angularjs ng-repeat the dropdown values from diffe

问题:

Here is an example json i18n language file for English:

{
  "project": {
    "SPONSORINFO": {
      "MAIN" : "Select the Sponsor Name",
      "SPONSORLIST": [
        {"spons" :"SponsorName 1" },
        {"spons" :"SponsorName 2" }
      ]
    }
  }
}

and here is my html view:

<div class="form-group" >
    <label for="form-field-select-1" translate="project.SPONSORINFO.MAIN">
    </label>
    <select class="form-control"  ng-model="myModel.sponsors">
       <option ng-repeat="s in projectJSON.project.SPONSORINFO.SPONSORLIST" value="{{s.spons}}">{{s.spons | translate}}</option>
    </select>
</div>

The translate="project.SPONSORINFO.MAIN" in the label is rightly showing the value "Select the Sponsor Name" as soon as the language toggle is clicked (no refresh is needed).

Question:

I am using the following function in my view controller to load the language file based on the selected language and pass it into $scope.projectJSON so that I can call it in ng-repeat in my html view:

var lang = $translate.use();
$http.get('assets/i18n/'+lang+'.json').success(function(data) {
    $scope.projectJSON= data;
});

The problem is that after toggling the language, the dropdown menus don't get changed to the selected language unless I refresh or change view and come back. How can I fix this issue so that it works like the label?

annex:

Translation global config in my main.js like the following:

app.config(['$translateProvider',
function ($translateProvider) {

    // prefix and suffix information  is required to specify a pattern
    // You can simply use the static-files loader with this pattern:
    $translateProvider.useStaticFilesLoader({
        prefix: 'assets/i18n/',
        suffix: '.json'
    });

    // Since you've now registered more then one translation table, angular-translate has to know which one to use.
    // This is where preferredLanguage(langKey) comes in.
    $translateProvider.preferredLanguage('en');

    // Store the language in the local storage
    $translateProvider.useLocalStorage();

}]);

translation config in my mainCtrl.js:

app.controller('AppCtrl', ['$rootScope', '$scope', '$state', '$translate', 
function ($rootScope, $scope, $state, $translate) {

    $scope.language = {
        // Handles language dropdown
        listIsOpen: false,
        // list of available languages
        available: {
            'en': 'English',
            //'it_IT': 'Italiano',
            'de_DE': 'Deutsch'
        },
        // display always the current ui language
        init: function () {
            var proposedLanguage = $translate.proposedLanguage() || $translate.use();
            var preferredLanguage = $translate.preferredLanguage();
            // we know we have set a preferred one in app.config
            $scope.language.selected = $scope.language.available[(proposedLanguage || preferredLanguage)];
        },
        set: function (localeId, ev) {
            $translate.use(localeId);
            $scope.language.selected = $scope.language.available[localeId];
            $scope.language.listIsOpen = !$scope.language.listIsOpen;
        }
    };

    $scope.language.init();

回答1:

You are iterating array from translation json file. This translation json file is loaded by $translate service and you will not have access on loaded content, but you need the data from this json file to iterate it, thus you have to make your own request to fetch this array. Maybe you do not want but you have to make $http.get call.

In your code one request is made by executing this line var lang = $translate.use(newLang); and second call is done by $http.get BUT in case if $http.get is resolved before call in $translate.use is resolved It will not translate content in dropdown because request in $translate.use is not resolved yet and $translate service does not have these translations to translate.

What you can do is to listen on $translateChangeSuccess event (emitted by $translate service) on $rootScope and then make your ajax call in this handler.

I have tested the following code in your example and it works fine.

[UPDATED]

$rootScope.$on('$translateChangeSuccess', function () {
  // Get new current new language
  var lang = $translate.use();
  $http.get('assets/i18n/'+lang+'.json').success(function(data) {
    $scope.projectJSON = data;
  });
});

For detailed explanation about events section on angular translate module, checkout this link.

Whenever you call $translate.use(localeId) it will make ajax call internally and when this call is resolved it will emit $translateChangeSuccess event, then you make your request, load data and update $scope.projectJSON.
The only thing is to trigger this event first time, when you refresh browser, when $translate.use is not called.

For this you can just call $translate.use one time on page reload.

[UPDATED]

Put the following code at the end of your $scope.language.init function.

$translate.use(proposedLanguage || preferredLanguage);

This should solve your problem.

回答2:

Try to use promise pattern:

$http.get(..).then(function(response){..})

So, looks like problem not in ng-repeat, so I would change the title of the question. Back to the subject:

$http.get('assets/i18n/'+lang+'.json').then(function(response) {
    //check what exactly are you getting in the response
    //console.log(response)
    $scope.projectJSON = response;
});

And I would check what is the response actually, probably, you need to do

$scope.projectJSON = response.data;

回答3:

Old

Because you are using an async function angular won't recognize the change immediately. After downloading the files add

$scope.$apply();

To make angular rescan everything and apply changes. Here you can read more about it.

That means for you ($$phase check by @lascort)

$http.get('assets/i18n/'+lang+'.json').success(function(data) {
$scope.projectJSON= data;
$translate.use(lang);
if (!$scope.$$phase)
    $scope.$apply();
  $translate.refresh();
});

Edit

But official resources recommend to use their loaders and not load manually: Here

You are using a staticFilesLoader so install the following extension:

bower install angular-translate-loader-static-files

Then in your language change function:

$translateProvider.preferredLanguage(lang);

This should work (says the documentation). Maybe you have to do a $scope.$apply(); but I think this is already included.

回答4:

Lets go through step by step:
1) The translate="project.SPONSORINFO.MAIN" in the label is rightly showing the value "Select the Sponsor Name" without refresh needed
2) the dropdown menus don't get changed to the selected language unless you refresh or change view and come back.

So, the toggle for translation is actually working.

But why it does not work for dropdown menus? One thing we can note is that label for project.SPONSORINFO.MAIN is a static text while s.spons is dynamic based on value return.

The select option is being compiled first time when entering the page and not being recompiled after you toggle your languages changes. As such, when you toggle the translation, you retrieve the text, but the select option element is not being recompiled and thus not being translated on the fly till your next reentering/reload of the view.

You have few ways to solve the problem:
1) programmitically refresh the state/route once translate is complete. (quick fix but bad way)
2) Write an angular directive that recompile the element once detect language changes. (better approach)

An idea of how to achieve second solution:

var lang = $translate.use();
$http.get('assets/i18n/'+lang+'.json').success(function(data) {
    $scope.projectJSON= data;
    $scope.newLanguage = $translate.use();
});

.directive('recompileLanguage', function($compile) {
  return {
    restrict: 'E',
    scope: {
      lang: '='
    },
    link: function(scope, element, attr) {
      $compile(element.contents())(scope);
      scope.$watch('lang', funcion (newValue, oldvalue) {
        $compile(element.contents())(scope);
      });
    }
  }
});

<select recompile-language lang={{newLanguage}}> </select>

回答5:

Have you tried reloading the state?

$state.reload();

app.controller('AppCtrl', ['$rootScope', '$scope', '$state', '$translate', function ($rootScope, $scope, $state, $translate) {

$scope.language = {
    // Handles language dropdown
    listIsOpen: false,
    // list of available languages
    available: {
        'en': 'English',
        //'it_IT': 'Italiano',
        'de_DE': 'Deutsch'
    },
    // display always the current ui language
    init: function () {
        var proposedLanguage = $translate.proposedLanguage() || $translate.use();
        var preferredLanguage = $translate.preferredLanguage();
        // we know we have set a preferred one in app.config
        $scope.language.selected = $scope.language.available[(proposedLanguage || preferredLanguage)];
    },
    set: function (localeId, ev) {
        $translate.use(localeId);
        $scope.language.selected = $scope.language.available[localeId];
        $scope.language.listIsOpen = !$scope.language.listIsOpen;
    },
    uiReload: function(){
      $state.reload();
    }
};

$scope.language.init();
$scope.language.uiReload();    //call this for ui-router