Hi Folks,
I have built a very simple parser using CFHTTP to grab prices
and stock availability on various products. Using the same theory,
it works fine with some sites but no with others. I figured I'd
pick out one of them as an example to see where it might be falling
down.
My question is two-fold - firstly, why does this example
produce an error, and secondly, is there a better way of doing this
(I don't have access to anything other than the page data).
So, on to the script;
<!--- cfhttp scraper --->
<!--- price --->
<cfset nstartcode='<div class="standard-price">
<span class="label">Price </span> £'>
<cfset nendcode='</div>
<div class="deliveryShortcut">'>
<!--- get the page --->
<cfhttp url="
http://www.dixons.co.uk/martprd/product/seo/626225/?int=pleo"
method="get">
</cfhttp>
<!--- parse the output --->
<cfset nStart=Find(nstartcode, cfhttp.FileContent) +0>
<cfset nEnd=Find(nendcode, cfhttp.FileContent,
nStart+1)>
<cfset liveprice=Mid(cfhttp.FileContent, nStart, nEnd -
nStart)>
<!--- stock --->
<cfset astartcode='class="stock">'>
<cfset aendcode='</div>'>
<!--- get the page --->
<cfhttp url="
http://www.dixons.co.uk/martprd/product/seo/626225/?int=pleo"
method="get">
</cfhttp>
<!--- parse the output --->
<cfset nStart=Find(astartcode, cfhttp.FileContent)
+14>
<cfset nEnd=Find(aendcode, cfhttp.FileContent,
nStart+1)>
<cfset stock_status=Mid(cfhttp.FileContent, nStart, nEnd
- nStart)>
<cfset stock='#stock_status#'>
<!--- --->
The following error is returned when I run the above;
<!--- error message --->
The 3 parameter of the Mid function, which is now -14295,
must be a non-negative integer
The error occurred in **removed**\parse.cfm: line 11
9 : <cfset nStart=Find(nstartcode, cfhttp.FileContent)
+0>
10 : <cfset nEnd=Find(nendcode, cfhttp.FileContent,
nStart+1)>
11 : <cfset liveprice=Mid(cfhttp.FileContent, nStart, nEnd
- nStart)>
12 : <!--- stock --->
13 : <cfset astartcode='class="stock">'>
<!--- --->
Any help or advice would be greatly appreciated.
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