[2005] Reading from xml

[Kimmy4]

Hey guys,

I was wondering if someone could help me with getting data out of my xml file and storing it in arrays

My xml file looks as follows

<?xml version="1.0" encoding="utf-8"?>
<Users>
    <User Name="David Jones" Occupation="Student" OverallPercentage="50">
        	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Reception</ActivityLevel>
		<RightAnswers>2</RightAnswers>
		<WrongAnswers>2</WrongAnswers>
		<PercentRight>50</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Year1</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Year2</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Reception</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Year1</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Year2</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
    </User>
    <User Name = "John Smith" Occupation = "Student" OverallPercentage = "0">
        	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Reception</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Year1</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Numbers</ActivityName>
		<ActivityLevel>Year2</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Reception</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Year1</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	  <Activity>
		<ActivityName>Addition</ActivityName>
		<ActivityLevel>Year2</ActivityLevel>
		<RightAnswers>0</RightAnswers>
		<WrongAnswers>0</WrongAnswers>
		<PercentRight>0</PercentRight>
	  </Activity>
	</User>
</Users>

and so i far i have the following code to load the xml file:

        Dim xmlDoc As XmlDocument = New XmlDocument
        Dim xmlNodelist As XmlNodeList
        Dim xmlNode As XmlNode
        Dim i As Integer = 0

        xmlDoc.Load(xmlFilePath)
        xmlNodelist = xmlDoc.SelectNodes("/Users/User")

Now what i need is for the name, occupation and overall percentage for each user to be stored in one array (which i have already set up) so that it will look as follows:

users(0).Name = "David Jones"
users(0).Occupation = "Student"
users(0).OverallPercentage = 50
users(1).Name = "John Smith"
users(1).Occupation = "Student"
users(1).OverallPercentage = 0

and then i was all the data for the several activities to be stored in a seperate array (which again i already have declared) so that it will look as follows:

activity(0).Name = "Numbers"
activity(0).Level = "Reception"
activity(0).Right = 2
activity(0).wrong = 2
activity(0).percent = 50
activity(1).Name = "Numbers"
activity(1).Level = "Year1"
activity(1).Right = 0
activity(1).Wrong = 0
activity(1).Percent = 0
.
..
...
etc

Thanks in advance for any help offered.

[jmcilhinney]

Don't use an XmlDocument if you just want to read XML data. It is the least efficient way to access XML. The advantage it offers is that it offers read/write, random access to the XML data. You'd only use it when that's what you need. If all you want to do is read the data from top to bottom then the most efficient way, and therefore the correct way, is to use an XmlDataReader.

I don't have time to post more than that for the moment but I suggest that you investigate the class and see what you can come with until I get back or someone else provides more info.

[Kimmy4]

Thanks for the reply.

Well i will be writing to an xml file at some point in the project aswell. I am basically creating a little game, so i will need to read the data in, use it and update it within the program and the write (or update if thats possible) an xml file following the exact same layout.

But i will investigate the xmlDataReader to see what that offers me, but if someone could post a little bit of code to help me along, it will be greatly appreciated.

Thanks again.

[Kimmy4]

*bump*

[wild_bill]

XSD.exe is a cool tool you can use to auto generate a schema from a XML file. With the schema you can create a strongly typed data set, which I think is what you're going for. The following assumes you've put your data in c:\myfile.xml

1. Open the visual studio command prompt
2. Enter xsd.exe C:\myfile.xml /outputdir:C:\
3. Right click your project, select Add > Existing Item
4. Select myfile.xsd, hit Add
5. Add the following code to your app to test it

Dim u As New Users
u.ReadXml("C:\myfile.xml")
'test 
For Each drUser As Users.UserRow In u.User
    Console.WriteLine("<<<<New User>>>>")
    Console.WriteLine(drUser.Name)
    Console.WriteLine(drUser.Occupation)
    Console.WriteLine(drUser.OverallPercentage)
    For Each drActivity As Users.ActivityRow In drUser.GetActivityRows
        Console.WriteLine(drActivity.ActivityName)
        Console.WriteLine(drActivity.ActivityLevel)
        Console.WriteLine(drActivity.RightAnswers)
        Console.WriteLine(drActivity.WrongAnswers)
        Console.WriteLine(drActivity.PercentRight)
    Next
Next

[Kimmy4]

Hi there,

Thanks for the reply but is there any chance you could explain how that works as i may have to explain the process to a lecturer if he asks? Also what process would i use when i came to write to xml after i have used the information i have gotten out of the previous xml?

Or if anybody has any code using the xmldatareader or xmldocument method as i understand how that works and will have no problem explaining to my lecturer if needed.

Thanks again

[wild_bill]

Writing is easy, should be

u.ReadXml("C:\myfile.xml")

All your doing is using a microsoft tool to create a strongly typed dataset based on an XML file you created. The advantages of using a strongly typed dataset, in my opinion, is intellisense through the IDE, and all type converstion is done for you. So with a strongly typed dataset you can use

drUser.Name

rather than

drUser.Item("Name").ToString