input to use for reading the data</td></tr><tr><td><span class="term"><i><tt>enc</tt></i>:</span></td><td>an optional encoding information</td></tr><tr><td><span class="term"><i><tt>sax</tt></i>:</span></td><td>a SAX handler for the resulting events</td></tr><tr><td><span class="term"><i><tt>user_data</tt></i>:</span></td><td>the context to provide to the SAX handler.</td></tr><tr><td><span class="term"><i><tt>Returns</tt></i>:</span></td><td>0 if the document is schemas valid, a positive error code number 