I'm using angular-translate for i18n in an AngularJS application.
For every application view, there is a dedicated controller. In the controllers below, I set the value to be shown as the page title.
<h1>{{ pageTitle }}</h1>
.controller('FirstPageCtrl', ['$scope', '$filter', function ($scope, $filter) {
$scope.pageTitle = $filter('translate')('HELLO_WORLD');
}])
.controller('SecondPageCtrl', ['$scope', '$filter', function ($scope, $filter) {
$scope.pageTitle = 'Second page title';
}])
I'm loading the translation files using the angular-translate-loader-url extension.
On the initial page load, the translation key is shown instead of the translation for that key. The translation is Hello, World!
, but I'm seeing HELLO_WORLD
.
The second time I go to the page, all is well and the translated version is shown.
I assume the issue has to do with the fact that maybe the translation file is not yet loaded when the controller is assigning the value to $scope.pageTitle
.
When using <h1>{{ pageTitle | translate }}</h1>
and $scope.pageTitle = 'HELLO_WORLD';
, the translation works perfect from the first time. The problem with this is that I don't always want to use translations (eg. for the second controller I just want to pass a raw string).
Is this a known issue / limitation? How can this be solved?
I'd recommend to keep your controller free from translation logic and translate your strings directly inside your view like this:
<h1>{{ 'TITLE.HELLO_WORLD' | translate }}</h1>
Angular Translate provides the $translate
service which you can use in your Controllers.
An example usage of the $translate
service can be:
.controller('TranslateMe', ['$scope', '$translate', function ($scope, $translate) {
$translate('PAGE.TITLE')
.then(function (translatedValue) {
$scope.pageTitle = translatedValue;
});
});
The translate service also has a method for directly translating strings without the need to handle a promise, using $translate.instant()
:
.controller('TranslateMe', ['$scope', '$translate', function ($scope, $translate) {
$scope.pageTitle = $translate.instant('TITLE.DASHBOARD'); // Assuming TITLE.DASHBOARD is defined
});
The downside with using $translate.instant()
could be that the language file isn't loaded yet if you are loading it async.
This is my preferred way since I don't have to handle promises this way. The output of the filter can be directly set to a scope variable.
.controller('TranslateMe', ['$scope', '$filter', function ($scope, $filter) {
var $translate = $filter('translate');
$scope.pageTitle = $translate('TITLE.DASHBOARD'); // Assuming TITLE.DASHBOARD is defined
});
Since @PascalPrecht is the creator of this awesome library, I'd recommend going with his advise (see his answer below) and use the provided directive which seems to handle translations very intelligent.
The directive takes care of asynchronous execution and is also clever enough to unwatch translation ids on the scope if the translation has no dynamic values.