== GRAMPS and XML ==
GRAMPS is capable of importing and exporting an [[
GRAMPS XML|XML file]] that contains all the information in the database. This file is useful for transferring data from one machine to another or for XML processing.
=== Generating XML ===
GRAMPS uses the [http://freedesktop.org/wiki/Software/shared-mime-info Shared Mime System] defined by [http://freedesktop.org Free Desktop] project, and used by all major desktops, including KDE and GNOME. GRAMPS relies on the MIME type identified by the Shared Mime System to determine the file type of the file.
The Share Mime System allows you to identify a file's type by either using a file extension or by looking at the contents of a small section of the file. The first problem is, usually the filename or extension pattern has the higher priority compared to the contents: if the file is named <code>something.jpg</code> then it is likely to be JPEG image, not text. So if the
GRAMPS XML file had added <code>.gz</code> extension to the name, the Shared Mime system would tell us that the file's type is <code>application/x-gzip</code> instead of the expected <code>application/x-gramps-xml</code>. Unfortunately, it cannot tell us that it is a gzip'd GRAMPS XML file.
The second problem is, if we looked at the contents, we would not be able to tell the difference between a gzip'd
GRAMPS XML file or any other gzip'd file. If we looked at uncompressed data, we would not be able to tell the difference between a GRAMPS XML file and other XML files. So again, the Shared Mime system could not tell us that it is a gzip'd GRAMPS XML file.
For these reasons, we must rely on the <code>.gramps</code> extension. If we don't, we would not be able to tell if this was a valid file. Even worse, the mime type of <code>application/x-gzip</code> would be associated with another application (such as File Roller or Ark) instead of GRAMPS. The mime type of <code>application/xml</code> may be associated with XML editors (Bluefish, Conglomerate, Emacs, etc). In that situation, the user double-clicking on the file in the file manager (or performing the default action for the type by any other means) will never launch GRAMPS with this data,