Nested dp.Select not working

Describe the bug In the docs concerning Select, there is a note:

Select expects a list of Blocks, e.g. a Plot or Table, but also including Select or Groups themselves, but if a Python object is passed, e.g. a Dataframe, Datapane will attempt to convert it automatically.

However, I am not able to get nested selects working. Instead, the outer selection method (tab or dropdown doesn’t matter) shows, and the inner one is missing, in its place being an empty doc symbol:

To Reproduce Execute the following repro script:

import datapane as dp


def create_plot_selection() -> dp.Select:
    test_dict = {
        "outer1": {
            "inner11label": "inner11",
            "inner12label": "inner12"
        },
        "outer2": {
            "inner21label": "inner21",
            "inner22label": "inner22",
            "inner23label": "inner23"
        }
    }

    outer_choice_blocks = []
    for outer_choice_label, inner_choices in test_dict.items():
        inner_choice_blocks = []
        for label, test_item in inner_choices.items():
            inner_choice_blocks.append(dp.Text(test_item, label=label))

        outer_choice_blocks.append(dp.Select(blocks=inner_choice_blocks, label=outer_choice_label, type=dp.SelectType.TABS))

    return dp.Select(blocks=outer_choice_blocks, type=dp.SelectType.DROPDOWN)


report = dp.Report(blocks=["Should see more than a document icon after selecting an outer choice:", create_plot_selection()])
report.save(path='report.html')

Expected behavior When opening the generated report, I’d expect to be able to use an inner select

Desktop (please complete the following information):

• OS: Linux Mint 20,
• Browser: Firefox on Linux,
• Version 84.0.1 (64-bit) on Linux, on android

Smartphone (please complete the following information):

• Device: Redmi 7
• OS: Android 10
• Browser: Firefox and Chrome
• Version: firefox 84.1.2 and chrome 87.0.4280

[Buroni]

@mands Yep the FE deserialiser doesn’t allow Selects to be direct ancestors of other Selects. Should be quick to allow this though.

[mands]

@Buroni - have added a unit test on the CLI side and can successfully generate valid reports with nested Selects - I think the issue may be on the FE renderer