Revit Selection vs Paracore Selection

There are two primary ways to target Revit elements: selecting them from curated lists in the Paracore UI, or picking them directly from the Revit viewport.

1. Paracore UI Selection

The dropdowns and multi-select lists in the Parameters tab are examples of UI selection.

• Process: You select items from a list prepared by the Parameter Engine.
• Benefit: Ideal for curated tasks where you need to choose from specified types (e.g., "Wall Types") or managed lists (e.g., "Rooms in Phase 1").

public class Params 
{
    // Renders a dropdown listing every Wall Type in the project
    public WallType TargetType { get; set; }

    // Renders a multi-select list for targeting specific Rooms
    public List<Room> MyRooms { get; set; }

    // Curation: Listing only 'Doors' using an attribute
    [RevitElements(Category = "Doors")]
    public FamilySymbol? DoorType { get; set; }
}

2. Direct Revit Picking

Some tasks require spatial precision, such as picking a specific wall or a coordinate point.

Common Pick Types

Define these types inside your public class Params to trigger Revit's native selection cursor:

public class Params
{
    // Pick a coordinate point
    public XYZ? MyPoint { get; set; }

    // Pick any element in the active view
    public Reference? MySelectedRef { get; set; }

    // Specifically target element geometry
    public Edge? SelectedEdge { get; set; }
    public Face? SelectedFace { get; set; }
}

The [Select] Attribute

You can force a standard element type to trigger a direct pick instead of a dropdown list using the [Select] attribute.

public class Params
{
    [Select(SelectionType.Element)]
    public Wall? MyTargetWall { get; set; } // Forces a direct Revit element pick

    // Constraining the Pick: Only allow picking Walls
    [RevitElements(Category = "Walls")]
    public Reference? WallRef { get; set; } 
}

3. Selection Feedback

• Visual Cues: A selection cursor icon appears in the Parameters tab when a "Pick" type is detected in your Params class.
• Immediate Verification: Once an object is picked, the Paracore UI instantly displays its Name or ID for verification.

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Next Step: Practice picking elements in the 06 - Step-by-Step Exercise.