Documentation
Core
Elements
Persistent

Persistent<T extends PersistentContent>

In the past, we could only modify the state of Storable through Script, but Persistent provides a set of useful methods to easily control the flow.

Persistent requires the name and initial state of a namespace. Persistent with the same name will share the same state.

⚠️

The namespace cannot be an existing built-in namespace (built-in namespaces include: "game")

type PersisData = {
    flag: boolean;
    coin: number;
    name: string;
    // ...
};
const persis = new Persistent<PersisData>("persis", {
    flag: false,
    coin: 0,
    name: "John Smith",
    // ...
});

Note: The stored content must be serializable, the serializable values supported by NarraLeaf-React include:

  • string
  • number
  • boolean
  • object: key is string, value is the above serializable value
  • array: elements are the above serializable value
  • undefined
  • null
  • Date: standard JavaScript date object
⚠️

If the script content contains Persistent, it must be registered with Story.

story.registerPersistent(persis);

Public Methods

constructor

  • namespace: string - the name of the namespace
  • defaultContent: T - initial state

equals<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • value: T[K] - the value of the state
  • Returns: Lambda<boolean>
scene.action([
    Condition
        .If(persis.equals("name", "John Smith"), [
            character1.say("Hello, John Smith!")
        ])
]);

notEquals<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • value: T[K] - the value of the state
  • Returns: Lambda<boolean>

isTrue<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • Returns: Lambda<boolean>
scene.action([
    Condition
        .If(persis.isTrue("flag"), [
            character1.say("Flag is true")
        ])
]);

isFalse<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • Returns: Lambda<boolean>

isNotNull<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • Returns: Lambda<boolean>

toWords<K extends StringKeyOf<T>>

  • key: K - the key of the state
  • Returns: Word<DynamicWord>
character.say`You have ${persis.toWords("coin")} coins`;

get<K extends StringKeyOf<T>>

Alias of get

  • key: K - the key of the state
  • Returns: Word<DynamicWord>
character.say`Your have ${persis.get("coin")} coins`;

conditional

  • condition: Lambda<boolean> | LambdaHandler<boolean>
  • ifTrue: DynamicWordResult
  • ifFalse: DynamicWordResult
  • Returns: Word
character.say`Your flag is ${persis.conditional(
    persis.isTrue("flag"),
    "true",
    "false"
)}`;

evaluate<K extends StringKeyOf<T>>

Evaluate the state with a JavaScript function

  • key: K - the key of the state
  • fn: (value: T[K]) => boolean - a JavaScript function to evaluate the state
  • Returns Lambda<boolean>
scene.action([
    Condition
        .If(persis.evaluate("coin", (coin) => coin < 10), [
            character1.say`You don't have enough coins!`
        ])
]);

Chainable Methods

set<K extends StringKeyOf<T>>

Overload 1 of 2

  • key: K - the key of the state
  • value: T[K] - the value of the state
scene.action([
    persis.set("coin", 10)
]);

Overload 2 of 2

  • key: K - the key of the state
  • handler: (value: T[K]) => T[K]) - the handler to modify the value
scene.action([
    persis.set("coin", (coin) => coin + 10) // coin will increase by 10
]);
TextStory