TweetFollow Us on Twitter

Oct 97 - Getting Started

Volume Number: 13 (1997)
Issue Number: 10
Column Tag: Getting Started

OPENSTEP Localization

by Dave Mark, ©1997, All Rights Reserved

One of the strengths of the Mac OS is the way it handles localization. For example, pulling the strings out of your application and storing them as resources makes the app relatively simple to translate into another language. Of course there's more to localization than that, but the point is, the Mac OS supports an underlying mechanism that makes localization possible. Fortunately, OPENSTEP (and presumably Rhapsody) features a similar mechanism that greatly simplifies the localization process.

A Localization Example

Let's start off with a look at an existing application that takes advantage of the OPENSTEP localization mechanism.

  • In the Workspace, navigate into the directory:
/NextDeveloper/Examples/AppKit/TextEdit/English.lproj

These files are all part of the TextEdit ProjectBuilder project. Among the files in this directory, you'll find a series of nib files including one named FindPanel.nib. Each nib file implements a portion of the user interface. For example, the file Info.nib contains the specs for the TextEdit info panel (NeXTSpeak for about box).FindPanel.nib contains the specs for the Find panel.

In the same directory, you'll also notice a pair of files named Localizable.strings and FindPanel.strings. The collection of .strings files act as a repository for all the text strings embedded in the TextEdit source code. These files are created at build-time in response to a set of function calls you'll place in your code. Before we get to the functions, take a closer look at these files.

  • Double-click on the file Localizable.strings.

The file will open in Edit. As you scroll through the file, you'll notice that it consists of pairs of C comments and assignment statements. Here's an example:

/* Menu item to make the current document rich text */
"&Make Rich Text" = "&Make Rich Text";

Though this may look like some sick C code, this is really just a database of strings, where each entry consists of a comment, followed by a left side and right side pair of strings. The left side is the default string, which you'll specify in your code. The right side is the version of this string used by this particular language. This example specifies the text to use in the TextEdit menu item that specifies RTF (rich text format). The left side is the string that appeared in the source code, presumably done in the native language of the programmer. The right string is the localized string. Since we are in the directory English.lproj, the right string is in English.

One localization approach kicks in once you've done your final project build. Once your source is frozen, you duplicate the English.lproj directory, creating a copy for each foreign language you plan on supporting. For example, you might make a copy of English.lproj named German.lproj. You'd then hand this directory to your German translator. The German translator would step through each of the .strings files, translating all the right-hand strings in each of the assignment statements to German.

When you ship your application, you'll actually ship an accompanying directory that includes all your XXX.lproj subdirectories. When the user specifies their preferred language using the Preferences application, then runs your application, the system uses the .lproj directory that matches the current language. So on an English system, the strings in English.lproj will be used. On a German system, the German.lproj strings will be used. Of course, you don't have to support multiple languages, but since localization is so easy to do, you'll likely want to consider supporting more than just your native language.

An Existing Localized Example

Let's take a look at a shipping application that supports more than one language.

  • In the Workspace, point your browser to the /NextDeveloper/Demos directory.

A series of applications will appear in the directory (Figure 1). As you'd expect, if you double-click on any of these, they'll run. These .App files are known as "application wrappers". They hide the underlying directory structure that ships with your application and makes them appear as a single application file. The Workspace does give you a way to view this accompanying directory.

Figure 1. The /NextDeveloper/Demos directory.

  • In the File Viewer, click on TextEdit.App to select it.
  • Select Open as Folder from the Workspace's File menu.

A new File Viewer will appear, showing you the directory structure beneath the TextEdit.app application wrapper (Figure 2). At the top level of this directory is a directory named Resources. The XXX.lproj directories live inside this directory. Each of the XXX.lproj directories contains localized versions of the FindPanel.strings and Localizable.strings files.

Figure 2. TextEdit.App, opened as a folder instead of as an application.

Take some time to look at some other directories and applications. Check out some of the other applications in /NextDeveloper/Demos. Check out /NextDeveloper/Apps and /NextApps. Note that some of the applications are localized, others are not. Some are only partially localized. Some feature a Resources directory, othersplace their XXX.lproj directories one level higher, directly in the app's main directory. This last is a clue to the version of ProjectBuilder used to create the application. The Project Builder that shipped with OPENSTEP 4.0 was the first version to embed the XXX.lproj directories in a Resources directory.

A Simple Example

Let's use ProjectBuilder to build a simple application, then localize it.

  • Launch ProjectBuilder, then select New from the Project menu.
  • When the New Project panel appears, select Application from the Project Type popup men, type the name Foo into the Name field, then click OK.
  • In ProjectBuilder's browser, under Interfaces, double-click on NEXTSTEP_Foo.nib (assuming you are running under NextStep -- otherwise, double-click on your appropriate nib file).

You will now find yourself in InterfaceBuilder. As you've seen in past columns, InterfaceBuilder provides your application with a default window named My Window. We'll add a button and a static text item to this window, then localize the text associated with these two items, just to see localization in action. After that, we'll take a look at the functions that bring localization to life.

  • In InterfaceBuilder, select Palettes from the Tools menu, Palettes submenu.
  • When the Palettes window appears, click on the Views icon.
  • Drag a static text item (the text in the palette says "Title") into "My Window".
  • Double-click on the static text item and change the text to read:
This application allows you to control a vehicle on another planet
  • Go back to the Palettes window and drag a button into the window.
  • Double-click on the button and change the text to say OK.
  • Select Save from the Document menu.
  • Quit InterfaceBuilder.
  • Back in ProjectBuilder, click on the hammer icon to bring up the Project Build window.
  • Click on the hammer icon in the Project Build window to start the build process.

You should get a message that says build succeeded.

  • Quit ProjectBuilder.

Now we'll run the app, just to verify that our window appears with its static text and button. Once we know the app runs, we'll localize it in German, set the system prefs to German, then run the app again showing the German localization at work.

  • * In the workspace, find the file Foo.app (it'll be inside the Foo folder you created when you first built the ProjectBuilder project).
  • * Double-click Foo.app.

The window should appear containing our static text and button (Figure 3).

Figure 3. Foo.app, before localization.

  • Quit Foo.app.

In the workspace, select Foo.app, then select Open as Folder from the File menu.

  • In the Foo.app file viewer, open the Resources directory, select English.lproj, then select Duplicate from the File menu.
  • Rename the duplicate to German.lproj.
  • Inside the German.lproj directory, Double-click NEXTSTEP_foo.nib.

You'll find yourself in InterfaceBuilder, editing the version of the nib file that lives in German.proj.

  • In InterfaceBuilder, edit the static text in the main window and change it to read:
Diese anwendung erlaubt es ihnen ein fahrzeug auf einem anderen planeten

Big thanks to Andreas Hommel, compiler writer extraordinaire, for the German translation! ;)

  • Save, then Quit InterfaceBuilder.

Note that we didn't change the button text. As it turns out, OK in German is OK! Our next step is to run the preferences application and change the order of preferred languages so that German is first.

  • Double-click on the Preferences application (it's the icon in the dock that looks like a clock).
  • In the Preferences window, click on the left-most icon (the one that looks like a series of flags).
  • In the scrolling list of Languages, click on Deutsch and drag it to the top of the list (Figure 4).

Figure 4. The Localization Preferences, with German (Deutsch) selected as the preferred language.

The scrolling list of languages allow you to order the set of languages on your machine. On my machine, I have it set to German first (just for this demo), then English, French, Italian, and Swedish. When I run an application on my machine, the order of languages in my preferences determine which .lproj directory is used to fetch the application's nib files. In this case, the directory German.lproj is used first, then English.lproj, French.lproj, etc.

  • Quit the Preferences application.
  • Go back into the file viewer and run Foo.App.

This time, the text should appear in German (Figure 5). Wunderbar!

Figure 5. Foo.app running in German. Cool!

The Localization Functions

The sample program we just created was relatively simple. All localization was done directly in the nib file. Earlier in the column, we explored the TextEdit application and saw that the TextEdit text strings were stored in a set of .strings files. Instead of editing the TextEdit nib files, localization was done on these .strings files. This is made possible by a set of localization functions called by your program any time it needs to access a localized string. The functions go out to the appropriate .strings file and retrieve the localized version of the specified string.

The three localization functions we're referring to all start with the name NSLocalizedString. Here's a cool trick you can use to search for routines in the precompiled headers used by your projects.

  • Launch the Edit application.
  • Type the text NSLocalizedString.
  • select the text, then select the Services menu, Header Viewer submenu, Find item (Alt-Shift-H).

The HeaderViewer app will do a search and find the selected routine in the various precompiled headers (in HeaderViewer, select Info/Preferences to see the list of precompiled headers to be searched). When we used this technique to search for NSLocalizedString we get:

#define NSLocalizedString(key, comment) \
_  [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:nil]
#define NSLocalizedStringFromTable(key, tbl, comment) \
_  [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:(tbl)]
#define NSLocalizedStringFromTableInBundle(key, tbl, bundle, comment) \
_  [bundle localizedStringForKey:(key) value:@"" table:(tbl)]

These three routines are the keys to localizing your strings.

NSLocalizedString takes a key and a comment, both of which are NSStrings. When ProjectBuilder encounters a call of NSLocalizedString, it uses the key and comment to build an entry in the file Localizable.strings. Here's an example:

NSString *untitled = NSLocalizedString(@"UNTITLED",
		@"Name of new, untitled document");

This piece of code defines an NSString pointer named untitled, which gets the string retrieved by the call of NSLocalizedString. The NSLocalizedString call takes two parameters, both of them NSStrings. The first one is the default value of the string. In this case, the default value is "UNTITLED". The second NSString is the comment that leads off the entry. ProjectBuilder will use this line of code to generate this entry in the file Localizable.strings:

/* Name of new, untitled document */
"&UNTITLED" = "&UNTITLED";

Note that the first parameter to NSLocalizedString serves as both the left and right side of the pseudo-assignment statement. Instead of embedding the string @"UNTITLED" directly in your code, pass it as a parameter to NSLocalizedString (or one of the other routines we'll look at in a sec), then use the NSString returned by NSLocalizedString instead. Think of NSLocalizedString as a bottleneck routine. By using it, your strings will automatically be exported into a .strings file. Once your strings are exported into a .strings file, you can hand the file to your translator, then place the localized copy in the appropriate XXX.lproj directory. Remember to tell your translator to translate the right hand side of all the assignment statements only. The left side provides the link to the NSLocalizedString call in your code. If your default language is English, the left side of the assignment statement in each .strings file will also be in English, as will all the first parameters to NSLocalizedString. The right side of each assignment statement might be in German, French, Swedish, Kanji, whatever.

By the way, though the comment and assignment statement might look like straight C code, it is actually intended as an NSStringTable. Just thought you'd like to know.

The function NSLocalizedStringFromTable takes a key, table name, and comment. key and comment serve the same purpose they did with NSLocalizedString. The table name is an NSString that specifies the name of an NSStringTable in which you'd like this entry stored. For example, this call will create an entry in the file FindPanel.strings.

NSString *untitled = NSLocalizedStringFromTable(
	@"Enter Find String:",
	@"FindPanel",
	@"Prompt for Find panel");

Why not stick all your strings in Localizable.strings? One approach used by OPENSTEP programmers is to create one .strings file for each panel/window in their interface. If your application supported a Find panel, an Info panel, and a main window, you might have three .strings files: FindPanel.strings, InfoPanel.strings, and MainPanel.strings. You might choose to keep all your strings in Localizable.strings or not use Localizable.strings at all. The point is, NSLocalizedStringFromTable is designed to let you store strings in the .strings file you choose.

The second parameter to NSLocalizedStringFromTable assumes the .strings suffix. So passing in the NSString @"FindPanel" will store the string in the file FindPanel.strings. Of course, if you create more than one .strings file, you'll have more files to manage and to pass on to your translator, so make the design choice that's right for your situation.

Terminology note: @"mystring" asks the runtime to create a temporary NSString object with the specified string and pass the reference to wherever it is used.

Finally, NSLocalizedStringFromTableInBundle lets you do the above but from a table associated with a bundle. Bundles are like plugins -- we'll get to them in a future column.

Till Next Month...

Your homework for this month: Add some NSLocalizedString calls to the VerySimpleText application that we built two months ago. You can add the code to the AboutWindowController class, inside the show method. Check out the .strings files generated by ProjectBuilder in response to your additional code. Do you see when these files get generated?

In Digital Librarian, open the bookshelf /NextLibrary/Bookshelves/DevTools.bshlf. Spend some time with this bookshelf, and pay special attention to Part 2: Creating the Interface. It has documents that describe creating a nib file, creating menus, initializing text, and tons more.

See you next month!

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Geekbench 4.4.0 - Measure processor and...
Geekbench provides a comprehensive set of benchmarks engineered to quickly and accurately measure processor and memory performance. Designed to make benchmarks easy to run and easy to understand,... Read more
CleanMyMac X 4.4.4 - Delete files that w...
CleanMyMac makes space for the things you love. Sporting a range of ingenious new features, CleanMyMac lets you safely and intelligently scan and clean your entire system, delete large, unused files... Read more
TeamViewer 14.4.2669 - Establish remote...
TeamViewer gives you remote control of any computer or Mac over the Internet within seconds or can be used for online meetings. Find out why more than 200 million users trust TeamViewer! Free for non... Read more
Paperless 3.0.6 - $69.95
Paperless is a digital documents manager. Remember when everyone talked about how we would soon be a paperless society? Now it seems like we use paper more than ever. Let's face it - we need and we... Read more
BetterTouchTool 3.141 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more
TextMate 2.0.rc.29 - Code/markup editor...
TextMate is a versatile plain text editor with a unique and innovative feature set which caused it to win an Apple Design Award for Best Mac OS X Developer Tool in August 2006 A rapidly growing... Read more
Little Snitch 4.4.1 - Alerts you about o...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more
Little Snitch 4.4 - Alerts you about out...
Little Snitch gives you control over your private outgoing data. Track background activity As soon as your computer connects to the Internet, applications often have permission to send any... Read more
MPlayer OSX Extended 16 - Multimedia pla...
MPlayer OSX Extended is the future of MPlayer OSX. Leveraging the power of the MPlayer and FFmpeg open source projects, MPlayer OSX Extended aims to deliver a powerful, functional and no frills video... Read more
Google Chrome 75.0.3770.142 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more

Latest Forum Discussions

See All

TEPPEN guide - Tips and tricks for new p...
TEPPEN is a wild game that nobody asked for, but I’m sure glad it exists. Who would’ve thought that a CCG featuring Capcom characters could be so cool and weird? In case you’re not completely sure what TEPPEN is, make sure to check out our review... | Read more »
Dr. Mario World guide - Other games that...
We now live in a post-Dr. Mario World world, and I gotta say, things don’t feel too different. Nintendo continues to squirt out bad games on phones, causing all but the most stalwart fans of mobile games to question why they even bother... | Read more »
Strategy RPG Brown Dust introduces its b...
Epic turn-based RPG Brown Dust is set to turn 500 days old next week, and to celebrate, Neowiz has just unveiled its biggest and most exciting update yet, offering a host of new rewards, increased gacha rates, and a brand new feature that will... | Read more »
Dr. Mario World is yet another disappoin...
As soon as I booted up Dr. Mario World, I knew I wasn’t going to have fun with it. Nintendo’s record on phones thus far has been pretty spotty, with things trending downward as of late. [Read more] | Read more »
Retro Space Shooter P.3 is now available...
Shoot-em-ups tend to be a dime a dozen on the App Store, but every so often you come across one gem that aims to shake up the genre in a unique way. Developer Devjgame’s P.3 is the latest game seeking to do so this, working as a love letter to the... | Read more »
Void Tyrant guide - Guildins guide
I’ve still been putting a lot of time into Void Tyrant since it officially released last week, and it’s surprising how much stuff there is to uncover in such a simple-looking game. Just toray, I finished spending my Guildins on all available... | Read more »
Tactical RPG Brown Dust celebrates the s...
Neowiz is set to celebrate the summer by launching a 2-month long festival in its smash-hit RPG Brown Dust. The event kicks off today, and it’s divided into 4 parts, each of which will last two weeks. Brown Dust is all about collecting, upgrading,... | Read more »
Flappy Royale is an incredibly clever ta...
I spent the better part of my weekend playing Flappy Royale. I didn’t necessarily want to. I just felt like I had to. It’s a hypnotic experience that’s way too easy to just keep playing. | Read more »
Void Tyrant guide - General tips and tri...
Void Tyrant is a card-based dungeon-crawler that doesn’t fit in the mold of other games in the genre. Between the Blackjack-style combat and strange gear system alone, you’re left to your own devices to figure out how best to use everything to your... | Read more »
Webzen’s latest RPG First Hero is offici...
You might be busy sending your hulking Dark Knight into the midst of battle in Webzen’s other recent release: the long-anticipated MU Origin 2. But for something a little different, the South Korean publisher has launched First Hero. Released today... | Read more »

Price Scanner via MacPrices.net

Amazon drops prices, now offers clearance 13″...
Amazon has new dropped prices on clearance 13″ 2.3GHz Dual-Core non-Touch Bar MacBook Pros by $200 off Apple’s original MSRP, with prices now available starting at $1099. Shipping is free. Be sure to... Read more
2018 15″ MacBook Pros now on sale for $500 of...
Amazon has dropped prices on select clearance 2018 15″ 6-Core MacBook Pros to $500 off Apple’s original MSRP. Prices now start at $1899 shipped: – 2018 15″ 2.2GHz Touch Bar MacBook Pro Silver: $1899.... Read more
Price drop! Clearance 12″ 1.2GHz Silver MacBo...
Amazon has dropped their price on the recently-discontinued 12″ 1.2GHz Silver MacBook to $849.99 shipped. That’s $450 off Apple’s original MSRP for this model, and it’s the cheapest price available... Read more
Apple’s 21″ 3.0GHz 4K iMac drops to only $936...
Abt Electronics has dropped their price on clearance, previous-generation 21″ 3.0GHz 4K iMacs to only $936 shipped. That’s $363 off Apple’s original MSRP, and it’s the cheapest price we’ve seen so... Read more
Amazon’s Prime Day savings on Apple 11″ iPad...
Amazon has new 2018 Apple 11″ iPad Pros in stock today and on sale for up to $250 off Apple’s MSRP as part of their Prime Day sale (but Prime membership is NOT required for these savings). These are... Read more
Prime Day Apple iPhone deal: $100 off all iPh...
Boost Mobile is offering Apple’s new 2018 iPhone Xr, iPhone Xs, and Xs Max for $100 off MSRP. Their discount reduces the cost of an Xs to $899 for the 64GB models and $999 for the 64GB Xs Max. Price... Read more
Clearance 13″ 2.3GHz Dual-Core MacBook Pros a...
Focus Camera has clearance 2017 13″ 2.3GHz/128GB non-Touch Bar Dual-Core MacBook Pros on sale for $169 off Apple’s original MSRP. Shipping is free. Focus charges sales tax for NY & NJ residents... Read more
Amazon Prime Day deal: 9.7″ Apple iPads for $...
Amazon is offering new 9.7″ WiFi iPads with Apple Pencil support for $80-$100 off MSRP as part of their Prime Day sale, starting at only $249. These are the same iPads found in Apple’s retail and... Read more
Amazon Prime Day deal: 10% (up to $20) off Ap...
Amazon is offering discounts on new 2019 Apple AirPods ranging up to $20 (10%) off MSRP as part of their Prime Day sales. Shipping is free: – AirPods with Charging Case: $144.99 $15 off MSRP –... Read more
Amazon Prime Day deal: $50-$80 off Apple Watc...
Amazon has Apple Watch Series 4 and Series 3 models on sale for $50-$80 off Apple’s MSRP as part of their Prime Day deals with prices starting at only $199. Choose Amazon as the seller rather than a... Read more

Jobs Board

*Apple* Systems Architect/Engineer, Vice Pre...
…its vision to be the world's most trusted financial group. **Summary:** Apple Systems Architect/Engineer with strong knowledge of products and services related to Read more
*Apple* Graders/Inspectors (Seasonal/Hourly/...
…requirements. #COVAentryleveljobs ## Minimum Qualifications Some knowledge of agricultural and/or the apple industry is helpful as well as the ability to comprehend, Read more
Best Buy *Apple* Computing Master - Best Bu...
**710003BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 000171-Winchester Road-Store **Job Description:** Read more
Best Buy *Apple* Computing Master - Best Bu...
**709786BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 000430-Orange Park-Store **Job Description:** **What does a Read more
Geek Squad *Apple* Master Consultation Agen...
**709918BR** **Job Title:** Geek Squad Apple Master Consultation Agent **Job Category:** Services/Installation/Repair **Location Number:** 000106-Palmdale-Store Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.