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javascriptangularjsangular-translate

How to fix angular-translate FOUC issues while using translatePartialLoader?


I've been experiencing FOUC (flash of untranslated content) issues while using angular-translate. This is my setup:

.config(function ($translateProvider, defaultI18n) {
    $translateProvider
        .useSanitizeValueStrategy('sanitize')
        .translations('en-GB', defaultI18n.en)
        .useCookieStorage()
        .useLoader('$translatePartialLoader', {
            urlTemplate: '/{part}/{lang}.json'
        })
        .preferredLanguage('en-GB')
        .fallbackLanguage('en-GB');
})
.run(function ($rootScope, $translate) {
    $rootScope.$on('$translatePartialLoaderStructureChanged', function () {
        $translate.refresh();
});

Since I'm using $translatePartialLoader in each controller view I have:

.controller('SomeController', function ($translatePartialLoader) {
    $translatePartialLoader.addPart('path-to-some-view-i18n');
})

If I remove $translate.refresh() FOUC goes away, but the text isn't updated with the new locale. Not sure if having text in my HTML files maybe causing a conflict here.

How can I remove FOUC completely but still keeping the app translating correctly?

Should I remove all text from my HTML files?

Thanks in advance.


Solution

  • I changed the logic a bit and the FOUC issues seem to disappear. Instead of executing $translatePartialLoader.addPart('path-to-some-view-i18n'); in each controller, I defined for each state the respective i18n route(s) like this:

    .state('state1', {
        url: '/state1',
        templateUrl: 'path-to-some-view',
        data: {
            i18n: ['path-to-some-view-i18n']
        }
    })
    

    And then, when the event $stateChangeStart is triggered:

    .run(function ($rootScope, $translate, $translatePartialLoader) {
        $rootScope.$on('$stateChangeStart', function (event, toState, toParams, fromState, fromParams) {
            if(toState.data.i18n) {
                angular.forEach(toState.data.i18n, function (value) {
                    $translatePartialLoader.addPart(value);
                });
            }
        });
    
        $rootScope.$on('$translatePartialLoaderStructureChanged', function () {
            $translate.refresh();
        });
    });