How to determine if XML is well formed?

Question

I've got a large xml document in a string. What's the best way to determine if the xml is well formed?

score 15 · Accepted Answer · answered Apr 08 '09 at 08:33

Something like:

    static void Main() {
        Test("<abc><def/></abc>");
        Test("<abc><def/><abc>");
    }
    static void Test(string xml) {
        using (XmlReader xr = XmlReader.Create(
                new StringReader(xml))) {
            try {
                while (xr.Read()) { }
                Console.WriteLine("Pass");
            } catch (Exception ex) {
                Console.WriteLine("Fail: " + ex.Message);
            }
        }
    }

If you need to check against an xsd, then use XmlReaderSettings.

score 5 · Answer 2 · answered Apr 08 '09 at 08:18

Simply run it through a parser. That will perform the appropriate checks (whether it parses ok).

If it's a large document (as indicated) then an event-based parser (e.g. SAX) will be appropriate since it won't store the document in memory.

It's often useful to have XML utilities around to check this sort of stuff. I use XMLStarlet, which is a command-line set of tools for XML checking/manipulation.

score 3 · Answer 3 · answered Apr 08 '09 at 08:19

3

XmlReader seems a good choice as it should stream the data (not load the whole xml in one go)

http://msdn.microsoft.com/en-us/library/9d83k261.aspx

answered Apr 08 '09 at 08:19

bh213

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score 2 · Answer 4 · answered Apr 08 '09 at 08:20

2

Try using an XmlReader with an XmlReaderSettings that has ConformanceLevel.Document set.

answered Apr 08 '09 at 08:20

dommer

19,610
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How to determine if XML is well formed?

4 Answers4