Add searching to Select widget?

[manforowicz]

The Select widget lets the user select from a scrollable list of options.

It would be great if the user could type with their keyboard to select an option.

Use case: Selecting from a large list, such as time zones or countries.

[arcivanov]

I have implemented this with an Input and a Suggester and a Validator. Select doesn't seem to work well (performance-wise) when the number of options is truly large.

[manforowicz]

Thanks for the suggestion! I think I'll go with that approach then.

[arcivanov]

I can actually share this part of code as well. In my case the "values" are dynamically reloadable numerics as well, so it affects what you want to do in the Suggester

    class SelectValidator(Validator):
        class NotFoundResults(Failure):
            """Indicates validation failed because the string is empty."""

        def __init__(self, values, failure_description: str | None = None) -> None:
            super().__init__(failure_description)
            self._values = values

        def validate(self, value: str) -> ValidationResult:
            values = list(self._values)
            if not values or value not in values:
                failures = [self.NotFoundResults(self)]
                return self.failure(failures=failures)
            return self.success()

        def describe_failure(self, failure: Failure) -> str | None:
            """Describes why the validator failed.

            Args:
                failure: Information about why the validation failed.

            Returns:
                A string description of the failure.
            """
            return f"Must be one of the values."

    class SelectSuggester(Suggester):

        def __init__(self, values) -> None:
            super().__init__(use_cache=False, case_sensitive=False)
            self._values = values

        async def get_suggestion(self, value: str) -> str | None:
            prefix = len(value)
            return ",".join(value + v if not idx else v
                            for idx, v in enumerate({p[prefix:prefix + 1]: p
                                                     for p in (s for s in self._values if s.startswith(value))}.keys())
                            )