由ReactJS的Hello world说开来_基础知识

/
 // This is the parent component comprising of two inner components
 // One of the component is UserName which is used to allow user to enter their name
 // Other component is HelloText which displays the text such as Hello, World
 //
 var SayHello = React.createClass({
 // This is used to set the state, "data" which is 
 // accessed later in HelloText component to display the updated state
 // 
 getInitialState: function() {
  return {data: 'World'}
 },
 // It is recommended to capture events happening with any children
 // at the parent level and set the new state that updates the children appropriately
 handleNameSubmit: function(name) {
  this.setState({data: name});
 },
 // Render method which is comprised of two components such as UserName and HelloText
 //
 render: function() {
  return(
  

  
  
  
  );
 }
 });

var UserName = React.createClass({
 handleChange: function() {
  var username = this.refs.username.getDOMNode().value.trim();
  this.props.onNameSubmit({username: username });
  this.refs.username.getDOMNode().value = '';
  return false;
 },
 render: function() {
  return(
  

   

   
   
  
  );
 }
 });

 render：包含了展示HelloText组件内容的代码
 
var HelloText = React.createClass({
  render: function() {
  return (
  

   
Hello, {this.props.data}
  
  );
  }
 });