Improvements over HtmlSelect to allow using hashable objects (#47)

yewprint-doc/src/html_select/example.rs

@@ -3,6 +3,8 @@ use yewprint::HtmlSelect;
 
 pub struct Example {
     props: ExampleProps,
+    link: ComponentLink<Self>,
+    log_level: LogLevel,
 }
 
 #[derive(Clone, PartialEq, Properties)]
@@ -14,14 +16,19 @@ pub struct ExampleProps {
 }
 
 impl Component for Example {
-    type Message = ();
+    type Message = LogLevel;
     type Properties = ExampleProps;
 
-    fn create(props: Self::Properties, _link: ComponentLink<Self>) -> Self {
-        Example { props }
+    fn create(props: Self::Properties, link: ComponentLink<Self>) -> Self {
+        Example {
+            props,
+            link,
+            log_level: LogLevel::Info,
+        }
     }
 
-    fn update(&mut self, _msg: Self::Message) -> ShouldRender {
+    fn update(&mut self, msg: Self::Message) -> ShouldRender {
+        self.log_level = msg;
         true
     }
 
@@ -37,21 +44,34 @@ impl Component for Example {
     fn view(&self) -> Html {
         html! {
             <div style="width: 400px; text-align: center;">
-                <HtmlSelect
+                <HtmlSelect<LogLevel>
                     options={vec![
-                        ("trace".to_string(), "TRACE".to_string()),
-                        ("debug".to_string(), "DEBUG".to_string()),
-                        ("info".to_string(), "INFO".to_string()),
-                        ("warn".to_string(), "WARN".to_string()),
-                        ("error".to_string(), "ERROR".to_string()),
-                        ("off".to_string(), "OFF".to_string()),
-                        ]}
+                        (LogLevel::Trace, "TRACE".to_string()),
+                        (LogLevel::Debug, "DEBUG".to_string()),
+                        (LogLevel::Info, "INFO".to_string()),
+                        (LogLevel::Warn, "WARN".to_string()),
+                        (LogLevel::Error, "ERROR".to_string()),
+                        (LogLevel::Off, "OFF".to_string()),
+                    ]}
                     minimal=self.props.minimal
                     fill=self.props.fill
                     disabled=self.props.disabled
                     large=self.props.large
+                    value=Some(self.log_level)
+                    onchange=self.link.callback(|x| x)
+                    title=format!("Selected: {:?}", self.log_level)
                 />
             </div>
         }
     }
 }
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq)]
+pub enum LogLevel {
+    Trace,
+    Debug,
+    Info,
+    Warn,
+    Error,
+    Off,
+}

yewprint/src/html_select.rs

@@ -1,12 +1,15 @@
 use crate::{ConditionalClass, Icon, IconName};
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
 use yew::prelude::*;
 
-pub struct HtmlSelect {
-    props: Props,
+pub struct HtmlSelect<T: Clone + PartialEq + Hash + 'static> {
+    props: Props<T>,
+    link: ComponentLink<Self>,
 }
 
 #[derive(Clone, PartialEq, Properties)]
-pub struct Props {
+pub struct Props<T: Clone + PartialEq + 'static> {
     #[prop_or_default]
     pub fill: ConditionalClass,
     #[prop_or_default]
@@ -20,23 +23,32 @@ pub struct Props {
     #[prop_or_default]
     pub title: Option<String>,
     #[prop_or_default]
-    pub onchange: Callback<ChangeData>,
+    pub onchange: Callback<T>,
+    pub options: Vec<(T, String)>,
     #[prop_or_default]
-    pub options: Vec<(String, String)>,
-    #[prop_or_default]
-    pub value: String,
+    pub value: Option<T>,
 }
 
-impl Component for HtmlSelect {
-    type Message = ();
-    type Properties = Props;
+impl<T: Clone + PartialEq + Hash + 'static> Component for HtmlSelect<T> {
+    type Message = ChangeData;
+    type Properties = Props<T>;
 
-    fn create(props: Self::Properties, _link: ComponentLink<Self>) -> Self {
-        HtmlSelect { props }
+    fn create(props: Self::Properties, link: ComponentLink<Self>) -> Self {
+        Self { props, link }
     }
 
-    fn update(&mut self, _msg: Self::Message) -> ShouldRender {
-        true
+    fn update(&mut self, msg: Self::Message) -> ShouldRender {
+        let i = if let ChangeData::Select(select) = msg {
+            select.selected_index()
+        } else {
+            unreachable!("unexpected ChangeData variant: {:?}", msg);
+        };
+        if i >= 0 {
+            let i = i as usize;
+            let variant = self.props.options[i].0.clone();
+            self.props.onchange.emit(variant);
+        }
+        false
     }
 
     fn change(&mut self, props: Self::Properties) -> ShouldRender {
@@ -53,7 +65,25 @@ impl Component for HtmlSelect {
             .props
             .options
             .iter()
-            .map(|(value, label)| html!(<option value=value>{label}</option>))
+            .map(|(value, label)| {
+                let selected = self
+                    .props
+                    .value
+                    .as_ref()
+                    .map(|x| value == x)
+                    .unwrap_or_default();
+                let value = {
+                    let mut hasher = DefaultHasher::new();
+                    value.hash(&mut hasher);
+                    hasher.finish()
+                };
+
+                html! {
+                    <option selected=selected value=value>
+                        {label}
+                    </option>
+                }
+            })
             .collect::<Html>();
 
         html! {
@@ -68,8 +98,16 @@ impl Component for HtmlSelect {
             >
                 <select
                     disabled=*self.props.disabled
-                    onchange={self.props.onchange.clone()}
-                    value={self.props.value.clone()}
+                    onchange={self.link.callback(|x| x)}
+                    value?={
+                        self.props.value
+                            .as_ref()
+                            .map(|value| {
+                                let mut hasher = DefaultHasher::new();
+                                value.hash(&mut hasher);
+                                hasher.finish()
+                            })
+                    }
                     title?={self.props.title.clone()}
                 >
                     {option_children}