Saving and loading topic

Save a story's state and restore it later, in this runtime or another.

Save and load

final saved = story.state.toJson();   // a String; store it anywhere

// Later, on a fresh Story made from the same compiled JSON:
final story = Story.fromJson(jsonString);
story.state.loadJson(saved);

The save holds everything that changes as the story plays: position, call stack and threads, variables, visit and turn counts, the random seed, the current text and choices, and every flow. It doesn't hold the story itself, so load it into a story made from the same JSON. External function bindings, observers and onError aren't saved either: set them up again before continuing.

Save at a choice, which is where games usually save, or between lines. Don't save in the middle of a continueStory call.

Moving saves between runtimes

ink_dart writes the same save format as inkle's C# runtime, byte for byte (inkSaveVersion 10), and loads saves back to version 8. A save from a Unity build of the same story loads here and plays on identically, and the other way round. Saves made by inkjs load too.

One behaviour comes along with the format: a save doesn't record that a choice is an invisible default (a fallback choice with no text), so after loading, it's offered as an empty choice. The C# runtime does the same.

Saving without stopping

For very large stories, copyStateForBackgroundThreadSave() freezes a copy of the state that you can write out while the story carries on; call backgroundSaveComplete() when you're done. Switching flow isn't allowed in between.

Classes

Story

A Story is the core class that represents a complete Ink narrative, and manages the evaluation and state of it.

StoryState

All story state information is included in the StoryState class, including global variables, read counts, the pointer to the current point in the story, the call stack (for tunnels, functions, etc), and a few other smaller bits and pieces. You can save the current state using the json serialisation functions ToJson and LoadJson.