[Feature Request] Support for nested objects in ViewModel?

I’ve read the source and I understand perfectly how it works and why nested objects aren’t supported by createViewModel, but what would it take to add support for that?

I’m creating ViewModels for objects like this

type DataEntry = {
    [key: string]: {
        $metadata; {}
        value: any
    }
} & {
    clear(): void
    set(data: {}): void
}

With clear setting all values to undefined and set taking an object representing the data entry and setting all the corresponding values.

Without support for nested objects I can’t use either methods or set a value directly, with severely limits my use of the ViewModel.

I’m totally open to work on this myself, but I’d like to make sure that it makes sense and that it’s doable before jumping in.

Thanks.

[JabX]

This is the solution I came up with:

function createViewModel(model: DataEntry) {
    const viewModel = observable(toJS(model));

    const reset = () => viewModel.set(toFlatValues(model));

    viewModel.reset = action(reset);
    viewModel.submit = action(() => _.merge(model, viewModel));
    viewModel.subscribe = () => {
        if (!viewModel.isSubscribed) {
            const disposer = autorun(reset);
            viewModel.unsubscribe = () => {
                disposer();
                viewModel.isSubscribed = false;
            };
            viewModel.isSubscribed = true;
        }
    };

    viewModel.subscribe();
    return viewModel;
}

toFlatValues() is a method I use to recursively transform my {$metadata, value} objects into value, just like toJS() does for observables.

The only pain point is that I kinda have to handle the model reactions manually, meaning that I have to call unsubscribe() before I destroy my viewModel (in componentWillUnmount() in my case). But this allows to control the interaction model -> viewModel, which might come handy someday.

[mweststrate]

I do see the use case for this feature, but I think mobx-state-tree will in the end provide a more generic solution to this problem. Therefor closing this issue for now.