DAG extension

Visualizes the DAG (directed acyclic graph) underlying a board and provides UI elements to manipulate the board.

Usage

new_dag_extension(positions = NULL, ...)

Arguments

positions

Optional node positions overlaid on the board-derived nodes, as a named list keyed by block id, each element a list with numeric x and y (e.g. list(a = list(x = 100, y = 200))). Persisted across save / restore. Unknown or stale block ids are ignored. This handle is externally controllable: positions can be set programmatically through the board update lifecycle (update(list(extensions = list(mod = list(<ext_id> = list(positions = ...)))))), which moves the corresponding nodes. Note: the auto-layout currently computes final node placement at cold start, so supplied positions are not yet honored over it (a follow-up will let positions pin over the layout).

...

Forwarded to blockr.dock::new_dock_extension().

Value

A dag_extension object that extends the dock extension system for visualizing and manipulating DAG workflows.

Options

blockr.dag.svg_renderer: when TRUE, the DAG is rendered with the SVG renderer instead of the default canvas renderer. Canvas is the default because the SVG element reports offsetWidth == 0, which makes the underlying g-lite client/canvas coordinate scaling ignore the page zoom factor and desyncs hit-testing below 100% browser zoom. The SVG renderer keeps every element in the DOM, which the shinytest2 end-to-end tests need to query and screenshot, so they opt in via AppDriver$new(options = list(blockr.dag.svg_renderer = TRUE)).