Revert "Improve nested html! expansion by unwrapping VNodes (yewstack…

…#820)" (yewstack#842)

This reverts commit a900fbe.

crates/macro/Cargo.toml

@@ -23,7 +23,7 @@ lazy_static = "1.3.0"
 proc-macro-hack = "0.5"
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["full", "extra-traits", "visit-mut"] }
+syn = { version = "1.0", features = ["full", "extra-traits"] }
 
 [dev-dependencies]
 yew = { path = "../.." }

crates/macro/src/html_tree/html_block.rs

@@ -26,7 +26,7 @@ impl PeekValue<()> for HtmlBlock {
 
 impl Parse for HtmlBlock {
     fn parse(input: ParseStream) -> ParseResult<Self> {
-        let content: syn::parse::ParseBuffer<'_>;
+        let content;
         let brace = braced!(content in input);
         let content = if HtmlIterable::peek(content.cursor()).is_some() {
             BlockContent::Iterable(content.parse()?)

crates/macro/src/html_tree/html_component.rs

@@ -12,8 +12,8 @@ use syn::parse::{Parse, ParseStream, Result as ParseResult};
 use syn::punctuated::Punctuated;
 use syn::spanned::Spanned;
 use syn::{
-    AngleBracketedGenericArguments, Expr, GenericArgument, Ident, Index, Path, PathArguments,
-    PathSegment, Token, Type, TypePath,
+    AngleBracketedGenericArguments, Expr, GenericArgument, Ident, Path, PathArguments, PathSegment,
+    Token, Type, TypePath,
 };
 
 pub struct HtmlComponent {
@@ -126,17 +126,10 @@ impl ToTokens for HtmlComponent {
         };
 
         let set_children = if !children.is_empty() {
-            let i = (0..children.len())
-                .map(|x| Index::from(x))
-                .collect::<Vec<_>>();
             quote! {
-                .children(::yew::html::ChildrenRenderer::new({
-                    let mut v = Vec::new();
-                    let comps = (#(#children,)*);
-                    #(::yew::utils::NodeSeq::from(comps.#i).into_iter()
-                        .for_each(|x| v.push(x.into()));)*
-                    v
-                }))
+                .children(::yew::html::ChildrenRenderer::new(
+                    vec![#(#children.into(),)*]
+                ))
             }
         } else {
             quote! {}

crates/macro/src/html_tree/html_iterable.rs

@@ -7,10 +7,6 @@ use syn::parse::{Parse, ParseStream, Result as ParseResult};
 use syn::spanned::Spanned;
 use syn::{Expr, Token};
 
-use proc_macro2::{Ident, Span};
-use syn::visit_mut::{self, VisitMut};
-use syn::Macro;
-
 pub struct HtmlIterable(Expr);
 
 impl PeekValue<()> for HtmlIterable {
@@ -20,28 +16,12 @@ impl PeekValue<()> for HtmlIterable {
     }
 }
 
-struct HtmlInnerModifier;
-impl VisitMut for HtmlInnerModifier {
-    fn visit_macro_mut(&mut self, node: &mut Macro) {
-        if node.path.is_ident("html") {
-            let ident = &mut node.path.segments.last_mut().unwrap().ident;
-            *ident = Ident::new("html_nested", Span::call_site());
-        }
-
-        // Delegate to the default impl to visit any nested functions.
-        visit_mut::visit_macro_mut(self, node);
-    }
-}
-
 impl Parse for HtmlIterable {
     fn parse(input: ParseStream) -> ParseResult<Self> {
         let for_token = input.parse::<Token![for]>()?;
 
         match input.parse() {
-            Ok(mut expr) => {
-                HtmlInnerModifier.visit_expr_mut(&mut expr);
-                Ok(HtmlIterable(expr))
-            }
+            Ok(expr) => Ok(HtmlIterable(expr)),
             Err(err) => {
                 if err.to_string().starts_with("unexpected end of input") {
                     Err(syn::Error::new_spanned(

crates/macro/src/html_tree/html_node.rs

@@ -4,26 +4,8 @@ use quote::{quote, quote_spanned, ToTokens};
 use syn::buffer::Cursor;
 use syn::parse::{Parse, ParseStream, Result};
 use syn::spanned::Spanned;
-use syn::Expr;
 use syn::Lit;
 
-use proc_macro2::{Ident, Span};
-use syn::visit_mut::{self, VisitMut};
-use syn::Macro;
-
-struct HtmlInnerModifier;
-impl VisitMut for HtmlInnerModifier {
-    fn visit_macro_mut(&mut self, node: &mut Macro) {
-        if node.path.is_ident("html") {
-            let ident = &mut node.path.segments.last_mut().unwrap().ident;
-            *ident = Ident::new("html_nested", Span::call_site());
-        }
-
-        // Delegate to the default impl to visit any nested functions.
-        visit_mut::visit_macro_mut(self, node);
-    }
-}
-
 pub struct HtmlNode(Node);
 
 impl Parse for HtmlNode {
@@ -36,9 +18,7 @@ impl Parse for HtmlNode {
             }
             Node::Literal(lit)
         } else {
-            let mut expr: Expr = input.parse()?;
-            HtmlInnerModifier.visit_expr_mut(&mut expr);
-            Node::Expression(expr)
+            Node::Raw(input.parse()?)
         };
 
         Ok(HtmlNode(node))
@@ -66,8 +46,12 @@ impl ToTokens for HtmlNode {
 impl ToTokens for Node {
     fn to_tokens(&self, tokens: &mut TokenStream) {
         let node_token = match &self {
-            Node::Literal(lit) => quote! {#lit},
-            Node::Expression(expr) => quote_spanned! {expr.span()=> {#expr} },
+            Node::Literal(lit) => quote! {
+                ::yew::virtual_dom::VNode::from(#lit)
+            },
+            Node::Raw(stream) => quote_spanned! {stream.span()=>
+                ::yew::virtual_dom::VNode::from({#stream})
+            },
         };
 
         tokens.extend(node_token);
@@ -76,5 +60,5 @@ impl ToTokens for Node {
 
 enum Node {
     Literal(Lit),
-    Expression(Expr),
+    Raw(TokenStream),
 }

crates/macro/src/html_tree/mod.rs

@@ -126,19 +126,6 @@ impl HtmlTree {
     }
 }
 
-pub struct HtmlRootNested(HtmlTreeNested);
-impl Parse for HtmlRootNested {
-    fn parse(input: ParseStream) -> Result<Self> {
-        Ok(HtmlRootNested(HtmlTreeNested::parse(input)?))
-    }
-}
-
-impl ToTokens for HtmlRootNested {
-    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
-        self.0.to_tokens(tokens);
-    }
-}
-
 pub struct HtmlTreeNested(HtmlTree);
 impl Parse for HtmlTreeNested {
     fn parse(input: ParseStream) -> Result<Self> {

crates/macro/src/lib.rs

@@ -63,7 +63,7 @@ mod derive_props;
 mod html_tree;
 
 use derive_props::DerivePropsInput;
-use html_tree::{HtmlRoot, HtmlRootNested};
+use html_tree::HtmlRoot;
 use proc_macro::TokenStream;
 use proc_macro_hack::proc_macro_hack;
 use quote::{quote, ToTokens};
@@ -94,12 +94,6 @@ pub fn derive_props(input: TokenStream) -> TokenStream {
     TokenStream::from(input.into_token_stream())
 }
 
-#[proc_macro_hack]
-pub fn html_nested(input: TokenStream) -> TokenStream {
-    let root = parse_macro_input!(input as HtmlRootNested);
-    TokenStream::from(quote! {#root})
-}
-
 #[proc_macro_hack]
 pub fn html(input: TokenStream) -> TokenStream {
     let root = parse_macro_input!(input as HtmlRoot);

src/lib.rs

@@ -72,14 +72,9 @@ use proc_macro_hack::proc_macro_hack;
 #[proc_macro_hack(support_nested)]
 pub use yew_macro::html;
 
-#[doc(hidden)]
-#[proc_macro_hack(support_nested)]
-pub use yew_macro::html_nested;
-
 /// This module contains macros which implements html! macro and JSX-like templates
 pub mod macros {
     pub use crate::html;
-    pub use crate::html_nested;
     pub use yew_macro::Properties;
 }
 
@@ -163,7 +158,6 @@ pub mod prelude {
         Renderable, ShouldRender,
     };
     pub use crate::macros::*;
-    pub use crate::utils::NodeSeq;
     pub use crate::virtual_dom::Classes;
 
     /// Prelude module for creating worker.

src/utils.rs

@@ -3,39 +3,10 @@
 use failure::{err_msg, Error};
 use stdweb::web::document;
 
-use crate::virtual_dom::VNode;
-
 /// Returns `host` for the current document. Useful to connect to a server that server the app.
 pub fn host() -> Result<String, Error> {
     document()
         .location()
         .ok_or_else(|| err_msg("can't get location"))
         .and_then(|l| l.host().map_err(Error::from))
 }
-
-/// Specialty type necessary for helping flattening components returned from nested html macros.
-#[derive(Debug)]
-pub struct NodeSeq<T>(Vec<T>)
-where
-    T: Into<VNode>;
-
-impl<T: Into<VNode>> From<T> for NodeSeq<T> {
-    fn from(val: T) -> Self {
-        NodeSeq(vec![val])
-    }
-}
-
-impl<T: Into<VNode>> From<Vec<T>> for NodeSeq<T> {
-    fn from(val: Vec<T>) -> Self {
-        NodeSeq(val)
-    }
-}
-
-impl<T: Into<VNode>> IntoIterator for NodeSeq<T> {
-    type Item = T;
-    type IntoIter = std::vec::IntoIter<Self::Item>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.0.into_iter()
-    }
-}

tests/macro/html-component-fail.rs

@@ -2,6 +2,7 @@
 
 use std::marker::PhantomData;
 use yew::prelude::*;
+use yew::virtual_dom::{VChild, VComp, VNode};
 
 #[derive(Clone, Properties, PartialEq)]
 pub struct ChildProperties {
@@ -20,6 +21,18 @@ impl Component for Child {
     fn view(&self) -> Html { unimplemented!() }
 }
 
+impl From<VChild<Child>> for ChildProperties {
+    fn from(comp: VChild<Child>) -> Self {
+        comp.props
+    }
+}
+
+impl Into<VNode> for ChildProperties {
+    fn into(self) -> VNode {
+        VComp::new::<Child>(self, NodeRef::default()).into()
+    }
+}
+
 #[derive(Clone, Properties)]
 pub struct ChildContainerProperties {
     #[props(required)]