Trait Options

Source

pub trait Options {
    // Required method
    fn options() -> Vec<(String, String)>;

    // Provided method
    fn label_of(value: &str) -> String { ... }
}

Expand description

A closed set of values, each with its label.

Derive it on a unit-variant enum with #[derive(Options)]: each variant’s value is its snake_case name and its label that name in sentence case, and #[option(value = "..", label = "..")] overrides either.

The derive also makes the enum a FormScalar that a form posts as its value and a column reads as its label, so a model field of the enum’s type, derived toasty::Embed, binds without a string in between:

#[derive(Debug, Clone, Copy, PartialEq, Eq, toasty::Embed, tablo_core::Options)]
enum Status {
    Draft,
    #[option(label = "Live")]
    Published,
}

#[derive(Debug, Clone, toasty::Model)]
struct Post {
    #[key]
    #[auto]
    id: uuid::Uuid,
    status: Status,
}

Field::choice(lens!(Post.status)).options(Status::options());
SelectFilter::of(lens!(Post.status));
Table::new(TextColumn::new(lens!(Post.status))).group_by(lens!(Post.status));
Post::filter(Post::fields().status().eq(Status::Published));

Toasty stores the variant under its own discriminant, snake_case by default; the option’s value is only the form’s spelling. A String field takes the same list, storing the value itself: SelectFilter::new(lens!(Post.kind), Kind::options()).

The derive also gives the enum value(), label() and from_value().