`hover_text_html_template` unintuitively ignored in several situations

[richardmillson]

Setup:

from pathlib import Path

import datamapplot
import numpy as np
import pandas as pd

data_map = np.random.uniform(size=[10, 2])
label_layers = ["a"] * data_map.shape[0]
extra_point_data = pd.DataFrame({"col" : ["b"] * data_map.shape[0]})

hover_text_html_template = """
<div>
  From hover_text_html_template
</div>
"""
plot = datamapplot.create_interactive_plot(
    data_map,
    label_layers,
    hover_text_html_template=hover_text_html_template,
)
Path("test.html").write_text(plot._html_str)

No hover.

hover_text_html_template = """
<div>
  From hover_text_html_template
</div>
"""
plot = datamapplot.create_interactive_plot(
    data_map,
    label_layers,
    hover_text=label_layers,
    hover_text_html_template=hover_text_html_template,
)

Displays hover_text not hover_text_html_template.

hover_text_html_template = """
<div>
  From hover_text_html_template: {col}
</div>
"""
plot = datamapplot.create_interactive_plot(
    data_map,
    label_layers,
    extra_point_data=extra_point_data,
    hover_text_html_template=hover_text_html_template,
)

Raises Uncaught (in promise) TypeError: this.metaData[this.searchField] is undefined if extra_point_data is specified without hover_text.

hover_text_html_template = """
<div>
  From hover_text_html_template: {hover_text}
</div>
"""
plot = datamapplot.create_interactive_plot(
    data_map,
    label_layers,
    hover_text=label_layers,
    hover_text_html_template=hover_text_html_template,
)

Displays hover_text and not hover_text_html_template.

extra_point_data = pd.DataFrame({"col" : ["b"] * data_map.shape[0]})
hover_text_html_template = """
<div>
  From hover_text_html_template: {col}
</div>
"""
plot = datamapplot.create_interactive_plot(
    data_map,
    label_layers,
    extra_point_data=extra_point_data,
    hover_text=label_layers,
    hover_text_html_template=hover_text_html_template,
)

Displays correctly. Here hover_text must be specified for hover_text_html_template to work even though it will be overridden by hover_text_html_template.

[lmcinnes]

Is there something consistent in the cause of these to be missed, or is it a different edge case for each and every one? At this point the code is quite complicated (due to many potentially interacting features) and barring a major refactor, this could be hard to fix without a lot of messing around. Do you know if this is simply resolvable?