Enum lignin::web::DomRef

pub enum DomRef<T> {
    Added(T),
    Removing(T),
}

Used as DOM reference callback parameter. (Expand for implementation contract!)

When you receive a DomRef containing a stand-in type, use Materialize::materialize to convert it to the actual value.

Implementation Contract

This is not a soundness contract. Code using this type must not rely on it for soundness. However, it is free to panic when encountering an incorrect implementation.

For VDOM-to-DOM renderers:

If a renderer invoked a callback with the Added variant, it must invoke it with the Removing variant before destroying or reusing the relevant part of the DOM.

This includes cases where the identity of the CallbackRef or DOM node changes, in which case the new reference is Added after, in this order, Removing the old reference and updating the relevant part(s) of the DOM.

For apps/VDOM renderers:

Tearing down and reconstructing the child DOM according to the current child VDOM must be possible at any time.

Please refer to the variant documentation for more information.

Variants

Added(T)

When constructing the DOM, this variant is passed after all child elements have been processed and, if applicable, the element has been added to the document tree.

In particular, this means:

• Manipulating child elements is possible (but this can cause panics to occur later on if an incompatible child diff occurs).
• Traversing ancestors and their attributes should work.
• Scrolling the node into view and grabbing focus should work.
• Any siblings and ancestor siblings may be in an indeterminate state at this point!

Removing(T)

When tearing down the DOM, this variant is passed before any child elements are processed and, if applicable, the element is removed from to the document tree.

In particular, this means:

• Child elements must be restored to a clean state compatible with their VDOM here!
• Traversing ancestors and their attributes should still work.
• Any siblings and ancestor siblings may be in an indeterminate state at this point!

Trait Implementations

impl<T: Clone> Clone for DomRef<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for DomRef<T>

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

Formats the value using the given formatter.

impl<T: Hash> Hash for DomRef<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T: Materialize<U>, U> Materialize<DomRef<U>> for DomRef<T>

fn materialize(self) -> DomRef<U>

Convert a DOM stand-in to its web type value. This is a no-op with the "callbacks" feature and unreachable otherwise.

impl<T: Ord> Ord for DomRef<T>

fn cmp(&self, other: &DomRef<T>) -> Ordering

This method returns an Ordering between self and other.

#[must_use]

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq<DomRef<T>> for DomRef<T>

fn eq(&self, other: &DomRef<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &DomRef<T>) -> bool

This method tests for !=.

impl<T: PartialOrd> PartialOrd<DomRef<T>> for DomRef<T>

fn partial_cmp(&self, other: &DomRef<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Copy> Copy for DomRef<T>

impl<T: Eq> Eq for DomRef<T>

impl<T> StructuralEq for DomRef<T>

impl<T> StructuralPartialEq for DomRef<T>