Add a helper to enable hot-reloading of the preview-frame.

[tomprince]

This uses undocumented hook mentioned in sveltejs/svelte-hmr#57 to automatically update the
preview frame, when the preview frame gets reloaded.

[resonant-gamedesign]

Can you explain what this is doing? What is "on:hot-reload" and when will that trigger?

[tomprince]

Can you explain what this is doing? What is "on:hot-reload" and when will that trigger?

When using npm run dev, that runs a local web server that serves the app. That server is intended for being used while editing the app, so it has some features to make that process smoother. In particular, when you make a change to a file (and save it), the server notices that and tells the browser to update that bit of code. The easiest way would be to just refresh that page, but that is more disruptive than necessary a lot of the time. In practice, what happens is that when a component is updated, just that component is recreated (see here for a discussion of some of the details). That doesn't work for the preview frame, as it will just be empty. This adds some hooks for adding to that behaviour. In particular, after the preview frame is recreated, we now update the preview.

[resonant-gamedesign]

Thanks, that makes sense and sounds very helpful.

…

On Fri, Jan 20, 2023 at 12:31 PM Tom Prince ***@***.***> wrote: Can you explain what this is doing? What is "on:hot-reload" and when will that trigger? When using npm run dev, that runs a local web server that serves the app. That server is intended for being used while editing the app, so it has some features to make that process smoother. In particular, when you make a change to a file (and *save* it), the server notices that and tells the browser to update that bit of code. The easiest way would be to just refresh that page, but that is more disruptive than necessary a lot of the time. In practice, what happens is that when a component is updated, just that component is recreated (see here <https://github.com/sveltejs/svelte-hmr/tree/master/packages/svelte-hmr#whats-hmr-by-the-way> for a discussion of some of the details). That doesn't work for the preview frame, as it will just be empty. This adds some hooks for adding to that behaviour. In particular, after the preview frame is recreated, we now update the preview. — Reply to this email directly, view it on GitHub <#202 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKUHWTMBFWTYPNKCEWSDUG3WTLKXTANCNFSM6AAAAAAT5OIV4Q> . You are receiving this because you commented.Message ID: ***@***.***>

[tomprince]

I also added in a cleanup of an unused variable that was accidentally left in #157.