Parse and replace element in an xml file

[gtk]

Hello,
i have an xml file, and what i want to do is to replace the value of a specific element (<umps>) with some text dynamically.
More specifically, here is the xml life:

<rule id = "onlyFirstName">
        <tag>FirstName=''; userID=''</tag>
        <one-of>
            <item><umps>PersonalDetails:FirstName</umps><tag>FirstName=<umps>PersonalDetails:FirstName</umps>; userID=<umps>userID</umps></tag></item>
        </one-of>
</rule>

and here is what i want to do:

<rule id = "onlyFirstName">
        <tag>FirstName=''; userID=''</tag>
        <one-of>
            <item><umps>new_Data</umps><tag>FirstName=<umps>another_new_Data_dynamically</umps>; userID=<umps>another_new_one</umps></tag></item>
        </one-of>
</rule>

I'm trying to replace the content of the "umps" element with another text. I mean, i don't care about the current content of the umps element.

I tried to use Regular expressions , but i found difficulty in managing it.

Any help??

[Shashi Sadasivan]

Are you trying to do this by parsing the string or by using the DOM model?

using the DOM model will be a lot easier.

The XmlDocument Class is what you would need for this.

If you face issues with searching for examples using the XmlDocument do get back.

[gtk]

By parsing the string.
Now, i'm trying to do it with Xml classes like XmlTextReader, XmlNodeType, but i have been confused.

Which is the best way to edit xml node values dynamically? i mean, i don't want to search for the substring "<umps>Personal Details:FirstNa me</umps>" but each <umps>...</umps>

[Shashi Sadasivan]

hi
i have not yet used the XMLReader....i think thats based on the SAX model

i have written a code snippet which works for your xml type.

System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
            doc.LoadXml("<rule id = 'onlyFirstName'><tag>FirstName=''; userID=''</tag><one-of><item><umps>PersonalDetails:FirstName</umps><tag>FirstName=<umps>PersonalDetails:FirstName</umps>; userID=<umps>userID</umps></tag></item></one-of></rule>");
 
            System.Xml.XmlNode ruleNode = doc.GetElementsByTagName("rule")[0];
            System.Xml.XmlNode umpsNode = ruleNode.SelectSingleNode("one-of/item/umps");
 
            MessageBox.Show(umpsNode.InnerText);
            umpsNode.InnerText = "new value";
            MessageBox.Show(umpsNode.InnerText);
            MessageBox.Show(doc.InnerXml);

Please note that when loading you might have to use the Load Method instead of the LoadXML ifyou are loading the xml from a streat / file !

[gtk]

thank you for your help.
One more question: if i dont know anything about the exact position of the <umps> tag ( e.g.we don't know the location "one-of/item/umps" as we previously did) in the xml file, is it possible to accomplish the same task ?

Thanks in advance

[Shashi Sadasivan]

yes, you get all the nodes of umps tags
or all nodes whose parent node is one-of

thats where expath comes in
the code whcich says tag/one-of/umps is xpath

take some tutorails on xpath and it will get clearer