Fine-Tuning Selection Set Filtering with Callbacks in PyRx

As of version 2.2.58, most selection set actions in PyRx have received a powerful overload that allows developers to attach a

When executing a selection command, the callback function automatically intercepts a Db.ObjectIdArray containing the candidate objects. Your logic then evaluates these objects and returns a list of integers representing the indexes of the IDs that should be discarded from the final selection.

Key Benefits of Selection Callbacks

• Advanced Criteria: Filter by complex properties (like geometric limits or dynamic states) that standard DXF group codes cannot check.
• Streamlined Workflow: Eliminate the need to manually iterate over and clean up selection sets after user input.
• Real-time Precision: Ensure your commands only process exactly what they are intended to handle.

The Complete Python Code

Here is how to implement a dynamic block filter using the new callback overload.

 

import traceback

from pyrx import Ap, Db, Ed, Ge, Rx

def dyn_filter(ids: Db.ObjectIdArray) -> list[int]:

    """

    Callback filter that evaluates a list of selected Object IDs.

    Returns a list of list indexes pointing to objects that should be removed.

    """

    itemsToRemove = []

   

    # Enumerate through the selection array to track both index and object ID

    for idx, id in enumerate(ids):

        # Open the ID as a BlockReference to inspect its properties

        ref = Db.BlockReference(id)

       

        # Check if the block reference is NOT a dynamic block

        if not ref.isDynamicBlock():

            # Flag the index for removal if it fails the condition

            itemsToRemove.append(idx)

           

    return itemsToRemove

@Ap.Command()

def pyselectfcb():

    """

    Custom PyRx command to prompt user selection using the custom filter.

    """

    try:

        # Prompt selection filtering for 'INSERT' (Block References)

        # Pass the 'dyn_filter' function as the second argument callback

        ps, ss = Ed.Editor.select([(0, "INSERT")], dyn_filter)

       

        # If the selection prompt was successful, print the result status and size

        if ps == Ed.PromptStatus.eOk:

            print(f"Selection Status: {ps}, Filtered Count: {ss.size()}")

           

    except Exception:

        # Catch and print any runtime exceptions for debugging

        print(traceback.format_exc())

 

Code Walkthrough

1. Ed.Editor.select Overload: We pass dyn_filter as a functional parameter directly into our selection method.
2. Indexing Strategy: The callback tracks idx. If a block fails the isDynamicBlock() check, its exact list index is recorded.
3. Array Cleanup: PyRx reads the returned itemsToRemove list and instantly strips those matching positions out of your final selection set ss.

 

 

Only the Dynamic Blocks are selected, yay!