Add group and label to hover tooltip if provided by user

[droumis]

Adds the group and label args to the bokeh hover tooltip if provided by user.

It seems to me like a good idea to have this enabled by default, but I'm guessing that there's a reason why it wasn't already in place. Opinions welcome.

Fixes #3603

Code

import numpy as np
import panel as pn
import holoviews as hv
hv.extension('bokeh')

x = np.linspace(0, 10*np.pi)
curves = {}
j = 0.5
yvals = j * np.sin(x)

curves = []
curves.append(hv.Curve((x, yvals)).opts(tools=['hover'], color='blue'))
curves.append(hv.Curve((x + 2 * np.pi/2, 2 * yvals), label='curve2').opts(tools=['hover'], color='red'))
curves.append(hv.Curve((x + 3 * np.pi/2, 3 * yvals), group='A').opts(tools=['hover'], color='green'))
curves.append(hv.Curve((x + 4 * np.pi/2, 4 * yvals), label='curve4', group='A').opts(tools=['hover'], color='orange'))
pn.Row(hv.Overlay(curves).opts(width=600, height=600)).servable()

Screen.Recording.2024-02-20.at.11.59.48.AM.mov

TODO:

• add tests

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.55%. Comparing base (c3c211e) to head (000f159).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6125      +/-   ##
==========================================
- Coverage   88.70%   88.55%   -0.15%     
==========================================
  Files         314      316       +2     
  Lines       65993    66050      +57     
==========================================
- Hits        58537    58490      -47     
- Misses       7456     7560     +104     

Flag	Coverage Δ
ui-tests	?

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[hoxbro]

It seems to me like a good idea to have this enabled by default, but I'm guessing that there's a reason why it wasn't already in place.

A reason why it hasn't been implemented can be as simple as there has been no demand for it.

I don't really have high hopes for this getting merged

You shouldn't put down the effort you have put into the PR. If you don't believe in it yourself, it is hard to get others to believe in you 👍

---

I would like to see a unit test. To get the tooltips after creation you can play look around with hv.renderer('bokeh').get_plot(hv.Curve([])).handles (in test we have bokeh_renderer as shorthand for the first part).

---

This has nothing to do with this PR, but the legend seems wrong for your example.

[droumis]

You shouldn't put down the effort you have put into the PR. If you don't believe in it yourself, it is hard to get others to believe in you 👍

Thanks, I adjusted my language.

[droumis]

This has nothing to do with this PR, but the legend seems wrong for your example.

What's wrong about it? seems accurate to me and reflects the labels of the curves for which a label was given

[hoxbro]

What's wrong about it? seems accurate to me and reflects the labels of the curves for which a label was given

It looks like it has a blue border at the top. But I can't recreate it locally, so just ignore that comment.

[droumis]

Tests added

[hoxbro]

One last thing: Can you try setting the group/label to something like hel lo, {hello (testing for edge-cases)

[droumis]

One last thing: Can you try setting the group/label to something like hel lo, {hello (testing for edge-cases)

added a test for whitespace and special chars

[maximlt]

Just tried hvPlot from that branch.

Before:

After:

I think it's coming from these lines:
https://github.com/holoviz/hvplot/blob/f17f4705afe40f4c8e4e388823004b14ec938519/hvplot/converter.py#L1567-L1568

There are maybe more cases, I just did a very quick check.

[maximlt]

Another case, before this branch there's no Label field in the tooltip.

---

Btw I'm just exposing changes in hvPlot. I don't yet have a firm opinion on whether they're good or bad, and whether hvPlot itself should be improved to better deal with labels/groups/titles.

[ahuang11]

Maybe if isinstance element, 2D, then don't include the label?

[droumis]

At a HoloViz meeting, there was discussion about supporting a better syntax for a custom hover tool.

Here is the unearthed thread on the topic: #1816

I would prefer a more fully featured custom hover tool syntax as originally proposed, as long as it supports adding arbitrary entries like 'label' and 'group' arg values, in addition to standard data dims.

I will close this current PR, unmerged.