Vmeda.Online/src/providers/lang.ts

347 lines
13 KiB
TypeScript

// (C) Copyright 2015 Martin Dougiamas
//
// 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.
import { Injectable } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';
import * as moment from 'moment';
import { Globalization } from '@ionic-native/globalization';
import { Platform } from 'ionic-angular';
import { CoreConfigProvider } from './config';
import { CoreConfigConstants } from '../configconstants';
/*
* Service to handle language features, like changing the current language.
*/
@Injectable()
export class CoreLangProvider {
protected fallbackLanguage = 'en'; // Always use English as fallback language since it contains all strings.
protected defaultLanguage = CoreConfigConstants.default_lang || 'en'; // Lang to use if device lang not valid or is forced.
protected currentLanguage: string; // Save current language in a variable to speed up the get function.
protected customStrings = {}; // Strings defined using the admin tool.
protected customStringsRaw: string;
protected sitePluginsStrings = {}; // Strings defined by site plugins.
constructor(private translate: TranslateService, private configProvider: CoreConfigProvider, platform: Platform,
private globalization: Globalization) {
// Set fallback language and language to use until the app determines the right language to use.
translate.setDefaultLang(this.fallbackLanguage);
translate.use(this.defaultLanguage);
platform.ready().then(() => {
this.getCurrentLanguage().then((language) => {
translate.use(language);
moment.locale(language);
});
});
}
/**
* Add a set of site plugins strings for a certain language.
*
* @param {string} lang The language where to add the strings.
* @param {any} strings Object with the strings to add.
* @param {string} [prefix] A prefix to add to all keys.
*/
addSitePluginsStrings(lang: string, strings: any, prefix?: string): void {
// Initialize structure if it doesn't exist.
if (!this.sitePluginsStrings[lang]) {
this.sitePluginsStrings[lang] = {};
}
for (const key in strings) {
const prefixedKey = prefix + key;
let value = strings[key];
if (this.customStrings[lang] && this.customStrings[lang][prefixedKey]) {
// This string is overridden by a custom string, ignore it.
continue;
}
// Replace the way to access subproperties.
value = value.replace(/\$a->/gm, '$a.');
// Add another curly bracket to string params ({$a} -> {{$a}}).
value = value.replace(/{([^ ]+)}/gm, '{{$1}}');
// Make sure we didn't add to many brackets in some case.
value = value.replace(/{{{([^ ]+)}}}/gm, '{{$1}}');
// Load the string.
this.loadString(this.sitePluginsStrings, lang, prefixedKey, value);
}
}
/**
* Change current language.
*
* @param {string} language New language to use.
* @return {Promise<any>} Promise resolved when the change is finished.
*/
changeCurrentLanguage(language: string): Promise<any> {
const promises = [];
// Change the language, resolving the promise when we receive the first value.
promises.push(new Promise((resolve, reject): void => {
const subscription = this.translate.use(language).subscribe((data) => {
resolve(data);
// Data received, unsubscribe. Use a timeout because we can receive a value immediately.
setTimeout(() => {
subscription.unsubscribe();
});
}, (error) => {
reject(error);
// Error received, unsubscribe. Use a timeout because we can receive a value immediately.
setTimeout(() => {
subscription.unsubscribe();
});
});
}));
// Change the config.
promises.push(this.configProvider.set('current_language', language));
moment.locale(language);
this.currentLanguage = language;
return Promise.all(promises).finally(() => {
// Load the custom and site plugins strings for the language.
if (this.loadLangStrings(this.customStrings, language) || this.loadLangStrings(this.sitePluginsStrings, language)) {
// Some lang strings have changed, emit an event to update the pipes.
this.translate.onLangChange.emit({lang: language, translations: this.translate.translations[language]});
}
});
}
/**
* Clear current custom strings.
*/
clearCustomStrings(): void {
this.unloadStrings(this.customStrings);
this.customStrings = {};
this.customStringsRaw = '';
}
/**
* Clear current site plugins strings.
*/
clearSitePluginsStrings(): void {
this.unloadStrings(this.sitePluginsStrings);
this.sitePluginsStrings = {};
}
/**
* Get all current custom strings.
*
* @return {any} Custom strings.
*/
getAllCustomStrings(): any {
return this.customStrings;
}
/**
* Get all current site plugins strings.
*
* @return {any} Site plugins strings.
*/
getAllSitePluginsStrings(): any {
return this.sitePluginsStrings;
}
/**
* Get current language.
*
* @return {Promise<string>} Promise resolved with the current language.
*/
getCurrentLanguage(): Promise<string> {
if (typeof this.currentLanguage != 'undefined') {
return Promise.resolve(this.currentLanguage);
}
// Get current language from config (user might have changed it).
return this.configProvider.get('current_language').then((language) => {
return language;
}).catch(() => {
// User hasn't defined a language. If default language is forced, use it.
if (CoreConfigConstants.default_lang && CoreConfigConstants.forcedefaultlanguage) {
return CoreConfigConstants.default_lang;
}
try {
// No forced language, try to get current language from cordova globalization.
return this.globalization.getPreferredLanguage().then((result) => {
let language = result.value.toLowerCase();
if (language.indexOf('-') > -1) {
// Language code defined by locale has a dash, like en-US or es-ES. Check if it's supported.
if (CoreConfigConstants.languages && typeof CoreConfigConstants.languages[language] == 'undefined') {
// Code is NOT supported. Fallback to language without dash. E.g. 'en-US' would fallback to 'en'.
language = language.substr(0, language.indexOf('-'));
}
}
if (typeof CoreConfigConstants.languages[language] == 'undefined') {
// Language not supported, use default language.
return this.defaultLanguage;
}
return language;
}).catch(() => {
// Error getting locale. Use default language.
return this.defaultLanguage;
});
} catch (err) {
// Error getting locale. Use default language.
return Promise.resolve(this.defaultLanguage);
}
}).then((language) => {
this.currentLanguage = language; // Save it for later.
return language;
});
}
/**
* Load certain custom strings.
*
* @param {string} strings Custom strings to load (tool_mobile_customlangstrings).
*/
loadCustomStrings(strings: string): void {
if (strings == this.customStringsRaw) {
// Strings haven't changed, stop.
return;
}
// Reset current values.
this.clearCustomStrings();
if (!strings) {
return;
}
const list: string[] = strings.split(/(?:\r\n|\r|\n)/);
list.forEach((entry: string) => {
const values: string[] = entry.split('|');
let lang: string;
if (values.length < 3) {
// Not enough data, ignore the entry.
return;
}
lang = values[2];
if (!this.customStrings[lang]) {
this.customStrings[lang] = {};
}
// Convert old keys format to new one.
const key = values[0].replace(/^mm\.core/, 'core').replace(/^mm\./, 'core.').replace(/^mma\./, 'addon.')
.replace(/^core\.sidemenu/, 'core.mainmenu').replace(/^addon\.grades/, 'core.grades')
.replace(/^addon\.participants/, 'core.user');
this.loadString(this.customStrings, lang, key, values[1]);
});
this.customStringsRaw = strings;
}
/**
* Load custom strings for a certain language that weren't loaded because the language wasn't active.
*
* @param {any} langObject The object with the strings to load.
* @param {string} lang Language to load.
* @return {boolean} Whether the translation table was modified.
*/
loadLangStrings(langObject: any, lang: string): boolean {
let langApplied = false;
if (langObject[lang]) {
for (const key in langObject[lang]) {
const entry = langObject[lang][key];
if (!entry.applied) {
// Store the original value of the string.
entry.original = this.translate.translations[lang][key];
// Store the string in the translations table.
this.translate.translations[lang][key] = entry.value;
entry.applied = true;
langApplied = true;
}
}
}
return langApplied;
}
/**
* Load a string in a certain lang object and in the translate table if the lang is loaded.
*
* @param {any} langObject The object where to store the lang.
* @param {string} lang Language code.
* @param {string} key String key.
* @param {string} value String value.
*/
loadString(langObject: any, lang: string, key: string, value: string): void {
if (this.translate.translations[lang]) {
// The language is loaded.
// Store the original value of the string.
langObject[lang][key] = {
original: this.translate.translations[lang][key],
value: value,
applied: true
};
// Store the string in the translations table.
this.translate.translations[lang][key] = value;
} else {
// The language isn't loaded.
// Save it in our object but not in the translations table, it will be loaded when the lang is loaded.
langObject[lang][key] = {
value: value,
applied: false
};
}
}
/**
* Unload custom or site plugin strings, removing them from the translations table.
*
* @param {any} strings Strings to unload.
*/
protected unloadStrings(strings: any): void {
// Iterate over all languages and strings.
for (const lang in strings) {
if (!this.translate.translations[lang]) {
// Language isn't loaded, nothing to unload.
continue;
}
const langStrings = strings[lang];
for (const key in langStrings) {
const entry = langStrings[key];
if (entry.original) {
// The string had a value, restore it.
this.translate.translations[lang][key] = entry.original;
} else {
// The string didn't exist, delete it.
delete this.translate.translations[lang][key];
}
}
}
}
}