How to nicelly edit each field of a (very) big struct with nested structs ?

[KarlitosVII]

Hello,
I'm working on a save editor for the Mass Effect trilogy and I use Yew as the user interface executed in a web view (with the wry crate).

I use serde to deserialize the save then the user can edit every value of the deserialized structure (that can be a value in a few levels of nested structures) then I use serde again to serialize the save.

The view is auto generated based of the content of the save and looks like this:

Until now my approach was to use Rc<RefCell<T>> in every fields in every structures and I used a macro to "rcize" these fields :

#[rcize_fields]
#[derive(Deserialize, Serialize, Clone)]
pub struct Example {
    string: String,
    integer: i32,
    float: f32,
    vec: Vec<NestedStruct>,
}

becomes

#[derive(Deserialize, Serialize, Clone)]
pub struct Example {
    string: Rc<RefCell<String>>,
    integer: Rc<RefCell<i32>>,
    float: Rc<RefCell<f32>>,
    vec: Rc<RefCell<Vec<Rc<RefCell<NestedStruct>>>>>,
}

then I clone the Rc of each field into the props of the corresponding component and use the inner mutability of the RefCell to edit the value in the update function.

You can see an exemple of a components in the following example with :

type RcUi<T> = Rc<RefCell<T>>;

https://github.com/KarlitosVII/trilogy-save-editor/blob/main/src/gui/components/check_box.rs

Using this approach works but it have a lot of downsides :

• The rcize macro is a bit complicated
• The macro generating adds a few seconds of compilation time because it has to generated a new struct for tens of strutures each time
• I have to clone a Rc each time I need to use a value in a component
• I have to use .borrow(), .borrow_mut() and deref * everywhere
• Using Rc<RefCell<T>> for every data of hundreds of kilobytes has a non negligible runtime cost
• If I want to use a function component I can't because I'm not supposed to mutate a prop (or it will requires even more boilerplate and possibly runtime cost)
• I feel like this is more of a hack than anything

So, here is my question: is there a better / nicer way to do the same but with less boilerplate, less hacky tricks, cheaper runtime cost and/or with more readable code ?

Thanks in advance !

[voidpumpkin]

I think what you are looking for is for a way to not have to clone your bits of the struct all the time and just keep it in one place.
My suggestion would be to make use of libraries like bounce or yewdux and store your big structure there. (Both libraries I believe use yew context https://yew.rs/docs/concepts/contexts )

[KarlitosVII]

Yes, my first attempt to solve this problem was to use Context, but where I get stuck with this approach is how to target a specific value when it is contained in a structure that is contained in a Vec that is contained in another structure, etc.?
A savegame can have dozens of nested sublevels.

Edit: an example of a nested structure
https://github.com/KarlitosVII/trilogy-save-editor/blob/main/src/save_data/mass_effect_1_le/player.rs

[voidpumpkin]

bounce slices should work then, here is the example link from bounce readme - https://github.com/futursolo/bounce/blob/master/examples/partial-render/src/main.rs