Tài liệu Creating Applications with Mozilla-Chapter 11. Localization-P3 pdf

Note that this issue of text in RDF is separate from the topic of using RDF as the mechanism in the chrome registry to register your locale and set up a switching mechanism.. Once you ha

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Chapter 11 Localization-P3

11.4.4 Localizable Resources in HTML

As a web application, Mozilla permits seamless integration of web content, both local and remote, in many formats If you have verbose text that just needs to be displayed somewhere in the framework of your application, HTML or XML content may be ideal for this purpose Through the use of XUL content widgets, such as <iframe> and <browser>, you have ready-made frames to slot your content into:

Therefore, a simple modification of xFly.html with a local language leaves the main application untouched Some other uses of HTML or XML content include an "About" dialog/page, Help pages, a wizard interface, or a getting started/introduction page

11.4.5 Localizable Resources in RDF

Strings to be converted in RDF content can take more than one form You can use entities directly in your RDF file or have the text inline in your node descriptions Whichever method you choose, you must ensure that the file is installed in the right place in the tree and registered correctly for the

application to pick up on it

As an XML markup, RDF can handle inline entity definitions These entity definitions have been covered thoroughly in the chapter so far Example

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11-8 looks at localizable strings contained directly in RDF node descriptions This example is taken from the Help table of contents in the Mozilla tree

Example 11-8 RDF Description node with localizable text

<rdf:Description about="#nav-doc">

<nc:subheadings>

<rdf:Seq>

<rdf:li>

<rdf:Description ID="nav-doc-language"

nc:name="Language and Translation Services"

nc:link="chrome://help/locale/nav_help.html#nav_lan guage"/>

</rdf:li>

</rdf:Seq>

</nc:subheadings>

</rdf:Description>

The text in the nc:name attribute is the text that will be changed Note that this issue of text in RDF is separate from the topic of using RDF as the mechanism in the chrome registry to register your locale and set up a

switching mechanism This difference is addressed in the next section

11.5 The Chrome Registry and Locale

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Your application is built and you're ready to upload your shiny new Mozilla program to your server for download The last piece of the puzzle, locale versions, has been put in place With the structures that Mozilla has in place,

it no longer has to be an afterthought Once you have the translated files, you need to make the decision about how you want to distribute your language versions, the languages you want to make available to the users, and the level of customization that you want to give to them

In this section, we look at how the Mozilla application suite handles the chrome's locale component Then you see how to apply these chrome

registry structures and utilities on a more generic level for your application

11.5.1 The Directory Structure

A typical application chrome structure looks like the directory structure in

Figure 11-2 A folder for each language is under the locale directory The general format is that each language has a unique identifier based on country code and the region This conforms to the 639 two-letter code with

ISO-3166 two-letter country code standards

The W3C site has good resources that provide information about the ISO-639 and ISO-3166 standards at http://www.w3.org/International/O-HTML-tags.html

For example, the unique identifier for Scots, Great Britain, is Sc-GB The

first code, Sc, is for the Scots (Scottish) dialect, and the second code, GB, is

for the country code for Great Britain This is the standard that Mozilla follows

Figure 11-2 Locale's placement in typical chrome layout

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The folder that is registered is the language folder, which is what has to be changed on an install Thus, the URL chrome://package/locale actually points to package/locale/en-US or whichever language is turned on at the time The language folder may in turn include subfolders that contain logical units for your application

11.5.2 Interaction with the Chrome Registry

As pointed out in Chapter 6, your packages directories need to be registered

as chrome with the chrome registry The first step is to ensure that the entry for your package component is in the file chrome.rdf in the root chrome directory

A resource:/ URL points to the folder for your files to be picked up and recognized by the chrome mechanism and accessed via chrome:// URLs

in your application code The locale is no exception

<RDF:Description

about="urn:mozilla:locale:en-US:xfly"

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c:baseURL="resource:/chrome/xfly/locale/en-US/">

c:localeVersion="0.1.0.0"

<c:package resource="urn:mozilla:package:xfly"/>

</RDF:Description>

A built-in versioning system in the chrome registry uses

c:localeVersion descriptor, if you plan on distributing multiple

language packs for your application Other descriptors are available if you choose to use them: display name (c:displayName), internal name

(c:name), location type (c:locType), and author (c:author)

11.5.3 Distribution

Language distribution may not be an issue for you If, for example, your application were only going to be localized into a finite number of

languages, bundling each of them up with the main installer would be most convenient If, however, the need for new language versions arises at various intervals in the release process, you need to find a way to make them

available and install them on top of an existing installation

For example, as more people from various locations in the world are

becoming aware of the Mozilla project, they want to customize it into their own language Here are the steps that you need to take to set up your

version

1 Register as a contributor and set up the resources that you need, if any (web page, mailing list) This will ensure that you are added to the project page on the mozilla.org site

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2 Get a copy of Mozilla to test either via a binary distribution or by downloading and building your own source (see Appendix A for more information)

3 Translate the files

4 Package your new files for distribution

5 Test and submit your work

Step 4, the packaging of the new language pack, is discussed next Mozilla's Cross-Platform Install (XPI) is the ideal candidate for achieving this

packaging This method is discussed extensively in Chapter 6 This

distribution method provides great flexibility and has the benefit of being native to Mozilla, thus bypassing the search for external install technologies for your application

11.5.3.1 The anatomy of an install script

Example 11-9 presents a script that is based on the Mozilla process that distributes localized language packs It presumes that there is a single JAR file for the language that is installed and registered in the Mozilla binary's chrome root

The XPI archive consists of the JAR file in a bin/chrome directory and the install.js file, together in a compressed archive with an xpi extension Simply clicking on a web page link to this file invokes the

Mozilla software installation service and installs your language For

convenience, inline comments in Example 11-9 explain what is happening

Example 11-9 The locale XPI install script, install.js

function verifyDiskSpace(dirPath, spaceRequired)

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{

var spaceAvailable;

spaceAvailable =

fileGetDiskSpaceAvailable(dirPath);

spaceAvailable = parseInt(spaceAvailable / 1024); if(spaceAvailable < spaceRequired)

{

logComment("Insufficient disk space: " +

dirPath);

logComment(" required : " + spaceRequired + " K");

logComment(" available: " + spaceAvailable + " K");

return(false);

}

return(true);

}

// platform detection

function getPlatform( ) {

var platformStr;

var platformNode;

if('platform' in Install) {

platformStr = new String(Install.platform);

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if (!platformStr.search(/^Macintosh/)) platformNode = 'mac';

else if (!platformStr.search(/^Win/)) platformNode = 'win';

else

platformNode = 'unix';

}

else {

var fOSMac = getFolder("Mac System"); var fOSWin = getFolder("Win System"); logComment("fOSMac: " + fOSMac);

logComment("fOSWin: " + fOSWin);

if(fOSMac != null)

platformNode = 'mac';

else if(fOSWin != null)

platformNode = 'win';

else

platformNode = 'unix';

}

return platformNode;

}

// Size in KB of JAR file

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var srDest = 500;

var err;

var fProgram;

var platformNode;

platformNode = getPlatform( );

// LOCALIZATION NOTE: translate only these

// These fields are changeable in this generic

script

var prettyName = "Irish";

var langcode = "ie";

var regioncode = "GA";

var chromeNode = langcode + "-" + regioncode;

// - END LOCALIZABLE RESOURCES -

// build the paths and file names for registry and chrome:// url access

var regName = "locales/mozilla/" + chromeNode; var chromeName = chromeNode + ".jar";

var regionFile = regioncode + ".jar";

var platformName = langcode + "-" + platformNode +

".jar";

var localeName = "locale/" + chromeNode + "/";

// Start the installation

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err = initInstall(prettyName, regName, "0.1.0.0"); logComment("initInstall: " + err);

fProgram = getFolder("Program");

logComment("fProgram: " + fProgram);

// Check disk space using utility function at the start of the script

if (verifyDiskSpace(fProgram, srDest))

{

err = addDirectory("",

"bin",

fProgram,

"");

logComment("addDirectory( ) returned: " + err);

// register chrome

var cf = getFolder(fProgram,

"chrome/"+chromeName);

var pf = getFolder(fProgram,

"chrome/"+platformName);

var rf = getFolder(fProgram,

"chrome/"+regionFile);

var chromeType = LOCALE | DELAYED_CHROME;

registerChrome(chromeType, cf, localeName +

"global/");

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"communicator/");

"content-packs/");

"cookie/");

"editor/");

"forms/");

"help/");

"messenger/");

"messenger-smime/");

"mozldap/");

"navigator/");

"necko/");

"pipnss/");

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"pippki/");

"wallet/");

registerChrome(chromeType, pf, localeName +

"global-platform/");

"communicator-platform/");

"navigator-platform/");

if (platformNode == "win") {

"messenger-mapi/");

}

registerChrome(chromeType, rf, regionName +

"global-region/");

"communicator-region/");

"editor-region/");

"messenger-region/");

"navigator-region/");

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if (err == SUCCESS)

{

// complete the installation

err = performInstall( );

logComment("performInstall( ) returned: " + err);

}

else

{

// cancel the installation

cancelInstall(err);

logComment("cancelInstall due to error: " + err);

}

else

{

// if we enter this section,

// there is not enough disk space for

installation

cancelInstall(INSUFFICIENT_DISK_SPACE);

}

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By changing some values of the changeable fields, you can tailor this script

to handle the install in any directory in the chrome (cf) that you want and register the chrome URL (localeName) for use The rest is handled by the built-in functionality in XPI provided by such functions as initInstall and performInstall

11.5.3.2 Switching languages

The mechanism for switching languages can take many forms Mozilla

switches languages by updating an RDF datasource when a language pack is installed The UI for switching languages in Mozilla is in the main

Preferences (Edit > Preferences) Within the preferences area, the

language/content panel (Appearance > Languages/Content) interacts with the chrome registry when loaded, reading in the installed language packs and populating a selectable list with the available language identifier Selecting one language and restarting Mozilla changes the interface for the user

Example 11-10 is a simple script for switching locales

Example 11-10 Locale-switching script

function switchLocale(langcode)

{

try {

var chromeRegistry =

Components.classes["@mozilla.org/chrome/chrome-registry;1"].getService(Components.interfaces.nsICh romeRegistry);

chromeRegistry.selectLocale(langcode, true);

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var observerService = Components.classes["

@mozilla.org/observer-service;1"]

getService(Components.interfaces.nsIObserverService );

observerService.notifyObservers(null, "locale-selected", null);

var prefUtilBundle = srGetStrBundle

("chrome://communicator/locale/pref/prefutilities.p roperties");

var brandBundle = srGetStrBundle

("chrome://global/locale/brand.properties");

var alertText =

prefUtilBundle.GetStringFromName("languageAlert"); var titleText =

prefUtilBundle.GetStringFromName("languageTitle"); alertText = alertText.replace(/%brand%/g,

brandBundle.GetStringFromName("brandShortName")); var promptService = Components.classes["

@mozilla.org/embedcomp/prompt-service;1"].getService( );

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promptService = promptService.QueryInterface (Components.interfaces.nsIPromptService) promptService.alert(window, titleText,

alertText);

}

catch(e) {

return false;

}

return true;

}

The language code is passed in as a parameter to the switchLocale JavaScript method in Example 11-10 The locale is set via the

nsIChromeRegistry component, which uses a method named

selectLocale This locale selection is located in the first few lines, and the rest of the code prepares and shows a prompt to the user This prompt reminds you to restart Mozilla to ensure that the new locale takes effect

11.6 Localization Issues

This section aims to dig a little deeper into the issues of UI aesthetics and principles, in order to provide some background into the underlying

encoding of documents in the XPFE framework The main portion is taken

up by a discussion of Unicode There is some background to what Unicode

is, how Mozilla uses it, and some practical conversion utilities to ensure that your files are in the correct encoding

11.6.1 XPFE and Unicode

Tiêu đề	Localization
Trường học	Mozilla University
Chuyên ngành	Web Development
Thể loại	Tài liệu
Năm xuất bản	2025
Thành phố	Mountain View

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Số trang	19
Dung lượng	38,99 KB