Looking at an incoming page and determing if a form is being passed

Question

I need to determine whether or not a page is passing a form to our internal site. We need to redirect if the page comes from an outside domain.

A coworker came up with this code:

<cfif isDefined("form")>
  <cfif not findnocase("our_domain", http_referer)>
    <cflocation url="redirect_link">
  </cfif>
</cfif>

I don't think he is using isDefined() properly because isDefined() looks for a variable. We need to look for the form itself. I've also looked into structKeyExists(), but again, this looks for variables within the form. How can I look for the form itself?

Answer 1

There's two ways. You can check CGI.REQUEST_METHOD to check for whether a POST is being sent.

You can also check structKeyExists(form,"fieldNames") which will only be the case when a form has actually been submitted.

Although not in the question, I'd also avoid referencing http_referer without a scope. Use CGI.http_referer as it's easier to read. You could also combine the test for FORM and the external referer into one statement:

<cfif structKeyExists(form,"fieldNames") AND NOT findnocase("our_domain", CGI.http_referer)>
   <cflocation url="redirect_link">
</cfif>

Also, you know that the redirect won't carry any of the form fields over with it? I'm guessing that's what you want, but it's worth mentioning.