repo_zf1/documentation/manual/en/module_specs/Zend_Translate-Adapters.xml

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<sect1 id="zend.translate.adapter">

    <title>Adapters for Zend_Translate</title>

    <para>
        <classname>Zend_Translate</classname> can handle different adapters for translation.
        Each adapter has its own advantages and disadvantages.
        Below is a comprehensive list of all supported adapters for
        translation source files.
    </para>

    <table id="zend.translate.adapter.table">
        <title>Adapters for Zend_Translate</title>
        <tgroup cols="3">
            <thead>
                <row>
                    <entry>Adapter</entry>
                    <entry>Description</entry>
                    <entry>Usage</entry>
                </row>
            </thead>
            <tbody>
                <row>
                    <entry>Array</entry>
                    <entry>Use <acronym>PHP</acronym> arrays</entry>
                    <entry>Small pages; simplest usage; only for programmers</entry>
                </row>
                <row>
                    <entry>Csv</entry>
                    <entry>Use comma seperated (*.csv/*.txt) files</entry>
                    <entry>Simple text file format; fast; possible problems with unicode characters</entry>
                </row>
                <row>
                    <entry>Gettext</entry>
                    <entry>Use binary gettext (*.mo) files</entry>
                    <entry>GNU standard for linux; thread-safe; needs tools for translation</entry>
                </row>
                <row>
                    <entry>Ini</entry>
                    <entry>Use simple ini (*.ini) files</entry>
                    <entry>Simple text file format; fast; possible problems with unicode characters</entry>
                </row>
                <row>
                    <entry>Tbx</entry>
                    <entry>Use termbase exchange (*.tbx/*.xml) files</entry>
                    <entry>Industry standard for inter application terminology strings; <acronym>XML</acronym> format</entry>
                </row>
                <row>
                    <entry>Tmx</entry>
                    <entry>Use tmx (*.tmx/*.xml) files</entry>
                    <entry>Industry standard for inter application translation; <acronym>XML</acronym> format; human readable</entry>
                </row>
                <row>
                    <entry>Qt</entry>
                    <entry>Use qt linguist (*.ts) files</entry>
                    <entry>Cross platform application framework; <acronym>XML</acronym> format; human readable</entry>
                </row>
                <row>
                    <entry>Xliff</entry>
                    <entry>Use xliff (*.xliff/*.xml) files</entry>
                    <entry>A simpler format as <constant>TMX</constant> but related to it; <acronym>XML</acronym> format; human readable</entry>
                </row>
                <row>
                    <entry>XmlTm</entry>
                    <entry>Use xmltm (*.xml) files</entry>
                    <entry>Industry standard for <acronym>XML</acronym> document translation memory; <acronym>XML</acronym> format; human readable</entry>
                </row>
                <row>
                    <entry>Others</entry>
                    <entry>*.sql</entry>
                    <entry>Different other adapters may be implemented in the future</entry>
                </row>
            </tbody>
        </tgroup>
    </table>

    <sect2 id="zend.translate.adapter.decision">

        <title>How to decide which translation adapter to use</title>

        <para>
            You should decide which Adapter you want to use for <classname>Zend_Translate</classname>.
            Frequently, external criteria such as a project requirement or
            a customer requirement determines this for you, but if you are in
            the position to do this yourself, the following hints may simplify
            your decision.
        </para>

        <note>
            <para>
                When deciding your adapter you should also be aware of the used
                encoding. Even if Zend Framework declares UTF-8 as default
                encoding you will sometimes be in the need of other encoding.
                <classname>Zend_Translate</classname> will not change any encoding which is defined
                within the source file which means that if your Gettext source
                is build upon ISO-8859-1 it will also return strings in this encoding
                without converting them. There is only one restriction:
            </para>

            <para>
                When you use a xml based source format like TMX or XLIFF you must
                define the encoding within the xml files header because xml files
                without defined encoding will be treated as UTF-8 by any xml parser
                by default. You should also be aware that actually the encoding of
                xml files is limited to the encodings supported by <acronym>PHP</acronym> which are
                UTF-8, ISO-8859-1 and US-ASCII.
            </para>
        </note>

        <sect3 id="zend.translate.adapter.array">

            <title>Zend_Translate_Adapter_Array</title>

            <para>
                The Array Adapter is the Adapter which is simplest to use for
                programmers.
                But when you have numerous translation strings or many
                languages you should think about another Adapter.
                For example, if you have 5000 translation strings,
                the Array Adapter is possibly not the best choice for you.
            </para>

            <para>
                You should only use this Adapter for small sites with a handful
                of languages, and if you or your programmer team creates the
                translations yourselves.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.csv">

            <title>Zend_Translate_Adapter_Csv</title>

            <para>
                The Csv Adapter is the Adapter which is simplest to use for
                customers.
                CSV files are readable by standard text editors, but
                text editors often do not support utf8 character sets.
            </para>

            <para>
                You should only use this Adapter if your customer wants to do
                translations himself.
            </para>

            <note>
                <para>
                    Beware that the Csv Adapter has problems when your Csv files are encoded differently than
                    the locale setting of your environment. This is due to a Bug of <acronym>PHP</acronym> itself which will not
                    be fixed before <acronym>PHP</acronym> 6.0 (http://bugs.php.net/bug.php?id=38471). So you should be aware
                    that the Csv Adapter due to <acronym>PHP</acronym> restrictions is not locale aware.
                </para>
            </note>
        </sect3>

        <sect3 id="zend.translate.adapter.gettext">

            <title>Zend_Translate_Adapter_Gettext</title>

            <para>
                The Gettext Adapter is the Adapter which is used most
                frequently. Gettext is a translation source format which was
                introduced by GNU, and is now used worldwide.
                It is not human readable, but there are several freeware tools
                (for instance, <ulink url="http://sourceforge.net/projects/poedit/">POEdit</ulink>), which are very helpful.
                The <classname>Zend_Translate</classname> Gettext Adapter is not implemented using
                <acronym>PHP</acronym>'s gettext extension.
                You can use the Gettext Adapter even if you do not have
                the <acronym>PHP</acronym> gettext extension installed.
                Also the Adapter is thread-safe and the <acronym>PHP</acronym> gettext extension
                is currently not thread-safe.
            </para>

            <para>
                Most people will use this adapter.
                With the available tools, professional translation is
                very simple. But gettext data are is stored in a
                machine-readable format, which is not readable without tools.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.ini">

            <title>Zend_Translate_Adapter_Ini</title>

            <para>
                The Ini Adapter is a very simple Adapter which can even be used
                directly by customers.
                <acronym>INI</acronym> files are readable by standard text editors, but
                text editors often do not support utf8 character sets.
            </para>

            <para>
                You should only use this Adapter when your customer wants to do translations
                himself. Do not use this adapter as generic translation source.
            </para>

            <warning>
                <title>Regression in PHP 5.3</title>

                <para>
                    Prior to <acronym>PHP</acronym> 5.3, <function>parse_ini_file()</function> and
                    <function>parse_ini_string()</function> handled non-ASCII characters
                    within <acronym>INI</acronym> option keys worked without an issue. However, starting with <acronym>PHP</acronym> 5.3,
                    any such keys will now be silently dropped in the returned array from either
                    function. If you had keys utilizing UTF-8 or Latin-1 characters, you may find
                    your translations no longer work when using the <acronym>INI</acronym> adapter. If this is the
                    case, we recommend utilizing a different adapter.
                </para>
            </warning>
        </sect3>

        <sect3 id="zend.translate.adapter.tbx">

            <title>Zend_Translate_Adapter_Tbx</title>

            <para>
                The Tbx Adapter is an Adapter which will be used by customers
                which already use the TBX format for their internal translation
                system. Tbx is no standard translation format but more a collection
                of already translated and pre translated source strings. When you
                use this adapter you have to be sure that all your needed source
                string are translated.
                TBX is a <acronym>XML</acronym> file based format and a completely new format.
                <acronym>XML</acronym> files are human-readable, but the parsing is not as fast
                as with gettext files.
            </para>

            <para>
                This adapter is perfect for companies when pre translated
                source files already exist.
                The files are human readable and system-independent.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.tmx">

            <title>Zend_Translate_Adapter_Tmx</title>

            <para>
                The Tmx Adapter is the Adapter which will be used by most
                customers which have multiple systems which use the same
                translation source, or when the translation source must be
                system-independent.
                TMX is a <acronym>XML</acronym> file based format, which is announced to be the
                next industry standard.
                <acronym>XML</acronym> files are human-readable, but the parsing is not as fast
                as with gettext files.
            </para>

            <para>
                Most medium to large companies use this adapter.
                The files are human readable and system-independent.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.qt">

            <title>Zend_Translate_Adapter_Qt</title>

            <para>
                The Qt Adapter is for all customers which have TS files as their
                translation source which are made by QtLinguist.
                QT is a <acronym>XML</acronym> file based format.
                <acronym>XML</acronym> files are human-readable, but the parsing is not as fast
                as with gettext files.
            </para>

            <para>
                Several big players have build software upon the QT framework.
                The files are human readable and system-independent.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.xliff">

            <title>Zend_Translate_Adapter_Xliff</title>

            <para>
                The Xliff Adapter is the Adapter which will be used by most
                customers which want to have <acronym>XML</acronym> files but do not have tools
                for TMX.
                XLIFF is a <acronym>XML</acronym> file based format, which is related to TMX but
                simpler as it does not support all possibilities of it.
                <acronym>XML</acronym> files are human-readable, but the parsing is not as fast
                as with gettext files.
            </para>

            <para>
                Most medium companies use this adapter.
                The files are human readable and system-independent.
            </para>
        </sect3>

        <sect3 id="zend.translate.adapter.xmltm">

            <title>Zend_Translate_Adapter_XmlTm</title>

            <para>
                The XmlTm Adapter is the Adapter which will be used by customers
                which do their layout themself. XmlTm is a format which allows the
                complete html source to be included in the translation source, so
                the translation is coupled with the layout.
                XLIFF is a <acronym>XML</acronym> file based format, which is related to XLIFF but
                its not as simple to read.
            </para>

            <para>
                This adapter should only be used when source files already exist.
                The files are human readable and system-independent.
            </para>
        </sect3>

    </sect2>

    <sect2 id="zend.translate.adapter.selfwritten">

        <title>Integrate self written Adapters</title>

        <para>
            <classname>Zend_Translate</classname> allows you to integrate and use self written Adapter
            classes. They can be used like the standard Adapter classes which
            are already included within <classname>Zend_Translate</classname>.
        </para>

        <para>
            Any adapter class you want to use with <classname>Zend_Translate</classname> must be a subclass
            of <classname>Zend_Translate_Adapter</classname>. <classname>Zend_Translate_Adapter</classname> is an abstract class
            which already defines all what is needed for translation. What has to be
            done by you, is the definition of the reader for translation datas.
        </para>

        <para>
            The usage of the prefix "Zend" should be limited to Zend Framework.
            If you extend <classname>Zend_Translate</classname> with your own adapter, you should name it
            like "Company_Translate_Adapter_MyFormat". The following code shows an
            example of how a self written adapter class could be implemented:
        </para>

        <programlisting language="php"><![CDATA[
try {
    $translate = new Zend_Translate('Company_Translate_Adapter_MyFormat',
                                    '/path/to/translate.xx',
                                    'en',
                                    array('myoption' => 'myvalue'));
} catch (Exception $e) {
    // File not found, no adapter class...
    // General failure
}
]]></programlisting>

    </sect2>

    <sect2 id="zend.translate.adapter.caching">

        <title>Speedup all Adapters</title>

        <para>
            <classname>Zend_Translate</classname> allows you use internally <classname>Zend_Cache</classname> to
            fasten the loading of translation sources. This comes very handy if you use many
            translation sources or extensive source formats like <acronym>XML</acronym> based files.
        </para>

        <para>
            To use caching you will just have to give a cache object to the
            <methodname>Zend_Translate::setCache()</methodname> method. It takes a instance of
            <classname>Zend_Cache</classname> as only parameter. Also if you use any adapter direct you
            can use the <methodname>setCache()</methodname> method. For convenience there are also the static methods
            <methodname>getCache()</methodname>, <methodname>hasCache()</methodname>, <methodname>clearCache()</methodname> and
            <methodname>removeCache()</methodname>.
        </para>

        <programlisting language="php"><![CDATA[
$cache = Zend_Cache::factory('Core',
                             'File',
                             $frontendOptions,
                             $backendOptions);
Zend_Translate::setCache($cache);
$translate = new Zend_Translate('gettext',
                                '/path/to/translate.mo',
                                'en');
]]></programlisting>

        <note>
            <para>
                You must set the cache <emphasis>before</emphasis> you use or initiate
                any adapter or instance of <classname>Zend_Translate</classname>. Otherwise your translation
                source will not be cached until you add a new source with the
                <methodname>addTranslation()</methodname> method.
            </para>
        </note>

    </sect2>

</sect1>
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