react经典进阶demo

这是我在官方文档上看到的,功能是实现(具体是什么，请往下看)

以下是json数据:

1 [
2   {category: "Sporting Goods", price: "$49.99", stocked: true, name: "Football"},
3   {category: "Sporting Goods", price: "$9.99", stocked: true, name: "Baseball"},
4   {category: "Sporting Goods", price: "$29.99", stocked: false, name: "Basketball"},
5   {category: "Electronics", price: "$99.99", stocked: true, name: "iPod Touch"},
6   {category: "Electronics", price: "$399.99", stocked: false, name: "iPhone 5"},
7   {category: "Electronics", price: "$199.99", stocked: true, name: "Nexus 7"}
8 ];

显示红色的物品，是没有库存的(stocked:false),如$29.99的basketball和$399.99的iphone5。

在我看来react的结构就像‘包饺子’，一层夹着一层，可以看一下上图的几个边框，不同颜色代表着不同区域划分。

1.(orange): contains the entirety of the example 外边的黄色区域，包含整个例子。

2.(blue): receives all user input 里面一层的蓝色框框，度用户的输入进行serach。

3.(green): displays and filters the data collection based onuser input 绿色框展示用户筛选的物品信息。

4. (turquoise): displays a heading for each category 显示产品种类，这里是sproting goods和electronics。

5.(red): displays a row for each product 红色框，每件物品。

 1 //这是结构的最外一层  它里面包含searchBar和producTable两个组件
 2 var FilterableProductTable = React.createClass({
 3   render: function() {
 4     return (
 5       <div>
 6         <SearchBar /> 
 7         <ProductTable products={this.props.products} />
 8       </div>
 9     );
10   }
11 });
12 
13 
14 var PRODUCTS = [
15   {category: 'Sporting Goods', price: '$49.99', stocked: true, name: 'Football'},
16   {category: 'Sporting Goods', price: '$9.99', stocked: true, name: 'Baseball'},
17   {category: 'Sporting Goods', price: '$29.99', stocked: false, name: 'Basketball'},
18   {category: 'Electronics', price: '$99.99', stocked: true, name: 'iPod Touch'},
19   {category: 'Electronics', price: '$399.99', stocked: false, name: 'iPhone 5'},
20   {category: 'Electronics', price: '$199.99', stocked: true, name: 'Nexus 7'}
21 ];
22  //这里的prop属性定义了product  引用字上面的json数据
23 ReactDOM.render(
24   <FilterableProductTable products={PRODUCTS} />,
25   document.getElementById('container')
26 );
27 
28 //这是最简单的搜索框组件
29 var SearchBar = React.createClass({
30   render: function() {
31     return (
32       <form>
33         <input type="text" placeholder="Search..." />
34         <p>
35           <input type="checkbox" />
36           {' '}
37           Only show products in stock
38         </p>
39       </form>
40     );
41   }
42 });
43 
44 //关键的来了  这个productTable里面还包含了一些组件
45 var ProductTable = React.createClass({
46   render: function() {
47     var rows = [];
48     var lastCategory = null;
49     //遍历json数据
50     this.props.products.forEach(function(product) {
51       if (product.category !== lastCategory) {  //注意这里的判断，并不是每回都要把类别加一次
52        //这里有一个产品种类的组件
53       rows.push(<ProductCategoryRow category={product.category} key={product.category} />);
54       }
55       //还有一个产品行的组件   
56       rows.push(<ProductRow product={product} key={product.name} />);
57       lastCategory = product.category;
58     });
59     return (
60       <table>
61         <thead>
62           <tr>
63             <th>Name</th>
64             <th>Price</th>
65           </tr>
66         </thead>
67         <tbody>{rows}</tbody>
68       </table>
69     );
70   }
71 });
72 
73 //category在上面可以找到
74 var ProductCategoryRow = React.createClass({
75   render: function() {
76     return (<tr><th colSpan="2">{this.props.category}</th></tr>);
77   }
78 });
79 
80 var ProductRow = React.createClass({
81   render: function() {
82     //如果没有货存  红色字体显示
83    var name = this.props.product.stocked ?
84       this.props.product.name :
85       <span style={{color: 'red'}}>
86         {this.props.product.name}
87       </span>;
88     return (
89       <tr>
90         <td>{name}</td>
91         <td>{this.props.product.price}</td>
92       </tr>
93     );
94   }
95 });

就这样玩了吗？还没有，以上还没实现搜索和过滤功能。

  1 var ProductCategoryRow = React.createClass({
  2   render: function() {
  3     return (<tr><th colSpan="2">{this.props.category}</th></tr>);
  4   }
  5 });
  6 
  7 var ProductRow = React.createClass({
  8   render: function() {
  9     var name = this.props.product.stocked ?
 10       this.props.product.name :
 11       <span style={{color: 'red'}}>
 12         {this.props.product.name}
 13       </span>;
 14     return (
 15       <tr>
 16         <td>{name}</td>
 17         <td>{this.props.product.price}</td>
 18       </tr>
 19     );
 20   }
 21 });   //这里都没变
 22 
 23 //注意这里有改动 
 24 var ProductTable = React.createClass({
 25   render: function() {
 26     var rows = [];
 27     var lastCategory = null;
 28     this.props.products.forEach(function(product) {
 29     //用于过滤产品(用户输入的关键字和库存)
 30       if (product.name.indexOf(this.props.filterText) === -1 || (!product.stocked && this.props.inStockOnly)) { //注意此处的逻辑
 31         return;
 32       }
 33       if (product.category !== lastCategory) {
 34         rows.push(<ProductCategoryRow category={product.category} key={product.category} />);
 35       }
 36       rows.push(<ProductRow product={product} key={product.name} />);
 37       lastCategory = product.category;
 38     }.bind(this));  //由于函数里面用到了this  这里bind一下
 39     return (
 40       <table>
 41         <thead>
 42           <tr>
 43             <th>Name</th>
 44             <th>Price</th>
 45           </tr>
 46         </thead>
 47         <tbody>{rows}</tbody>
 48       </table>
 49     );
 50   }
 51 });
 52 
 53 //serachBar现在膨胀了  这么多
 54 var SearchBar = React.createClass({
 55   handleChange: function() {
 56      //上面肯定有个函数  肯定在父组件上
 57       this.props.onUserInput(
 58       this.refs.filterTextInput.value,
 59       this.refs.inStockOnlyInput.checked  //注意这里的ref用法
 60     );
 61   },
 62   render: function() {
 63     return (
 64       <form>
 65         <input
 66           type="text"
 67           placeholder="Search..."
 68           value={this.props.filterText}
 69           ref="filterTextInput"
 70           onChange={this.handleChange} //文本改变回调事件  它的作用是什么？  下面有答案
 71         />
 72         <p>
 73           <input
 74             type="checkbox"
 75             checked={this.props.inStockOnly}
 76             ref="inStockOnlyInput"
 77             onChange={this.handleChange} //checkbox的判断
 78           />
 79           {' '}
 80           Only show products in stock
 81         </p>
 82       </form>
 83     );
 84   }
 85 });
 86 
 87 //关键的来了   这个里面就是饺子皮
 88 var FilterableProductTable = React.createClass({
 89   getInitialState: function() {
 90     return {
 91       filterText: '',
 92       inStockOnly: false
 93     };
 94   },  //这里初始化的state  文本为空  默认checkbox=false
 95 
 96   handleUserInput: function(filterText, inStockOnly) {
 97     this.setState({
 98       filterText: filterText,
 99       inStockOnly: inStockOnly
100     });
101   },
102 
103   render: function() {
104     return (
105       <div>
106         <SearchBar
107          //prop定义的的位置  可以对照着看
108           filterText={this.state.filterText}
109           inStockOnly={this.state.inStockOnly}
110           onUserInput={this.handleUserInput} //这个函数用于改变初始state
111         />
112         //prop定义的位置  要注意这里的ProductTable里面的filterText和instockOnly  是随着serachBar的输入变动的
113         <ProductTable
114           products={this.props.products}
115           filterText={this.state.filterText}
116           inStockOnly={this.state.inStockOnly}
117         />
118       </div>
119     );
120   }
121 });
122 
123 var PRODUCTS = [
124   {category: 'Sporting Goods', price: '$49.99', stocked: true, name: 'Football'},
125   {category: 'Sporting Goods', price: '$9.99', stocked: true, name: 'Baseball'},
126   {category: 'Sporting Goods', price: '$29.99', stocked: false, name: 'Basketball'},
127   {category: 'Electronics', price: '$99.99', stocked: true, name: 'iPod Touch'},
128   {category: 'Electronics', price: '$399.99', stocked: false, name: 'iPhone 5'},
129   {category: 'Electronics', price: '$199.99', stocked: true, name: 'Nexus 7'}
130 ];
131 
132 ReactDOM.render(
133   <FilterableProductTable products={PRODUCTS} />,
134   document.getElementById('container')
135 );

好了，代码量并不大，但是这里面的逻辑和每层之间的关系确实有点搞人呀。。。希望大家看懂了react想表达的是什么