Missing API: cannot bind callback to story.onError

[hsandt]

Describe the bug

This is a repost of https://github.com/inkle/ink/issues/873 for the inkjs repo. It's not as much a bug as a missing API.

The doc says how to bind onError in C#:

https://github.com/inkle/ink/blob/master/Documentation/RunningYourInk.md

_inkStory = new Story(inkAsset.text);

_inkStory.onError += (msg, type) => {
    if( type == Ink.ErrorType.Warning )
        Debug.LogWarning(msg);
    else
        Debug.LogError(msg);
};

but not in Javascript. I tried to modify main.js to display the error directly on the page:

    // Create ink story from the content using inkjs
    var story = new inkjs.Story(storyContent);

    story.onError += (msg, type) => {
        if( type == Ink.ErrorType.Warning ) {
            var paragraphElement = document.createElement('p');
            paragraphElement.innerHTML = msg;
            storyContainer.appendChild(paragraphElement);
        } else {
            var paragraphElement = document.createElement('p');
            paragraphElement.innerHTML = msg;
            storyContainer.appendChild(paragraphElement);
        }
    };

but I got:

Uncaught TypeError: this.onError is not a function at s.value (ink.js:1:118736) at s.value (ink.js:1:115775) at s.value (ink.js:1:115489) at continueStory (main.js:74:39) at main.js:58:5 at main.js:394:3

Maybe there is no binding in JS, only C#? But then why the console log error message in browser?

To Reproduce

Try to insert story.onError += (msg, type) => {} after story definition.

Expected behavior

I expect an equivalent to onError to exist in JS bindings.

Ink files

This happens in JS not the ink script itself, so copy the JS suggested above into main.js instead.

Environment

• OS: Linux Ubuntu 22.04
• Web browser version: Chrome Version 118.0.5993.88 (Official Build) (64-bit)
• inklecate version: ? (not written in About Inky and not trivial to get it from command-line, see https://github.com/inkle/ink/issues/721)
  • Inky version: 0.14.1
  • ink version: 1.1.1
• inkjs version: 2.1.0

[smwhr]

You're trying to use a += operator on a function. It effectively transforms that function into a string. Then when onError is called, it errors (a string can't be called)

Try

story.onError = (msg, type) => {

instead of +=