Pre-select latest run on graph view

[steveahnahn]

Problem

When opening a DAG in Graph View that has existing runs, the graph displays with no run selected, showing all tasks in grey without state information. Users must manually select a run to see task states, even though there is a latest run available.

Solution

Added auto-selection of the latest dag run when Graph View is opened without a specific run in the URL to improve quality of life.

Before:

After:

Related Issues

Part of #56250

[guan404ming]

The code change looks reasonable, but I have a small concern for functional wise. Since we already have an overview page for dag and if we preselect the latest run, users might not see the overview page initially. imo the overview serves as the “home page” for a dag, so for me I would say it is ok to enter the dag page without pre-select dag run. But I’d appreciate hearing another opinion on this, thanks!

[bbovenzi]

Yeah I don't want to lose the Dag Overview page. But we could still show the latest dag run, if there is one, on the dag graph even when there isn't a dag run explicitly selected.

[pierrejeambrun]

Personally I like the fact that when on the 'dag' if I go on the graph I get a 'dag structure' graph which isn't related to a specific DagRun. I'm basically coming from a 'dag' and I want a dag related graph, I would find this surprising to end up on a dagrun related graph.

So I prefer not to have a dagrun selected by default.

Maybe that's just me, and I'm not against this change if other people prefer it this way.

[steveahnahn]

Thanks for the feedback all, will be closing on the reviewed judgment.