使用嵌套對象數組的JSON.Stringify數組TypeScript/JS

Question

我正在生成一系列嵌套對象（在元素的'failReasons'和'照片'下）的對象數組 - 然後我想將結果數組作爲JSON到一個Web API，它將期望一個對象列表，以及嵌套的對象列表。第一部分工作 - 數組接收對象列表並可以解析它們，但是，在將數組轉換爲JSON時，嵌套數組爲空。

這是我產生了數組： 這裏是個什麼樣子，當我字符串化是這樣的：

{"capeNo":"ABCD1234","insDate":"2016-11-10 15:03:18","inspector":"User.Name","inspectionResult":"Pass","comments":"","site":"Site Name","dismCompleteDate":"","failReasons":[],"photos":[]} 

正如你所看到的，failReasons，它有它的數組中的6個對象被字符串化之前，現在只是一個空陣列。

我用下面的代碼來生成數組：

接口：

export interface inspectionUpload { 
     capeNo: string; 
     insDate: string; 
     inspector: string; 
     inspectionResult: string; 
     comments: string; 
     site: string; 
     dismCompleteDate; 
     failReasons: Array<Object>; 
     photos: Array<Object>; 
} 

export interface inspectionFailures { 
     failCategory: string; 
     failReason: string; 
     resolution: string; 
     inspectionId: string; 
} 

export interface inspectionPhotos { 
     base64: string; 
} 

而這種填充陣列：

this.sql.query('SELECT rowid,* FROM InspectionResults_tbl').then((res) => { 
    var arr = [] 

    for (var i = 0; i < res.res.rows.length; i++) { 
     var item = res.res.rows.item(i); 
     var header: inspectionUpload = { 
      capeNo: item.capeNo, 
      insDate: item.inspectionDT, 
      inspector: item.inspectedBy, 
      inspectionResult: item.result, 
      comments: item.comment, 
      site: this.SharedService.site, 
      dismCompleteDate: item.dismantleDate, 
      failReasons: <inspectionFailures[]> [], 
      photos: <inspectionPhotos[]> [] 
     } 

     if (item.result == 'Fail') { 
      console.log(item); 
      this.sql.query('SELECT * FROM InspectionFailures_tbl WHERE inspectionId = ?', [item.rowid]).then((res) => { 
       for (var i = 0; i < res.res.rows.length; i++) { 
        var item = res.res.rows.item(i); 
        header.failReasons.push({ 
         failCategory: item.failCategory, 
         failReason: item.failreason, 
         resolution: item.resolution, 
         FRId: item.FRId 
        }) 
       } 
      }) 
     } 

     this.sql.query('SELECT * FROM InspectionPhotos_tbl WHERE inspectionId = ?', [item.rowid]).then((res) => { 
      for (var i = 0; i < res.res.rows.length; i++) { 
       var item = res.res.rows.item(i); 
       header.photos.push({ 
        base64: item.base64 
       }) 
      } 
     }) 



     arr.push(header); 
     if ((i + 1) == res.res.rows.length) upload(arr) 
    } 
}) 

最後，以字符串化它：

function upload(a) { 
      console.log(a); 
      console.log(JSON.stringify(a)); 
     } 

幫助將不勝感激:)

Answer 1

這可能是因爲你在承諾解決之前打印字符串數組。

 this.sql.query('SELECT * FROM InspectionFailures_tbl WHERE inspectionId = ?', [item.rowid]).then((res) => { 
      for (var i = 0; i < res.res.rows.length; i++) { 
       var item = res.res.rows.item(i); 
       header.failReasons.push({ 
        failCategory: item.failCategory, 
        failReason: item.failreason, 
        resolution: item.resolution, 
        FRId: item.FRId 
       }) 
      } 
     }) 
    ... 

    arr.push(header); 
    if ((i + 1) == res.res.rows.length) upload(arr) 

，如果你做了下面的代碼將正確字符串化（這是不是做了正確的方法，我只是證明你不能字符串化，直到然後完成推填充數組...）：

 var queryComplete = false; 

     this.sql.query('SELECT * FROM InspectionFailures_tbl WHERE inspectionId = ?', [item.rowid]).then((res) => { 
      for (var i = 0; i < res.res.rows.length; i++) { 
       var item = res.res.rows.item(i); 
       header.failReasons.push({ 
        failCategory: item.failCategory, 
        failReason: item.failreason, 
        resolution: item.resolution, 
        FRId: item.FRId 
       }) 
      } 
      queryComplete = true; 
     }) 
    ... 

    while (!queryComplete){ 
     //noop 
    } 

    arr.push(header); 
    if ((i + 1) == res.res.rows.length) upload(arr)