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A branching dialogue

This lesson builds a conversation with choices. The example bundle is your model: a tree of nodes, where each node has a speaker, a line, and options that lead to other nodes.

It assumes you finished the earlier lessons and know how entrypoints register things in onLoad().

A dialogue tree​

A dialogue is a DialogueTree. It starts at a node and moves between nodes as the player picks options.

Build a small guide conversation:

import de.luckymcdev.foundryengine.common.Common
import de.luckymcdev.foundryengine.common.dialogue.DialogueTree
import de.luckymcdev.foundryengine.common.dialogue.DialogueNode
import de.luckymcdev.foundryengine.common.dialogue.DialogueOption
import de.luckymcdev.foundryengine.common.dialogue.DialogueStyle

void onLoad() {
    def manager = Common.getDialogueManager()

    def tree = new DialogueTree(id("welcome_guide"), "start")
    tree.setStyle(new DialogueStyle())
    manager.registerTree(tree)
}

new DialogueTree(id("welcome_guide"), "start") names the tree and sets the id of the first node, "start".

Add nodes and options​

A node is a line of dialogue with a speaker, and any number of options.

def startNode = new DialogueNode("start", "Guide",
        "Welcome, adventurer! I can teach you about this world.")
def farewellNode = new DialogueNode("farewell", "Guide",
        "Good luck on your journey!")

startNode.getOptions().add(new DialogueOption("opt_leave", "Goodbye!", "farewell"))

Read it as: the start node is spoken by "Guide", says the welcome line, and offers one option. The option, "opt_leave", shows the text Goodbye!, and when chosen moves the conversation to the node whose id is "farewell".

Wire the nodes into the tree and register them:

tree.addNode(startNode)
tree.addNode(farewellNode)

Run an action when an option is chosen​

A node can run an action when the player enters it. Register an action by name, then attach that name to the node.

import de.luckymcdev.foundryengine.common.dialogue.DialogueAction
import net.minecraft.network.chat.Component

manager.registerAction("give_starting_kit", { player, session ->
    player.sendSystemMessage(Component.literal("§aYou received a starting kit!"))
} as DialogueAction)

farewellNode.getEnterActionIds().add("give_starting_kit")

registerAction stores a block of code under a name. The block receives the player and the session and runs when the node is entered. getEnterActionIds().add(...) points the node at that action.

Chain the whole tree​

A complete tree has several nodes and passes control between them. The pattern is the same as above repeated:

  1. Create each DialogueNode with its speaker and line.
  2. Add DialogueOptions to a node; each option names a target node id.
  3. Add every node to the tree.
  4. Register the tree.

The example bundle's start node offers three options (items, areas, goodbye), each leading to another node, and those nodes offer options that loop back. Build a copy of that to see the full shape.

Run the dialogue​

Dialogue runs from a command or an event, so the player can start it. The Run a dialogue recipe shows how to start a tree from a command. Use it to launch id("welcome_guide") and the conversation opens.

Next, add areas and waypoints.