Question

I have two rich text boxes, and two buttons on my screen. The first button grabs HTML from a URL and then converts the HTML to XML which resides in rich text box 1.

The second button is to grab the XML from the rich text box1 and then parse it to grab all the input elements by their ID.

My issue is that my parser isn’t doing anything. My guess is that I’m not quite getting the XML from the first rich text box.

What would be the best way to grab the XML from a rich text box load it into memory and then parse the XML to grab all the ID tags?

Here is my code — Thanks for any help.

Imports mshtml
Imports System.Text
Imports System.Net
Imports System.Xml
Imports System.IO
Imports System.Xml.XPath

Public Class Scraper

    Private Sub Scraper_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '  Note: This example uses two Chilkat products: Chilkat HTTP
        '  and Chilkat HTML-to-XML.  The "Chilkat Bundle" can be licensed
        '  at a price that is less than purchasing each product individually.
        '  The "Chilkat Bundle" provides licenses to all existing Chilkat components.  Also, new-version upgrades are always free.

        Dim http As New Chilkat.Http()

        '  Any string argument automatically begins the 30-day trial.
        Dim success As Boolean
        success = http.UnlockComponent("30-day trial")
        If (success <> True) Then
            TextBox1.Text = TextBox1.Text & http.LastErrorText & vbCrLf
            Exit Sub
        End If

        Dim html As String
        html = http.QuickGetStr("http://www.quiltingboard.com/register.php")
        If (html = vbNullString) Then
            TextBox1.Text = TextBox1.Text & http.LastErrorText & vbCrLf
            Exit Sub
        End If

        Dim htmlToXml As New Chilkat.HtmlToXml()

        '  Any string argument automatically begins the 30-day trial.
        success = htmlToXml.UnlockComponent("30-day trial")
        If (success <> True) Then
            TextBox1.Text = TextBox1.Text & htmlToXml.LastErrorText & vbCrLf
            Exit Sub
        End If

        '  Indicate the charset of the output XML we'll want.
        htmlToXml.XmlCharset = "utf-8"

        '  Set the HTML:
        htmlToXml.Html = html

        '  Convert to XML:
        Dim xml As String
        xml = htmlToXml.ToXml()

        '  Save the XML to a file.
        '  Make sure your charset here matches the charset
        '  used for the XmlCharset property.
        htmlToXml.WriteStringToFile(xml, "out.xml", "utf-8")

        RichTextBox1.Text = xml
    End Sub

    Private Sub LoopThroughXmlDoc(ByVal nodeList As XmlNodeList)
        For Each elem As XmlElement In nodeList
            If elem.HasChildNodes Then
                LoopThroughXmlDoc(elem.ChildNodes)
            Else
                '' Extract the information
                If elem.HasAttribute("id") Then
                    'elem.Attributes("AssetID").Value.ToString()
                ElseIf elem.HasAttribute("name") Then
                    'elem.Attributes("AttributeID").Value.ToString()
                End If
            End If
        Next
    End Sub

    Private Sub Button2_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim doc As XmlDocument = New XmlDocument
        doc.Load("xmlFile.xml")
        Dim nodeList As XmlNodeList = doc.GetElementsByTagName("input")
        LoopThroughXmlDoc(nodeList)
    End Sub
End Class

Answer 1

The second button doesn’t grab the XML from the RichTextBox, it attempts to load it from xmlFile.xml.

This file is different than the one that is saved to in button1, which is out.xml.

If the user can change the XML in the richtextbox, then the solution is to change the code in button2 to retrieve the text from the RTB.

Otherwise, the solution is to change the name of the file being read in button2 to out.xml.