| Groups | Blog | Home |
dotnet xml : Create a single xml node
I need to be able to create a single xml node in utf-8 and do it efficiently as this is called a lot (reason below). What is the best way to do this? I need to end up with a string like "<node attr1='dave'>hi there</node>" where &"<>' are all encoded and chars > 127 are turned into utf-8. I then write this to a file (and what is the best way to do that)? Now as to why for the curious. This is for an audit trail and therefore each node must be written and flushed to disk and the file is opened in append mode where the permissions on the file allow appending, but not overwriting. The app can stop and re-start in the middle of the day so when it starts and we have no audit file, we write <root>. We then add nodes as actions occur. On the first write after midnight, we write </root>, clode & rename the file, then open another. So we can't use XmlWriter as we are not writing a complete xml file and we need to be able to flush. -- thanks - dave david_at_windward_dot_net http://www.windwardreports.com
Hi Dave,
Thank you for posting. As for writing XML element or append element into XML file, it depends on the detailed condition. Is the log file very large? If each of the file is not very large, we can just use XMLDocument class which load the document into memory and manipulate it. If the file's size will increase to a very large value, we need to consider using raw XmlWriter to write xml data into the file. Here is one msdn article discussing on large XML file manipulating: #Efficient Techniques for Modifying Large XML Files http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnxmlnet/ht ml/largexml.asp Hope this helps. Regards, Steven Cheng Microsoft Online Community Support ================================================== When responding to posts, please "Reply to Group" via your newsreader so that others may learn and benefit from your issue. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights.
Hello;
No, I need to be able to create a string like "<item date='1/2/06'>new data</item>" and then I will write that to the file. I cannot use the .NET XML classes to write to the file because: 1) The file is append only so it cannot be read or re-written. 2) The file is not correct XML until midnight - up till then I have the start <root> but not the end </root> and if the system is stopped and restarted it needs to close the file without adding </root> and then open it again in append only mode so all existing text in the file cannot be read. So is there a way to create an XML element and then get it as a string? -- thanks - dave david_at_windward_dot_net http://www.windwardreports.com [quoted text, click to view] "Steven Cheng[MSFT]" wrote:
> Hi Dave, > > Thank you for posting. > > As for writing XML element or append element into XML file, it depends on > the detailed condition. Is the log file very large? If each of the file is > not very large, we can just use XMLDocument class which load the document > into memory and manipulate it. If the file's size will increase to a very > large value, we need to consider using raw XmlWriter to write xml data into > the file. Here is one msdn article discussing on large XML file > manipulating: > > #Efficient Techniques for Modifying Large XML Files > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnxmlnet/ht > ml/largexml.asp > > Hope this helps. > > Regards, > > Steven Cheng > Microsoft Online Community Support > > > ================================================== > > When responding to posts, please "Reply to Group" via your newsreader so > that others may learn and benefit from your issue. > > ================================================== > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > >
Hi;
And in UTF-8 for the node value if at all possible. -- thanks - dave david_at_windward_dot_net http://www.windwardreports.com [quoted text, click to view] "David Thielen" wrote:
> Hello; > > No, I need to be able to create a string like "<item date='1/2/06'>new > data</item>" and then I will write that to the file. > > I cannot use the .NET XML classes to write to the file because: > 1) The file is append only so it cannot be read or re-written. > 2) The file is not correct XML until midnight - up till then I have the > start <root> but not the end </root> and if the system is stopped and > restarted it needs to close the file without adding </root> and then open it > again in append only mode so all existing text in the file cannot be read. > > So is there a way to create an XML element and then get it as a string? > > > -- > thanks - dave > david_at_windward_dot_net > http://www.windwardreports.com > > > > "Steven Cheng[MSFT]" wrote: > > > Hi Dave, > > > > Thank you for posting. > > > > As for writing XML element or append element into XML file, it depends on > > the detailed condition. Is the log file very large? If each of the file is > > not very large, we can just use XMLDocument class which load the document > > into memory and manipulate it. If the file's size will increase to a very > > large value, we need to consider using raw XmlWriter to write xml data into > > the file. Here is one msdn article discussing on large XML file > > manipulating: > > > > #Efficient Techniques for Modifying Large XML Files > > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnxmlnet/ht > > ml/largexml.asp > > > > Hope this helps. > > > > Regards, > > > > Steven Cheng > > Microsoft Online Community Support > > > > > > ================================================== > > > > When responding to posts, please "Reply to Group" via your newsreader so > > that others may learn and benefit from your issue. > > > > ================================================== > > > > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > > > > >
Hi;
Yes that does it. I was looking at using XmlTextWriter because I figure that might be more efficient than creating an XmlDocument each time - is XmlDocument lighter weight? I was really hoping there was a static call like HttpUtility.HtmlEncode that would do it in a very lightweight manner. -- thanks - dave david_at_windward_dot_net http://www.windwardreports.com [quoted text, click to view] "Steven Cheng[MSFT]" wrote:
> Thanks for your followup Dave, > > Then, I think you can just create the Node through > XmlDocument.CreateElement or other method, and the XmlNode or XmlElement > class has the "OuterXml" property which can return the complete XML > fragment of that node. You can write it out to the output stream as normal > string value. Does this helps? > > Regards, > > Steven Cheng > Microsoft Online Community Support > > > ================================================== > > When responding to posts, please "Reply to Group" via your newsreader so > that others may learn and benefit from your issue. > > ================================================== > > > This posting is provided "AS IS" with no warranties, and confers no rights. > > > > Get Secure! www.microsoft.com/security > (This posting is provided "AS IS", with no warranties, and confers no > rights.) >
Thanks for your quick response Dave,
I think just create a XmlDocument instance and use it to create some single Node is not very expensive on performance. The time when we would consider using XmlDocument expensive is when loading a large xml file or stream into xmldocument. And if you use XmlTextReader to do the work(construcing simple node, I don't think it quite convenient since you need to construct extra stream instances to work with it. If you do think using XmlDocument not quite good, you can consider create a custom utility class with static method to create such simple string based xml node. Regards, Steven Cheng Microsoft Online Community Support ================================================== When responding to posts, please "Reply to Group" via your newsreader so that others may learn and benefit from your issue. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. Get Secure! www.microsoft.com/security (This posting is provided "AS IS", with no warranties, and confers no rights.)
Thanks for your followup Dave,
Then, I think you can just create the Node through XmlDocument.CreateElement or other method, and the XmlNode or XmlElement class has the "OuterXml" property which can return the complete XML fragment of that node. You can write it out to the output stream as normal string value. Does this helps? Regards, Steven Cheng Microsoft Online Community Support ================================================== When responding to posts, please "Reply to Group" via your newsreader so that others may learn and benefit from your issue. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. Get Secure! www.microsoft.com/security (This posting is provided "AS IS", with no warranties, and confers no rights.)
Ok, I ran some timing tests. This is what I got (100,000 times):
XmlTextWriter: 2.28 seconds HttpUtility.HtmlEncode: 2.46 seconds XmlDocument: 3.05 seconds So the winner is XmlTextWriter code: // test DateTime start = DateTime.Now; for (int ind = 0; ind < 100000; ind++) { StringWriter sw = new StringWriter(); XmlTextWriter xtw = new XmlTextWriter(sw); xtw.WriteStartElement(ModToNode(mod)); xtw.WriteAttributeString("op", OpToAttr(op)); xtw.WriteString(message); xtw.WriteEndElement(); xtw.Close(); String str = sw.ToString(); str = null; } TimeSpan ts1 = DateTime.Now.Subtract(start); start = DateTime.Now; for (int ind = 0; ind < 100000; ind++) { String str = " <" + ModToNode(mod) + " op='" + OpToAttr(op) + "'>" + TextToAttr(message) + "</" + ModToNode(mod) + ">"; str = null; } TimeSpan ts2 = DateTime.Now.Subtract(start); XmlDocument doc = new XmlDocument(); start = DateTime.Now; for (int ind = 0; ind < 100000; ind++) { XmlElement elem = doc.CreateElement(ModToNode(mod)); XmlAttribute attr = elem.SetAttributeNode("op", ""); attr.Value = OpToAttr(op); elem.InnerText = message; String str = elem.OuterXml; str = null; } TimeSpan ts3 = DateTime.Now.Subtract(start); .... private static string ModToNode(MODULE mod) { return mod.ToString().ToLower().Replace('_', '-'); } private static string OpToAttr(OPERATION op) { return op.ToString().ToLower(); } private static string TextToAttr(string text) { return HttpUtility.HtmlEncode(text); } -- thanks - dave david_at_windward_dot_net http://www.windwardreports.com
That's fine. I agree that a real test will say many words:)
Regards, Steven Cheng Microsoft Online Community Support ================================================== When responding to posts, please "Reply to Group" via your newsreader so that others may learn and benefit from your issue. ================================================== This posting is provided "AS IS" with no warranties, and confers no rights. Get Secure! www.microsoft.com/security (This posting is provided "AS IS", with no warranties, and confers no rights.)
Don't see what you're looking for? Try a search.
|
June 2003
July 2003
August 2003
September 2003
October 2003
November 2003
December 2003
January 2004
February 2004
March 2004
April 2004
May 2004
June 2004
July 2004
August 2004
September 2004
October 2004
November 2004
December 2004
January 2005
February 2005
March 2005
April 2005
May 2005
June 2005
July 2005
August 2005
September 2005
October 2005
November 2005
December 2005
January 2006
February 2006
March 2006
April 2006
May 2006
June 2006
July 2006
August 2006
September 2006
October 2006
November 2006
December 2006
January 2007
February 2007
March 2007
April 2007
May 2007
June 2007
July 2007
August 2007
September 2007
October 2007
November 2007
| home · blog · groups | Questions? Comments? Contact the dn |