Advanced label features

In this section, we will cover advanced label features. These features are not necessary to create a game, but they can help you to create a more complex and interactive game.

onLoadingLabel

onLoadingLabel is a function that will be executed in onStepStart if the index of the step is 0 and when the user laods a save file.

When you load a save file, will be executed all onLoadingLabel functions of the narration.openedLabels (current label and all labels that are in the stack).

It is useful for example to make sure all images used have been cached before the label starts.

You can intercept this function by passing a function to the onLoadingLabel property of the label options. This function will receive 2 parameters:

• stepIndex: The index of the step that is being executed
• label: The label that is being executed

newLabel("start", [
    () => {
        await showImage("image1", "path/to/image1.png")
        await showImage("image2", "path/to/image2.png")
    }
], {
    onLoadingLabel: async (stepIndex, label) => { 
        await Assets.load("path/to/image1.png") 
        await Assets.load("path/to/image2.png") 
    } 
})

onStepStart

onStepStart is a function that will be executed before each step of the label. You can intercept this function by passing a function to the onStepStart property of the label options. This function will receive 2 parameters:

• stepIndex: The index of the step that is being executed
• label: The label in which it is the step

newLabel("start", [
    () => {
        narration.dialogue = "Step 1"
    },
    () => {
        narration.dialogue = "Step 2"
    }
], {
    onStepStart: (stepIndex, label) => { 
        console.log(`Step ${stepIndex} started`) 
    } 
})

onStepEnd

onStepEnd is a function that will be executed after each step of the label. You can intercept this function by passing a function to the onStepEnd property of the label options. This function will receive 2 parameters:

• stepIndex: The index of the step that is ended
• label: The label in which it is the step

newLabel("start", [
    () => {
        narration.dialogue = "Step 1"
    },
    () => {
        narration.dialogue = "Step 2"
    }
], {
    onStepEnd: (stepIndex, label) => { 
        console.log(`Step ${stepIndex} ended`) 
    } 
})

How to return different step lists based on a condition

When you create a new label you can pass a function that returns the steps of the label.

// /labels/startLabel.ts
import { getFlag, narration, newLabel, setFlag } from "@drincs/pixi-vn"

export const startLabel = newLabel("start_label",
    () => {
        let condition = getFlag("condition")
        if (condition) {
            return [
                () => {
                    narration.dialogue = "Step 2"
                },
                () => {
                    narration.dialogue = "Restart";
                },
            ]
        } else {
            return [
                () => {
                    narration.dialogue = "Step 1"
                },
                async (props, { labelId }) => {
                    setFlag("condition", true)
                    return await narration.jumpLabel(labelId, props)
                }
            ]
        }
    }
)