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Hello:
I want to know how to parse(read) the information contained in a web page, using a VB applet that will refresh this information every 2 or 3 seconds. The web page is very simple, does not contain images and only a marquee (which can be eliminated), it only contaings text that displays temperature readings etcetera.
I know that i have to use the webbrowser control, and after the document has loaded i have to parse it, what i dont know is how to parse it.
Thanks
whats the URL? (or is it a local page)
We will need to see the source to be able to give u some code to do this.
if this page is online, the 2 to 3 seconds may not be possible with the webbrowser control. but what can be done is reload as soon as its done parsing which should still be very fast.
The webpage is local (its being generated by a microcontroller board), i dont really have that much of a source code, but i have read some. I also want to know if it is possible to just extract the information, ignoring a marquee thats on the page.
thanks
Yes. but I need to see the full source and what u want to get from it.
Using the webbrowser control combined with a reference to the HTML Object Library..
it should be a snap.
Can u post the full source? (or attach the page)
Thanks!
ok
i will post the full source
It would be easiest using the webbrowser control, but I suggest you use the Inet control to increase the speed of the download (if that is a priority to you).
Post the source code of the page as Static said, and we will be able to help you generate code to parse it.
Web Server for Embedded Applications\
</I>\r\n\
<BR>\
<A HREF=http://www.violasystems.com>\
www.violasystems.com - Embedding The Internet</A>\
</BODY>";
char Https_TestIndexPage[] = "HTTP/1.0 200 OK\r\n\
Last-modified: Fri, 18 Oct 2002 12:04:32 GMT\r\n\
Server: ESERV-10/1.0\nContent-type: text/html\r\n\
Content-length: 400\r\n\
\r\n\
<HEAD>\
<TITLE>UPRB Sistema de monitoreo de Sensores</TITLE></HEAD>\
<BODY>\
<DIV align=center>\
<H2><MARQUEE behavior=scroll direction=right width=500> MCF5282 Microcontroller</DIV></MARQUEE></H2>\
<BR>\
<DIV align=center>\
UPRB Salón 121 \
<HR>\
<BR> Temperatura Fahrenh = \
<I>\r\n\
<BR> Humedad Relativa = \
<BR> Intensidad de luz = \
<BR> Sensor de Humo = \
<BR> Sensor de Movimiento = \
<BR> Sensor de Puerta = \
<BR> Servidor WEB <BR></I>\r\n\
<BR>\
<A HREF=http://www.uprb.edu>\
www.uprb.edu</A>\
<BR><BR>\
<HR>\
</DIV>\
</BODY>";
this the part of the C code that generates the web page
;)
we need just the final result (the HTML) with data included for testing
the thing is that the variables that are displayed are made in another section of the microcontroller, can u suggest any code with what you have up until now and i will fill in the gaps
where it says
<BR> Temperatura Fahrenh = \
<I>\r\n\
<BR> Humedad Relativa = \
<BR> Intensidad de luz = \
<BR> Sensor de Humo = \
<BR> Sensor de Movimiento = \
<BR> Sensor de Puerta = \
this is the part of the html that i want to read (its in spanish)
ok i have been able to parse the inner text out of the web-page,now i have another problem:
when i try to reload the page after a variable(im controlling) changes, the information "read" by the program is not updated, and i know its a problem with the cache.
Any Info on this i will post the source code following this
Option Explicit
Private Sub cmdExit_Click()
If MsgBox("Are you sure?", vbYesNo, "Exiting the application") = vbYes Then
Unload Me
End If
End Sub
Private Sub cmdGo_Click()
Dim objLink As HTMLLinkElement
Dim objMSHTML As New MSHTML.HTMLDocument
Dim objDocument As MSHTML.HTMLDocument
lblStatus.Caption = "Gettting document via HTTP"
' This function is only available with Internet Explorer 5
Set objDocument = objMSHTML.createDocumentFromUrl(txtURL.Text, vbNullString)
lblStatus.Caption = "Getting and parsing HTML document"
' Tricky, to make the function wait for the document to complete, usually
' the transfer is asynchronus. Note that this string might be different if
' you have another language than english for Internet Explorer on the
' machine where the code is executed.
While objDocument.readyState <> "complete"
DoEvents
Wend
lblStatus.Caption = "Document completed"
' Copying the source to the text box
txtSource.Text = objDocument.documentElement.innerText
DoEvents
' Copying the title of the page to the label
lblTitle.Caption = "Title : " & objDocument.Title
DoEvents
lblStatus.Caption = "Extracting links"
' Processing the link collection of the HTMLDocument object
For Each objLink In objDocument.links
lstLinks.AddItem objLink
lblStatus.Caption = "Extracted " & objLink
DoEvents
Next
lblStatus.Caption = "Done"
Beep
End Sub
is there a way to make the program always look on the web page for the document instead of the cache?