没能弄清楚承诺在角HTTP是如何工作的 [英] not able to figure out how promises work in angular http

问题描述

我有以下的code，它通过自动完成指令作出HTTP调用从服务器检索用户名：

  VAR APP2 = angular.module（'MyModule的'，[]）;app2.directive（自动完成，函数（$超时）{
    返回功能（范围，iElement，iAttrs）{
        iElement.autocomplete（{
            来源：函数（）{
                //无法调用此像这样：$范围适用（'的getSource'）;。我得到$正在进行中的错误已经适用
                变种名称= scope.getSource（）;
                。范围$适用（）;
                的console.log（地名）;
                返回名称;
            }，
            异步：假的，
            的minLength：3，
            选择：功能（）{
                $超时（函数（）{
                    iElement.trigger（'输入'）;
                }，0）;
            }
        }）;
    };
}）;app2.controller（'DefaultCtrl'，函数（$范围，$ HTTP）{
    $ scope.getSource =功能（）{
        返回$ http.get（'/ AccountRequest / GetMatchingEmployeeNames？和matchstr ='+ $ scope.selected）
            。然后（功能（数据）{
                变种名称= [];
                对于（VAR I = 0; I＆LT; data.length;我++）{
                    names.push（数据[I] .Name点）;
                }
                返回名称;
            }）;
    };
}）;
 

我试图使用自动完成源的承诺：因为有一个在HTTP方法的延迟，我得到一个空数组，否则。任何人都可以请告诉我，我怎样才能使它发挥作用？我不知道如何提取的名称数组走出承诺的功能传递给源：

解决方案

 来源：功能（要求，responseCallback）{
            变种名称= [];
            VAR承诺= scope.getSource（）;
            promise.success（功能（数据）{
                名称=数据;
                的console.log（地名）;
                responseCallback（地名）;
            }）错误（函数（）{
                的console.log（出现了错误）;
                responseCallback（地名）;
            }）;
        }，
 

或者

 来源：功能（要求，responseCallback）{
            变种名称= [];
            VAR承诺= scope.getSource（）;
            promise.then（功能（数据）{
                名称=数据;
                的console.log（地名）;
                responseCallback（地名）;
            }，函数（）{
                的console.log（出现了错误）;
                responseCallback（地名）;
            }）;
        }，
 

我写这本基于jQuery的自动完成文件它说的来源需要传递请求和响应回调函数的函数。

查看更多关于一般承诺在这里是如何工作的： http://docs.angularjs.org/ API / NG。$ q

看这是具体如何延长为$ http服务 HTTP：//docs.angularjs。组织/ API / NG。$ HTTP

I have the following code that retrieves user names from the server by making an http call on an autocomplete directive:

var app2 = angular.module('MyModule', []);

app2.directive('autoComplete', function ($timeout) {
    return function (scope, iElement, iAttrs) {
        iElement.autocomplete({
            source: function () {
                //can't call this like so: scope.$apply('getSource'); I get "$apply already in progress error"
                var names = scope.getSource();
                scope.$apply();
                console.log(names);
                return names;
            },
            async:false,
            minLength: 3,
            select: function () {
                $timeout(function () {
                    iElement.trigger('input');
                }, 0);
            }
        });
    };
});

app2.controller('DefaultCtrl', function($scope, $http) {
    $scope.getSource = function() {
        return $http.get('/AccountRequest/GetMatchingEmployeeNames?matchStr=' + $scope.selected)
            .then(function (data) {
                var names = [];
                for (var i = 0; i < data.length; i++) {
                    names.push(data[i].Name);
                }
                return names;
            });
    };
});

I'm trying to use a promise in the autocomplete source: because there's a delay in http method and I get an empty array otherwise. Can anybody please tell me how I can make it work? I don't know how to extract the names array out of the promise function to pass to source:

解决方案

source: function (request,responseCallback) {
            var names = [];
            var promise = scope.getSource();
            promise.success(function(data){
                names = data;
                console.log(names);
                responseCallback(names);
            }).error(function() {
                console.log("some error occurred");
                responseCallback(names);
            });
        },

or maybe

source: function (request,responseCallback) {
            var names = [];
            var promise = scope.getSource();
            promise.then(function(data){
                names = data;
                console.log(names);
                responseCallback(names);
            },function() {
                console.log("some error occurred");
                responseCallback(names);
            });
        },

I'm writing this based on the jQuery autocomplete documentation which says the source takes a function that is passed the request and response callback function.

See more on generally how promises work here: http://docs.angularjs.org/api/ng.$q

See specifically how this is extended for the $http service http://docs.angularjs.org/api/ng.$http

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