AngularUI-Bootstrap 的 Typeahead 无法读取 `undefined` 的 `length` 属性 [英] AngularUI-Bootstrap's Typeahead Can't Read `length` Property of `undefined`

问题描述

当我尝试使用承诺从 AngularUI-Bootstrap 获取预先输入的值时出现以下错误.

I am getting the following error when I attempt to get a typeahead values from AngularUI-Bootstrap, using a promise.

TypeError: Cannot read property 'length' of undefined
  at http://localhost:8000/static/js/ui-bootstrap-tpls-0.6.0.min.js:1:37982
  at i (http://localhost:8000/static/js/angular.min.js:79:437)
  at i (http://localhost:8000/static/js/angular.min.js:79:437)
  at http://localhost:8000/static/js/angular.min.js:80:485
  at Object.e.$eval (http://localhost:8000/static/js/angular.min.js:92:272)
  at Object.e.$digest (http://localhost:8000/static/js/angular.min.js:90:142)
  at Object.e.$apply (http://localhost:8000/static/js/angular.min.js:92:431)
  at HTMLInputElement.Va.i (http://localhost:8000/static/js/angular.min.js:120:156)
  at HTMLInputElement.x.event.dispatch (http://localhost:8000/static/js/jquery-1.10.2.min.js:5:14129)
  at HTMLInputElement.v.handle (http://localhost:8000/static/js/jquery-1.10.2.min.js:5:10866) 

我的 HTML 标签是:

My HTML tag is:

<input type="text" class="form-control" id="guestName" ng-model="name" typeahead="name for name in getTypeaheadValues($viewValue)">

使用我的 getTypeaheadValues 函数执行以下操作:

With my getTypeaheadValues function doing the following:

$scope.getTypeaheadValues = function($viewValue)
{
    // return ['1','2','3','4'];

    $http({
        method: 'GET',
        url: 'api/v1/person?name__icontains=' + $viewValue
    }).error(function ($data) {
        console.log("failed to fetch typeahead data");
    }).success(function ($data) {
        var output = [];
        $data.objects.forEach(function (person)
        {
            output.push(person.name);
        });
        console.log(output);
        return output;
    });
}

我不明白 AngularUI-Bootstrap 抱怨什么未定义.如果我删除最顶部 return 上的注释，则值显示正常.success 中的 console.log 输出也返回我期望在数组中的所有值.

I do not understand what AngularUI-Bootstrap is complaining about as being undefined. If I remove the comment on the top-most return the values show up fine. The console.log output in the success also return all the values I'm expecting in an array.

我遗漏了什么会导致 AngularUI-Bootstrap 看不到返回的数组?

What am I missing that would cause AngularUI-Bootstrap not see the returned array?

推荐答案

这个问题有两个方面.

首先是我没有返回 promise 事件($http 调用).缺少 return 语句(正如@tobo 指出的那样)是直接导致错误的原因.不过，我需要返回承诺，而不是数组.

The first is that I was not returning the promise event (the $http call). The lack of a return statement (as @tobo points out) is what was causing the error directly. I needed to be returning the promise though, not the array.

第二个是我需要使用 .then 而不是 .success 来让 AngularUI-Bootstrap 获取结果.

The second is that I need to be using .then rather than .success for AngularUI-Bootstrap to pick up the results.

我遇到了以下问题:如何通过 $http 将 angular-ui 的预先输入与服务器绑定以进行服务器端优化?

将我的函数调用更新为以下内容:

Which updated my function call to the below:

$scope.getTypeaheadValues = function($viewValue)
{
    return $http({
        method: 'GET',
        url: 'api/v1/person?name__icontains=' + $viewValue
    }).then(function ($response) {
        var output = [];

        console.log($data);

        $response.data.objects.forEach(function (person)
        {
            output.push(person.name);
        });

        console.log(output);
        return output;
    });
}

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