About
This article shows how to create multilingual MVC applications with JS bundles based on various languages. Here,
you will learn about multilingual MVC application implementation flow,
the creation of customized JavaScript bundles with translated alert
messages based on user language, custom HTML helper classes, how to set
user language in a cookie based on his login, displaying resource
translation values in a form and how to maintain names and values in
resource files.
Scenario
You
will implement an MVC application to be displayed in various languages
based on the user selected language. The form content is being displayed
from the resource file based on the name and respective language and it
would need to display the alert kind of information from customized bundled JavaScript based on user language whenever the user has done a form submission or input validation and so on.
RoadMap
When implementing the previous sample MVC application, you will learn the following concepts.
- Resource File creation with key, value pair combination for required language.
- Resource Key value display in a form based on user language.
- Cookie implementation in MVC.
- Bundling and Minification.
- Custom HTML helper class.
- Customized Bundle creation.
- Translate the JavaScript alert messages into user selected language.
- Localized JavaScripts minified and bundled, It helps to increase the performance of form.
Create a new project named “MultilingualMVCApp” and choose the template “MVC” then it creates an MVC template project.
Step 2
Add a new application folder named “App_GlobalResources” to maintain the resource files with key/value pair combinations for various languages.
Right-click on the Project “MultiLingualMVCApp” and select on “Add” and
then select “Add ASP.NET Folder” and then click on
“App_GlobalResources” like the following.
Create
a resource file named “Notifications.resx” for the default language
English by following the following screenshots. Right-click on the
“App_GlobalResources” folder, select “Add” and then click on “Resource
file” and specify the name as “Notifications” and then click on the “Ok”
button.
Click on "Resources File" and provide the name as "Notifications" as shown in the following screenshot.
In the similar way, create another resource file named
“Notifications.fr.resx” under the App_GlobalResources file. After
completion of these aforesaid procedure, the Solution Explorer looks
like the following.
In
this step, you will add sample resource keys with translation values
for English and French languages. For that double click on the
“Notifications.resx” file, then the displayed file has three columns
named Name, Value and Comments.
Name: This name field is treated as the Resource Key value and it should be unique in the file and not be empty.
You can now enter the sample key and respective values as shown in the following screenshot for the default language (English).
In the same way, you can add the same key values, whichever were
specified in the “Notifications.resx” with respective translated values
for the French language in the “Notifications.fr.resx” file is as
follows.
Note: Here, I have used the Google translator to translate the sample English content to French content.
In
the same way, you can add various resource files for different
languages as said and you can add multiple resource types to the resx
files (like strings, images, icons and so on) based on your needs.Step 5
You
can now create one controller named “DemoController” with the following
procedure. Right-click on the “Controllers” folder and select the
“Add” option and click on the “Controller” link.
Click on the "Controller.." link and select the option “MVC 5 Controller – Empty” and then click on the “Add” button. Then, specify the name as “DemoController” then click on the “Add” button.
Now, the controller is created with the default action named “Index” like the following.
Add
a view to the Index action method by right-clicking on the View
function and click on “Add View” and then click on the Ok button. The
following screenshots help you do that.
Click on "Add View..." then it opens a popup like the following.
Now, click on the "Add" button and then it will create an Index.cshtml file.
Step 7
Replace
the existing design with the following design format that contains a
sample form to enter the user name, select the user preferred language
and the submit button.
@{ ViewBag.Title = "Index"; }Demo
@using (Html.BeginForm("Index", "Demo", FormMethod.Post)) {
}
Now, build the application (F6) and run the application (F5) with the following URL (http://localhost:49624/Demo/Index) then the displayed form looks like the following.
In
this step, write a piece of code for the post action of the submit
button to set the user language code in the cookie, the user name in the
TempData object (that helps to send data from one controller request to another) and then redirects to the home page.
[HttpPost] public ActionResult Index(FormCollection collection) { TempData.Add("LoggedInUser", collection["txtName"]); string language = collection["ddlLanguage"]; SetCulture(language); return RedirectToAction("Home"); } ////// Set the culture based on culture code and set the /// value in cookie /// /// private void SetCulture(string cultureCode) { var cookieCultureLanguage = new HttpCookie("UserLanguage") { Value = cultureCode }; Response.Cookies.Set(cookieCultureLanguage); //Sets Culture for Current thread Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.CreateSpecificCulture("en"); //Ui Culture for Localized text in the UI Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(cultureCode); }
The cookie that you have set in the previous code using the method “SetCulture” helps to display the respective user-selected language translated values in a form from the resource file.
Step 9
In this step, add one controller action method named “Home” to the "DemoController.cs" file with the respective view named “Home.cshtml” file.
////// Home Action Controller Method /// ///public ActionResult Home() { return View(); }
Then, right-click on the View() method
in the Home action and then click on "Add View..". After clicking on
“Add View” it opens a template then click on the “Add” button then it
creates a “Home.cshtml” page with default design. You can leave the
design as it is, in later steps you can add the respective design
changes.
Step 10
Add a method named “Application_AcquireRequestState” to the Global.asax.cs file that helps to set the culture based on the user-selected language if the cookie exists else it sets the default culture to English.
////// Application AcquireRequestState /// /// /// protected void Application_AcquireRequestState(object sender, EventArgs e) { string culture; HttpCookie cookie = Request.Cookies["UserLanguage"]; if (cookie != null && cookie.Value != null && cookie.Value.Trim() != string.Empty) culture = cookie.Value; else culture = "en"; //Default Language/Culture for all number, Date format System.Threading.Thread.CurrentThread.CurrentCulture = System.Globalization.CultureInfo.CreateSpecificCulture("en"); //Ui Culture for Localized text in the UI System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(culture); }
Step 11
In
this step, you will implement a customized JavaScript bundle translator
class. It helps to bundle the JavaScript with the respective
user-selected language translated messages if any exists in the
JavaScript file like alert, input validation messages and so on.
So,
first create a new folder named “ResourceHandler”. For that right-click
on the project “MultiLingualMVCApp” then select “Add” and click on “Add
New Folder” and provide the name as “ResourceHandler” and then add a
class file “JSTranslator” under the newly created folder
"ResourceHandler".
using System.Text.RegularExpressions; using System.Web; using System.Web.Optimization; namespace MultiLingualMVCApp.ResourceHandler { public class JSTranslator : IBundleTransform { #region IBundleTransform ////// IBundleTransform Process method /// /// Bundle Context /// Bundle Response public void Process(BundleContext context, BundleResponse response) { string translated = ScriptTranslator(response.Content); response.Content = translated; } #endregion #region Localization Of Js Bundle Flow private static readonly Regex Regex = new Regex(@"GetResourceValue\(([^\))]*)\)", RegexOptions.Singleline | RegexOptions.Compiled); ////// Translated script based on JavaScript content /// /// ///private string ScriptTranslator(string text) { MatchCollection matches = Regex.Matches(text); foreach (Match match in matches) { object obj = HttpContext.GetGlobalResourceObject("Notifications", match.Groups[1].Value); if (obj != null) text = text.Replace(match.Value, CleanText(obj.ToString())); } return text; } /// /// Format the text as Clean while displaying /// in JavaScript notifications /// /// ///private static string CleanText(string text) { text = text.Replace("'", ""); return text; } #endregion } }
About JSTranslator.cs code
- The JsTranslator class is inherited from the “IbundleTransform”.
- The Process method is implemented, as it just gets the BundleResponse content and translates the JavaScript with user-selected language alerts, if any, using the ScriptTranslator method and will be assigned back to that content to the BundleResonse.
- The Regex expression is the key term we used in script files, based on that formatted the regex expression.
- The Regex Key Term example, you used in scripts is: GetResourceValue(ResourceKeyName)
- The ScriptTranslator method first gets the MatchCollection object based on regex expression and then based on the Match collection key name get the translated value using the method “GetGlobalResourceObject”
- The GetGlobalResourceObject takes the parameters of Resource file name and Resource Key name.
- The CleanText method helps to clean if any characters that creates a problem when displaying in JavaScript.
So, you have now successfully added a custom JavaScript bundle class.
Step 12
In this step, you will add two JavaScript files with sample functions under the “Scripts” folder.
The first JavaScript file named “UserNotifications” file. It contains the following function.
function UserTermsNotification() { alert('GetResourceValue(UserTermsDisplayNotification)'); }
The second JavaScript file is named “UserOperations”. It contains the following functions.
function AddUserMessage() { alert('GetResourceValue(UserAdded)'); } function DeleteUserMessage() { alert('GetResourceValue(UserDeleted)'); }
Step 13
In this step, you will bundle the previously created JavaScript files in BundleConfig.cs (that exists in the App_Start
folder) using a custom JavaScript bundle that you have created in the
JSTranslator.cs file. So, add the following code block to the RegisterBundles method and also add the required namespaces; those are:
using System.Collections.Generic;
using MultiLingualMVCApp.ResourceHandler;
using MultiLingualMVCApp.ResourceHandler;
using System.Web; namespace MultiLingualMVCApp { public class HtmlHelpers { ////// Localized JavaScript bundle /// /// ///public static HtmlString LocalizedJsBundle(string fileName) { string culture; var cookie = HttpContext.Current.Request.Cookies["UserLanguage"]; if (cookie != null && cookie.Value != null && cookie.Value.Trim() != string.Empty) culture = cookie.Value; else culture = "en"; fileName = string.Concat(fileName, "-", culture); var output = (HtmlString)System.Web.Optimization.Scripts .Render(fileName); return output; } } }
Step 14
In
this step, you will implement the custom HTML helper class that helps
to create a custom JavaScript bundle based on your needs. So, add a new
class file named HtmlHelpers under the App_Start folder and then replace that with the following code.
using System.Web; namespace MultiLingualMVCApp { public class HtmlHelpers { ////// Localized JavaScript bundle /// /// ///public static HtmlString LocalizedJsBundle(string fileName) { string culture; var cookie = HttpContext.Current.Request.Cookies["UserLanguage"]; if (cookie != null && cookie.Value != null && cookie.Value.Trim() != string.Empty) culture = cookie.Value; else culture = "en"; fileName = string.Concat(fileName, "-", culture); var output = (HtmlString)System.Web.Optimization.Scripts .Render(fileName); return output; } } }
In the aforesaid Steps 13 and 14, you have included the custom JavaScript bundle in the BundleConfig.cs file and created a custom HTML helper class to use that specified language bundle based on the user-selected language.
The
Bundling and Minification concept is very helpful to reduce the network
traffic and file size while loading the form since it minifies the
multiple JavaScript files into one file and the file is being cached. If
you change the file content then it automatically gets the fresh
content with a new version number. So it helps to increase the page
performance in all aspects.
Step 15
In this step, you update the “Home.cshtml” form design with the following design.
You are done with the multi-language MVC application implementation
process with user language-specific JavaScript bundled minified files. So, build the application (F6) and hit the (F5) key to run the application with the following URL (http://localhost:49624/Demo/Index).
Enter the user name and select the preferred language as English then the form will be displayed like the following.
Now, click on the Submit button then it navigates to the home page like the following.
The preceding page is self-explanatory about the implemented
functionality. In the similar way when you click on the "Add User" and
"Delete User" buttons then it displays the alerts in the English
language.
In this step, again you navigate to this URL (http://localhost:49624/Demo/Index) and select the user language as French and check the respective outputs as shown below.
Now, click on the "Submit" button, then it navigates to the home page.
The preceding page is self-explanatory
about the implemented functionality. In the similar way when you click
on the "Add User" and "Delete User" buttons then it displays the alerts
in the French language.
You can download the preceding discussed sample project at Source Code.
Conclusion
I
hope this article provides an idea of the implementation of
multilingual MVC application flow, creation of customized JavaScript
bundles with translated alert messages based on user language, custom
HTML helper classes, how to set user language in a cookie based on his
login, Displaying Resource translation values in a form and how to
maintain names and values in resource files.
Hi, Ramchand! If you're interested in tools that can help manage localization projects using resx files, know that you can use this collaborative online translation app, it has a very well-designed interface: https://poeditor.com/
ReplyDeleteGood Post! Thank you so much for sharing this pretty post, it was so good to read and useful to improve my knowledge as updated one, keep blogging.
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