Keywords: Multilanguage, multilingual, bilingual, TsiLang Components Suite

How to build multilingual applications.

There are at least three reasons why most serious programmers need to build multilingual applications:

1. You want to build professional well-distributed software that will be popular all over the world.
2. You have customers in other country with different from your native language.
3. You are in country with two or more state languages.

There are also at least three ways how to build multilingual applications using Delphi:

1. You could use Delphi's Resource DLL Wizard (if you have Delphi 4 or later).
2. You could design your own technology and realize it.
3. You could use third party components and tools that provide way to make your applications multilingual.

Using Delphi's Resource DLL Wizard contains a lot of pros and cons so each developer should decide by himself to use or not this feature of Delphi. There is a lot of documentation in online Delphi help about Resource DLL Wizard so we will discuss only about two other ways.

Before starting to develop your own technology for creating multilingual applications you should analyze two aspects:

1. How much time you'll spend for realizing it?
2. Would it fill all your requests?

Of course, there are strict rules in some companies that require using only self-developed programs that were written without using any third-party code or tools. But you should admit that following this way your company will be always at least one step back from other companies in producing software.

The Delphi component oriented environment allows you to find ready third party component and to use it in your application without spending a lot of time for developing your own. So on my opinion, before creating something by yourself try to check if there are no the same component worldwide available. When you find something that could fulfill your requests you or your manager should analyze what is better for your company:

1. To pay you for your time spent for creating the same component and to stop development of main application while your component will be ready.
2. To buy ready to use component and continue development of main application that is the main target of your development.

If you decided to use your own technology and design for building multilingual application then you could stop reading this article since I couldn't give you any ideas since I don't know what you think.

Now I will describe how to build ready-to-use multilingual application using TsiLang Components Suite that could be downloaded from http://www.sicomponents.com. The last version that was released at this article time was version 4.9.

For starting to use TsiLang Components Suite you should install it in Delphi IDE. If you used setup program and you have Delphi 3 or later then it is already installed in Delphi IDE, otherwise you can read "INSTALL.TXT" file for installation instruction.

We will demonstrate just the few features of TsiLang Components Suite on Richedit example that is included in standard Delphi install set. Lets try to build multilingual application in 16 steps:

1. Open RICHEDIT.DPR project in Delphi.
2. Open TsiLang Expert from Delphi menu. Select "Tools|TsiLang Expert". You will have appeared the TsiLang Expert form with list of project forms available like on picture below:

3. Select main form (MainForm) in the list of forms. You will see that disabled buttons are enabled now. Click on the button with "0" caption (it indicates the number of languages for selected form) and in appeared edit filed input the amount of languages that you need to have in this form. For example 2, we will have bilingual application.

4. Double-click on the MainForm in the list of forms and you will have appeared TsiLang Captions Editor where you can input translation values for components' "Caption" property for second language.

5. Input translation values for second languages. We will have the German as second language of our application and English as primary language.

6. In the same way we can translate all other properties for performing this just click on the buttons on Expert's tool bar.
7. Repeat these actions for second form. After this you will have the situation as presented on picture below:

8. Now we can translate all string constants hard-coded in the source files. Select MainForm and select in Expert's menu "File|Source|With form…". You will have appeared form with all string constants that were found in your unit source.

9. You can delete any constant from this list if you don't want that this constant will be multilingual. Just select the row with this constant and click "Delete" button. As you could see on picture above the first column displays the string ID that will be used for this constant, for equal constants this ID is the same. Second column contains the value of string constant. Third column displays the text that will be placed in your source instead of this constant; you can add here any modifications if you want that they will be placed too. And forth column displays the line of source where this constant was found. As you could see all string constants will be replaced by respective call GetText() method of TsiLang component. This method returns the string value according input string ID in respect with active language of interface. So in our case we will delete rows for IDS_0, IDS_2 and IDS_3 and click "Replace" button.
10. After this all selected string constants will be placed in "Strings" property of TsiLang component placed on form and in your source lines they will be replaced by respective call of GetText() method of TsiLang. So for input translation for these strings just open TsiLang Strings Editor by double-click on "Strings" property of TsiLang in object inspector.
11. For creating real bilingual project replace TSaveDialog, TOpenDialog, TFontDialog and TPrintDialog components to TsiSaveDialog, TsiOpenDialog, TsiFontDialog and TsiPrintDialog components available from "SiDialogs" components palette page. Link them to TsiLang by setting "siLang" property. Open "Standard Dialogs Captions" editor by double-click on "DlgsCaptions" property of TsiLang in Object Inspector and input translations for common dialog strings.
12. Now, place TsiLangDispatcher component on the MainForm (it is available on "SiComponents" components palette page). Set NumOfLanguages property to 2 and input language names in LangNames property (English and German).
13. Select TsiLang component on the form and set LangDispatcher property. You could see that LangNames property of TsiLang was changed respective the same property of TsiLangDispatcher. TsiLangDispatcher component helps to manage the language switching process. Once you change its ActiveLanguage property it changes this property in all TsiLang components linked to this dispatcher.
14. Activate second of form of project (AboutBox), add REMain unit to uses clause of Reabout unit, select TsiLang component on the AboutBox and set LangDispatcher property to TsiLangDispatcher component placed on the main form.
15. Now the last and easiest step, including language switching realization. For example it could be like the following:

• Add in the main menu of main form new top level item called "Language".
• Add two sub-items "English" and "German" to this item. Set "RadioItem" property of these items to TRUE. Set "Checked" property of "English" item to TRUE. Set "Tag" property to "1" for "English" item and "2" for "German" item.
• Select both items and add OnClick event handler. Be sure that you have the same handler for both items. Place the following code in event handler:
  
  procedure TMainForm.German1Click(Sender: TObject);
  begin
  siLangDispatcher1.ActiveLanguage := TComponent(Sender).Tag;
  TMenuItem(Sender).Checked := True;
  end;

16. Compile your project and run it. Now you have multilingual project.

Following this way you will have single executable file with included multilingual support. You don't need any additional files, databases and so on. But you could use TsiLangRT or TsiLangRTSE components instead of TsiLang component if you need to build light multilingual applications. These components allow using external files with stored translation for building multilingual interface. TsiLangRT component contains embedded editor for translations that allows your users to modify and to add new languages to your application without your assistance. TsiLangRTSE uses the COM interface to SIL Editor application included into delivery that allows editing SIL files easy. The SIL Editor application is freeware so you can provide it to your users.

Also you can store your translations in Dictionary Manager that is included in delivery for future utilizing in other project. All TsiLang Editors allow automating the translation process. You can always make automatic translation of your project with translations stored in Dictionary Manager.

As you could see the building multilingual project using TsiLang Components Suite is quite easy and fast. You can find additional information about using TsiLang Components Suite in online help file or on SiComponents home page at http://www.sicomponents.com.