angular-i18n-module.js

/*
 Copyright 2014 Loïc Ortola

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

var i18nFilter = function (i18nService) {

    return function () {
        return i18nService.getString(arguments);
    }

}

/** Module declaration */
var i18nModule = angular.module('i18n', ['ngCookies', 'ngSanitize']);


var i18nService = function () {

    /*
     Internationalization i18n container
     language: Retrieve the previously stored language. If none, retrieve language of navigator
     locales:  Declare all locale resource file URI-path, including mandatory "default" entry
     Example:
     locales: {
     'default': '../i18n/resources-locale_en_US.json',
     'en': '../i18n/resources-locale_fr.json'
     }
     */
    this.language = null;
    this.dictionary = [];
    this.loaded = false;
    this.locales = null;

    //SetLocales to init the library
    this.setLocales = function (locales) {
        this.locales = locales;
    };

    this.$get = function ($cookieStore, $http, $window, $sce) {

        var i18nService = {
            i18n: {
                language: null,
                dictionary: this.dictionary,
                loaded: false,
                locales: null
            },

            // Resource loading method
            loadResources: function (url) {
                $http.get(url)
                    .success(function (data) {
                        i18nService.i18n.dictionary = data;
                        i18nService.i18n.loaded = true;
                        console.debug('i18n: locale successfully loaded');
                    })
                    .error(function () {
                        console.error('i18n: Cannot load locale');
                    });
            },

            // Language selection method
            selectLanguage: function (language) {

                i18nService.i18n.language = language;

                console.info("i18n: Selected language:", i18nService.i18n.language);


                // Load selected locale or default if none
                // example:
                // browser language: en_US
                // match "en_US" in locales? no
                // > match "en" in locales? yes
                // (otherwise, default locale will be returned)
                var url = i18nService.i18n.locales['default'];

                if (i18nService.i18n.language in i18nService.i18n.locales) {
                    url = i18nService.i18n.locales[i18nService.i18n.language];
                }
                else {
                    if (i18nService.i18n.language.substr(0, 2) in i18nService.i18n.locales) {
                        url = i18nService.i18n.locales[i18nService.i18n.language.substr(0, 2)];
                    }
                    else {
                        console.log("i18n: Did not find a matching locale resource. Falling back to default");
                    }
                }

                // Save language selection to client's cookie
                $cookieStore.put('locale', i18nService.i18n.language);

                i18nService.loadResources(url);
            },

            // Replace function for parametered localized strings
            replaceArgs: function (val, isConditional, args) {
                var multiParams = false;
                // If we have a plural/conditional string definition, we need to handle the {n} replacement
                if (args.length > 1)
                    if (isConditional) {
                        val = val.replace('{}', args[1]);
                        if (args.length > 2)
                            multiParams = true;
                    }
                    else if (args.length > 1)
                        multiParams = true;

                // Parameters browse for either generic or named parameters
                for (var i = isConditional ? 2 : 1; i < args.length; i++) {
                    // For named parameters
                    if (args[i] instanceof Object)
                        for (var p in args[i])
                            val = val.replace(new RegExp('\\{' + p + '\\}', 'g'), args[i][p]);
                    // For generic parameters, either multi params or not
                    else if (multiParams) {
                        var toReplace = '\\{' + (isConditional ? (i - 1) : i) + '\\}';
                        val = val.replace(new RegExp(toReplace, 'g'), args[i]);
                    }
                    else
                        val = val.replace(new RegExp('\\{\\}', 'g'), args[i]);
                }
                return val;
            },
            // Computed local string retrieval method
            getString: function (args) {
                var input = args[0];
                if (!(args instanceof Object))
                    input = args;

                if (i18nService.i18n.loaded && input in i18nService.i18n.dictionary) {
                    var val = i18nService.i18n.dictionary[input];
                    // For plural/conditional separated entries
                    if (val instanceof Object) {
                        if (val.hasOwnProperty('zero') && (!args[1]  || args[1] == 0))
                            val = val['zero'];
                        else if (val.hasOwnProperty('one') && args[1] == 1)
                            val = val['one'];
                        else if (val.hasOwnProperty('true') && args[1])
                            val = val['true'];
                        else if (val.hasOwnProperty('false') && !args[1])
                            val = val['false'];
                        else if (val.hasOwnProperty('default'))
                            val = val['default'];
                        else
                            console.error("i18n: You need to provide at least a 'default' entry in your lang resources for the conditional property " + input);
                        return this.replaceArgs(val, true, args);
                    }
                    // String replace if arguments supplied
                    return $sce.trustAsHtml(this.replaceArgs(val, false, args));
                }
                else {
                    return input;
                }
            },

            //IsLocaleEmpty to test if locales were set or not
            isLocaleEmpty: function () {
                var locale = i18nService.i18n.locales;
                return i18nService.i18n.locales ? false : true;
            }

        }

        //Init
        i18nService.i18n.language = this.language || $cookieStore.get('locale') || $window.navigator.userLanguage || $window.navigator.language;
        i18nService.i18n.locales = this.locales;
        i18nService.i18n.dictionary = this.dictionary;
        i18nService.selectLanguage(i18nService.i18n.language);

        return i18nService;
    }
}

/** Provider declaration */
i18nModule.provider('i18nService', i18nService);

/** Filter declaration */
i18nModule.filter('i18n', ['i18nService', i18nFilter]);

/** Directive declaration */
i18nModule.directive('i18nLanguageSelector', ['$compile', 'i18nService', function($compile, service){
       return {
           restrict: 'A',
           replace: false,
           terminal: true,
           priority: 1000,
           scope: {
               "i18nLanguageSelector": '='
           },
           compile: function compile(element, attrs){
             element.attr('ng-click', 'select()');
             element.removeAttr('i18n-language-selector');
             element.removeAttr('data-i18n-language-selector');
                return {
                    pre: function preLink(scope, iElement, iAttrs, controller){
                    },
                    post: function postLink(scope, iElement){
                        scope.select = function() {
                            service.selectLanguage(scope.i18nLanguageSelector);
                        }
                        $compile(iElement)(scope);
                    }
                };
           }

       }
}]);