Angular + NodeJS：使用Promise（fs.fileRead和fs.readdir）从文件夹读取文件

Question

我正在尝试使用NodeJS和Angular从文件夹读取文件。我可以迭代文件夹并访问文件数据，这里没有问题。 我的主要问题是我无法将结果（名称数组）传递给$ scope并将其显示给用户 - 数组始终为空。我认为这与fs异步行为有关。

我做了以下内容：

角服务：

myApp.service('peopleService', ['$q', '$http', function($q, $http) { 

    var self = this; 
    this.people = []; 

    var peopleService = new Promise(function(resolve, reject) { 
     fs.readdir(folderPath, function(err, files) { 
      files.forEach(function(file) { 
       var obj; 
       fs.readFile(filePath, 'utf8', function (err, data) { 
        obj = JSON.parse(data); 

        var person = { name: obj.obituary.name, ... }; 

        self.people.push(person); 
       }); 
      }); 
     }); 

     resolve(self.people); 
    }).then(function(people) { 
     return people; 
    }); 

    return peopleService; 
}]); 

角控制器：

myApp.controller('homeController', ['$scope', '$http', 'peopleService', function($scope, $http, peopleService) { 

    $scope.people = []; 

    peopleService.then(function(people) { 
     $scope.people = people; 
     console.log($scope.people); //empty array (Array[0]) 
    }); 

}]); 

角页：

<div class="list-group"> 
    <a href="#" class="list-group-item" ng-repeat="person in people"> 
     {{person.name}} 
    </a> 
</div> 

我在做什么错？

Answer 1

为什么你将nodeJS代码与angularJS代码混合？

问题resolve(self.people)是readdir之前执行和readFile回调被执行，因为他们是异步的，所以你必须确保resolve(self.people)会后readdir和readFile回调执行：

new Promise(function(resolve, reject) { 
     fs.readdir(folderPath, function(err, files) { 
      var count = 0; 
      files.forEach(function(file) { 
       var obj; 
       fs.readFile(filePath, 'utf8', function (err, data) { 
        obj = JSON.parse(data); 

        var person = { name: obj.obituary.name, ... }; 

        self.people.push(person); 

        count++; 
        if(count === files.length){ 
         resolve(self.people); 
        } 
       }); 
      }); 
     }); 

    }).then(function(people) { 
     return people; 
    });