这可能听起来像一个非常简单/愚蠢的问题，但我需要问它，因为我之前没有遇到过这种情况......好吧我在angularJS应用程序中有服务。 此服务目前包含4个方法，所有方法都执行80％相同的功能/代码，我希望提高效率。 这是我的服务的样子（删除了大量代码）：
.factory('townDataService', function ($http) { var townList = {}; townList.getTownList = function () { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated CODE return returnArray; // this is array, we don't do any formatting here }); }; townList.getCurrentTown = function (place) { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated code // now the format further / work with the returnArray... for (var i = 0; i < returnArray.length; i++) { // do stuff } return currentTown; // this is a string }); }; townList.getCurrentCountry = function (place) { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated code // now the format further / work with the returnArray... for (var i = 0; i < returnArray.length; i++) { // do stuff } return currentCountry; // this is a string }); }; return townList; } ) ;现在我在返回对象数组或字符串之前，在每个方法和相同的格式代码（这是很多嵌套循环）中重复相同的$http 'GET' 。 这远远没有效果！ 将此功能放入其自身功能的最佳方法是什么，所以我们只调用一次GET url但仍然返回每个方法的承诺？ 我应该将$http({method: 'GET', url: '/api/country/cities'})为var并在必要时格式化数据之前将其注入/传递到每个方法中吗？ 我应该使用某种$cacheFactory吗？
对不起，如果这是一个愚蠢的问题，如果我没有很好地解释自己，我会重新解释这些问题。
提前致谢。
This may sound like a really simply/stupid question but I need to ask it as I haven't came across this scenario before... okay I have a service in my angularJS app. this service currently contains 4 methods that all perform 80% the same functionality/code and I wish to make this more efficient. Here is what my service looks like (with a lot of code removed):
.factory('townDataService', function ($http) { var townList = {}; townList.getTownList = function () { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated CODE return returnArray; // this is array, we don't do any formatting here }); }; townList.getCurrentTown = function (place) { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated code // now the format further / work with the returnArray... for (var i = 0; i < returnArray.length; i++) { // do stuff } return currentTown; // this is a string }); }; townList.getCurrentCountry = function (place) { return $http({method: 'GET', url: '/api/country/cities'}) .then(function (response) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = []; // loop through the countries var JsonData = response.data; for (key in JsonData['countries']) { // formatting code... } // end of repeated code // now the format further / work with the returnArray... for (var i = 0; i < returnArray.length; i++) { // do stuff } return currentCountry; // this is a string }); }; return townList; } ) ;Now I repeat the same $http 'GET' in each method and the same formatting code (which is a lot of nested loops) before returning a object array or a string. This is far from efficent! What is the best way to put this functionality into it's own function so we only call the GET url once but still return a promise with each method? Should I set the results of the $http({method: 'GET', url: '/api/country/cities'}) as a var and inject / pass it into each method before formatting the data if necessary? Should I use some sort of $cacheFactory?
Sorry if this is a dumb question and if I haven't explained myself well I shall rephrase the questions.
Thanks in advance.
最满意答案
就像你说的那样; 这段代码可以（并且应该）以多种方式进行重构。 一个例子：
让我们将HTTP内容分解为一个单独的服务，它也将负责缓存。 （另一个想法是为HTTP /远程调用提供服务，另一个 - 也许是一般用途装饰器 - 来处理缓存。现在我们不要详细介绍。）让我们把格式化代码放入另一种方法：
远程呼叫服务：
.service('townHttpService', function($http, $q) { var cache; function getCities() { var d = $q.defer(); if( cache ) { d.resolve(cache); } else { $http({method: 'GET', url: '/api/country/cities'}).then( function success(response) { cache = response.data; d.resolve(cache); }, function failure(reason) { d.reject(reason); } }); } return d.promise; } function clearCache() { cache = null; } return { getCities: getCities, clearCache: clearCache }; })格式化程序：
.service('townFormatter', function() { return function townFormatter(jsonData) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = [], key; // loop through the countries for (key in jsonData['countries']) { // formatting code... } // end of repeated CODE return returnArray; // this is array, we don't do any formatting here }; })您的townDataService ，以上述方式编写：
.factory('townDataService', function (townHttpService, townFormatter) { var townList = {}; townList.getTownList = function () { return townHttpService.getCities().then(townFormatter); }; townList.getCurrentTown = function (place) { return townHttpService.getCities().then(townFormatter).then(function(cityList) { var currentTown; for (var i = 0; i < cityList.length; i++) { // do stuff } return currentTown; // this is a string }); }; townList.getCurrentCountry = function (place) { return townHttpService.getCities().then(townFormatter).then(function(cityList) { var currentCountry; for (var i = 0; i < cityList.length; i++) { // do stuff } return currentCountry; // this is a string }); return townList; })It is just as you say; this code can (and should) be refactored in many ways. One example:
Let us factor the HTTP stuff into a separate service, that will also take care of caching. (Another idea for this would be to have a service for the HTTP/remote calls and another - maybe a general use decorator - to handle caching. LEt us not go into so much detail for now.) And let us put the formatting code in another method:
The remote call service:
.service('townHttpService', function($http, $q) { var cache; function getCities() { var d = $q.defer(); if( cache ) { d.resolve(cache); } else { $http({method: 'GET', url: '/api/country/cities'}).then( function success(response) { cache = response.data; d.resolve(cache); }, function failure(reason) { d.reject(reason); } }); } return d.promise; } function clearCache() { cache = null; } return { getCities: getCities, clearCache: clearCache }; })The formatter:
.service('townFormatter', function() { return function townFormatter(jsonData) { // HERE WE FORMAT THE response as desired... that creates a returnArray var returnArray = [], key; // loop through the countries for (key in jsonData['countries']) { // formatting code... } // end of repeated CODE return returnArray; // this is array, we don't do any formatting here }; })Your townDataService, written in terms of the above:
.factory('townDataService', function (townHttpService, townFormatter) { var townList = {}; townList.getTownList = function () { return townHttpService.getCities().then(townFormatter); }; townList.getCurrentTown = function (place) { return townHttpService.getCities().then(townFormatter).then(function(cityList) { var currentTown; for (var i = 0; i < cityList.length; i++) { // do stuff } return currentTown; // this is a string }); }; townList.getCurrentCountry = function (place) { return townHttpService.getCities().then(townFormatter).then(function(cityList) { var currentCountry; for (var i = 0; i < cityList.length; i++) { // do stuff } return currentCountry; // this is a string }); return townList; })更多推荐
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