AngularJS: code not working when iterating through

问题:

This question already has an answer here:

• 'this' vs $scope in AngularJS controllers 7 answers

I am trying to populate a list of employee objects from my controller empctrl in a template.

Here's the controller:

app.controller('employeeController', function ($scope, employeeService) {

    this.employees = {};

    this.populateTable = function (data) {

        this.employees = data;
    };

    var error = function (err) {
        console.log("Error: " + err);
    };

    // Call Service to List all Employees
    console.log("Service called to populate table.");
    employeeService.output().then(this.populateTable, error);
    this.populateTable();

});

However, this code that I wrote isn't working:

<div ng-repeat="employee in empctrl.employees.allEmployees" class="table_row">
    <div class="table_column" style="width:2%">{{ $index + 1 }}</div>
    <div class="table_column" style="width:8%">{{ employee.employeeName}}</div>
    <!-- 7 more columns -->
</div>

Nothing shows up in the UI.
Instead, if I write $scope.employees in the controller, it works:

<div ng-repeat="employee in employees.allEmployees" class="table_row">

Since I know how tempting it is to do $scope.<everything> in the controller, I'm trying to avoid using $scope as much as possible.

---

If someone could demonstrate the proper use of $scope and difference betwee alias.abc and $scope.abc (where alias is an alias of controller), I'll be thankful.

Edit: Exact same question is this: 'this' vs $scope in AngularJS controllers

Thanks for this link, PankajParkar.

回答1:

The problem is this which you are accessing inside populateTable function is not this which you have there in your controller function.

Better do keep this variable inside some variable, so that by having it you will make sure you are referring to correct object.

Controller

app.controller('employeeController', function ($scope, employeeService) {
    var vm = this;
    vm.employees = {};

    vm.populateTable = function (data) {
        vm.employees = data;
    };

    var error = function (err) {
        console.log("Error: " + err);
    };

    // Call Service to List all Employees
    console.log("Service called to populate table.");
    employeeService.output().then(vm.populateTable, error);
    vm.populateTable();
});

For more detail, I'd highly recommend you to readup on this article

If you are confused with this vs scope then do read up on this answer

回答2:

Add your variables to the $scope instead of this like:

$scope.customers = {};

$scope.populateTable = function (data) {
    $scope.employees = data;
};

Edit: both methods work. See this article for a in depth explanation.

回答3:

Substituting "this" to vm (View-Model) will solve your issue. Not polluting $scope object is a groovy thing. this is a global context and its value depends on a function call.

So, in your controller just assign,

var vm = this;
  vm.empTable = function (data) {
  vm.employeeList = data.data; 
};

..and use the vm object elsewhere in your controller. It will be useful to keep the code clean while working with multiple controllers in a view.

Don't forget to give an alias name to the controller,

<div ng-controller="MainCtrl as main">
    <div ng-repeat=" employee in main.vm.employeeList ">
        {{employee.name}}
    </div>
</div>