Localizing the interface of a DITA Map to WebHelp Classic output: Adding a new language

To add a new language for WebHelp transformations, you need to create a DITA-OT extension plugin that uses the dita.xsl.messages extension point. The following sample procedure is for adding translation files for the Polish language, but you can adapt it for any language:

Create a com.oxygenxml.webhelp.localization plugin directory inside the [DITA-OT DIR]/plugins/ location.

Create a plugin.xml file inside that com.oxygenxml.webhelp.localization directory with the following content:

<plugin id="com.oxygenxml.webhelp.localization">
    <require plugin="com.oxygenxml.webhelp.classic"/>
    <require plugin="com.oxygenxml.webhelp.responsive"/>
						
    <feature extension="dita.xsl.strings" file="webhelp-extension-strings.xml"/>
</plugin>

Create a webhelp-extension-strings.xml file with the following content:

<langlist>
    <lang xml:lang="pl"    filename="strings-pl-pl.xml"/>
    <lang xml:lang="pl-PL"    filename="strings-pl-pl.xml"/>
</langlist>

Copy the WebHelp strings file ([DITA-OT DIR]/plugins/com.oxygenxml.webhelp.classic/oxygen-webhelp/resources/localization/strings-en-us.xml) to your plugin directory, and rename it as strings-pl-pl.xml.
In the strings-pl-pl.xml file, change the @xml:lang attribute on the root element that conforms with the new language.
```
<strings xml:lang="pl-PL">
  ...
</strings>
```

Translate the content of each <str> element (make sure to leave the name attribute unchanged).

<strings xml:lang="pl-PL">
...
  <str name="webhelp.content" js="true" php="false">Polish translation for "Content".</str>
  <str name="webhelp.search" js="true" php="false">Polish translation for "Search"</str>
...
</strings>

Copy the common DITA-OT strings defined in the [DITA-OT DIR]/xsl/common/strings-en-us.xml file. It defines a set generated text available for HTML based transformations (such as note, fig, and table elements). Translate the content of each <str> element.

<strings xml:lang="pl-PL">
...
  <str name="webhelp.content" js="true" php="false">Polish translation for "Content".</str>
  <str name="webhelp.search" js="true" php="false">Polish translation for "Search"</str>
...
  <str name="Figure">Polish translation for "Figure"</str>
  <str name="Table">Polish translation for "Table"</str>
...
</strings>

Within oXygen XML Editor, use the Run DITA-OT Integrator transformation scenario found in the DITA Map section in the Configure Transformation Scenario(s) dialog box.
In the [DITA-OT DIR]/bin directory of the DITA Open Toolkit, run one of the following scripts, depending on your operating system:
- Windows: [DITA-OT DIR]/bin/dita.bat --install
- Linux: [DITA-OT DIR]/bin/dita.sh --install