Template format

webPDF uses the Apache FreeMarker template engine for templates. All templates are written in FreeMarker Template Language (FTL) and are essentially based on HTML and a macro language with variable replacement.

All templates are found in the templates/ folder and have .ftl as their extension. Moreover, the files are text-based and built with HTML. The templates are used to convert specific file formats.

The entire FreeMarker macro engine is available for the templates.

tip

For more information on the FreeMarker template engine, please visit https://freemarker.apache.org/docs/index.html

When converting documents, the templates are loaded, the existing variables are replaced with the corresponding document contents, and the entire document is converted as an HTML document to PDF format using the Chromium engine.

There can be various variables, all starting with a prefix, available in the documents, with the specific variables depending on the specific template.

Template	File format	Variable prefix
mail.ftl	MIME/Outlook mail	${mail. ...}
ics.ftl	iCalendar/vCalendar	${ics. ...}
vcf.ftl	vCard	${vcf. ...}
svg.ftl	Serial Vector Format	${svg. ...}
text.ftl	Text document	${text. ...}

You can take the templates as a basis, modify them, and then pass the modified templates when calling the Converter web service. This way, you can customize the conversion of specific file formats according to your own specific needs.

caution

It is strongly recommended that you do not customize the templates in the templates/ folder, as otherwise necessary changes to the standard templates cannot be applied during an update. Instead, pass the customized templates when calling the web service.

You can create a completely new PDF document using HTML, the FreeMarker template language, and a definition of your own custom variables. Moreover, you can use all HTML and CSS functionalities in addition to the macro language and the variables. For more information, please refer to the "HTML as template" document