The xml extension is enabled in a default php build (like SPL).

If only the graphs fail to display, then the XML extension is optional (since the report tables will display fine).
However it would be nice to display it nicely (eg. when a user has a partial working Piwik, let him know that the graph don't work because he is missing xml extension)

Temporarily re-opening for investigation. I'm recompiling php on my test box with --disable-xml (and --without-pear) to document what the full impact is.

FYI the FreeBSD ports collection has a dependency check for:

mysql gd pdo pdo_mysql zlib iconv dom json session xml

Base functionality (including graphs) works with --disable-xml.

Going to rebuild without libxml.

Ok... compiling withput libxml also means no xml, xmlreader, xmlwriter, simplexml, or dom.

Graphs still work but:

• Feedburner stats show:

Fatal error: Class 'SimpleXMLElement' not found in /home/apang/work/piwik/dev/trunk/plugins/ExampleFeedburner/ExampleFeedburner.php on line 112

• Piwik.org blog shows:

Fatal error: Call to undefined function libxml_use_internal_errors() in /home/apang/work/piwik/dev/trunk/libs/Zend/Feed.php on line 194

• SEO widget is empty

(In [3504]) fixes #1575 - removed special logic re: json and xml; add generic check for "other extensions" (json, libxml, dom, and SimpleXML)

(In [3505]) refs #1575 - handle missing "session" extension