Published: Wednesday, August 09, 2000
Parsing WML into HTML, Part 2
By Thomas Winningham
Read Part 1
In Part 1 we looked at how to use ASPTear to grab the headlines from
Slashdot in XML form.
In this part we will look at the source to parse the WML version of Slashdot's article list. You'll notice a
few things:
- My use of ASPTear instead of the XMLDOC.load to get the WML file.
- My use of random numbers which create a unique but harmless extraneous url -
slashdot.wml?random=23048 -
to overcome caching by ASPTear, and c) parsing of WML just like XML.
<%
response.buffer = true
Response.ExpiresAbsolute = Now() - 1
Response.AddHeader "Cache-Control", "private"
Set XMLdoc = Server.CreateObject( "Microsoft.XMLDOM" )
Set xObj = Server.CreateObject("SOFTWING.AspTear")
'start the random number generator
Randomize
'generate a nice random number
randomnum = cstr(Int((100 - 10 + 1) * Rnd + 10))
'get the WML, using a random number to produce a unique
'url to prevent caching
strRetVal = xObj.Retrieve("http://slashdot.org/slashdot.wml" & _
"?random=" & _randomnum,Request_GET,"","","")
set xobj = nothing
'process the WML, and make a link for each article
if xmldoc.loadxml(strRetVal) then
response.write "<html><body>"
response.write "Current Slashdot Articles:<p>"
XSLString = "wml/card/p/select/*"
Set oNodeList = xmlDoc.selectNodes(XSLString)
'for each article, lets just make a link
For Each Item in oNodeList
response.write "<a href="""
response.write "showarticle.asp?url=" & _
Item.attributes.item(1).text
response.write """>"
response.write Item.text
response.write "</a>"
response.write "<br>" & vbcrlf
Next
response.write "</body></html>"
set xmldoc = nothing
else
response.write "nope."
response.write "</body></html>"
set xmldoc = nothing
end if
%>
|
This produces an output like this:
Current Slashdot Articles:
Linux In A Box
HP Plans The Uber-Calculator
Transmeta Testing Mass Production
Windows ME - The End Of UMSDOS And BeOSfs Over Vfat?
Hacker Crackdown?
File Packaging Formats - What To Do?
Sir Alec Guinness Dies
New Images Of Titan's Surface Released
HelixCode Releases Admin Tools
Sega Shutting Down Hundreds Of ROM Sites
Which is great for using a HTML to Email service like Grabpage
or Speedylink. Now, HTML is a markup language
just like XML and WML are. It's all just tags. I have found that most web browsers are rather forgiving, as are
HTML to Email services, so in the last block of code, we like each article to a file called
showarticle.asp, which simply displays the WML without any modification. Most web browsers seem
to display this with little problem, and both email services I mentioned do too. Here's the code for the
showarticle.asp:
<%
response.buffer = true
Response.ExpiresAbsolute = Now() - 1
Response.AddHeader "Cache-Control", "private"
'get the article url from the url to launch this .ASP document
thisarticle = request("url")
Const Request_POST = 1
Const Request_GET = 2
Set xObj = Server.CreateObject("SOFTWING.AspTear")
Randomize
randomnum = cstr(Int((100 - 10 + 1) * Rnd + 10))
strRetVal = xObj.Retrieve("http://slashdot.org" & thisarticle & _
"&random=" & randomnum,Request_GET,"","","")
set xobj = nothing 'Clean up!!
response.write strRetVal 'basically, just write the straight WML to the browser
%>
|
As you can see, we're basically getting the WML, and displaying it. The purpose for this, is that since we
are circumventing WML as a reusable resource for raw data, we need to realize that most browsers upon seeing
the .WML will try to save or otherwise not display it. It is essentially text, and we can grab it from the
server for processing. An example output of this code is here:
Linux In A Box
Henrik pointed us to the Linux in a Box project, which is a bitchin' little
project to create an inexpensive little Linux box: it boots a 2.0.36 kernel from
a ramdisk, and it's pingable and Telenetable, as well as being usable as a Web
server. Only for the brave of heart and willing to hack.
Back
The Palm interface (http://slashdot.org/palm) to Slashdot goes further
than the WML to also offer the top 10 comments from users, and honestly I've started using it as my Slashdot
fix while on the road. It's reasonably current lately, and is of course a great read.
So, as you can see, WML is a valuable resource even though it is intended for wireless devices. The Internet's
trend to XML has been somewhat encouraged by WML, and we should observe the data portability that WML can still
offer, since it essentially is just XML data. Again, a good way to avoid ASPTear or ISP caching is to use
random number generators to add extra url strings (that will be ignored by the remote scripts usually), and
the Microsoft XMLHTTPREQUEST is currently broken for use in server side applications. Thanks for reading!
By Thomas Winningham
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