I have been given the task of calling a web service which returns an xml data feed which I am doing like so;
For Each r As DataRow in SomeDataTable
Dim msFeed As String = string.format("http://some-feed.com?param={0}", r!SOME_VAL)
Dim x As XDocument = XDocument.Load(msFeed)
Next
This is all fine but as you can see x just gets overwritten with every iteration. What I need is create an xDocument and add each feed from my loop but I am unsure how to proceed.
Thanks
Solution
Dim xAllFeeds As XElement = New XElement("Feeds")
For Each r As DataRow in SomeDataTable
Dim msFeed As String = string.format("http://some-feed.com?param={0}", r!SOME_VAL)
Dim x As XDocument = XDocument.Load(msFeed)
xAllFeeds.Add(x.Root)
Next
Not 100% sure of the VB syntax (C# is my language of choice), but this should be the gist of what you're after.
Dim xAllFeeds As XElement = New XElement("Feeds")
For Each r As DataRow in SomeDataTable
Dim msFeed As String = string.format("http://some-feed.com?param={0}", r!SOME_VAL)
Dim xDoc As XDocument = XDocument.Load(msFeed)
xAllFeeds.Add(xDoc.Root)
Next
Related
I am trying to download a webpage as string. Can someone please explain why the following code doesn't work?
Dim URL As String = "http://stackoverflow.com/"
Dim client As WebClient = New WebClient()
Dim data As Stream = client.OpenRead(URL)
Dim reader As StreamReader = New StreamReader(data)
Dim str As String = ""
str = reader.ReadLine()
Do While str.Length > 0
Console.WriteLine(str)
str = reader.ReadLine()
Loop
When I run it it never goes inside the loop.
Give this a shot...
Dim URL As String = "http://stackoverflow.com/"
Dim html As String = New WebClient().DownloadString(URL)
Better Solution (Releases resources that the network stack is using. Also ensure's (hope) the CLR cleans these up when needed.)
Using client As New WebClient()
html = client.DownloadString(URL)
End Using
I've an XML string in database column like this
<trueFalseQuestion id="585" status="correct" maxPoints="10"
maxAttempts="1"
awardedPoints="10"
usedAttempts="1"
xmlns="http://www.ispringsolutions.com/ispring/quizbuilder/quizresults">
<direction>You have NO control over how you treat customers.</direction>
<answers correctAnswerIndex="1" userAnswerIndex="1">
<answer>True</answer>
<answer>False</answer>
</answers>
</trueFalseQuestion>
But I need to do XML operations on this string like select its name, attributes values,inner text etc. How can I make this possible from this string
EDIT
Im sharing the code snippet I tried, but not working
Dim myXML As String
Dim gDt As New DataTable
gDt.Columns.Add("id")
gDt.Columns.Add("questionid")
gDt.Columns.Add("serial")
gDt.Columns.Add("direction")
Dim dr As DataRow
myXML ='<my above shared XML>'
Dim xmlDoc As New XmlDocument
xmlDoc.LoadXml(myXML)
dr = gDt.NewRow
dr("serial") = 1
dr("id") = xmlDoc.Attributes("id").Value
dr("direction") = xmlDoc("direction").InnerText
gDt.Rows.Add(dr)
But thats not working at all as I wish
There are many ways to parse XML in .NET, such as using one of the serialization classes or the XmlReader class, but the two most popular options would be to parse it with either XElement or XmlDocument. For instance:
Dim input As String = "<trueFalseQuestion id=""585"" status=""correct"" maxPoints=""10"" maxAttempts=""1"" awardedPoints=""10"" usedAttempts=""1"" xmlns=""http://www.ispringsolutions.com/ispring/quizbuilder/quizresults""><direction>You have NO control over how you treat customers.</direction><answers correctAnswerIndex=""1"" userAnswerIndex=""1""><answer>True</answer><answer>False</answer></answers></trueFalseQuestion>"
Dim element As XElement = XElement.Parse(input)
Dim id As String = element.#id
Or:
Dim input As String = "<trueFalseQuestion id=""585"" status=""correct"" maxPoints=""10"" maxAttempts=""1"" awardedPoints=""10"" usedAttempts=""1"" xmlns=""http://www.ispringsolutions.com/ispring/quizbuilder/quizresults""><direction>You have NO control over how you treat customers.</direction><answers correctAnswerIndex=""1"" userAnswerIndex=""1""><answer>True</answer><answer>False</answer></answers></trueFalseQuestion>"
Dim doc As New XmlDocument()
doc.LoadXml(input)
Dim nsmgr As New XmlNamespaceManager(doc.NameTable)
nsmgr.AddNamespace("q", "http://www.ispringsolutions.com/ispring/quizbuilder/quizresults")
Dim id As String = doc.SelectSingleNode("/q:trueFalseQuestion/#id", nsmgr).InnerText
Based on your updated question, it looks like the trouble you were having is that you weren't properly specifying the namespace. If you use XElement, it's much more forgiving (i.e. loose), but when you use XPath to select nodes in an XmlDocument, you need to specify every namespace, even when it's the default namespace on the top-level element of the document.
I have a couple of problems relating to one of the parameters passing a number of values to a stored procedure and the result that comes back converting to dataset in order for this to be bound to an MS ReportViewer.
The error I am getting says that the the reader is closed.
My relevant code snippet is:
Dim _listOfSites As New StringBuilder()
Dim _resultDataSet As DataSet = New DataSet
Using _conn as New SqlConnection()
_conn.ConnectionString = _connString
Try
For i as Integer = 0 To _sites.Count - 1
_listOfSites.Append(_sites(i))
If _sites.Count > 1 Then
_listOfSites.Append(",")
End If
Next
_conn.Open()
Dim _sqlCommand as SqlCommand = New SqlCommand("GetResults", _conn)
_sqlCommand.Parameters.Add("#Sites", SqlDbType.Varchar).Value = _listOfSites
_sqlCommand.Parameters.Add("#Date", SqlDbType.Date).Value = _date
Dim _reader as SqlDataReader = _sqlCommand.ExecuteReader
While _reader.Read
_resultDataSet.Load(_reader, LoadOption.PreserveChanges, New String() {"RegionalResults"})
End While
_reader.Close()
Can anyone please help?
Thanks
Looks like you should not call _reader.Read as _resultDataSet.Load do it by itself and it could close the SqlDataReader. So instead of
Dim _reader as SqlDataReader = _sqlCommand.ExecuteReader
While _reader.Read
_resultDataSet.Load(_reader, LoadOption.PreserveChanges, New String() {"RegionalResults"})
End While
_reader.Close()
Just write
Using _reader as SqlDataReader = _sqlCommand.ExecuteReader
_resultDataSet.Load(_reader, LoadOption.PreserveChanges, New String() {"RegionalResults"})
End Using
Hope that helps
I'm receiving an xml response and I now want to parse this.
Currently what I have to receive the XML response is:
Dim textReader = New IO.StreamReader(Request.InputStream)
Request.InputStream.Seek(0, IO.SeekOrigin.Begin)
textReader.DiscardBufferedData()
Dim Xmlin = XDocument.Load(textReader)
How can I go ahead now a process this and pick out the element values?
<subscription>
<reference>abc123</reference>
<status>active</status>
<customer>
<fname>Joe</fname>
<lname>bloggs</lname>
<company>Bloggs inc</company>
<phone>1234567890</phone>
<email>joebloggs#hotmail.com</email>
</customer>
</subscription>
If I have it in string format I can do this using
Dim xmlE As XElement = XElement.Parse(strXML) ' strXML is string version of XML
Dim strRef As String = xmlE.Element("reference")
Do I need to convert the request.inputstream to a strign format or is there another better way?
Thanks
Do I need to convert the request.inputstream to a strign format or is there another better way?
You could directly load it from the request stream, you don't need to convert it to a string:
Request.InputStream.Position = 0
Dim Xmlin = XDocument.Load(Request.InputStream)
Dim reference = Xmlin.Element("subscription").Element("reference").Value
or:
Dim reference = Xmlin.Descendants("reference").First().Value
In the end after much testing I could only get this to work:
Dim textReader = New IO.StreamReader(Request.InputStream)
Request.InputStream.Seek(0, IO.SeekOrigin.Begin)
textReader.DiscardBufferedData()
Dim Xmlin = XDocument.Load(textReader)
Dim strXml As String = Xmlin.ToString
Dim xmlE As XElement = XElement.Parse(strXml)
Dim strRef As String = xmlE.Element("reference")
Dim strStatus As String = xmlE.Element("status")
Dim strFname As String = xmlE.Element("customer").Element("fname").Value()
Dim strLname As String = xmlE.Element("customer").Element("lname").Value()
Dim strCompany As String = xmlE.Element("customer").Element("company").Value()
Dim strPhone As String = xmlE.Element("customer").Element("phone").Value()
Dim strEmail As String = xmlE.Element("customer").Element("email").Value()
Using the following code:
Private Sub MakeMeSomeXmlBeforeRyanGetsAngry()
Dim db As New MyDBDataContext
Dim customer = From c In db.Customers Select c
Dim dcs As New DataContractSerializer(GetType(Customer))
Dim sb As StringBuilder = New StringBuilder
Dim writer As XmlWriter = XmlWriter.Create(sb)
dcs.WriteObject(writer, customer)
Dim xml As String = sb.ToString
Response.Write(xml)
End Sub
I am attempting to serialize my linq collection of customers. But it keeps throwing
Type 'System.Data.Linq.DataQuery`1[MyDB.Customer]' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. See the Microsoft .NET Framework documentation for other supported types.
My issue is that I have already marked the dbml Serialization Mode to UniDirectional and when I check the dbml codebehind all of the DataContract()> and DataMember()> elements are there.
I am not sure how to proceed. I have tried adding various dataloadoptions and setting deferredloading to false, but no luck.
Ideas?
This is working for me with Serialization Mode property of .dbml set to UniDirectional:
Public Shared Function CreateXml(Of T)(ByVal item As T) As String
Dim result As String = ""
Dim memoryStream As New IO.MemoryStream()
Dim serializer As New DataContractSerializer(GetType(T))
serializer.WriteObject(memoryStream, item)
memoryStream.Position = 0
Using reader As New StreamReader(memoryStream)
result = reader.ReadToEnd()
End Using
memoryStream.Close()
Return result
End Function
Dim db As New SerializerDataContext()
Dim questions = db.Questions.ToList()
Dim xmlFileName As String = "D:\\xml_test.xml"
If My.Computer.FileSystem.FileExists(xmlFileName) Then My.Computer.FileSystem.DeleteFile(xmlFileName)
Dim xml As String = XmlHelper.CreateXml(Of List(Of Question))(questions)
My.Computer.FileSystem.WriteAllText(xmlFileName, xml, True)
I think the problem arises because LINQ queries are processed only on demand, and are not serializable. Try to serialize a serializable data type resulting from your LINQ query (array, list, a single item, etc.)
dcs.WriteObject(writer, customer.ToArray)
(I assume you only need to serialize the results of the query, and not the query itself)