如何建立一個表動態

Question

我嘗試動態地建立一個表reactJS但有我不能解決兩個問題：

1. 在GridList組件我此行<GridRow data={data1} key={i} />我真的不希望獲取「全局」變量，而是使用發送到該方法的數據？我該怎麼做呢？
2. 在GridRow我需要太多循環的列（如我現在做的），但我需要得到正確的單元格的值和右邊不，我只是得到這個異常：Error while rendering "GridBox" to "react1": Unable to get property 'data' of undefined or null reference

代碼

var data1 = {"Columns":[{"Title":"Title1","HTMLClass":"g1_Title"},{"Title":"Title2","HTMLClass":"g2_Title"},{"Title":"Title3","HTMLClass":"g3_Title"}],"Rows":[{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]},{"Cells":["Cell0","Cell1","Cell2"]}]}; 



var GridRow = React.createClass({ 
    render: function() { 
     if(this.props.data){ 
      var Cell = this.props.data.Columns.map(function (column, i) { 
       return (
        <div className={column.HTMLClass}>{this.props.data.Cells[i]}</div> 
       ); 
      }) 
     } 
     return (
      <li>{Cell}</li> 
     ); 
    } 
}); 
var GridHead = React.createClass({ 
    render: function() { 
     if(this.props.data){ 
      var Cell = this.props.data.Title; 
      var HtmlClass = this.props.data.HTMLClass; 
     } 
     return (
      <div className={HtmlClass}>{Cell}</div> 
     ); 
    } 
}); 
var GridList = React.createClass({ 
    render: function() { 
     if(this.props.data){ 
      var Header = this.props.data.Columns.map(function (columns) { 
       return (
        <GridHead data={columns} /> 
       ); 
      }); 
      var Row = this.props.data.Rows.map(function (data, i) { 
       return (
        <GridRow data={data1} key={i} /> 
       ); 
      }); 
     } 
     return (
      <ul> 
       <li>{Header}</li> 
       {Row} 
      </ul> 
     ); 
    } 
}); 


var GridBox = React.createClass({ 
    render: function(){ 
     return (
      <GridList data={data1} /> 
     ); 
    } 
}); 

Answer 1

除非您使用bind來維護實例this，否則您只能引用傳入map中的函數的內容，以便在map中使用的組件和函數內的內容相同。這將允許您在映射功能中使用this.props。

由於header正在使用直接傳遞到函數map中的函數，因此不一定需要綁定。在row中，爲了訪問this.props，必須綁定該函數。例如，如果你有somedata你想內this.props訪問：

var header = this.props.data.Columns.map(function (columns) { 
    return (
     <GridHead data={columns} /> 
    ); 
}); 
var Row = this.props.data.Rows.map(function (data, i) { 
    return (
     <GridRow data={this.props.somedata} key={i} /> 
    ); 
}.bind(this)); 

注意，在JSX常規變量名稱應該以小寫字母（如上頭）開始，而組件名稱應以大寫字母開頭。