Bring back &str assignment to optional properties

This drops the "optional" conversion concept in favor of directly
converting to `Option<T>`.

fixes #1888

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

@@ -219,10 +219,10 @@ error[E0277]: the trait bound `{integer}: IntoPropValue<String>` is not satisfie
    |
    = help: the following implementations were found:
              <&'static str as IntoPropValue<Cow<'static, str>>>
+             <&'static str as IntoPropValue<Option<Cow<'static, str>>>>
+             <&'static str as IntoPropValue<Option<String>>>
              <&'static str as IntoPropValue<String>>
-             <&T as IntoPropValue<Option<T>>>
-             <&T as IntoPropValue<T>>
-           and 4 others
+           and 11 others
 
 error[E0277]: the trait bound `{integer}: IntoPropValue<String>` is not satisfied
    --> $DIR/html-component-fail.rs:100:26
@@ -232,10 +232,10 @@ error[E0277]: the trait bound `{integer}: IntoPropValue<String>` is not satisfie
     |
     = help: the following implementations were found:
               <&'static str as IntoPropValue<Cow<'static, str>>>
+              <&'static str as IntoPropValue<Option<Cow<'static, str>>>>
+              <&'static str as IntoPropValue<Option<String>>>
               <&'static str as IntoPropValue<String>>
-              <&T as IntoPropValue<Option<T>>>
-              <&T as IntoPropValue<T>>
-            and 4 others
+            and 11 others
 
 error[E0308]: mismatched types
    --> $DIR/html-component-fail.rs:101:30

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

@@ -185,16 +185,12 @@ error[E0277]: the trait bound `(): IntoPropValue<Option<Cow<'static, str>>>` is
    |
 43 |     html! { <input type=() /> };
    |                         ^^ the trait `IntoPropValue<Option<Cow<'static, str>>>` is not implemented for `()`
-   |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `()`
 
 error[E0277]: the trait bound `(): IntoPropValue<Option<Cow<'static, str>>>` is not satisfied
   --> $DIR/html-element-fail.rs:44:26
    |
 44 |     html! { <input value=() /> };
    |                          ^^ the trait `IntoPropValue<Option<Cow<'static, str>>>` is not implemented for `()`
-   |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `()`
 
 error[E0277]: the trait bound `(): IntoPropValue<Option<Cow<'static, str>>>` is not satisfied
   --> $DIR/html-element-fail.rs:45:21
@@ -204,10 +200,8 @@ error[E0277]: the trait bound `(): IntoPropValue<Option<Cow<'static, str>>>` is
    |
   ::: $WORKSPACE/packages/yew/src/virtual_dom/mod.rs:69:47
    |
-69 |     pub fn new(key: &'static str, value: impl IntoOptPropValue<AttrValue>) -> Self {
-   |                                               --------------------------- required by this bound in `PositionalAttr::new`
-   |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `()`
+69 |     pub fn new(key: &'static str, value: impl IntoPropValue<Option<AttrValue>>) -> Self {
+   |                                               -------------------------------- required by this bound in `PositionalAttr::new`
 
 error[E0277]: the trait bound `NotToString: IntoPropValue<Option<Cow<'static, str>>>` is not satisfied
   --> $DIR/html-element-fail.rs:46:27
@@ -217,10 +211,8 @@ error[E0277]: the trait bound `NotToString: IntoPropValue<Option<Cow<'static, st
    |
   ::: $WORKSPACE/packages/yew/src/virtual_dom/mod.rs:69:47
    |
-69 |     pub fn new(key: &'static str, value: impl IntoOptPropValue<AttrValue>) -> Self {
-   |                                               --------------------------- required by this bound in `PositionalAttr::new`
-   |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `NotToString`
+69 |     pub fn new(key: &'static str, value: impl IntoPropValue<Option<AttrValue>>) -> Self {
+   |                                               -------------------------------- required by this bound in `PositionalAttr::new`
 
 error[E0277]: the trait bound `Option<NotToString>: IntoPropValue<Option<Cow<'static, str>>>` is not satisfied
   --> $DIR/html-element-fail.rs:47:22
@@ -230,10 +222,13 @@ error[E0277]: the trait bound `Option<NotToString>: IntoPropValue<Option<Cow<'st
    |
   ::: $WORKSPACE/packages/yew/src/virtual_dom/mod.rs:69:47
    |
-69 |     pub fn new(key: &'static str, value: impl IntoOptPropValue<AttrValue>) -> Self {
-   |                                               --------------------------- required by this bound in `PositionalAttr::new`
+69 |     pub fn new(key: &'static str, value: impl IntoPropValue<Option<AttrValue>>) -> Self {
+   |                                               -------------------------------- required by this bound in `PositionalAttr::new`
    |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `Option<NotToString>`
+   = help: the following implementations were found:
+             <Option<&'static str> as IntoPropValue<Option<Cow<'static, str>>>>
+             <Option<&'static str> as IntoPropValue<Option<String>>>
+             <Option<String> as IntoPropValue<Option<Cow<'static, str>>>>
 
 error[E0277]: the trait bound `Option<{integer}>: IntoPropValue<Option<Cow<'static, str>>>` is not satisfied
   --> $DIR/html-element-fail.rs:48:21
@@ -243,10 +238,13 @@ error[E0277]: the trait bound `Option<{integer}>: IntoPropValue<Option<Cow<'stat
    |
   ::: $WORKSPACE/packages/yew/src/virtual_dom/mod.rs:69:47
    |
-69 |     pub fn new(key: &'static str, value: impl IntoOptPropValue<AttrValue>) -> Self {
-   |                                               --------------------------- required by this bound in `PositionalAttr::new`
+69 |     pub fn new(key: &'static str, value: impl IntoPropValue<Option<AttrValue>>) -> Self {
+   |                                               -------------------------------- required by this bound in `PositionalAttr::new`
    |
-   = note: required because of the requirements on the impl of `IntoOptPropValue<Cow<'static, str>>` for `Option<{integer}>`
+   = help: the following implementations were found:
+             <Option<&'static str> as IntoPropValue<Option<Cow<'static, str>>>>
+             <Option<&'static str> as IntoPropValue<Option<String>>>
+             <Option<String> as IntoPropValue<Option<Cow<'static, str>>>>
 
 error[E0277]: the trait bound `{integer}: IntoPropValue<Option<yew::Callback<MouseEvent>>>` is not satisfied
    --> $DIR/html-element-fail.rs:51:28
@@ -267,11 +265,10 @@ error[E0277]: the trait bound `{integer}: IntoPropValue<Option<yew::Callback<Mou
     |
     = help: the following implementations were found:
               <&'static str as IntoPropValue<Cow<'static, str>>>
+              <&'static str as IntoPropValue<Option<Cow<'static, str>>>>
+              <&'static str as IntoPropValue<Option<String>>>
               <&'static str as IntoPropValue<String>>
-              <&T as IntoPropValue<Option<T>>>
-              <&T as IntoPropValue<T>>
-            and 4 others
-    = note: required because of the requirements on the impl of `IntoOptPropValue<yew::Callback<MouseEvent>>` for `{integer}`
+            and 11 others
 
 error[E0277]: the trait bound `yew::Callback<String>: IntoPropValue<Option<yew::Callback<MouseEvent>>>` is not satisfied
    --> $DIR/html-element-fail.rs:52:28
@@ -289,8 +286,6 @@ error[E0277]: the trait bound `yew::Callback<String>: IntoPropValue<Option<yew::
 99  | |     ontransitionstart(name: "transitionstart", event: TransitionEvent) -> web_sys::TransitionEvent => |_, event| { event }
 100 | | }
     | |_- required by this bound in `yew::html::onclick::Wrapper::__macro_new`
-    |
-    = note: required because of the requirements on the impl of `IntoOptPropValue<yew::Callback<MouseEvent>>` for `yew::Callback<String>`
 
 error[E0277]: the trait bound `Option<{integer}>: IntoPropValue<Option<yew::Callback<FocusEvent>>>` is not satisfied
    --> $DIR/html-element-fail.rs:53:28
@@ -309,7 +304,10 @@ error[E0277]: the trait bound `Option<{integer}>: IntoPropValue<Option<yew::Call
 100 | | }
     | |_- required by this bound in `yew::html::onfocus::Wrapper::__macro_new`
     |
-    = note: required because of the requirements on the impl of `IntoOptPropValue<yew::Callback<FocusEvent>>` for `Option<{integer}>`
+    = help: the following implementations were found:
+              <Option<&'static str> as IntoPropValue<Option<Cow<'static, str>>>>
+              <Option<&'static str> as IntoPropValue<Option<String>>>
+              <Option<String> as IntoPropValue<Option<Cow<'static, str>>>>
 
 error[E0308]: mismatched types
   --> $DIR/html-element-fail.rs:56:24

packages/yew/src/html/classes.rs

@@ -1,4 +1,4 @@
-use super::{IntoOptPropValue, IntoPropValue};
+use super::IntoPropValue;
 use crate::virtual_dom::AttrValue;
 use indexmap::IndexSet;
 use std::{
@@ -74,8 +74,8 @@ impl IntoPropValue<AttrValue> for Classes {
     }
 }
 
-impl IntoOptPropValue<AttrValue> for Classes {
-    fn into_opt_prop_value(self) -> Option<AttrValue> {
+impl IntoPropValue<Option<AttrValue>> for Classes {
+    fn into_prop_value(self) -> Option<AttrValue> {
         if self.is_empty() {
             None
         } else {

packages/yew/src/html/conversion.rs

@@ -58,15 +58,15 @@ macro_rules! impl_into_prop {
             }
         }
         // implement V -> Option<T>
-        impl IntoOptPropValue<$to_ty> for $from_ty {
-            fn into_opt_prop_value(self) -> Option<$to_ty> {
+        impl IntoPropValue<Option<$to_ty>> for $from_ty {
+            fn into_prop_value(self) -> Option<$to_ty> {
                 let $value = self;
                 Some({ $conversion })
             }
         }
         // implement Option<V> -> Option<T>
-        impl IntoOptPropValue<$to_ty> for Option<$from_ty> {
-            fn into_opt_prop_value(self) -> Option<$to_ty> {
+        impl IntoPropValue<Option<$to_ty>> for Option<$from_ty> {
+            fn into_prop_value(self) -> Option<$to_ty> {
                 self.map(IntoPropValue::into_prop_value)
             }
         }
@@ -79,17 +79,15 @@ impl_into_prop!(|value: &'static str| -> String { value.to_owned() });
 impl_into_prop!(|value: &'static str| -> Cow<'static, str> { Cow::Borrowed(value) });
 impl_into_prop!(|value: String| -> Cow<'static, str> { Cow::Owned(value) });
 
-/// A trait similar to `Into<Option<T>>` which allows conversion to an optional value of a
-/// `Properties` struct.
-pub trait IntoOptPropValue<T> {
-    /// Convert `self` to an optional value of a `Properties` struct.
-    fn into_opt_prop_value(self) -> Option<T>;
-}
-impl<T, V> IntoOptPropValue<V> for T
-where
-    T: IntoPropValue<Option<V>>,
-{
-    fn into_opt_prop_value(self) -> Option<V> {
-        self.into_prop_value()
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_str() {
+        let _: String = "foo".into_prop_value();
+        let _: Option<String> = "foo".into_prop_value();
+        let _: Cow<'static, str> = "foo".into_prop_value();
+        let _: Option<Cow<'static, str>> = "foo".into_prop_value();
     }
 }

packages/yew/src/html/listener/macros.rs

@@ -11,7 +11,7 @@ macro_rules! impl_action {
             use cfg_match::cfg_match;
             use crate::callback::Callback;
             #[allow(unused_imports)]
-            use crate::html::{listener::*, IntoOptPropValue};
+            use crate::html::{listener::*, IntoPropValue};
             use crate::virtual_dom::Listener;
             use std::rc::Rc;
             cfg_if! {
@@ -38,8 +38,8 @@ macro_rules! impl_action {
                 }
 
                 #[doc(hidden)]
-                pub fn __macro_new(callback: impl IntoOptPropValue<Callback<Event>>) -> Option<Rc<dyn Listener>> {
-                    let callback = callback.into_opt_prop_value()?;
+                pub fn __macro_new(callback: impl IntoPropValue<Option<Callback<Event>>>) -> Option<Rc<dyn Listener>> {
+                    let callback = callback.into_prop_value()?;
                     Some(Rc::new(Self::new(callback)))
                 }
             }

packages/yew/src/virtual_dom/mod.rs

@@ -13,7 +13,7 @@ pub mod vtag;
 #[doc(hidden)]
 pub mod vtext;
 
-use crate::html::{AnyScope, IntoOptPropValue, NodeRef};
+use crate::html::{AnyScope, IntoPropValue, NodeRef};
 use cfg_if::cfg_if;
 use indexmap::IndexMap;
 use std::{borrow::Cow, collections::HashMap, fmt, hint::unreachable_unchecked, iter, mem, rc::Rc};
@@ -66,8 +66,8 @@ pub type AttrValue = Cow<'static, str>;
 pub struct PositionalAttr(pub &'static str, pub Option<AttrValue>);
 impl PositionalAttr {
     /// Create a positional attribute
-    pub fn new(key: &'static str, value: impl IntoOptPropValue<AttrValue>) -> Self {
-        Self(key, value.into_opt_prop_value())
+    pub fn new(key: &'static str, value: impl IntoPropValue<Option<AttrValue>>) -> Self {
+        Self(key, value.into_prop_value())
     }
 
     /// Create a boolean attribute.

packages/yew/src/virtual_dom/vtag.rs

@@ -3,7 +3,7 @@
 use super::{
     AttrValue, Attributes, Key, Listener, Listeners, Patch, PositionalAttr, VDiff, VList, VNode,
 };
-use crate::html::{AnyScope, IntoOptPropValue, IntoPropValue, NodeRef};
+use crate::html::{AnyScope, IntoPropValue, NodeRef};
 use crate::utils::document;
 use cfg_if::cfg_if;
 use cfg_match::cfg_match;
@@ -152,15 +152,15 @@ impl VTag {
 
     /// Sets `value` for an
     /// [InputElement](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input).
-    pub fn set_value(&mut self, value: impl IntoOptPropValue<AttrValue>) {
-        self.value = value.into_opt_prop_value();
+    pub fn set_value(&mut self, value: impl IntoPropValue<Option<AttrValue>>) {
+        self.value = value.into_prop_value();
     }
 
     /// Sets `kind` property of an
     /// [InputElement](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input).
     /// Same as set `type` attribute.
-    pub fn set_kind(&mut self, value: impl IntoOptPropValue<AttrValue>) {
-        self.kind = value.into_opt_prop_value();
+    pub fn set_kind(&mut self, value: impl IntoPropValue<Option<AttrValue>>) {
+        self.kind = value.into_prop_value();
     }
 
     #[doc(hidden)]