Refactor examples/helpers/checkbox.rs

[tevans-3]

Objective

• The checkbox helper in examples/helpers only lets callers create unchecked boxes. Callers should be able to create both checked and unchecked variants.

Solution

• Refactor the checkbox helper to accept an "IsChecked" flag and spawn both checked and unchecked checkboxes.
• Update the other users of checkbox.rs (examples/2d/2d_shapes.rs) to pass IsChecked to the helper. (I also updated the pending Migrate 3d_shapes to feathers #25436)

Testing

I tested examples that use the helper and verified that they still work as expected.

[Zeophlite]

Just needs a cargo fmt --all

[mnmaita]

Took a second look at this and found a few more nits 🙏🏻 thanks!

[mnmaita]

        {checkbox_identifier.and_then(|checkbox_identifier| {
            bsn! { template_value(checkbox_identifier) }
        })}

Would something like this work here to simplify things a bit?

[tevans-3]

Apparently, with and_then, the compiler expects the closure to return an option, so to get it to work, you have to wrap the bsn!: Some(bsn! { .. } )

But the linter objected to that, on the grounds that that's identical to this:

        {checkbox_identifier.map(|checkbox_identifier| {
            bsn! { template_value(checkbox_identifier) }
        })}

[mnmaita]

Oh yeah map makes more sense here, good catch.

Sorry that I was insisting on these refactors but I feel like they are great examples that we should show so people know they can optionally add components in BSN easily.

[tevans-3]

No need to apologize; the code is better because of your suggestions! And I'm learning stuff too, I didn't know bsn could "do" conditional components, or that .and_then / then could be used like that

[mnmaita]

It might be worthwile to also get rid of the almost identical branches here by doing something like:

{(!cfg!(target_arch = "wasm32")).then(|| {
    bsn! { feathers_option_checkbox("WIREFRAME", Some(CheckboxInput::Wireframe), IsChecked(false)) }
})}

[mnmaita]

Thanks for addressing the requested changes! I just tested the example locally and it looks good. I left a small clarification on the BSN formatting comment that you could address too but I don't want to block on that.

[alice-i-cecile]

Please resolve merge conflicts <3

[Zeophlite]

This needs an update with the recent bsn changes