Struct UpdateDraft 

pub struct UpdateDraft<T: Clone> {
    pub before: T,
    pub after: T,
}

Merged before/after snapshot of a model for before_update hooks.

UpdateDraft<T> holds the original (before) and proposed (after) state of a model. The after copy starts as a clone of before and can be mutated via after_mut or through per-field DraftField accessors generated by #[model].

Usage

let mut draft = UpdateDraft::new(existing_article);
// apply partial changes from the request …
draft.after_mut().title = new_title;

// per-field inspection via DraftField:
let title = DraftField::new(&draft.before().title, &mut draft.after_mut().title);
if title.changed() { /* … */ }

Fields

before: T

The original (pre-mutation) model state.

Public so that #[model]-generated per-field DraftField accessors can split-borrow before and after simultaneously.

after: T

The proposed (post-mutation) model state.

Public so that #[model]-generated per-field DraftField accessors can split-borrow before and after simultaneously.

Implementations

impl<T: Clone> UpdateDraft<T>

pub fn new(before: T) -> Self

Create a new draft from the current model state.

Clones before into after so that after starts as an identical copy that can be selectively mutated.

pub const fn new_with_changes(before: T, after: T) -> Self

Create a draft with explicit before and after values.

Useful in tests or when changes have already been applied.

pub const fn before(&self) -> &T

Reference to the original (pre-mutation) model.

pub const fn after(&self) -> &T

Reference to the proposed (post-mutation) model.

pub const fn after_mut(&mut self) -> &mut T

Mutable reference to the proposed (post-mutation) model.

Use this to apply changes before the update is persisted.

pub fn into_after(self) -> T

Consume the draft and return the proposed model.

Trait Implementations

impl<T: Clone + Clone> Clone for UpdateDraft<T>

fn clone(&self) -> UpdateDraft<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + Clone> Debug for UpdateDraft<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.