multilanguage course: not restoring learners' answers to questions on language change

[moloko]

Subject of the issue/enhancement/features

In earlier versions of Adapt, if the learner changed language when _languagePicker._restoreStateOnLanguageChange: true, the responses the learner gave to questions was restored.

Tested as working v5.1.0 - but I think should still work OK up until v5.7.0, at which point it looks like #2846 broke it

Your environment

• FW v5.7.1
• languagePicker v4.1.1

Steps to reproduce

Setup a course with multiple languages. In config.json, set _languagePicker._restoreStateOnLanguageChange: true. Build & run the course, answer a question, change languages.

Expected behaviour

The answer you gave in the original language should be restored

Actual behaviour

The question shows as completed but the answer is not restored

Findings

It looks like the issue was introduced by the addition of this check of Adapt.get('_isStarted') - which causes restoreUserAnswers to be invoked pretty much immediately when switching language, instead of waiting for the 'adapt:initialize' to be triggered.

(In Adapt v5.6.1, this particular bit of code was in questionModel.js and did not contain the same check for Adapt.get('_isStarted').)

The addition of the check for Adapt.get('_isStarted') causes the execution order to change so that restoreUserAnswers now runs before the 'app:dataLoaded' event is triggered - which means that restoreUserAnswers won't actually do anything because _isSubmitted is still set to false - on account of how languagePickerModel.setTrackableState now doesn't restore the state of _isSubmitted until after restoreUserAnswers has run.

Commenting out the check for Adapt.get('_isStarted') so that restoreUserAnswers doesn't run until the 'adapt:initialize' event is triggered certainly fixes this issue for me - I just wasn't sure of potential knock-on impact of changing this... @oliverfoster could do with your thoughts on this if you have a moment?

[oliverfoster]

This check is so that you can create new models after the initial data loading process.
Such as with cloning. The alternative would be to set _isStarted to false when switching languages.

[moloko]

This check is so that you can create new models after the initial data loading process.
Such as with cloning. The alternative would be to set _isStarted to false when switching languages.

Ah OK - no problem I'll try something along those lines next week.