Bind to properties instead of attributes by default (#2819)

* Set to properties, not attributes

* fix tests

* Add tests

* enable disabled test, fmt

* Introduce @key syntax to forcefully set as attribute

* Everything compiles

* More tests

* id as property

* This was not meant to be committed

* Make test pass, fmt + clippy

* fucking rustfmt

* is this enough formatting

* that was not supposed to be commited

* apply review

* fmt

* fix CI

* will you be happy now, clippy?

examples/counter_functional/src/main.rs

@@ -14,13 +14,13 @@ fn App() -> Html {
         Callback::from(move |_| state.set(*state - 1))
     };
 
-    html!(
+    html! {
         <>
-        <p> {"current count: "} {*state} </p>
+            <p> {"current count: "} {*state} </p>
-        <button onclick={incr_counter}> {"+"} </button>
+            <button onclick={incr_counter}> {"+"} </button>
-        <button onclick={decr_counter}> {"-"} </button>
+            <button onclick={decr_counter}> {"-"} </button>
         </>
-    )
+    }
 }
 
 fn main() {

packages/yew-macro/src/html_tree/html_element.rs

@@ -8,7 +8,7 @@ use syn::spanned::Spanned;
 use syn::{Block, Expr, Ident, Lit, LitStr, Token};
 
 use super::{HtmlChildrenTree, HtmlDashedName, TagTokens};
-use crate::props::{ClassesForm, ElementProps, Prop};
+use crate::props::{ClassesForm, ElementProps, Prop, PropDirective};
 use crate::stringify::{Stringify, Value};
 use crate::{non_capitalized_ascii, Peek, PeekValue};
 
@@ -135,39 +135,58 @@ impl ToTokens for HtmlElement {
         // other attributes
 
         let attributes = {
-            let normal_attrs = attributes.iter().map(|Prop { label, value, .. }| {
+            let normal_attrs = attributes.iter().map(
-                (label.to_lit_str(), value.optimize_literals_tagged())
+                |Prop {
-            });
+                     label,
-            let boolean_attrs = booleans.iter().filter_map(|Prop { label, value, .. }| {
+                     value,
-                let key = label.to_lit_str();
+                     directive,
-                Some((
+                     ..
-                    key.clone(),
+                 }| {
-                    match value {
+                    (
-                        Expr::Lit(e) => match &e.lit {
+                        label.to_lit_str(),
-                            Lit::Bool(b) => Value::Static(if b.value {
+                        value.optimize_literals_tagged(),
-                                quote! { #key }
+                        *directive,
-                            } else {
+                    )
-                                return None;
+                },
-                            }),
+            );
-                            _ => Value::Dynamic(quote_spanned! {value.span()=> {
+            let boolean_attrs = booleans.iter().filter_map(
-                                ::yew::utils::__ensure_type::<::std::primitive::bool>(#value);
+                |Prop {
-                                #key
+                     label,
-                            }}),
+                     value,
-                        },
+                     directive,
-                        expr => Value::Dynamic(
+                     ..
-                            quote_spanned! {expr.span().resolved_at(Span::call_site())=>
+                 }| {
-                                if #expr {
+                    let key = label.to_lit_str();
-                                    ::std::option::Option::Some(
+                    Some((
-                                        ::yew::virtual_dom::AttrValue::Static(#key)
+                        key.clone(),
-                                    )
+                        match value {
+                            Expr::Lit(e) => match &e.lit {
+                                Lit::Bool(b) => Value::Static(if b.value {
+                                    quote! { #key }
                                 } else {
-                                    ::std::option::Option::None
+                                    return None;
-                                }
+                                }),
+                                _ => Value::Dynamic(quote_spanned! {value.span()=> {
+                                    ::yew::utils::__ensure_type::<::std::primitive::bool>(#value);
+                                    #key
+                                }}),
                             },
-                        ),
+                            expr => Value::Dynamic(
-                    },
+                                quote_spanned! {expr.span().resolved_at(Span::call_site())=>
-                ))
+                                    if #expr {
-            });
+                                        ::std::option::Option::Some(
+                                            ::yew::virtual_dom::AttrValue::Static(#key)
+                                        )
+                                    } else {
+                                        ::std::option::Option::None
+                                    }
+                                },
+                            ),
+                        },
+                        *directive,
+                    ))
+                },
+            );
             let class_attr = classes.as_ref().and_then(|classes| match classes {
                 ClassesForm::Tuple(classes) => {
                     let span = classes.span();
@@ -196,6 +215,7 @@ impl ToTokens for HtmlElement {
                                 __yew_classes
                             }
                         }),
+                        None,
                     ))
                 }
                 ClassesForm::Single(classes) => {
@@ -207,6 +227,7 @@ impl ToTokens for HtmlElement {
                                 Some((
                                     LitStr::new("class", lit.span()),
                                     Value::Static(quote! { #lit }),
+                                    None,
                                 ))
                             }
                         }
@@ -216,21 +237,34 @@ impl ToTokens for HtmlElement {
                                 Value::Dynamic(quote! {
                                     ::std::convert::Into::<::yew::html::Classes>::into(#classes)
                                 }),
+                                None,
                             ))
                         }
                     }
                 }
             });
 
+            fn apply_as(directive: Option<&PropDirective>) -> TokenStream {
+                match directive {
+                    Some(PropDirective::ApplyAsProperty(token)) => {
+                        quote_spanned!(token.span()=> ::yew::virtual_dom::ApplyAttributeAs::Property)
+                    }
+                    None => quote!(::yew::virtual_dom::ApplyAttributeAs::Attribute),
+                }
+            }
+
             /// Try to turn attribute list into a `::yew::virtual_dom::Attributes::Static`
-            fn try_into_static(src: &[(LitStr, Value)]) -> Option<TokenStream> {
+            fn try_into_static(
+                src: &[(LitStr, Value, Option<PropDirective>)],
+            ) -> Option<TokenStream> {
                 let mut kv = Vec::with_capacity(src.len());
-                for (k, v) in src.iter() {
+                for (k, v, directive) in src.iter() {
                     let v = match v {
                         Value::Static(v) => quote! { #v },
                         Value::Dynamic(_) => return None,
                     };
-                    kv.push(quote! { [ #k, #v ] });
+                    let apply_as = apply_as(directive.as_ref());
+                    kv.push(quote! { ( #k, #v, #apply_as ) });
                 }
 
                 Some(quote! { ::yew::virtual_dom::Attributes::Static(&[#(#kv),*]) })
@@ -239,10 +273,14 @@ impl ToTokens for HtmlElement {
             let attrs = normal_attrs
                 .chain(boolean_attrs)
                 .chain(class_attr)
-                .collect::<Vec<(LitStr, Value)>>();
+                .collect::<Vec<(LitStr, Value, Option<PropDirective>)>>();
             try_into_static(&attrs).unwrap_or_else(|| {
-                let keys = attrs.iter().map(|(k, _)| quote! { #k });
+                let keys = attrs.iter().map(|(k, ..)| quote! { #k });
-                let values = attrs.iter().map(|(_, v)| wrap_attr_value(v));
+                let values = attrs.iter().map(|(_, v, directive)| {
+                    let apply_as = apply_as(directive.as_ref());
+                    let value = wrap_attr_value(v);
+                    quote! { ::std::option::Option::map(#value, |it| (it, #apply_as)) }
+                });
                 quote! {
                     ::yew::virtual_dom::Attributes::Dynamic{
                         keys: &[#(#keys),*],

packages/yew-macro/src/props/prop.rs

@@ -13,17 +13,27 @@ use super::CHILDREN_LABEL;
 use crate::html_tree::HtmlDashedName;
 use crate::stringify::Stringify;
 
+#[derive(Copy, Clone)]
+pub enum PropDirective {
+    ApplyAsProperty(Token![~]),
+}
+
 pub struct Prop {
+    pub directive: Option<PropDirective>,
     pub label: HtmlDashedName,
     /// Punctuation between `label` and `value`.
     pub value: Expr,
 }
 impl Parse for Prop {
     fn parse(input: ParseStream) -> syn::Result<Self> {
+        let directive = input
+            .parse::<Token![~]>()
+            .map(PropDirective::ApplyAsProperty)
+            .ok();
         if input.peek(Brace) {
-            Self::parse_shorthand_prop_assignment(input)
+            Self::parse_shorthand_prop_assignment(input, directive)
         } else {
-            Self::parse_prop_assignment(input)
+            Self::parse_prop_assignment(input, directive)
         }
     }
 }
@@ -33,7 +43,10 @@ impl Prop {
     /// Parse a prop using the shorthand syntax `{value}`, short for `value={value}`
     /// This only allows for labels with no hyphens, as it would otherwise create
     /// an ambiguity in the syntax
-    fn parse_shorthand_prop_assignment(input: ParseStream) -> syn::Result<Self> {
+    fn parse_shorthand_prop_assignment(
+        input: ParseStream,
+        directive: Option<PropDirective>,
+    ) -> syn::Result<Self> {
         let value;
         let _brace = braced!(value in input);
         let expr = value.parse::<Expr>()?;
@@ -44,7 +57,7 @@ impl Prop {
         }) = expr
         {
             if let (Some(ident), true) = (path.get_ident(), attrs.is_empty()) {
-                syn::Result::Ok(HtmlDashedName::from(ident.clone()))
+                Ok(HtmlDashedName::from(ident.clone()))
             } else {
                 Err(syn::Error::new_spanned(
                     path,
@@ -59,11 +72,18 @@ impl Prop {
             ));
         }?;
 
-        Ok(Self { label, value: expr })
+        Ok(Self {
+            label,
+            value: expr,
+            directive,
+        })
     }
 
     /// Parse a prop of the form `label={value}`
-    fn parse_prop_assignment(input: ParseStream) -> syn::Result<Self> {
+    fn parse_prop_assignment(
+        input: ParseStream,
+        directive: Option<PropDirective>,
+    ) -> syn::Result<Self> {
         let label = input.parse::<HtmlDashedName>()?;
         let equals = input.parse::<Token![=]>().map_err(|_| {
             syn::Error::new_spanned(
@@ -83,7 +103,11 @@ impl Prop {
         }
 
         let value = parse_prop_value(input)?;
-        Ok(Self { label, value })
+        Ok(Self {
+            label,
+            value,
+            directive,
+        })
     }
 }
 
@@ -105,10 +129,13 @@ fn parse_prop_value(input: &ParseBuffer) -> syn::Result<Expr> {
 
         match &expr {
             Expr::Lit(_) => Ok(expr),
-            _ => Err(syn::Error::new_spanned(
+            ref exp => Err(syn::Error::new_spanned(
                 &expr,
-                "the property value must be either a literal or enclosed in braces. Consider \
+                format!(
-                 adding braces around your expression.",
+                    "the property value must be either a literal or enclosed in braces. Consider \
+                     adding braces around your expression.: {:#?}",
+                    exp
+                ),
             )),
         }
     }

packages/yew-macro/src/props/prop_macro.rs

@@ -61,7 +61,11 @@ impl Parse for PropValue {
 impl From<PropValue> for Prop {
     fn from(prop_value: PropValue) -> Prop {
         let PropValue { label, value } = prop_value;
-        Prop { label, value }
+        Prop {
+            label,
+            value,
+            directive: None,
+        }
     }
 }
 

packages/yew-macro/tests/html_macro/component-fail.stderr

@@ -249,7 +249,13 @@ help: escape `type` to use it as an identifier
 85 |     html! { <Child r#type=0 /> };
    |                    ++
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [],
+           },
+       )
   --> tests/html_macro/component-fail.rs:86:24
    |
 86 |     html! { <Child ref=() /> };
@@ -309,7 +315,24 @@ error: only one root html element is allowed (hint: you can wrap multiple html e
 102 |     html! { <Child></Child><Child></Child> };
     |                            ^^^^^^^^^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Path(
+           ExprPath {
+               attrs: [],
+               qself: None,
+               path: Path {
+                   leading_colon: None,
+                   segments: [
+                       PathSegment {
+                           ident: Ident {
+                               ident: "num",
+                               span: #0 bytes(3894..3897),
+                           },
+                           arguments: None,
+                       },
+                   ],
+               },
+           },
+       )
    --> tests/html_macro/component-fail.rs:106:24
     |
 106 |     html! { <Child int=num ..props /> };

packages/yew-macro/tests/html_macro/element-fail.stderr

@@ -142,61 +142,260 @@ error: dynamic closing tags must not have a body (hint: replace it with just `</
 75 |     html! { <@{"test"}></@{"test"}> };
    |                           ^^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [
+                   Lit(
+                       ExprLit {
+                           attrs: [],
+                           lit: Str(
+                               LitStr {
+                                   token: "deprecated",
+                               },
+                           ),
+                       },
+                   ),
+                   Comma,
+                   Lit(
+                       ExprLit {
+                           attrs: [],
+                           lit: Str(
+                               LitStr {
+                                   token: "warning",
+                               },
+                           ),
+                       },
+                   ),
+               ],
+           },
+       )
   --> tests/html_macro/element-fail.rs:83:24
    |
 83 |     html! { <div class=("deprecated", "warning") /> };
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [],
+           },
+       )
   --> tests/html_macro/element-fail.rs:84:24
    |
 84 |     html! { <input ref=() /> };
    |                        ^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [],
+           },
+       )
   --> tests/html_macro/element-fail.rs:85:24
    |
 85 |     html! { <input ref=() ref=() /> };
    |                        ^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Call(
+           ExprCall {
+               attrs: [],
+               func: Path(
+                   ExprPath {
+                       attrs: [],
+                       qself: None,
+                       path: Path {
+                           leading_colon: None,
+                           segments: [
+                               PathSegment {
+                                   ident: Ident {
+                                       ident: "Some",
+                                       span: #0 bytes(2632..2636),
+                                   },
+                                   arguments: None,
+                               },
+                           ],
+                       },
+                   },
+               ),
+               paren_token: Paren,
+               args: [
+                   Lit(
+                       ExprLit {
+                           attrs: [],
+                           lit: Int(
+                               LitInt {
+                                   token: 5,
+                               },
+                           ),
+                       },
+                   ),
+               ],
+           },
+       )
   --> tests/html_macro/element-fail.rs:86:28
    |
 86 |     html! { <input onfocus=Some(5) /> };
    |                            ^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Path(
+           ExprPath {
+               attrs: [],
+               qself: None,
+               path: Path {
+                   leading_colon: None,
+                   segments: [
+                       PathSegment {
+                           ident: Ident {
+                               ident: "NotToString",
+                               span: #0 bytes(2672..2683),
+                           },
+                           arguments: None,
+                       },
+                   ],
+               },
+           },
+       )
   --> tests/html_macro/element-fail.rs:87:27
    |
 87 |     html! { <input string=NotToString /> };
    |                           ^^^^^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Call(
+           ExprCall {
+               attrs: [],
+               func: Path(
+                   ExprPath {
+                       attrs: [],
+                       qself: None,
+                       path: Path {
+                           leading_colon: None,
+                           segments: [
+                               PathSegment {
+                                   ident: Ident {
+                                       ident: "Some",
+                                       span: #0 bytes(2711..2715),
+                                   },
+                                   arguments: None,
+                               },
+                           ],
+                       },
+                   },
+               ),
+               paren_token: Paren,
+               args: [
+                   Path(
+                       ExprPath {
+                           attrs: [],
+                           qself: None,
+                           path: Path {
+                               leading_colon: None,
+                               segments: [
+                                   PathSegment {
+                                       ident: Ident {
+                                           ident: "NotToString",
+                                           span: #0 bytes(2716..2727),
+                                       },
+                                       arguments: None,
+                                   },
+                               ],
+                           },
+                       },
+                   ),
+               ],
+           },
+       )
   --> tests/html_macro/element-fail.rs:88:22
    |
 88 |     html! { <a media=Some(NotToString) /> };
    |                      ^^^^^^^^^^^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Call(
+           ExprCall {
+               attrs: [],
+               func: Path(
+                   ExprPath {
+                       attrs: [],
+                       qself: None,
+                       path: Path {
+                           leading_colon: None,
+                           segments: [
+                               PathSegment {
+                                   ident: Ident {
+                                       ident: "Some",
+                                       span: #0 bytes(2755..2759),
+                                   },
+                                   arguments: None,
+                               },
+                           ],
+                       },
+                   },
+               ),
+               paren_token: Paren,
+               args: [
+                   Lit(
+                       ExprLit {
+                           attrs: [],
+                           lit: Int(
+                               LitInt {
+                                   token: 5,
+                               },
+                           ),
+                       },
+                   ),
+               ],
+           },
+       )
   --> tests/html_macro/element-fail.rs:89:21
    |
 89 |     html! { <a href=Some(5) /> };
    |                     ^^^^^^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [],
+           },
+       )
   --> tests/html_macro/element-fail.rs:90:25
    |
 90 |     html! { <input type=() /> };
    |                         ^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Tuple(
+           ExprTuple {
+               attrs: [],
+               paren_token: Paren,
+               elems: [],
+           },
+       )
   --> tests/html_macro/element-fail.rs:91:26
    |
 91 |     html! { <input value=() /> };
    |                          ^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: Path(
+           ExprPath {
+               attrs: [],
+               qself: None,
+               path: Path {
+                   leading_colon: None,
+                   segments: [
+                       PathSegment {
+                           ident: Ident {
+                               ident: "NotToString",
+                               span: #0 bytes(2862..2873),
+                           },
+                           arguments: None,
+                       },
+                   ],
+               },
+           },
+       )
   --> tests/html_macro/element-fail.rs:92:27
    |
 92 |     html! { <input string=NotToString /> };

packages/yew-macro/tests/html_macro/list-fail.stderr

@@ -1,65 +1,87 @@
 error: this opening fragment has no corresponding closing fragment
- --> $DIR/list-fail.rs:5:13
+ --> tests/html_macro/list-fail.rs:5:13
   |
 5 |     html! { <> };
   |             ^^
 
 error: this opening fragment has no corresponding closing fragment
- --> $DIR/list-fail.rs:6:15
+ --> tests/html_macro/list-fail.rs:6:15
   |
 6 |     html! { <><> };
   |               ^^
 
 error: this opening fragment has no corresponding closing fragment
- --> $DIR/list-fail.rs:7:13
+ --> tests/html_macro/list-fail.rs:7:13
   |
 7 |     html! { <><></> };
   |             ^^
 
 error: this closing fragment has no corresponding opening fragment
-  --> $DIR/list-fail.rs:10:13
+  --> tests/html_macro/list-fail.rs:10:13
    |
 10 |     html! { </> };
    |             ^^^
 
 error: this closing fragment has no corresponding opening fragment
-  --> $DIR/list-fail.rs:11:13
+  --> tests/html_macro/list-fail.rs:11:13
    |
 11 |     html! { </></> };
    |             ^^^
 
 error: only one root html element is allowed (hint: you can wrap multiple html elements in a fragment `<></>`)
-  --> $DIR/list-fail.rs:14:18
+  --> tests/html_macro/list-fail.rs:14:18
    |
 14 |     html! { <></><></> };
    |                  ^^^^^
 
 error: expected a valid html element
-  --> $DIR/list-fail.rs:16:15
+  --> tests/html_macro/list-fail.rs:16:15
    |
 16 |     html! { <>invalid</> };
    |               ^^^^^^^
 
 error: expected an expression following this equals sign
-  --> $DIR/list-fail.rs:18:17
+  --> tests/html_macro/list-fail.rs:18:17
    |
 18 |     html! { <key=></> };
    |                 ^^
 
-error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.
+error: the property value must be either a literal or enclosed in braces. Consider adding braces around your expression.: MethodCall(
-  --> $DIR/list-fail.rs:20:18
+           ExprMethodCall {
+               attrs: [],
+               receiver: Lit(
+                   ExprLit {
+                       attrs: [],
+                       lit: Str(
+                           LitStr {
+                               token: "key",
+                           },
+                       ),
+                   },
+               ),
+               dot_token: Dot,
+               method: Ident {
+                   ident: "to_string",
+                   span: #0 bytes(404..413),
+               },
+               turbofish: None,
+               paren_token: Paren,
+               args: [],
+           },
+       )
+  --> tests/html_macro/list-fail.rs:20:18
    |
 20 |     html! { <key="key".to_string()></key> };
    |                  ^^^^^^^^^^^^^^^^^
 
 error: only a single `key` prop is allowed on a fragment
-  --> $DIR/list-fail.rs:23:30
+  --> tests/html_macro/list-fail.rs:23:30
    |
 23 |     html! { <key="first key" key="second key" /> };
    |                              ^^^
 
 error: fragments only accept the `key` prop
-  --> $DIR/list-fail.rs:25:14
+  --> tests/html_macro/list-fail.rs:25:14
    |
 25 |     html! { <some_attr="test"></> };
    |              ^^^^^^^^^

packages/yew/src/dom_bundle/btag/attributes.rs

@@ -2,13 +2,14 @@ use std::collections::HashMap;
 use std::ops::Deref;
 
 use indexmap::IndexMap;
+use wasm_bindgen::JsValue;
 use web_sys::{Element, HtmlInputElement as InputElement, HtmlTextAreaElement as TextAreaElement};
 use yew::AttrValue;
 
 use super::Apply;
 use crate::dom_bundle::BSubtree;
 use crate::virtual_dom::vtag::{InputFields, Value};
-use crate::virtual_dom::Attributes;
+use crate::virtual_dom::{ApplyAttributeAs, Attributes};
 
 impl<T: AccessValue> Apply for Value<T> {
     type Bundle = Self;
@@ -87,23 +88,23 @@ impl Attributes {
     #[cold]
     fn apply_diff_index_maps(
         el: &Element,
-        new: &IndexMap<AttrValue, AttrValue>,
+        new: &IndexMap<AttrValue, (AttrValue, ApplyAttributeAs)>,
-        old: &IndexMap<AttrValue, AttrValue>,
+        old: &IndexMap<AttrValue, (AttrValue, ApplyAttributeAs)>,
     ) {
         for (key, value) in new.iter() {
             match old.get(key) {
                 Some(old_value) => {
                     if value != old_value {
-                        Self::set_attribute(el, key, value);
+                        Self::set(el, key, value.0.as_ref(), value.1);
                     }
                 }
-                None => Self::set_attribute(el, key, value),
+                None => Self::set(el, key, value.0.as_ref(), value.1),
             }
         }
 
-        for (key, _value) in old.iter() {
+        for (key, (_, apply_as)) in old.iter() {
             if !new.contains_key(key) {
-                Self::remove_attribute(el, key);
+                Self::remove(el, key, *apply_as);
             }
         }
     }
@@ -112,17 +113,26 @@ impl Attributes {
     /// Works with any [Attributes] variants.
     #[cold]
     fn apply_diff_as_maps<'a>(el: &Element, new: &'a Self, old: &'a Self) {
-        fn collect(src: &Attributes) -> HashMap<&str, &str> {
+        fn collect(src: &Attributes) -> HashMap<&str, (&str, ApplyAttributeAs)> {
             use Attributes::*;
 
             match src {
-                Static(arr) => (*arr).iter().map(|[k, v]| (*k, *v)).collect(),
+                Static(arr) => (*arr)
+                    .iter()
+                    .map(|(k, v, apply_as)| (*k, (*v, *apply_as)))
+                    .collect(),
                 Dynamic { keys, values } => keys
                     .iter()
                     .zip(values.iter())
-                    .filter_map(|(k, v)| v.as_ref().map(|v| (*k, v.as_ref())))
+                    .filter_map(|(k, v)| {
+                        v.as_ref()
+                            .map(|(v, apply_as)| (*k, (v.as_ref(), *apply_as)))
+                    })
+                    .collect(),
+                IndexMap(m) => m
+                    .iter()
+                    .map(|(k, (v, apply_as))| (k.as_ref(), (v.as_ref(), *apply_as)))
                     .collect(),
-                IndexMap(m) => m.iter().map(|(k, v)| (k.as_ref(), v.as_ref())).collect(),
             }
         }
 
@@ -135,25 +145,42 @@ impl Attributes {
                 Some(old) => old != new,
                 None => true,
             } {
-                el.set_attribute(k, new).unwrap();
+                Self::set(el, k, new.0, new.1);
             }
         }
 
         // Remove missing
-        for k in old.keys() {
+        for (k, (_, apply_as)) in old.iter() {
             if !new.contains_key(k) {
-                Self::remove_attribute(el, k);
+                Self::remove(el, k, *apply_as);
             }
         }
     }
 
-    fn set_attribute(el: &Element, key: &str, value: &str) {
+    fn set(el: &Element, key: &str, value: &str, apply_as: ApplyAttributeAs) {
-        el.set_attribute(key, value).expect("invalid attribute key")
+        match apply_as {
+            ApplyAttributeAs::Attribute => {
+                el.set_attribute(key, value).expect("invalid attribute key")
+            }
+            ApplyAttributeAs::Property => {
+                let key = JsValue::from_str(key);
+                let value = JsValue::from_str(value);
+                js_sys::Reflect::set(el.as_ref(), &key, &value).expect("could not set property");
+            }
+        }
     }
 
-    fn remove_attribute(el: &Element, key: &str) {
+    fn remove(el: &Element, key: &str, apply_as: ApplyAttributeAs) {
-        el.remove_attribute(key)
+        match apply_as {
-            .expect("could not remove attribute")
+            ApplyAttributeAs::Attribute => el
+                .remove_attribute(key)
+                .expect("could not remove attribute"),
+            ApplyAttributeAs::Property => {
+                let key = JsValue::from_str(key);
+                js_sys::Reflect::set(el.as_ref(), &key, &JsValue::UNDEFINED)
+                    .expect("could not remove property");
+            }
+        }
     }
 }
 
@@ -164,20 +191,20 @@ impl Apply for Attributes {
     fn apply(self, _root: &BSubtree, el: &Element) -> Self {
         match &self {
             Self::Static(arr) => {
-                for kv in arr.iter() {
+                for (k, v, apply_as) in arr.iter() {
-                    Self::set_attribute(el, kv[0], kv[1]);
+                    Self::set(el, *k, *v, *apply_as);
                 }
             }
             Self::Dynamic { keys, values } => {
                 for (k, v) in keys.iter().zip(values.iter()) {
-                    if let Some(v) = v {
+                    if let Some((v, apply_as)) = v {
-                        Self::set_attribute(el, k, v)
+                        Self::set(el, k, v, *apply_as)
                     }
                 }
             }
             Self::IndexMap(m) => {
-                for (k, v) in m.iter() {
+                for (k, (v, apply_as)) in m.iter() {
-                    Self::set_attribute(el, k, v)
+                    Self::set(el, k, v, *apply_as)
                 }
             }
         }
@@ -217,7 +244,7 @@ impl Apply for Attributes {
                     }
                     macro_rules! set {
                         ($new:expr) => {
-                            Self::set_attribute(el, key!(), $new)
+                            Self::set(el, key!(), $new.0.as_ref(), $new.1)
                         };
                     }
 
@@ -228,8 +255,8 @@ impl Apply for Attributes {
                             }
                         }
                         (Some(new), None) => set!(new),
-                        (None, Some(_)) => {
+                        (None, Some(old)) => {
-                            Self::remove_attribute(el, key!());
+                            Self::remove(el, key!(), old.1);
                         }
                         (None, None) => (),
                     }
@@ -247,3 +274,111 @@ impl Apply for Attributes {
         }
     }
 }
+
+#[cfg(target_arch = "wasm32")]
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use gloo::utils::document;
+    use js_sys::Reflect;
+    use wasm_bindgen_test::{wasm_bindgen_test as test, wasm_bindgen_test_configure};
+
+    use super::*;
+    use crate::{function_component, html, Html};
+
+    wasm_bindgen_test_configure!(run_in_browser);
+
+    fn create_element() -> (Element, BSubtree) {
+        let element = document()
+            .create_element("a")
+            .expect("failed to create element");
+        let btree = BSubtree::create_root(&element);
+        (element, btree)
+    }
+
+    #[test]
+    fn properties_are_set() {
+        let attrs = Attributes::Static(&[
+            ("href", "https://example.com/", ApplyAttributeAs::Property),
+            ("alt", "somewhere", ApplyAttributeAs::Property),
+        ]);
+        let (element, btree) = create_element();
+        attrs.apply(&btree, &element);
+        assert_eq!(
+            Reflect::get(element.as_ref(), &JsValue::from_str("href"))
+                .expect("no href")
+                .as_string()
+                .expect("not a string"),
+            "https://example.com/",
+            "property `href` not set properly"
+        );
+        assert_eq!(
+            Reflect::get(element.as_ref(), &JsValue::from_str("alt"))
+                .expect("no alt")
+                .as_string()
+                .expect("not a string"),
+            "somewhere",
+            "property `alt` not set properly"
+        );
+    }
+
+    #[test]
+    fn respects_apply_as() {
+        let attrs = Attributes::Static(&[
+            ("href", "https://example.com/", ApplyAttributeAs::Attribute),
+            ("alt", "somewhere", ApplyAttributeAs::Property),
+        ]);
+        let (element, btree) = create_element();
+        attrs.apply(&btree, &element);
+        assert_eq!(
+            element.outer_html(),
+            "<a href=\"https://example.com/\"></a>",
+            "should be set as attribute"
+        );
+        assert_eq!(
+            Reflect::get(element.as_ref(), &JsValue::from_str("alt"))
+                .expect("no alt")
+                .as_string()
+                .expect("not a string"),
+            "somewhere",
+            "property `alt` not set properly"
+        );
+    }
+
+    #[test]
+    fn class_is_always_attrs() {
+        let attrs = Attributes::Static(&[("class", "thing", ApplyAttributeAs::Attribute)]);
+
+        let (element, btree) = create_element();
+        attrs.apply(&btree, &element);
+        assert_eq!(element.get_attribute("class").unwrap(), "thing");
+    }
+
+    #[test]
+    async fn macro_syntax_works() {
+        #[function_component]
+        fn Comp() -> Html {
+            html! { <a href="https://example.com/" ~alt="abc" /> }
+        }
+
+        let output = gloo::utils::document().get_element_by_id("output").unwrap();
+        yew::Renderer::<Comp>::with_root(output.clone()).render();
+
+        gloo::timers::future::sleep(Duration::from_secs(1)).await;
+        let element = output.query_selector("a").unwrap().unwrap();
+        assert_eq!(
+            element.get_attribute("href").unwrap(),
+            "https://example.com/"
+        );
+
+        assert_eq!(
+            Reflect::get(element.as_ref(), &JsValue::from_str("alt"))
+                .expect("no alt")
+                .as_string()
+                .expect("not a string"),
+            "abc",
+            "property `alt` not set properly"
+        );
+    }
+}

packages/yew/src/dom_bundle/btag/mod.rs

@@ -970,7 +970,7 @@ mod tests {
                 .unwrap()
                 .outer_html(),
             "<div tabindex=\"0\"></div>"
-        )
+        );
     }
 }
 

packages/yew/src/virtual_dom/mod.rs

@@ -145,6 +145,14 @@ mod feat_ssr {
     }
 }
 
+/// Defines if the [`Attributes`] is set as element's attribute or property
+#[allow(missing_docs)]
+#[derive(PartialEq, Eq, Copy, Clone, Debug)]
+pub enum ApplyAttributeAs {
+    Attribute,
+    Property,
+}
+
 /// A collection of attributes for an element
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub enum Attributes {
@@ -152,7 +160,7 @@ pub enum Attributes {
     ///
     /// Allows optimizing comparison to a simple pointer equality check and reducing allocations,
     /// if the attributes do not change on a node.
-    Static(&'static [[&'static str; 2]]),
+    Static(&'static [(&'static str, &'static str, ApplyAttributeAs)]),
 
     /// Static list of attribute keys with possibility to exclude attributes and dynamic attribute
     /// values.
@@ -165,12 +173,12 @@ pub enum Attributes {
 
         /// Attribute values. Matches [keys](Attributes::Dynamic::keys). Optional attributes are
         /// designated by setting [None].
-        values: Box<[Option<AttrValue>]>,
+        values: Box<[Option<(AttrValue, ApplyAttributeAs)>]>,
     },
 
     /// IndexMap is used to provide runtime attribute deduplication in cases where the html! macro
     /// was not used to guarantee it.
-    IndexMap(IndexMap<AttrValue, AttrValue>),
+    IndexMap(IndexMap<AttrValue, (AttrValue, ApplyAttributeAs)>),
 }
 
 impl Attributes {
@@ -183,19 +191,19 @@ impl Attributes {
     /// This function is suboptimal and does not inline well. Avoid on hot paths.
     pub fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = (&'a str, &'a str)> + 'a> {
         match self {
-            Self::Static(arr) => Box::new(arr.iter().map(|kv| (kv[0], kv[1] as &'a str))),
+            Self::Static(arr) => Box::new(arr.iter().map(|(k, v, _)| (*k, *v as &'a str))),
             Self::Dynamic { keys, values } => Box::new(
                 keys.iter()
                     .zip(values.iter())
-                    .filter_map(|(k, v)| v.as_ref().map(|v| (*k, v.as_ref()))),
+                    .filter_map(|(k, v)| v.as_ref().map(|(v, _)| (*k, v.as_ref()))),
             ),
-            Self::IndexMap(m) => Box::new(m.iter().map(|(k, v)| (k.as_ref(), v.as_ref()))),
+            Self::IndexMap(m) => Box::new(m.iter().map(|(k, (v, _))| (k.as_ref(), v.as_ref()))),
         }
     }
 
     /// Get a mutable reference to the underlying `IndexMap`.
     /// If the attributes are stored in the `Vec` variant, it will be converted.
-    pub fn get_mut_index_map(&mut self) -> &mut IndexMap<AttrValue, AttrValue> {
+    pub fn get_mut_index_map(&mut self) -> &mut IndexMap<AttrValue, (AttrValue, ApplyAttributeAs)> {
         macro_rules! unpack {
             () => {
                 match self {
@@ -209,7 +217,11 @@ impl Attributes {
         match self {
             Self::IndexMap(m) => m,
             Self::Static(arr) => {
-                *self = Self::IndexMap(arr.iter().map(|kv| (kv[0].into(), kv[1].into())).collect());
+                *self = Self::IndexMap(
+                    arr.iter()
+                        .map(|(k, v, ty)| ((*k).into(), ((*v).into(), *ty)))
+                        .collect(),
+                );
                 unpack!()
             }
             Self::Dynamic { keys, values } => {
@@ -227,7 +239,11 @@ impl Attributes {
 }
 
 impl From<IndexMap<AttrValue, AttrValue>> for Attributes {
-    fn from(v: IndexMap<AttrValue, AttrValue>) -> Self {
+    fn from(map: IndexMap<AttrValue, AttrValue>) -> Self {
+        let v = map
+            .into_iter()
+            .map(|(k, v)| (k, (v, ApplyAttributeAs::Attribute)))
+            .collect();
         Self::IndexMap(v)
     }
 }
@@ -236,7 +252,7 @@ impl From<IndexMap<&'static str, AttrValue>> for Attributes {
     fn from(v: IndexMap<&'static str, AttrValue>) -> Self {
         let v = v
             .into_iter()
-            .map(|(k, v)| (AttrValue::Static(k), v))
+            .map(|(k, v)| (AttrValue::Static(k), (v, ApplyAttributeAs::Attribute)))
             .collect();
         Self::IndexMap(v)
     }

packages/yew/src/virtual_dom/vtag.rs

@@ -9,7 +9,7 @@ use std::rc::Rc;
 
 use web_sys::{HtmlInputElement as InputElement, HtmlTextAreaElement as TextAreaElement};
 
-use super::{AttrValue, Attributes, Key, Listener, Listeners, VList, VNode};
+use super::{ApplyAttributeAs, AttrValue, Attributes, Key, Listener, Listeners, VList, VNode};
 use crate::html::{IntoPropValue, NodeRef};
 
 /// SVG namespace string used for creating svg elements
@@ -363,9 +363,20 @@ impl VTag {
     /// Not every attribute works when it set as an attribute. We use workarounds for:
     /// `value` and `checked`.
     pub fn add_attribute(&mut self, key: &'static str, value: impl Into<AttrValue>) {
-        self.attributes
+        self.attributes.get_mut_index_map().insert(
-            .get_mut_index_map()
+            AttrValue::Static(key),
-            .insert(AttrValue::Static(key), value.into());
+            (value.into(), ApplyAttributeAs::Attribute),
+        );
+    }
+
+    /// Set the given key as property on the element
+    ///
+    /// [`js_sys::Reflect`] is used for setting properties.
+    pub fn add_property(&mut self, key: &'static str, value: impl Into<AttrValue>) {
+        self.attributes.get_mut_index_map().insert(
+            AttrValue::Static(key),
+            (value.into(), ApplyAttributeAs::Property),
+        );
     }
 
     /// Sets attributes to a virtual node.
@@ -378,9 +389,10 @@ impl VTag {
 
     #[doc(hidden)]
     pub fn __macro_push_attr(&mut self, key: &'static str, value: impl IntoPropValue<AttrValue>) {
-        self.attributes
+        self.attributes.get_mut_index_map().insert(
-            .get_mut_index_map()
+            AttrValue::from(key),
-            .insert(AttrValue::from(key), value.into_prop_value());
+            (value.into_prop_value(), ApplyAttributeAs::Property),
+        );
     }
 
     /// Add event listener on the [VTag]'s  [Element](web_sys::Element).

packages/yew/tests/suspense.rs

@@ -15,7 +15,7 @@ use yew::platform::time::sleep;
 use yew::prelude::*;
 use yew::suspense::{use_future, use_future_with_deps, Suspension, SuspensionResult};
 
-wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
+wasm_bindgen_test_configure!(run_in_browser);
 
 #[wasm_bindgen_test]
 async fn suspense_works() {