revit-api-option-handlers

name	revit-api-option-handlers
description	Supply small Autodesk Revit API callback interfaces with Nice3point.Revit.Toolkit ready-made handlers, not hand-rolled classes. USE FOR: passing IFamilyLoadOptions, IDuplicateTypeNamesHandler, or ISaveSharedCoordinatesCallback to a Revit API call. DO NOT USE FOR: constraining what a user can pick in an interactive selection, or building a dockable pane's UI element.
license	MIT

Revit API Option Handlers

Several Revit API calls demand a small callback interface. Nice3point.Revit.Toolkit ships ready implementations with a default behavior and lambda or enum customization; you do not hand-roll a class each time.

When to use

• A Revit API call requires IFamilyLoadOptions, IDuplicateTypeNamesHandler, or ISaveSharedCoordinatesCallback.

Workflow

Step 1: Family load options

document.LoadFamily(fileName, new FamilyLoadOptions(), out var family); //overwrite existing types, load from the family
document.LoadFamily(fileName, new FamilyLoadOptions(false, FamilySource.Project), out var family); // keep values, load from the project
document.LoadFamily(fileName, UIDocument.GetRevitUIFamilyLoadOptions(), out var family); //reuse Revit's interactive prompt

The default constructor overwrites the parameter values of existing types; the (overwrite, FamilySource) constructor sets those explicitly, and UIDocument.GetRevitUIFamilyLoadOptions() defers to Revit's own dialog.

Step 2: Duplicate type names handler

var options = new CopyPasteOptions();
options.SetDuplicateTypeNamesHandler(new DuplicateTypeNamesHandler()); //default: UseDestinationTypes
options.SetDuplicateTypeNamesHandler(new DuplicateTypeNamesHandler(DuplicateTypeAction.Abort)); //fixed action
options.SetDuplicateTypeNamesHandler(new DuplicateTypeNamesHandler(args => DuplicateTypeAction.Abort)); // decide per call

The default constructor keeps the destination types; pass a DuplicateTypeAction for a fixed action, or a lambda to decide per call from the args.

Step 3: Save shared coordinates callback

linkType.Unload(new SaveSharedCoordinatesCallback()); //default: SaveLinks
linkType.Unload(new SaveSharedCoordinatesCallback(SaveModifiedLinksOptions.DoNotSaveLinks)); //fixed option
linkType.Unload(new SaveSharedCoordinatesCallback(link => //decide per link
{
    if (link.AttachmentType == AttachmentType.Overlay) return SaveModifiedLinksOptions.SaveLinks;
    return SaveModifiedLinksOptions.DoNotSaveLinks;
}));

The default constructor saves the links; pass a SaveModifiedLinksOptions value for a fixed choice, or a lambda to decide per link.

Step 4: Verify

Call the API with the handler and confirm the intended behavior applies — the family loads with the chosen source, the duplicate resolves as selected, or the link unloads with the chosen coordinate option.

Validation

• The callback uses the Toolkit handler, not a hand-rolled interface implementation.
• Customization is expressed with the lambda or enum overload, not a new class.
• The selected default behavior matches the operation's requirement.

Common Pitfalls

Pitfall	Correct approach
Writing a class that implements IDuplicateTypeNamesHandler	Use DuplicateTypeNamesHandler with a lambda returning the action.
FamilyLoadOptions not found	The Nice3point.Revit.Toolkit package is not referenced.