortened(activeView As View, revDoc As Document) As ElementId
  Return New FilteredElementCollector(revDoc)
    .WherePasses(New ElementParameterFilter(
      New FilterElementIdRule(
        New ParameterValueProvider(
          New ElementId(CInt(BuiltInParameter.ID_PARAM))),
        New FilterNumericEquals(),
        activeView.Id)))
    .ToElementIds()
    .Except(New List(Of ElementId)(New ElementId() {activeView.Id})).FirstOrDefault
End Function

Much like your original, I had to exclude the element id of the view, as it also returns its own id from ID_PARAM.

Hope that this may help someone – I’m sure the Dynamo people who come here for inspiration will want to know this as well…

Many thanks to Konrads for sharing this nice efficient solution!

I ported it to C# and added it to The Building Coder Samples ↗ release 2018.0.135.2 ↗ and the extensive collection of filtered element examples in the module CmdCollectorPerformance.cs ↗:

  /// <summary>
  /// Return element id of crop box for a given view.
  /// The built-in parameter ID_PARAM of the crop box 
  /// contains the element id of the view it is used in;
  /// e.g., the crop box 'points' to the view using it 
  /// via ID_PARAM. Therefore, we can use a parameter 
  /// filter to retrieve all crop boxes with the 
  /// view's element id in that parameter.
  /// </summary>
  ElementId GetCropBoxFor( View view )
  {
    ParameterValueProvider provider
      = new ParameterValueProvider( new ElementId( 
        (int) BuiltInParameter.ID_PARAM ) );

    FilterElementIdRule rule 
      = new FilterElementIdRule( provider, 
        new FilterNumericEquals(), view.Id );

    ElementParameterFilter filter
      = new ElementParameterFilter( rule );

    return new FilteredElementCollector( view.Document )
      .WherePasses( filter )
      .ToElementIds()
      .Where<ElementId>( a => a.IntegerValue 
        != view.Id.IntegerValue )
      .FirstOrDefault<ElementId>();
  }