yew 0.14.3

A framework for making client-side single-page apps
Documentation 
# Changelog

## ✨ **0.14.3** *(2020-04-04)*

- #### 🛠 Fixes

  - Remove `html!` component validation to allow generic components. [[@mankinskin], [#1065](https://github.com/yewstack/yew/pull/1065)]
  - Improve `Debug` formatting for `VTag` and `VText`. [[@dancespiele], [#1059](https://github.com/yewstack/yew/pull/1059)]
  - Implement `Default` for `Callback`. [[@TheNeikos], [#1043](https://github.com/yewstack/yew/pull/1043)]

## ✨ **0.14.2** *(2020-03-23)*

- #### 🛠 Fixes

  - Fix issue where components were rendered out of order. [[@mrh0057] & [@jstarry], [#1051](https://github.com/yewstack/yew/pull/1051)]
  - Reset Select component correctly in Firefox / Edge. [[@kuy], [#987](https://github.com/yewstack/yew/pull/987)]

## ✨ **0.14.1** *(2020-03-14)*

- #### 🛠 Fixes

  - `Connected` message was only called for first bridge creation. [[@nicklaswj], [#1029](https://github.com/yewstack/yew/pull/1029)]

## ✨ **0.14** *(2020-03-14)*

Happy 🥧 (PI) Day! This release brings a number of bug fixes for `web-sys` apps and ergonomic improvements to the API. Huge thanks to the community for diving into the migration from `stdweb` to `web-sys` so quickly and uncovering these issues!

#### Changelog

- #### ⚡️ Features

  - Implemented `Clone` for `WebSocketStatus`. [[@kellytk], [#1023](https://github.com/yewstack/yew/pull/1023)]
  - Improved ergonomics for message APIs by accepting `Into<Msg>`. [[@captain-yossarian], [#999](https://github.com/yewstack/yew/pull/999)]
  - `html!` improved compiler messages and flexible syntax for `with props`. [[@captain-yossarian], [#960](https://github.com/yewstack/yew/pull/960)]

- #### 🛠 Fixes

  - Fixed panic in `stdweb` `ResizeService` event handling. [[@nicklaswj], [#1014](https://github.com/yewstack/yew/pull/1014)]
  - Removed build check for OS compatibility. [[@jstarry], [#1019](https://github.com/yewstack/yew/pull/1019)]
  - Fixed interval and timer usage in `web-sys` workers by updating `gloo`. [[@jstarry], [#1018](https://github.com/yewstack/yew/pull/1018)]
  - Send `Connected` message for Public agents. [[@TheNeikos], [#1007](https://github.com/yewstack/yew/pull/1007)]
  - Fixed `web-sys` Public / Private agent initialization. [[@jstarry], [#1006](https://github.com/yewstack/yew/pull/1006)]
  - Fixed websocket 'text' message handling for `web-sys` agents. [[@jstarry], [#1005](https://github.com/yewstack/yew/pull/1005)]

- #### 🚨 Breaking changes

  - `FetchError::FetchFailed` enum variant now wraps a `String` to hold the failure reason. [[@jstarry], [#1025](https://github.com/yewstack/yew/pull/1025)]
  - Message APIs now accept `Into<Msg>`, so calling `msg.into()` will cause compile errors. [[@captain-yossarian], [#999](https://github.com/yewstack/yew/pull/999)]

## ✨ **0.13.2** *(2020-03-05)*

- #### 🛠 Fixes

  - Fix clippy warning when building with `web_sys` feature. [[@jstarry], [#1001](https://github.com/yewstack/yew/pull/1001)]

## ✨ **0.13.1** *(2020-03-04)*

- #### 🛠 Fixes

  - Fix for `web-sys` version `0.3.36`. [[@detegr], [#997](https://github.com/yewstack/yew/pull/997)]

## ✨ **0.13** *(2020-03-01)*

`web-sys` support has arrived! [@daxpedda] spear-headed the effort and courageously integrated `web-sys` while maintaining support for `stdweb` through no small amount of `cfg` macro usage. We chose to continue support for apps built with `stdweb` because the dev experience is still quite a bit better _(Unfortunately `cargo-web` is incompatible with `web-sys`)_. However, the Yew team recognizes that the future of `cargo-web` of `stdweb` are uncertain. For this reason, we recommend devs start making the switch over to `web-sys` and `wasm-bindgen`. We will likely invest in improving the dev experience with these tools so that switching over is eventually a no-brainer. Please reach out with ideas and feedback for this migration through Github issues and in our Gitter chatroom!

After upgrading to v0.13, devs will now have to opt in to either `stdweb` or `web-sys` by using either the `"web_sys"` or `"std_web"` on the `yew` crate in their `Cargo.toml`.

```toml
# Choose `stdweb`
yew = { version = "0.13", features = ["std_web"] }

# Choose `web-sys`
yew = { version = "0.13", features = ["web_sys"] }
```

Lastly, take note that API docs on https://docs.rs/yew will be using the `"web_sys"` feature. For `"std_web"` docs, please visit https://docs.rs/yew-stdweb.

#### Changelog

- #### ⚡️ Features

  - Added support for building apps with `web-sys`. [[@daxpedda], [#961](https://github.com/yewstack/yew/pull/961)]
  - Properties 2.0 [[@AlephAlpha], [#975](https://github.com/yewstack/yew/pull/975)]

    Component properties are now assumed to be required unless otherwise annotated with a default value. Check out the proposal issue [#928](https://github.com/yewstack/yew/issues/928) for more details!

- #### 🛠 Fixes

  - Fixed `Component` children re-rendering bug. [[@jstarry], [#980](https://github.com/yewstack/yew/pull/980)]
  - Fixed panic when interacting with agents after receiving an agent message. [[@jstarry], [#981](https://github.com/yewstack/yew/pull/981)]
  - Fixed panic when a component with a root `VRef` node is detached. [[@jstarry], [#983](https://github.com/yewstack/yew/pull/983)]
  - Fixed annoying warning when a component with a root `VTag` node is detached. [[@jstarry], [#983](https://github.com/yewstack/yew/pull/983)]

- #### 🚨 Breaking changes

  - Changed `Properties` macro behavior. Check out the proposal issue [#928](https://github.com/yewstack/yew/issues/928) for more details! [[@AlephAlpha], [#975](https://github.com/yewstack/yew/pull/975)]
  - Cleaned up exported apis and doc visibility. [[@jstarry], [#977](https://github.com/yewstack/yew/pull/977)]
  - `ReaderService` methods now return a `Result` instead of panicking.  [[@daxpedda], [#868](https://github.com/yewstack/yew/pull/868)]
  - `FetchService` methods now return a `Result` instead of panicking.  [[@daxpedda], [#867](https://github.com/yewstack/yew/pull/867)]
  - `StorageService` methods now return a `Result` instead of panicking.  [[@daxpedda], [#827](https://github.com/yewstack/yew/pull/827)]

## ✨ **0.12** *(2020-02-16)*

- #### ⚡️ Features

  - Improved ergonomics for `html! { for .. }`. [[@jstarry], [#875](https://github.com/yewstack/yew/pull/875)]
  - Added `#[props(default = "fn_path")]` for specifying a default property value. [[@AlephAlpha], [#881](https://github.com/yewstack/yew/pull/881)]
  - Exposed the macros for creating format types. [[@ctm], [#883](https://github.com/yewstack/yew/pull/883)]
  - Added support for binary-only and text-only formats in `WebSocketService`. [[@ctm], [#851](https://github.com/yewstack/yew/pull/851)]
  - Implemented `PartialEq` for `ChildrenRenderer` to allow `children` comparison. [[@jstarry], [#916](https://github.com/yewstack/yew/pull/916)]
  - Reduced restrictions on `ComponentLink` methods to improve `Future` support. [[@jplatte], [#931](https://github.com/yewstack/yew/pull/931)]
  - Added `referrer`, `referrer_policy` and `integrity` to `FetchOptions`. [[@leo-lb], [#931](https://github.com/yewstack/yew/pull/931)]
 
- #### 🛠 Fixes

  - Fixed touch event listeners. [[@AlephAlpha], [#872](https://github.com/yewstack/yew/pull/872)]
  - Fixed bad behavior when setting a `ref` on a `Component`. [[@jstarry], [#913](https://github.com/yewstack/yew/pull/913)]
  - Fixed ResizeTask cancellation. [[@jstarry], [#915](https://github.com/yewstack/yew/pull/915)]

- #### 🚨 Breaking changes

  - Switched from using `failure` to `anyhow` and `thiserror` for Yew errors. [[@daxpedda], [#863](https://github.com/yewstack/yew/pull/863)]
  - Removed `cancel` method from `Task` trait in favor of relying on [`Drop`](https://doc.rust-lang.org/book/ch15-03-drop.html). [[@kakoc], [#899](https://github.com/yewstack/yew/pull/899)]
  - Renamed `NodeRef.try_into` to `NodeRef.cast` to avoid trait conflicts. [[@jstarry], [#917](https://github.com/yewstack/yew/pull/917)]

## ✨ **0.11** *(2020-01-06)*

This release aims to lay the groundwork for Yew component libraries and clean up the API for the ever elusive 1.0 release.

### Transition Guide

This release comes with a lot of breaking changes. We understand it's a hassle to update projects but the Yew team felt it was necessary to rip a few bandaids off now as we approach a 1.0 release in the (hopefully) near future. To ease the transition, here's a guide which outlines the main refactoring you will need to do for your project. (Note: all of the changes are reflected in the many example projects if you would like a proper reference example)

#### 1. Callback syntax

This is the main painful breaking change. It applies to both element listeners as well as `Component` callback properties. A good rule of thumb is that your components will now have to retain a `ComponentLink` to create callbacks on demand or initialize callbacks in your component's `create()` method.

Before:
```rust
struct Model;

enum Msg {
    Click,
}

impl Component for Model {
    type Message = Msg;
    type Properties = ();

    fn create(_: Self::Properties, _: ComponentLink<Self>) -> Self {
        Model
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        match msg {
            Msg::Click => true,
        }
    }

    fn view(&self) -> Html<Self> {
        // BEFORE: Callbacks were created implicitly from this closure syntax
        html! {
            <button onclick=|_| Msg::Click>{ "Click me!" }</button>
        }
    }
}
```

After:
```rust
struct Model {
  link: ComponentLink<Self>,
}

enum Msg {
    Click,
}

impl Component for Model {
    type Message = Msg;
    type Properties = ();

    fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
        Model { link }
    }

    fn update(&mut self, msg: Self::Message) -> ShouldRender {
        match msg {
            Msg::Click => true,
        }
    }

    fn view(&self) -> Html {
        // AFTER: Callbacks need to be explicitly created now
        let onclick = self.link.callback(|_| Msg::Click);
        html! {
            <button onclick=onclick>{ "Click me!" }</button>
        }
    }
}
```

If a closure has a parameter you will now need to specify the parameter's type.  A tip for finding the appropriate type is to search Yew's repo for the HTML attribute the closure is assigned to.

For example, `onkeydown` of `<button>`:

```
let onkeydown = self.link.callback(|e: KeyDownEvent| {
    // ...
});
```

and

```
html! {
    <button onkeydown=onkeydown type="button">
        { "button" }
    </button>
}
```

#### 2. Method Renames

It should be safe to do a project-wide find/replace for the following:

- `send_self(` -> `send_message(`
- `send_back(` -> `callback(`
- `response(` -> `respond(`
- `AgentUpdate` -> `AgentLifecycleEvent`

These renames will probably require some more care:

- `fn handle(` -> `fn handle_input(` *(for Agent trait implementations)*

#### 3. Drop Generic Types for `Html<Self>` -> `Html`

:tada: We are pretty excited about this change! The generic type parameter
was confusing and restrictive and is now a thing of the past!

Before:
```rust
impl Component for Model {
    // ...

    fn view(&self) -> Html<Self> {
        html! { /* ... */ }
    }
}
```

After:
```rust
impl Component for Model {
    // ...

    fn view(&self) -> Html {
        html! { /* ... */ }
    }
}
```

#### 4. Properties must implement `Clone`

In yew v0.8 we removed the requirement that component properties implement `Clone`
and in this release we are adding the requirement again. This change is needed
to improve the ergonomics of nested components. The only time properties will be
cloned is when a wrapper component re-renders nested children components.

- #### ⚡️ Features

  - Added `html_nested!` macro to support nested iterable children access. [[@trivigy], [#843](https://github.com/yewstack/yew/pull/843)]
  - Added `bincode` to the list of supported formats. [[@serzhiio], [#806](https://github.com/yewstack/yew/pull/806)]
  - Added a `noop()` convenience method to `Callback` which creates a no-op callback. [[@mdtusz], [#793](https://github.com/yewstack/yew/pull/793)]
  - The `html!` macro now accepts a `Callback` for element listeners. [[@jstarry], [#777](https://github.com/yewstack/yew/pull/777)]

  ```rust
  struct Model {
      onclick: Callback<ClickEvent>,
  }

  enum Msg {
      Click,
  }

  impl Component for Model {
      type Message = Msg;
      type Properties = ();

      fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
          Model {
              onclick: link.callback(|_| Msg::Click),
          }
      }

      fn update(&mut self, msg: Self::Message) -> ShouldRender {
          match msg {
              Msg::Click => true,
          }
      }

      fn view(&self) -> Html {
          html! {
              <button onclick=&self.onclick>{ "Click me!" }</button>
          }
      }
  }
  ```

  - Add `send_message_batch` method to `ComponentLink`. [[@hgzimmerman], [#748](https://github.com/yewstack/yew/pull/748)]
  - Allow compilation to `wasi` target without `wasm_bindgen`. [[@dunnock], [#746](https://github.com/yewstack/yew/pull/746)]
  - `AgentLink` now implements `Clone` which enables `Future` usage without explicit Yew framework support. [[@izissise], [#802](https://github.com/yewstack/yew/pull/802)]
  - `ComponentLink` now implements `Clone` which enables `Future` usage without explicit Yew framework support. [[@hgzimmerman], [#749](https://github.com/yewstack/yew/pull/749)]

  ```rust
  use wasm_bindgen::JsValue;
  use wasm_bindgen_futures::future_to_promise;

  // future must implement `Future<Output = Component::Message> + 'static`
  let link = self.link.clone();
  let js_future = async move {
      link.send_message(future.await);
      Ok(JsValue::NULL)
  };

  future_to_promise(js_future);
  ```

- #### 🛠 Fixes

  - Fixed handling of boolean tag attributes. [[@mrh0057], [#840](https://github.com/yewstack/yew/pull/840)]
  - Improved nested component ergonomics. [[@jstarry], [#780](https://github.com/yewstack/yew/pull/780)]

  ```rust
  fn view(&self) -> Html {
      html! {
          <Wrapper>
              // This is now valid. (before #780, this would cause a lifetime
              // compile error because children nodes were moved into a closure)
              <Nested on_click=&self.nested_on_click />
          </Wrapper>
      }
  }
  ```

  - Creating a `Callback` with `ComponentLink` is no longer restricted to mutable references, improving ergonomics. [[@jstarry], [#780](https://github.com/yewstack/yew/pull/780)]
  - The `Callback` `reform` method no longer consumes self making it easier to "reverse map" a `Callback`. [[@jstarry], [#779](https://github.com/yewstack/yew/pull/779)]

  ```rust
  pub struct ListHeader {
      props: Props,
  }

  #[derive(Properties, Clone)]
  pub struct Props {
      #[props(required)]
      pub on_hover: Callback<Hovered>,
      #[props(required)]
      pub text: String,
  }

  impl Component for ListHeader {
      type Message = ();
      type Properties = Props;

      fn create(props: Self::Properties, _: ComponentLink<Self>) -> Self {
          ListHeader { props }
      }

      fn update(&mut self, _: Self::Message) -> ShouldRender {
          false
      }

      fn view(&self) -> Html {
          let onmouseover = self.props.on_hover.reform(|_| Hovered::Header);
          html! {
              <div class="list-header" onmouseover=onmouseover>
                  { &self.props.text }
              </div>
          }
      }
  }
  ```

  - Reduced allocations in the `Classes` `to_string` method. [[@hgzimmerman], [#772](https://github.com/yewstack/yew/pull/772)]
  - Empty string class names are now filtered out to prevent panics. [[@jstarry], [#770](https://github.com/yewstack/yew/pull/770)]

- #### 🚨 Breaking changes

  - Components with generic args now need to be closed with the full type path. (e.g. `html! { <Wrapper<String>></Wrapper<String>>}`) [[@jstarry], [#837](https://github.com/yewstack/yew/pull/837)]
  - Changed `VTag` listener type from `Box<dyn Listener>` to `Rc<dyn Listener>`. [[@jstarry], [#786](https://github.com/yewstack/yew/pull/786)]
  - `Properties` need to implement `Clone` again in order to improve nested component ergonomics. [[@jstarry], [#786](https://github.com/yewstack/yew/pull/786)]
  - Removed `send_future` method from `ComponentLink` since it is no longer necessary for using Futures with Yew. [[@hgzimmerman], [#799](https://github.com/yewstack/yew/pull/799)]
  - Removed generic type parameter from `Html` and all virtual node types: `VNode`, `VComp`, `VTag`, `VList`, `VText`, etc. [[@jstarry], [#783](https://github.com/yewstack/yew/pull/783)]
  - Removed support for macro magic closure syntax for element listeners. (See transition guide for how to pass a `Callback` explicitly instead). [[@jstarry], [#782](https://github.com/yewstack/yew/pull/782)]
  - Renamed `Agent` methods and event type for clarity. `handle` -> `handle_input`, `AgentUpdate` -> `AgentLifecycleEvent`, `response` -> `respond`. [[@philip-peterson], [#751](https://github.com/yewstack/yew/pull/751)]
  - The `ComponentLink` `send_back` method has been renamed to `callback` for clarity. [[@jstarry], [#780](https://github.com/yewstack/yew/pull/780)]
  - The `ComponentLink` `send_self` and `send_self_batch` methods have been renamed to `send_message` and `send_message_batch` for clarity. [[@jstarry], [#780](https://github.com/yewstack/yew/pull/780)]
  - The `Agent` `send_back` method has been renamed to `callback` for clarity. [[@jstarry], [#780](https://github.com/yewstack/yew/pull/780)]
  - The `VTag` `children` value type has changed from `Vec<VNode>` to `VList`. [[@jstarry], [#754](https://github.com/yewstack/yew/pull/754)]


## ✨ **0.10** *(2019-11-11)*

- #### ⚡️ Features

  - `Future` support :tada: A `Component` can update following the completion of a `Future`. Check out [this example](https://github.com/yewstack/yew/tree/master/examples/futures) to see how it works. This approach was borrowed from a fork of Yew called [`plaster`](https://github.com/carlosdp/plaster) created by [@carlosdp]. [[@hgzimmerman], [#717](https://github.com/yewstack/yew/pull/717)]
  - Added the `agent` and `services` features so that this functionality can be disabled (useful if you are switching to using `Future`s). [[@hgzimmerman], [#684](https://github.com/yewstack/yew/pull/684)]
  - Add `ref` keyword for allowing a `Component` to have a direct reference to its rendered elements. For example, you can now easily focus an `<input>` element after mounting. [[@jstarry], [#715](https://github.com/yewstack/yew/pull/715)]

  ```rust
  use stdweb::web::html_element::InputElement;
  use stdweb::web::IHtmlElement;
  use yew::prelude::*;

  pub struct Input {
      node_ref: NodeRef,
  }

  impl Component for Input {
      type Message = ();
      type Properties = ();

      fn create(_: Self::Properties, _: ComponentLink<Self>) -> Self {
          Input {
              node_ref: NodeRef::default(),
          }
      }

      fn mounted(&mut self) -> ShouldRender {
          if let Some(input) = self.node_ref.try_into::<InputElement>() {
              input.focus();
          }
          false
      }

      fn update(&mut self, _: Self::Message) -> ShouldRender {
          false
      }

      fn view(&self) -> Html<Self> {
          html! {
              <input ref=self.node_ref.clone() type="text" />
          }
      }
  }
  ```

  - Make `Agent` related types `public` to allow other crates to create custom agents. [[@dunnock], [#721](https://github.com/yewstack/yew/pull/721)]
  - `Component::change` will now return `false` for components that have `Component::Properties == ()`. [[@kellytk], [#690](https://github.com/yewstack/yew/pull/690)]]
  - Updated `wasm-bindgen` dependency to `0.2.54`. Please update your `wasm-bindgen-cli` tool by running `cargo install --force --version 0.2.54 -- wasm-bindgen-cli`. [[@jstarry], [#730](https://github.com/yewstack/yew/pull/730)], [[@ctaggart], [#681](https://github.com/yewstack/yew/pull/681)]

- #### 🛠 Fixes

  - Fixed the mount order of components. The root component will be mounted after all descendants have been mounted. [[@jstarry], [#725](https://github.com/yewstack/yew/pull/725)]
  - All public items now implement `Debug`. [[@hgzimmerman], [#673](https://github.com/yewstack/yew/pull/673)]

- #### 🚨 Breaking changes

  - Minimum rustc version has been bumped to `1.39.0` for `Future` support. [[@jstarry], [#730](https://github.com/yewstack/yew/pull/730)]
  - `Component` now has a required `view` method and automatically implements the `Renderable` trait. The `view` method in the `Renderable` trait has been renamed to `render`. [[@jstarry], [#563](https://github.com/yewstack/yew/pull/563)]

    Before:
    ```rust
    impl Component for Model {
        type Message = Msg;
        type Properties = ();

        fn create(_: Self::Properties, _: ComponentLink<Self>) -> Self {
            Model {}
        }

        fn update(&mut self, msg: Self::Message) -> ShouldRender {
            true
        }
    }

    impl Renderable<Model> for Model {
        fn view(&self) -> Html<Self> {
            html! { "hello" }
        }
    }
    ```

    After:
    ```rust
    impl Component for Model {
        type Message = Msg;
        type Properties = ();

        fn create(_: Self::Properties, _: ComponentLink<Self>) -> Self {
            Model {}
        }

        fn update(&mut self, msg: Self::Message) -> ShouldRender {
            true
        }

        fn view(&self) -> Html<Self> {
            html! { "hello" }
        }
    }
    ```

  - Removed the `Transferable` trait since it did no more than extend the serde `Serialize` and `Deserialize` traits. [[@hgzimmerman], [#319](https://github.com/yewstack/yew/pull/319)]

    Before:
    ```rust
    impl Transferable for Input {}
    #[derive(Serialize, Deserialize)]
    pub enum Input {
      Connect,
    }
    ```

    After:
    ```rust
    #[derive(Serialize, Deserialize)]
    pub enum Input {
      Connect,
    }
    ```
  - `WebSocketService::connect` will now return a `Result` in order to stop panicking on malformed urls. [[@lizhaoxian], [#727](https://github.com/yewstack/yew/pull/727)]
  - `VTag` now is boxed within `VNode` to shrink the size of its enum representation. [[@hgzimmerman], [#675](https://github.com/yewstack/yew/pull/675)]

## ✨ **0.9.2** *(2019-10-12)*

- #### 🛠 Fixes

  - Fix `yew-macro` dependency version

## ✨ **0.9.1** *(2019-10-12)*

Happy Canadian Thanksgiving! 🦃

- #### ⚡️ Features

  - Implemented `Default` trait for `VNode` so that `unwrap_or_default` can be called on `Option<Html<Self>>`. [[@hgzimmerman], [#672](https://github.com/yewstack/yew/pull/672)]
  - Implemented `PartialEq` trait for `Classes` so that is more ergonomic to use `Classes` type in component props. [[@hgzimmerman], [#680](https://github.com/yewstack/yew/pull/680)]
  - Updated `wasm-bindgen` dependency to `0.2.50`. Please update your `wasm-bindgen-cli` tool by running `cargo install --force --version 0.2.50 -- wasm-bindgen-cli`. [[@jstarry], [#695](https://github.com/yewstack/yew/pull/695)]

- #### 🛠 Fixes

  - Fixed issue where text nodes were sometimes rendered out of order. [[@jstarry], [#697](https://github.com/yewstack/yew/pull/697)]
  - Fixed regression introduced in 0.9.0 that prevented tag attributes from updating properly. [[@jstarry], [#698](https://github.com/yewstack/yew/pull/698)]
  - Fixed emscripten builds by pinning the version for the `ryu` downstream dependency. [[@jstarry], [#703](https://github.com/yewstack/yew/pull/703)]
  - Updated `stdweb` to `0.4.20` which fixed emscripten builds and unblocked updating `wasm-bindgen` to `0.2.50`. [[@ctaggart], [@jstarry], [#683](https://github.com/yewstack/yew/pull/683), [#694](https://github.com/yewstack/yew/pull/694)]
  - Cleaned up build warnings for missing `dyn` keywords. [[@benreyn], [#687](https://github.com/yewstack/yew/pull/687)]

## ✨ **0.9** *(2019-09-27)*

- #### ⚡️ Features

  - New `KeyboardService` for setting up key listeners on browsers which support the feature. [[@hgzimmerman], [#647](https://github.com/yewstack/yew/pull/647)]
  - `ComponentLink` can now create a `Callback` with more than one `Message`. The `Message`'s will be batched together so that the `Component` will not be re-rendered more than necessary. [[@stkevintan], [#660](https://github.com/yewstack/yew/pull/660)]
  - `Message`'s to `Public` `Agent`'s will now be queued if the `Agent` hasn't finished setting up yet. [[@serzhiio], [#596](https://github.com/yewstack/yew/pull/596)]
  - `Agent`'s can now be connected to without a `Callback`. Instead of creating a bridge to the agent, create a dispatcher like so: `MyAgent::dispatcher()`. [[@hgzimmerman], [#639](https://github.com/yewstack/yew/pull/639)]
  - `Component`'s can now accept children in the `html!` macro. [[@jstarry], [#589](https://github.com/yewstack/yew/pull/589)]

    ```rust
    // app.rs

    html! {
      <MyList name="Grocery List">
        <MyListItem text="Apples" />
      </MyList>
    }
    ```

    ```rust
    // my_list.rs

    use yew::prelude::*;

    pub struct MyList(Props);

    #[derive(Properties)]
    pub struct Props {
        #[props(required)]
        pub name: String,
        pub children: Children<MyListItem>,
    }

    impl Renderable<MyList> for MyList {
      fn view(&self) -> Html<Self> {
        html! {{
          self.props.children.iter().collect::<Html<Self>>()
        }}
      }
    }
    ```

  - `Iterator`s can now be rendered in the `html!` macro without using the `for` keyword. [[@hgzimmerman], [#622](https://github.com/yewstack/yew/pull/622)]

    Before:
    ```rust
    html! {{
      for self.props.items.iter().map(renderItem)
    }}
    ```

    After:
    ```rust
    html! {{
      self.props.items.iter().map(renderItem).collect::<Html<Self>>()
    }}
    ```

  - Closures are now able to be transformed into optional `Callback` properties. [[@Wodann], [#612](https://github.com/yewstack/yew/pull/612)]
  - Improved CSS class ergonomics with new `Classes` type. [[@DenisKolodin], [#585](https://github.com/yewstack/yew/pull/585)], [[@hgzimmerman], [#626](https://github.com/yewstack/yew/pull/626)]
  - Touch events are now supported `<div ontouchstart=|_| Msg::TouchStart>` [[@boydjohnson], [#584](https://github.com/yewstack/yew/pull/584)], [[@jstarry], [#656](https://github.com/yewstack/yew/pull/656)]
  - The `Component` trait now has an `mounted` method which can be implemented to react to when your components have been mounted to the DOM. [[@hgzimmerman], [#583](https://github.com/yewstack/yew/pull/583)]
  - Additional Fetch options `mode`, `cache`, and `redirect` are now supported [[@davidkna], [#579](https://github.com/yewstack/yew/pull/579)]
  - The derive props macro now supports Properties with lifetimes [[@jstarry], [#580](https://github.com/yewstack/yew/pull/580)]
  - New `ResizeService` for registering for `window` size updates [[@hgzimmerman], [#577](https://github.com/yewstack/yew/pull/577)]

- #### 🛠 Fixes

  - Fixed JS typo in RenderService. This was causing animation frames to not be dropped correctly. [[@jstarry], [#658](https://github.com/yewstack/yew/pull/658)]
  - Fixed `VNode` orphaning bug when destroying `VTag` elements. This caused some `Component`s to not be properly destroyed when they should have been. [[@hgzimmerman], [#651](https://github.com/yewstack/yew/pull/651)]
  - Fix mishandling of Properties `where` clause in derive_props macro [[@astraw], [#640](https://github.com/yewstack/yew/pull/640)]

- #### 🚨 Breaking changes

  None

## ✨ **0.8** *(2019-08-10)*

***Props! Props! Props!***

This release introduces a more developer friendly way to handle your `Component` props. Use the new `#[derive(Properties)]` macro to beef up your props! Property values can now be annotated as `#[props(required)]` which will enforce that props are present at compile time. This means that your props struct no longer needs to implement `Default`, so time to clean up all of those prop values you wrapped in `Option` to have a default value.

- #### ⚡️ Features

  - `html!` - Self-closing html tags can now be used: `<div class="marker" />` [[@totorigolo], [#523](https://github.com/yewstack/yew/pull/523)]
  - `html!` - SVG name-spaced tags are now supported! [[@jstarry], [#550](https://github.com/yewstack/yew/pull/550)]
  - Properties can now be required at compile time [[@jstarry], [#553](https://github.com/yewstack/yew/pull/525)]
  - App components can now be mounted with properties [[@jstarry], [#567](https://github.com/yewstack/yew/pull/567)]
  - Apps can now be mounted as the `<body>` tag [[@jstarry], [@kellytk], [#540](https://github.com/yewstack/yew/pull/540)]
  - Content editable elements can now trigger `oninput` events [[@tiziano88], [#549](https://github.com/yewstack/yew/pull/549)]

- #### 🛠 Fixes

  - `html!` - Class name order is now preserved which unlocks the use of Semantic UI [[@charvp], [#424](https://github.com/yewstack/yew/pull/424)]
  - `html!` - Dashed tag names and properties are supported [[@jstarry], [#512](https://github.com/yewstack/yew/pull/512), [#550](https://github.com/yewstack/yew/pull/550)]
  - `html!` - All rust keywords can be used as tag attributes [[@jstarry], [#550](https://github.com/yewstack/yew/pull/550)]
  - `html!` - Support `Callback` closure with explicit return type [[@totorigolo], [#564](https://github.com/yewstack/yew/pull/564)]
  - `html!` - Fixed edge case where `>` token would break parser [[@totorigolo], [#565](https://github.com/yewstack/yew/pull/565)]
  - Performance improvement to the diff engine [[@totorigolo], [#539](https://github.com/yewstack/yew/pull/539)]
  - `Properties` no longer need to implement the `PartialEq`, `Clone`, or `Default` traits [[@jstarry], [#553](https://github.com/yewstack/yew/pull/553)]
  - `Component` will not panic if the `change` method is unimplemented [[@jstarry], [#554](https://github.com/yewstack/yew/pull/554)]

- #### 🚨 Breaking changes

  - The `Component::Properties` associated type must implement the new `Properties` trait [[@jstarry], [#553](https://github.com/yewstack/yew/pull/553)]

    The new `Properties` trait is what powers the ability to check required props are present at compile time. Use the derive props macro to implement automatically.

    ```rust
    use yew::Properties;

    #[derive(Properties)]
    pub struct Props {
      #[props(required)]
      pub value: MyStruct,
    }
    ```

  - `Callback` props no longer transform into `Option` types [[@jstarry], [#553](https://github.com/yewstack/yew/pull/553)]

    ```rust
    html! { <Button on_click=Msg::Click /> }
    ```

    ***before:***

    ```rust
    #[derive(PartialEq, Clone, Default)]
    pub struct Props {
        on_click: Option<Callback<()>>,
    }
    ```

    ***after:*** *note the `#[props(required)]` attribute*

    ```rust
    #[derive(PartialEq, Properties)]
    pub struct Props {
        #[props(required)]
        on_click: Callback<()>,
    }
    ```

## ✨ **0.7** *(2019-07-19)*

***Commas? We don't need no stinkin' commas!***

This release brings a new and improved `html!` macro for writing JSX-like syntax. Commas and colons are no longer necessary now that the macro is written as a procedural macro.

- #### ⚡️ Features
  - `html!{}` is now valid syntax and can be used to render nothing [[@jstarry], [#500](https://github.com/yewstack/yew/pull/500)]
  - Apps can now be built without `cargo-web` using `wasm-bindgen` [[@jstarry], [#497](https://github.com/yewstack/yew/pull/497)]
  - `Callback` now implements `Debug` [[@DenisKolodin], [#485](https://github.com/yewstack/yew/pull/485)]
  - New utility method for getting the `host` of the current page [[@DenisKolodin], [#509](https://github.com/yewstack/yew/pull/509)]

- #### 🛠 Fixes
  - `html!` - Commas are no longer necessary for splitting up attributes [[@jstarry], [#500](https://github.com/yewstack/yew/pull/500)]
  - `html!` - Colons are no longer necessary for denoting a `Component` tag [[@jstarry], [#500](https://github.com/yewstack/yew/pull/500)]
  - Textarea value can be now be set: `<textarea value="content">` [[@DenisKolodin], [#476](https://github.com/yewstack/yew/pull/476)]
  -  changed `StorageService::restore` to take an immutable receiver [[@dermetfan], [#480](https://github.com/yewstack/yew/pull/480)]
  - Fixed a component rendering bug [[@jstarry], [#502](https://github.com/yewstack/yew/pull/502)]

## ✨ **0.6** *(2019-02-20)*

- #### ⚡️ Features
  - Added `start_app` convenience method for initializing the app and mounting it to the body [[@DenisKolodin], [#462](https://github.com/yewstack/yew/pull/462)]
  - Added handling of files of `input` element. There is now a `ChangeData::Files` variant for the `onchange` handler [[@DenisKolodin], [#464](https://github.com/yewstack/yew/pull/464)]
  - Added `ReaderService` to read data from `File` instances. [[@DenisKolodin], [#464](https://github.com/yewstack/yew/pull/464), [#468](https://github.com/yewstack/yew/pull/468)]

- #### 🛠 Fixes
  - It was impossible to set `value` attribute for any tag instead of `option`, because it used
  inner value of `VTag` to keep the value for `input` element. Now `value` attribute works
  for `options`, `progress` tags, etc.


- #### 🔮 Examples
  - New example `file_upload` that prints sizes of uploaded files [[@DenisKolodin], [#464](https://github.com/yewstack/yew/pull/464)]

## ✨ **0.5** *(2019-02-01)*

**🎶 Secret Agent Man 🎶**

This release introduces the concept of an `Agent`. Agents are separate activities which you could run in the same thread or in a separate thread. There are three types of agents `Context`, `Job`, `Public` described below. To connect to an agent use the `Worker::bridge` method and pass a link of component's environment to it.

- #### ⚡️ Features
  - Introduced the concept of an `Agent` which can run processes in other contexts:
    - `Context` agent spawns once per thread
    - `Job` agent spawns for every bridge
    - `Public` agent spawns an agent in a separate thread (it uses [Web Workers API] under the hood).
  - Allow setting the whole properties struct of a component with `<Component: with props />`
  - `ComponentLink` now has a `send_self` method which allows components to update themselves [[@DenisKolodin], [#365](https://github.com/yewstack/yew/pull/365)]
  - All services are re-exported within the `yew::services` module.
  - `html!` macro supports multiple classes in a single string:
  `<a class="button is-primary",>`.
  - Added `FetchOptions` to allow setting `Credentials` of `fetch` request.
  - `FetchService` aborts requests using `AbortController`.
  - Added `SubmitEvent` with `onsubmit` rule.


- #### 🛠 Fixes

  - Bug with emscripten target `RuntimeError: index out of bounds` fixed with a new scheduler [[@DenisKolodin], [#272](https://github.com/yewstack/yew/pull/272)]

- #### 🚨 Breaking changes
  - `send_back` method requires a mutable reference to `self`. This was added to prevent creating callbacks in `view` implementations. [[@DenisKolodin], [#367](https://github.com/yewstack/yew/pull/367)]
  - `Context` requirement removed. It's no longer necessary to use `Component<CTX>` type parameter. Instead, a link to the environment is provided with the `Component::create` call. [[@DenisKolodin], [#272](https://github.com/yewstack/yew/pull/272)]

## ✨ **0.4** *(2018-06-01)*
## ✨ **0.3** *(2018-04-23)*
## ✨ **0.2** *(2018-01-08)*
## ✨ **0.1** *(2017-12-31)*

[Web Workers API]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API
[@AlephAlpha]: https://github.com/AlephAlpha
[@astraw]: https://github.com/astraw
[@boydjohnson]: https://github.com/boydjohnson
[@captain-yossarian]: https://github.com/captain-yossarian
[@carlosdp]: https://github.com/carlosdp
[@charvp]: https://github.com/charvp
[@ctaggart]: https://github.com/ctaggart
[@ctm]: https://github.com/ctm
[@dancespiele]: https://github.com/dancespiele
[@daxpedda]: https://github.com/daxpedda
[@davidkna]: https://github.com/davidkna
[@DenisKolodin]: https://github.com/DenisKolodin
[@dermetfan]: https://github.com/dermetfan
[@detegr]: https://github.com/Detegr
[@dunnock]: https://github.com/dunnock
[@hgzimmerman]: https://github.com/hgzimmerman
[@izissise]: https://github.com/izissise
[@jplatte]: https://github.com/jplatte
[@jstarry]: https://github.com/jstarry
[@kakoc]: https://github.com/kakoc
[@kellytk]: https://github.com/kellytk
[@kuy]: https://github.com/kuy
[@leo-lb]: https://github.com/leo-lb
[@lizhaoxian]: https://github.com/lizhaoxian
[@mankinskin]: https://github.com/mankinskin
[@mdtusz]: https://github.com/mdtusz
[@mrh0057]: https://github.com/mrh0057
[@nicklaswj]: https://github.com/nicklaswj
[@philip-peterson]: https://github.com/philip-peterson
[@serzhiio]: https://github.com/serzhiio
[@stkevintan]: https://github.com/stkevintan
[@TheNeikos]: https://github.com/TheNeikos
[@tiziano88]: https://github.com/tiziano88
[@trivigy]: https://github.com/trivigy
[@totorigolo]: https://github.com/totorigolo
[@Wodann]: https://github.com/Wodann