Transform App

Help and FAQs

Below are some answers to common questions. For additional help, contact support.

What do the indicator lights mean?
The indicator lights show if the selected source files are valid XML. Both the XML and XSLT file must be valid XML for the transform to occur.
Both indicator lights are green but an error still occurred, why?
The lights are indicating that both documents are individually valid XML, but an error may still occur during transformation. This usually occurs when an unknown function occurs.
How do I select an XML file with a non-xml file extension such as .html, .rss?
The file selector only allows you to open files of system known XML file types. To force Transform to open any file of your choosing, hold down the alt (option) key when clicking the XML or XSLT indicator button.
Why do I get an error when using <xsl:import>?
Transform is a 'sandboxed' app, meaning it can only access files that have been explicitly opened by the user. You might receive an error when using XSLT imports/includes like this:
Operation not permitted
warning :
failed to load external entity 
To workaround this problem, the external file needs to be granted access permission. To do this, select Edit > "Grant file access permission" from the menu, and select the imported file or parent folder.
What XSLT library is used to perform the transformation?
The amazingly fast libxslt.
Does it support XSLT 2.0?
Transform is powered by libxslt which currently does not support this.
Do all EXSLT functions work?
Libxslt implements most (but not all) of the EXSLT extension library. See the EXSLT website for the list of implemented functions.
When using the web view how do I specify the base URL for my HTML output?
Click the settings gear in the bottom right-hand window to add a web URL or file address to be used as the base URL.
Oh no, the application crashed, what should I do?
Oh dear. Transform has been painstakingly designed for fast and stable use. In the unlikely event of a crash, we want to fix it. First up, ensure you are running the latest version of the app by checking the app store for updates. If you able to, send a copy of the crash report and steps to reproduce the problem to the support email address listed below.


Having trouble?

Email: transformapp (at)