Matthew, Layouts support Header and Footer properties. These are written each time the file is opened or closed respectively. The issue is that a file may be opened and closed multiple times, therefore there may be multiple headers and footers in the file. To work as an XML file there must only be one pair of headers and footers and they must exist at all times. When a file is reopened for writing (e.g. when the app is restarted) the footer would have to be stripped off before writing the next events. This does not sit very neatly with the overwrite or append modes that we currently open the file with. I understand that the current situation is not very practical for file formats that are not restartable (e.g. XML, HTML).
Nicko > -----Original Message----- > From: Matthew Easlea [mailto:[EMAIL PROTECTED] > Sent: 07 June 2004 23:42 > To: 'Log4NET User' > Subject: RE: XML Layout > > Thanks Nicko, > > I can understand where you are coming from with keeping the > XMLLayout generating only the fragments. However, imagine the > following: > > <appender name="RollingFile" > type="log4net.Appender.RollingFileAppender"> > <file value="c:\\example.xml"/> > <appendToFile value="true"/> > <preMessage value="<?xml version="1.0" ?> > > <!DOCTYPE log4net:events SYSTEM > "log4net-events.dtd" [<!ENTITY data SYSTEM > "abc">]> > > <log4net:events version="1.2" > xmlns:log4net="http://log4net.sourceforge.net/"> > "/> > <postMessage value="</log4net:events>"/> > <maximumFileSize value="50KB"/> > <maxSizeRollBackups value="2"/> > > <layout type="log4net.Layout.XMLLayout"> > <conversionPattern value="%p %d [%t] - %m%n"/> > </layout> > </appender> > > As you can see I've added 2 appender parameters called > preMessage and PostMessage. Each time the rolling file > appender creates a new file it would put the preMessage at > the top and when it closes a file and moves onto the next one > it would put a postMessage at the end of the file. The > preMessage could be used for other things such as help > messages or copyright messages as well. It is thus > independent of the layout used. > > Does this sound like a reasonable solution? Do you think it > could be implemented and if I were to implement it would the > log4net community be interested in such an enhancement? > > Matthew James Easlea > > > -----Original Message----- > From: Nicko Cadell [mailto:[EMAIL PROTECTED] > Sent: Monday, 7 June 2004 10:17 AM > To: 'Log4NET User' > Subject: RE: XML Layout > > The XmlLayout generates XML Fragments for each message. XML > does not lend itself too well to a streaming format. > > When using the XmlLayout with the FileAppender or > RollingFileAppender the file written will not be a valid XML > document. It is a valid XML fragment. > However it can be included in a document. > > The output of the XmlLayout consists of a series of > log4net:event elements. > It does not output a complete well-formed XML file. The > output is designed to be included as an external entity in a > separate file to form a correct XML file. > > For example, if 'abc' is the name of the file where the > XmlLayout output goes, then a well-formed XML file would be: > > <?xml version="1.0" ?> > > <!DOCTYPE log4net:events SYSTEM "log4net-events.dtd" > [<!ENTITY data SYSTEM "abc">]> > > <log4net:events version="1.2" > xmlns:log4net="http://log4net.sourceforge.net/";> > &data; > </log4net:events> > > This approach enforces the independence of the XmlLayout and > the appender where it is embedded. > > > Nicko > > > -----Original Message----- > > From: Matthew Easlea [mailto:[EMAIL PROTECTED] > > Sent: 06 June 2004 23:46 > > To: 'Log4NET User' > > Subject: XML Layout > > > > Hi, > > > > When I use XMLLayout using the rolling file appender is > there anyway > > for it to create valid XML files. By this I mean with opening and > > closing <?XML> tag etc? > > > > Cheers > > > > Matthew James Easlea > > > > > > > >
