use leptos_reactive::Scope;
pub enum Class {
Value(bool),
Fn(Scope, Box<dyn Fn() -> bool>),
}
pub trait IntoClass {
fn into_class(self, cx: Scope) -> Class;
}
impl IntoClass for bool {
fn into_class(self, _cx: Scope) -> Class {
Class::Value(self)
}
}
impl<T> IntoClass for T
where
T: Fn() -> bool + 'static,
{
fn into_class(self, cx: Scope) -> Class {
let modified_fn = Box::new(self);
Class::Fn(cx, modified_fn)
}
}
impl Class {
pub fn as_value_string(&self, class_name: &'static str) -> &'static str {
match self {
Class::Value(value) => {
if *value {
class_name
} else {
""
}
}
Class::Fn(_, f) => {
let value = f();
if value {
class_name
} else {
""
}
}
}
}
}
impl<T: IntoClass> IntoClass for (Scope, T) {
fn into_class(self, _: Scope) -> Class {
self.1.into_class(self.0)
}
}
#[cfg(all(target_arch = "wasm32", feature = "web"))]
use std::borrow::Cow;
#[cfg(all(target_arch = "wasm32", feature = "web"))]
#[doc(hidden)]
pub fn class_helper(
el: &web_sys::Element,
name: Cow<'static, str>,
value: Class,
) {
use leptos_reactive::create_render_effect;
let class_list = el.class_list();
match value {
Class::Fn(cx, f) => {
create_render_effect(cx, move |old| {
let new = f();
if old.as_ref() != Some(&new) && (old.is_some() || new) {
class_expression(&class_list, &name, new, true)
}
new
});
}
Class::Value(value) => {
class_expression(&class_list, &name, value, false)
}
};
}
#[cfg(all(target_arch = "wasm32", feature = "web"))]
pub(crate) fn class_expression(
class_list: &web_sys::DomTokenList,
class_name: &str,
value: bool,
force: bool,
) {
use crate::HydrationCtx;
if force || !HydrationCtx::is_hydrating() {
let class_name = wasm_bindgen::intern(class_name);
if value {
if let Err(e) = class_list.add_1(class_name) {
crate::error!("[HtmlElement::class()] {e:?}");
}
} else {
if let Err(e) = class_list.remove_1(class_name) {
crate::error!("[HtmlElement::class()] {e:?}");
}
}
}
}