Auto refresh on Tree View

[bbovenzi]

Auto-refresh on Graph View was a very popular feature when 2.0.0 was released. This PR adds auto-refresh for Tree View.

• add a new tree_data endpoint to ping for updates every 3 seconds
• only rerender if the task instances have changed
• turn off autorefresh after there are no more running dag runs

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[ashb]

There's probably too much duplication between this new method and the existing tree view that we should pull out in to a function and call from both places.

[ashb]

Suggested change

	def get_tree_data(dag_runs, dag, base_date):
	def get_tree_data(dag_runs: Iterable[DagRun], dag: DAG, base_date: DateTime):

(I think those types should be in scope and correct)

[github-actions]

The Workflow run is cancelling this PR. It has some failed jobs matching ^Pylint$,^Static checks,^Build docs$,^Spell check docs$,^Provider packages,^Checks: Helm tests$,^Test OpenAPI*.

[github-actions]

The Workflow run is cancelling this PR. Building image for the PR has been cancelled

[ryanahamilton]

Found a little visual jank on wide screens. Looks like a float that wraps when the SVG body doesn't utilize the full screen width.

[bbovenzi]

Good catch. I added a min-width to the refresh actions so there is always space for the loading dots.

[uranusjr]

Some coding style suggestions that might help get rid of pylint’s too-many-locals warning as well (no idea how many is too many). Nothing logical incorrect from what I can tell.

[uranusjr]

Suggested change

	dates = sorted(dag_runs.keys())
	max_date = max(dates) if dates else None
	min_date = min(dates) if dates else None
	max_date = max(dag_runs, default=None)
	min_date = min(dag_runs, default=None)

[uranusjr]

Suggested change

	tis = dag.get_task_instances(start_date=min_date, end_date=base_date)
	task_instances: Dict[Tuple[str, datetime], models.TaskInstance] = {}
	for ti in tis:
	task_instances[(ti.task_id, ti.execution_date)] = ti
	task_instances = {
	(ti.task_id, ti.execution_date): ti
	for ti in dag.get_task_instances(start_date=min_date, end_date=base_date)
	}

[uranusjr]

Suggested change

	if base_date:
	base_date = timezone.parse(base_date)
	else:
	base_date = dag.get_latest_execution_date() or timezone.utcnow()
	try:
	base_date = timezone.parse(request.args["base_date"])
	except (KeyError, ValueError):
	base_date = dag.get_latest_execution_date() or timezone.utcnow()

and remove the base_date line above. There’s a similar one in the other view as well.

[ryanahamilton]

I did a bunch of local testing on this—it works great and I think people are really going to love it!

[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest master or amend the last commit of the PR, and push it with --force-with-lease.