pipeline

def defer(callable, timeout=0):
    """Defer a callable to the next event loop."""
    QtCore.QTimer.singleShot(timeout, callable)

def iter_containers(project=None, session=None):
    """Yield all source objects in the active project with AYON property
     AYON container ID"""

    if project is None:
        project = fx.activeProject()

    if not project:
        return

    # List all sources in project with `AYON` property
    for source in project.sources:
        data = parse_container(source, project=project)
        if data:
            yield data

    if session is None:
        session = fx.activeSession()

    if not session:
        return

    # List all nodes in session with `AYON` property
    for node in session.nodes:
        data = parse_container(node, project=project, session=session)
        if data:
            yield data

def iter_instances(session=None):
    """Yield all objects in the active session that have 'id' attribute set
    matching an AYON container ID"""

    if session is None:
        session = fx.activeSession()
    if not session:
        return

    for node in session.nodes:
        data = lib.read(node)
        if data and data.get("id") == AYON_INSTANCE_ID:
            data["_node"] = node
            yield data

def parse_container(source, project=None, session=None):
    """Return the container node's full container data.

    Args:
        source (fx.Source | fx.Node): A Silhouette source or node.
        project (Optional[fx.Project]): Project related to the source
            item or node so that we can track it back to the project.
        session (Optional[fx.Session]): Session related to the source
            item or node so that we can track it back to the session.

    Returns:
        dict[str, Any]: The container schema data for this container node.

    """
    data = lib.read(source)
    if not data:
        return

    # TODO: ensure object is actually a container by `id` value

    # Backwards compatibility pre-schemas for containers
    data["schema"] = data.get("schema", "ayon:container-3.0")
    data["objectName"] = source.label  # required for container data model

    # Append transient data
    data["_item"] = source
    if project is not None:
        data["_project"] = project
    if session is not None:
        data["_session"] = session

    return data