Parsing through an XML file

[pkonshak]

Hi,

I'm working with an XML file that is generated through Google's Books API.  I'm going to apologize in advance if I don't get the XML terminology quite correct -- this is my first foray into some of the CF XML tags.  I'm reading an XML file in, and attempting to output some data:

<cfhttp url="http://www.google.com/books/feeds/volumes?q=john+grisham+the+firm&min-viewability=partial" method="GET">

<CFSET xmlfile = xmlparse(cfhttp.filecontent)>

<cfset xmlsize = arraylen(xmlfile.feed.entry)>

<cfloop from="1" to="#xmlsize#" index="a">
    

<b>Title:</b> #xmlfile.feed.entry.title.xmlText#<br>
<b>Format:</b> #xmlfile.feed.entry.format.xmlText#<br>
<b>Author:</b> #xmlfile.feed.entry.creator.xmlText#<br>
<b>Identifier1:</b> #xmlfile.feed.entry.identifier.xmlText#<br>
<b>Identifier2:</b> #xmlfile.feed.entry.identifier[2].xmlText#<br>

</cfoutput>
</cfloop>

This works reasonably well.  Here's the problem:  there is often a third identifier field (xmlfile.feed.entry.identifier[3].xmlText) -- but not always.

I'm trying to test for the existence of this field before outputting it.  I've tried the following:

<CFIF isdefined("xmlfile.feed.entry.identifier[3].xmlText")>
is defined

<CFELSE>

is not defined
</cfif>

That gives the typical error:

Parameter 1 of function IsDefined, which is now xmlfile.feed.entry.identifier[3].xmlText, must be a syntactically valid variable name.

I would like to use structkeyExists, but I can't figure out how to reference the third node (?) using the code:

<cfif structKeyExists(xmlfile.feed.entry,"identifier")> only works for xmlfile.feed.entry.identifier[1].xmlText

<cfif structKeyExists(xmlfile.feed.entry,"identifier[3]")> isn't valid.

So with strucktkeyexists, I cannot figure how to appropriately reference the variable name....

Any help?  Or better ideas to check for the existence of this variable?

[Owainnorth · Accepted solution]

The node you're looking at is an array, therefore:

<cfif arraylen(xmlfile.feed.entry.identifier) GT 2 >

should do you. At present you're testing for the "xmltext" attribute rather than checking its parent node exists.

HTH.

[pkonshak]

So simple, and here I've been banging my head against a wall..

Thanks for the lightning-fast responses!

Peter

[Owainnorth]

Luckily, Adam and myself are clearly both trying to get out of doing any real work

[Adam Cameron.]

You want to be checking the length of the identifier array (ie: are there three elements?)

--

Adam