egroupware_official/doc/sgml/devlangsup.sgml

<chapter id="devlangsup">
	<title>Using Language Support</title>
	
	<simplesect>
		<title>Overview</title>
		<para>
			phpGroupWare is built using a multi-language support scheme. This means the pages can be
			translated to other languages very easily. Translations of text strings are
			stored in the phpGroupWare database, and can be modified by the phpGroupWare
			administrator.
		</para>
	</simplesect>
	<simplesect>
		<title>How to use lang support</title>
		<para>
			The  <classname>lang()</classname> function is your application's interface to phpGroupWare's
			internationalization support.

  			While developing your application, just wrap all your text output with calls to
  			lang(), as in the following code:
<programlisting>
  $x = 42;
  echo lang("The counter is %1",$x)."&lt;br&gt;";
</programlisting>
  			This will attempt to translate "The counter is %1", and return a translated version
  			based on the current application and language in use. Note how the position that
   			<classname>$x</classname> will end up is controlled by the format string, <emphasis>not</emphasis> by
  			building up the string in your code. This allows your application to be translated
  			to languages where the actual number is not placed at the end of the string.

  			When a translation is not found, the original text will be returned with a * after
  			the string.  This makes it easy to develop your application, then go back and
  			add missing translations (identified by the *) later.

			  Without a specific translation in the lang table, the above code will print:
<classname>
The counter is 42*&lt;br&gt;
</classname>
If the current user speaks Italian, they string returned may instead be:
<classname>
il contatore è 42&lt;br&gt;
</classname>
		</para>
	</simplesect>
	<simplesect>
		<title>The lang function</title>
		<para>
 			<classname>lang($key, $m1="", $m2="", $m3="", $m4="", $m5="",
        				$m6="", $m7="", $m8="", $m9="", $m10="")
  			</classname>
  			<variablelist>
        			<varlistentry>
               				<term>$key</term>
               				<listitem>
               					 <para>is the string to translate and may contain replacement directives of the form  <classname>%n</classname>. </para>
               				</listitem>
        			</varlistentry>
        			<varlistentry>
            				<term>$m1</term>
               				<listitem>
        					 <para> is the first replacement value or may be an array of replacement values (in which case $m2 and above are ignored). </para>
                			</listitem>
               			</varlistentry>
               			<varlistentry>
               				<term>$m2</term>
               				<listitem>
               					 <para>- $m10/ the 2nd through 10th replacement values if $m1 is not an array. </para>
               				</listitem>
               			</varlistentry>
            		</variablelist>
			The database is searched for rows with a  <classname>lang.message_id</classname> that matches  <classname>$key</classname>.
			If a translation is not found, the original  <classname>$key</classname> is used. The translation engine then replaces
			all tokens of the form  <classname>%N</classname> with the Nth parameter (either  <classname>$m1[N]</classname> or  <classname>$mN</classname>).
		</para>
	</simplesect>
	<simplesect>
		<title>Adding translation data</title>
		<para>
			An application called <emphasis>Transy</emphasis> is being developed to make this easier, until then you can create
			the translation data manually.
		</para>
	</simplesect>
	<simplesect>
		<title>The lang table</title>
		<para>
			The translation class uses the lang table for all translations.
			We are concerned with 4 of the columns to create a translation:
			<variablelist>
				<varlistentry>
					<term>message_id</term>
					<listitem>
						 <para>
							The key to identify the message (the  <classname>$key</classname> passed
							to the  <classname>lang()</classname> function). This is written in English.
						 </para>
					</listitem>
				</varlistentry>
				<varlistentry>	
					<term>app_name</term>
					<listitem>
						 <para>
							The application the translation applies to, or
							<classname>common</classname> if it is common across multiple applications.
						 </para>
					</listitem>
				</varlistentry>
		                <varlistentry>
		                       	<term>lang</term>
		                       	<listitem>
		                       		 <para>The code for the language the translation is in. </para>
		                       	</listitem>
		                </varlistentry>		
				<varlistentry>
					<term>content</term>
					<listitem>
						 <para>The translated string. </para>
					</listitem>
				</varlistentry>
			</variablelist>
		</para>
	</simplesect>
	<simplesect>	
		<title>lang.sql</title>
		<para>
			Currently all applications, and the core phpGroupWare source tree
			have a  <classname>lang.sql</classname> file. This is the place to add translation
			data. Just add lines of the form:
<programlisting>
REPLACE INTO lang (message_id, app_name, lang, content)
VALUES( 'account has been deleted','common','en','Account has been deleted');
</programlisting>
			translating the  <classname>content</classname> to reflect the  <classname>message_id</classname> string in the  <classname>lang</classname> language.
			If the string is specific to your application, put your application name in for  <classname>app_name</classname>
			otherwise use the name  <classname>common</classname>. The  <classname>message_id</classname> should be in lower case for a small
			increase in speed.
		</para>
        </simplesect>
	<simplesect>
		<title>Common return codes</title>
		<para>
			If you browse through the phpGroupWare sources, you may notice
			a pattern to the return codes used in the higher-level functions.
			The codes used are partially documented in the  <classname>doc/developers/CODES</classname>
			file.
	
			Codes are used as a simple way to communicate common error and progress
			conditions back to the user. They are mapped to a text string through the
			<classname>check_code()</classname> function, which passes the strings through
			<classname>lang()</classname> before returning.

			For example, calling
<programlisting>
echo check_code(13);
</programlisting>
			Would print
<classname>
Your message has been sent
</classname>
			translated into the current language.
		</para>
  	</simplesect>
</chapter>