Match Values inside Tags as

Question

Hi Folks,
I played with this for hours and can't seem to get it.
I need Regular Expression pattern that gets the values 1234569@XYZ2 like following

<BookID id="1234569@XYZ2" Duplicateid="1234569@XYZ2">

<name>XYZ bla bla</name>

</BookID>

Just need the pattern string.
Thanks

Answer 1

Is there any reason you can't use LINQ to XML to get the attributes? That would be ideal.

Otherwise, how about this:

string input = @"<BookID id=""1234569@XYZ2"" Duplicateid=""1234569@XYZ2"">
                    <name>XYZ bla bla</name>
                </BookID>";
string pattern = "=\"(?<Value>[^\"]+)\"";
foreach(Match m in Regex.Matches(input, pattern))
{
    Console.WriteLine(m.Groups["Value"].Value);
}

You could make the pattern stricter, if needed, but this should get you started.

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Document my code? Why do you think it's called "code"?

Answer 2

If possible, I would try to use either Linq to XML or the XmlDocument class to get at this information.  It will be much easier to accurately identify the attributes and their values using these classes than it will be using regular expressions.

Answer 3

Thank you both for the response.

I haven't played with LINQ and not sure how it works.

Without too much details, i wonder how it works?

Someone would load the source file to LINQ, then there is LINQ to XML functions/properties??

Also, in the above pattern; i meant the file will contain many lines each of wich is as follows, but values in it will be different each line: I just put the seperator to show you there will be morethan one line.
I can't put the numbers 1234569@XYZ because each line will different. can i use pattern that gets values behind the
BookID id=  and stops at the closing quotes like.


<BookID id="1234569@XYZ2" Duplicateid="1234569@XYZ2">

<name>XYZ bla bla</name>

</BookID>
-------------------------------------------------------------------------------------------------------
<BookID id="1234569@XYZ2" Duplicateid="1234569@XYZ2">

<name>XYZ bla bla</name>

</BookID>
--------------------------------------------------------------------------------------------------------
<BookID id="1234569@XYZ2" Duplicateid="1234569@XYZ2">

<name>XYZ bla bla</name>

</BookID>

Answer 4

The pattern I gave earlier achieved that. Here's a complete example to demonstrate both the regex and LINQ to XML approaches:

// sample of valid xml
string xml = @"<Books>
<BookID id=""1234569@XYZ2"" Duplicateid=""1234569@XYZ2"">
<name>XYZ</name>
</BookID>
<BookID id=""123@ABC1"" Duplicateid=""456@ABC2"">
<name>ABC</name>
</BookID>
<BookID id=""789@HIJ22"" Duplicateid=""321@HIJ90"">
<name>HIJ</name>
</BookID>
</Books>";

// Using Regex
string pattern = @"\bid=""(?<Id>[^""]+)""\s+Duplicateid=""(?<DuplicateId>[^""]+)""";
foreach (Match m in Regex.Matches(xml, pattern))
{
    Console.WriteLine("Id: {0} -- DuplicateId: {1}", m.Groups["Id"].Value, m.Groups["DuplicateId"].Value);
}

// Using LINQ to XML
XDocument doc = XDocument.Parse(xml);
var query = from element in doc.Root.Elements("BookID")
            select new
            {
                Id = element.Attribute("id").Value,
                DuplicateId = element.Attribute("Duplicateid").Value
            };
            
foreach (var book in query)
{
    Console.WriteLine("Id: {0} -- DuplicateId: {1}", book.Id, book.DuplicateId);
}

You really need to play with LINQ to get familiar with it. If you're interested in LINQ to XML you can get started here . I also highly recommend Joseph Albahari's free LINQPad tool . It is a light-weight snippet compiler with support for LINQ to SQL (and all LINQ flavors). In addition, it comes with sample code from his book, C# 3.0 in a Nutshell, which is helpful in demonstrating how LINQ works.

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Document my code? Why do you think it's called "code"?

Answer 5

The key to these sort of expression is the Non-Greedy Quantifier.

@"id=""(.*?)"""

Answer 6

Hi MAbshir,
Are those replies helpful for you, or you still have any concern about this issue? It will be very beneficial for other community members having the similar questions if  you mark useful replies as answers.

Thanks,
Eric

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Please remember to mark helpful replies as answers and unmark them if they provide no help.

Answer 7

Hi Eric,
Yeah the response was helpfull. I got off track and just getting back to the the linkQ thing.
 Sorry, i thought i marked it.

Appreciated everybody's help.