無法承諾在Ionic2打字稿中使用Trello

問題是，我希望確保數據在我繼續執行我的程序之前可用，所以我需要使用異步類型函數。根據ion.io，Promise似乎是標準方法。無法承諾在Ionic2打字稿中使用Trello

我有一個非常簡單的例子，下面基本上來自Trello.com網站製作一張卡片。然後，我將這個id加載到一個全局數組中，然後嘗試記錄它。

// myTry.ts開始的

import {Component} from '@angular/core'; 
import {NavController, NavParams} from 'ionic-angular'; 
//compile needs this and it seems to make the Trello functions work 
declare var Trello: any; 

@Component({ 
    templateUrl: 'build/pages/mytry/mytry.html' 
}) 
export class MyTryPage { 
    fileEntry: any; 
    myData: any;  
    myList: any = "MyList ID - get this from the sandbox screen in Trello.com please"; 

    newCard = {  
     name: '****My New Test Card', 
     desc: '****This is the description of our new card.', 
     idList: this.myList, 
     pos: 'top' 
    }; 

    readTrello: any = function() { 
     Trello.post('/cards/', this.newCard, this.creationSuccess); 
    } 

    constructor(private navController: NavController) { 

     Trello.authorize({ 
      type: "redirect", 
      interactive: "true", 
      name: "My Application", 
      scope: { 
       read: "true", 
       write: "true" }, 
      expiration: "never", 
      success: this.authenticationSuccess, 
      error: this.authenticationFailure 
     }); 

     this.testPromise(); 

     // this line does not work 
     console.log('My data ' + this.myData); // returns undefined 

    } 

    testPromise: any = function() {  
     var p1 = new Promise(resolve => { 
      this.readTrello(); 
      window.setTimeout(() => { 
       // this line is run after timeout completes so why is data not available 
       console.log("Since this is run after timeout, I expect data to exist???? "+ this.myData); 
       resolve(0); 
      }, 5000); 
     }); 

     p1.then(
      // Log the fulfillment value 
      () => { 
        //This fails - data is NOT available 
        console.log('Promise fullfilled. Data should be available:???? Array is no longer in scope at all????' + this.myData); 

        // I will load into displayable structure here later 

       }) 
     .catch(
      // Log the rejection reason 
      function(reason) { 
       console.log('Handle rejected promise ('+reason+') here.'); 
      }); 
    } 



    authenticationSuccess: any = function() { 
     //This works 
     console.log("Successful authentication"); 
    }; 
    authenticationFailure: any = function() { 
     console.log("Failed authentication"); 
    }; 

    creationSuccess: any = function(data) { 
     //This works 
     console.log('Trello callback successfull'); 
     this.myData = JSON.stringify(data.id); 
     //This works and the data returned is available and correct - great. 
     console.log('Card created successfully. Data returned:' + this.myData); 
    }; 

}

我失去了一些東西 - 數據是超時之前可用，但不是之後???很明顯，我的程序流程不正確。 ps我可以使用令牌做到上面，但我想使用Trello發佈的API。

來源

2016-09-03 Tonyeng

如果您希望this關鍵字被定義爲您在該函數體內使用它，則必須使用lambda函數。

而不是window.setTimeout(function() {使用window.setTimeout(() => {

做同樣的事情爲p1.then線。

而且，在這一行：Trello.post('/cards/', this.newCard, this.creationSuccess);強似this.creationSuccess嘗試通過this.creationSuccess.bind(this)

來源

2016-09-04 05:21:38 Paarth

謝謝Paarth，我更換了，因爲我認爲你曾建議讓他們拉姆達功能，但得到了同樣的結果，當我跑的代碼。數據在回調中可用，但不能在以後。我假設我的數據不在範圍內。 – Tonyeng

我還在構造函數中添加了一個console.log行，以查看myData是否可用 - 不是。也許我已經聲明瞭myData，這也是一個問題。 – Tonyeng

在這一行：'Trello.post（'/ cards /'，this.newCard，this.creationSuccess）; '而不是通過'this.creationSuccess'嘗試通過'this.creationSuccess.bind（this）' – Paarth

無法承諾在Ionic2打字稿中使用Trello

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