feat: Migrate Handling Events to typescript

content/docs/handling-events.md

@@ -11,7 +11,7 @@ redirect_from:
 Handling events with React elements is very similar to handling events on DOM elements. There are some syntactic differences:
 
 * React events are named using camelCase, rather than lowercase.
-* With JSX you pass a function as the event handler, rather than a string.
+* With TSX you pass a function as the event handler, rather than a string.
 
 For example, the HTML:
 
@@ -23,7 +23,7 @@ For example, the HTML:
 
 is slightly different in React:
 
-```js{1}
+```typescript
 <button onClick={activateLasers}>
   Activate Lasers
 </button>
@@ -39,7 +39,7 @@ Another difference is that you cannot return `false` to prevent default behavior
 
 In React, this could instead be:
 
-```js{2-5,8}
+```typescript
 function ActionLink() {
   function handleClick(e) {
     e.preventDefault();
@@ -60,8 +60,11 @@ When using React you should generally not need to call `addEventListener` to add
 
 When you define a component using an [ES6 class](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Classes), a common pattern is for an event handler to be a method on the class. For example, this `Toggle` component renders a button that lets the user toggle between "ON" and "OFF" states:
 
-```js{6,7,10-14,18}
-class Toggle extends React.Component {
+```typescript
+interface IOwnProps {}
+interface IState {}
+
+class Toggle extends React.Component<IOwnProps, IState> {
   constructor(props) {
     super(props);
     this.state = {isToggleOn: true};
@@ -70,13 +73,13 @@ class Toggle extends React.Component {
     this.handleClick = this.handleClick.bind(this);
   }
 
-  handleClick() {
+  private handleClick() {
     this.setState(prevState => ({
       isToggleOn: !prevState.isToggleOn
     }));
   }
 
-  render() {
+  public render() {
     return (
       <button onClick={this.handleClick}>
         {this.state.isToggleOn ? 'ON' : 'OFF'}
@@ -93,21 +96,24 @@ ReactDOM.render(
 
 [Try it on CodePen.](http://codepen.io/gaearon/pen/xEmzGg?editors=0010)
 
-You have to be careful about the meaning of `this` in JSX callbacks. In JavaScript, class methods are not [bound](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind) by default. If you forget to bind `this.handleClick` and pass it to `onClick`, `this` will be `undefined` when the function is actually called.
+You have to be careful about the meaning of `this` in TSX callbacks. In JavaScript, class methods are not [bound](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind) by default. If you forget to bind `this.handleClick` and pass it to `onClick`, `this` will be `undefined` when the function is actually called.
 
 This is not React-specific behavior; it is a part of [how functions work in JavaScript](https://www.smashingmagazine.com/2014/01/understanding-javascript-function-prototype-bind/). Generally, if you refer to a method without `()` after it, such as `onClick={this.handleClick}`, you should bind that method.
 
 If calling `bind` annoys you, there are two ways you can get around this. If you are using the experimental [public class fields syntax](https://babeljs.io/docs/plugins/transform-class-properties/), you can use class fields to correctly bind callbacks:
 
-```js{2-6}
-class LoggingButton extends React.Component {
+```typescript
+interface IOwnProps {}
+interface IState {}
+
+class LoggingButton extends React.Component<IOwnProps, IState> {
   // This syntax ensures `this` is bound within handleClick.
   // Warning: this is *experimental* syntax.
-  handleClick = () => {
+  private handleClick = () => {
     console.log('this is:', this);
   }
 
-  render() {
+  public render() {
     return (
       <button onClick={this.handleClick}>
         Click me
@@ -121,13 +127,16 @@ This syntax is enabled by default in [Create React App](https://github.com/faceb
 
 If you aren't using class fields syntax, you can use an [arrow function](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions/Arrow_functions) in the callback:
 
-```js{7-9}
-class LoggingButton extends React.Component {
-  handleClick() {
+```typescript
+interface IOwnProps {}
+interface IState {}
+
+class LoggingButton extends React.Component<IOwnProps, IState> {
+  private handleClick() {
     console.log('this is:', this);
   }
 
-  render() {
+  public render() {
     // This syntax ensures `this` is bound within handleClick
     return (
       <button onClick={(e) => this.handleClick(e)}>

content/docs/nav.yml

@@ -21,7 +21,7 @@
     - id: state-and-lifecycle
       title: State and Lifecycle (TS✓)
     - id: handling-events
-      title: Handling Events
+      title: Handling Events (TS 70%)
     - id: conditional-rendering
       title: Conditional Rendering
     - id: lists-and-keys