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use super::{
fragment_to_tokens, utils::is_nostrip_optional_and_update_key, TagType,
};
use crate::view::{attribute_absolute, utils::filter_prefixed_attrs};
use proc_macro2::{Ident, TokenStream, TokenTree};
use quote::{format_ident, quote, quote_spanned};
use rstml::node::{
CustomNode, KeyedAttributeValue, NodeAttribute, NodeBlock, NodeElement,
NodeName,
};
use std::collections::HashMap;
use syn::{spanned::Spanned, Expr, ExprPath, ExprRange, RangeLimits, Stmt};
pub(crate) fn component_to_tokens(
node: &mut NodeElement<impl CustomNode>,
global_class: Option<&TokenTree>,
disable_inert_html: bool,
) -> TokenStream {
#[allow(unused)] // TODO this is used by hot-reloading
#[cfg(debug_assertions)]
let component_name = super::ident_from_tag_name(node.name());
// an attribute that contains {..} can be used to split props from attributes
// anything before it is a prop, unless it uses the special attribute syntaxes
// (attr:, style:, on:, prop:, etc.)
// anything after it is a plain HTML attribute to be spread onto the prop
let spread_marker = node
.attributes()
.iter()
.position(|node| match node {
NodeAttribute::Block(NodeBlock::ValidBlock(block)) => {
matches!(
block.stmts.first(),
Some(Stmt::Expr(
Expr::Range(ExprRange {
start: None,
limits: RangeLimits::HalfOpen(_),
end: None,
..
}),
_,
))
)
}
_ => false,
})
.unwrap_or_else(|| node.attributes().len());
// Initially using uncloned mutable reference, as the node.key might be mutated during prop extraction (for nostrip:)
let mut attrs = node
.attributes_mut()
.iter_mut()
.filter_map(|node| {
if let NodeAttribute::Attribute(node) = node {
Some(node)
} else {
None
}
})
.collect::<Vec<_>>();
let mut required_props = vec![];
let mut optional_props = vec![];
for (_, attr) in attrs.iter_mut().enumerate().filter(|(idx, attr)| {
idx < &spread_marker && {
let attr_key = attr.key.to_string();
!is_attr_let(&attr.key)
&& !attr_key.starts_with("clone:")
&& !attr_key.starts_with("class:")
&& !attr_key.starts_with("style:")
&& !attr_key.starts_with("attr:")
&& !attr_key.starts_with("prop:")
&& !attr_key.starts_with("on:")
&& !attr_key.starts_with("use:")
}
}) {
let optional = is_nostrip_optional_and_update_key(&mut attr.key);
let name = &attr.key;
let value = attr
.value()
.map(|v| {
quote! { #v }
})
.unwrap_or_else(|| quote! { #name });
if optional {
optional_props.push(quote! {
props.#name = { #value }.map(Into::into);
})
} else {
required_props.push(quote! {
.#name(#[allow(unused_braces)] { #value })
})
}
}
// Drop the mutable reference to the node, go to an owned clone:
let attrs = attrs.into_iter().map(|a| a.clone()).collect::<Vec<_>>();
let items_to_bind = attrs
.iter()
.filter_map(|attr| {
if !is_attr_let(&attr.key) {
return None;
}
let KeyedAttributeValue::Binding(binding) = &attr.possible_value
else {
if let Some(ident) = attr.key.to_string().strip_prefix("let:") {
let span = match &attr.key {
NodeName::Punctuated(path) => path[1].span(),
_ => unreachable!(),
};
let ident1 = format_ident!("{ident}", span = span);
return Some(quote_spanned! { span => #ident1 });
} else {
return None;
}
};
let inputs = &binding.inputs;
Some(quote! { #inputs })
})
.collect::<Vec<_>>();
let items_to_clone = filter_prefixed_attrs(attrs.iter(), "clone:");
// include all attribute that are either
// 1) blocks ({..attrs} or {attrs}),
// 2) start with attr: and can be used as actual attributes, or
// 3) the custom attribute types (on:, class:, style:, prop:, use:)
let spreads = node
.attributes()
.iter()
.enumerate()
.filter_map(|(idx, attr)| {
if idx == spread_marker {
return None;
}
if let NodeAttribute::Block(block) = attr {
let dotted = if let NodeBlock::ValidBlock(block) = block {
match block.stmts.first() {
Some(Stmt::Expr(
Expr::Range(ExprRange {
start: None,
limits: RangeLimits::HalfOpen(_),
end: Some(end),
..
}),
_,
)) => Some(quote! { #end }),
_ => None,
}
} else {
None
};
Some(dotted.unwrap_or_else(|| {
quote! {
#node
}
}))
} else if let NodeAttribute::Attribute(node) = attr {
attribute_absolute(node, idx >= spread_marker)
} else {
None
}
})
.collect::<Vec<_>>();
let spreads = (!(spreads.is_empty())).then(|| {
quote! {
.add_any_attr((#(#spreads,)*).into_attr())
}
});
/*let directives = attrs
.clone()
.filter_map(|attr| {
attr.key
.to_string()
.strip_prefix("use:")
.map(|ident| directive_call_from_attribute_node(attr, ident))
})
.collect::<Vec<_>>();
let events_and_directives =
events.into_iter().chain(directives).collect::<Vec<_>>(); */
let mut slots = HashMap::new();
let children = if node.children.is_empty() {
quote! {}
} else {
let children = fragment_to_tokens(
&mut node.children,
TagType::Unknown,
Some(&mut slots),
global_class,
None,
disable_inert_html,
);
// TODO view marker for hot-reloading
/*
cfg_if::cfg_if! {
if #[cfg(debug_assertions)] {
let marker = format!("<{component_name}/>-children");
// For some reason spanning for `.children` breaks, unless `#view_marker`
// is also covered by `children.span()`.
let view_marker = quote_spanned!(children.span()=> .with_view_marker(#marker));
} else {
let view_marker = quote! {};
}
}
*/
if let Some(children) = children {
let bindables =
items_to_bind.iter().map(|ident| quote! { #ident, });
let clonables = items_to_clone.iter().map(|ident| {
let ident_ref = quote_spanned!(ident.span()=> &#ident);
quote! { let #ident = ::core::clone::Clone::clone(#ident_ref); }
});
if bindables.len() > 0 {
quote_spanned! {children.span()=>
.children({
#(#clonables)*
move |#(#bindables)*| #children
})
}
} else {
quote_spanned! {children.span()=>
.children({
#(#clonables)*
::leptos::children::ToChildren::to_children(move || #children)
})
}
}
} else {
quote! {}
}
};
let slots = slots.drain().map(|(slot, mut values)| {
let span = values
.last()
.expect("List of slots must not be empty")
.span();
let slot = Ident::new(&slot, span);
let value = if values.len() > 1 {
quote_spanned! {span=>
::std::vec![
#(#values)*
]
}
} else {
values.remove(0)
};
quote! { .#slot(#value) }
});
let generics = &node.open_tag.generics;
let generics = if generics.lt_token.is_some() {
quote! { ::#generics }
} else {
quote! {}
};
let name = node.name();
#[allow(unused_mut)] // used in debug
let mut component = quote! {
{
#[allow(unreachable_code)]
#[allow(unused_mut)]
#[allow(clippy::let_and_return)]
::leptos::component::component_view(
#[allow(clippy::needless_borrows_for_generic_args)]
&#name,
{
let mut props = ::leptos::component::component_props_builder(&#name #generics)
#(#required_props)*
#(#slots)*
#children
.build();
#(#optional_props)*
props
}
)
#spreads
}
};
// (Temporarily?) removed
// See note on the function itself below.
/* #[cfg(debug_assertions)]
IdeTagHelper::add_component_completion(&mut component, node); */
component
}
fn is_attr_let(key: &NodeName) -> bool {
if key.to_string().starts_with("let:") {
true
} else if let NodeName::Path(ExprPath { path, .. }) = key {
path.segments.len() == 1 && path.segments[0].ident == "let"
} else {
false
}
}