VB .NET HTMLAgilityPack Colon Separated Values - vb.net

Question

Is there a way to get the values within a tag using HTMLAgilityPack?
My variable dataNode is an HtmlAgilityPack.HtmlNode and contains:
Dim doc as New HtmlAgilityPack.HtmlDocument()
doc.LoadHtml("
<div id="container" data="id:12,country:usa,city:oregon,id:13,country:usa,city:atlanta">
Google
</div>
")
Would like to get the value of each id, country,city. They repeat within the tag and have different values.
Dim dataNode as HtmlAgililtyPack.HtmlNode
dataNode = doc.documentNode.SelectSingleNode("//div")
txtbox.text = dataNode.Attributes("id[1]").value
This gives an error System.NullReferenceException

Answer 1

You need the "data" attribute, not the "id" attribute.
Once you have the value of the correct attribute, you will need to parse it into some data structure suitable for holding each part of the data, for example:
Option Infer On
Option Strict On
Module Module1
Public Class LocationDatum
Property ID As Integer
Property Country As String
Property City As String
Public Overrides Function ToString() As String
Return $"ID={ID}, Country={Country}, City={City}"
End Function
End Class
Sub Main()
Dim doc As New HtmlAgilityPack.HtmlDocument()
doc.LoadHtml("
<div id=""container"" data=""id:12,country:usa,city:oregon,id:13,country:usa,city:atlanta"">
Google
</div>
")
Dim dataNode = doc.DocumentNode.SelectSingleNode("//div")
Dim rawData = dataNode.Attributes("data").Value
Dim dataParts = rawData.Split(","c)
Dim locationData As New List(Of LocationDatum)
' A simple way of parsing the data
For i = 0 To dataParts.Count - 1 Step 3
If i + 2 < dataParts.Count Then
Dim id As Integer = -1
Dim country As String = ""
Dim city As String = ""
' used to check all three required parts have been found:
Dim partsFoundFlags = 0
For j = 0 To 2
Dim itemParts = dataParts(i + j).Split(":"c)
Select Case itemParts(0)
Case "id"
id = CInt(itemParts(1))
partsFoundFlags = partsFoundFlags Or 1
Case "country"
country = itemParts(1)
partsFoundFlags = partsFoundFlags Or 2
Case "city"
city = itemParts(1)
partsFoundFlags = partsFoundFlags Or 4
End Select
Next
If partsFoundFlags = 7 Then
locationData.Add(New LocationDatum With {.ID = id, .Country = country, .City = city})
End If
End If
Next
For Each d In locationData
Console.WriteLine(d)
Next
Console.ReadLine()
End Sub
End Module
Which outputs:
ID=12, Country=usa, City=oregon
ID=13, Country=usa, City=atlanta
It is resistant to some data malformations, such as id/city/country being in a different order, and spurious data at the end.
You would, of course, put the parsing code into its own function.