Variables

Variables are the game state that dialogue reads and writes: has the player accepted the job, how much gold do they carry, what name did they pick. They also drive conditions and scripts on entries.

There are two halves: definitions in the database, and a live store at runtime.

Defining variables in the database

The database carries a list of variables with their starting values:

pub struct Variable {
    pub name: String,        // unique within the database
    pub initial: FieldValue, // what it starts as
    pub fields: Vec<Field>,  // custom data
}

In a .dialogue.ron file:

(
    version: "1",
    variables: [
        (name: "AcceptedJob", initial: Boolean(false)),
        (name: "Gold", initial: Number(10.0)),
        (name: "PlayerName", initial: Text("")),
    ],
    actors: [ /* … */ ],
    conversations: [ /* … */ ],
)

variables may be omitted entirely; old files load unchanged.

The Variables resource

At runtime all values live in one resource, a plain map from name to FieldValue:

#[derive(Resource)]
pub struct Variables(pub HashMap<String, FieldValue>);

When a database asset loads, the plugin seeds the store: every variable the store doesn’t know yet is inserted at its initial value. Values that already exist are left alone, so a hot-reloaded database never overwrites state the game has changed.

Read and write it like any resource:

fn accept_job(mut vars: ResMut<Variables>) {
    vars.set("AcceptedJob", true);
    vars.set("Gold", vars.number("Gold") + 50.0);
}

fn greet(vars: Res<Variables>) {
    if vars.truthy("AcceptedJob") {
        // ...
    }
}

set accepts anything convertible into a FieldValue (bool, f32, &str, String). Variables don’t have to be declared in the database. set creates them on the fly; the database list is just the authored starting state.

Reading values

A missing variable or a type mismatch returns the type’s default instead of panicking.

Variables reset when the game closes. To keep them across sessions, see Saving and Loading.