How can I retrieve a (quasi) Array from a URL string? - coldfusion

Question

I would like to achieve something I can easily do in .net.
What I would like to do is pass multiple URL parameters of the same name to build an array of those values.
In other words, I would like to take a URL string like so:
http://www.example.com/Test.cfc?method=myArrayTest&foo=1&foo=2&foo=3
And build an array from the URL parameter "foo".
In .net / C# I can do something like this:
[WebMethod]
myArrayTest(string[] foo)
And that will build a string array from the variable "foo".
What I have done so far is something like this:
<cffunction name="myArrayTest" access="remote" returntype="string">
<cfargument name="foo" type="string" required="yes">
This would output:
1,2,3
I'm not thrilled with that because it's just a comma separated string and I'm afraid that there may be commas passed in the URL (encoded of course) and then if I try to loop over the commas it may be misinterpreted as a separate param.
So, I'm stumped on how to achieve this.
Any ideas??
Thanks in advance!!

Answer 1

Edit: Sergii's method is more versatile. But if you are parsing the current url, and do not need to modify the resulting array, another option is using getPageContext() to extract the parameter from the underlying request. Just be aware of the two quirks noted below.
<!--- note: duplicate forces the map to be case-INsensitive --->
<cfset params = duplicate(getPageContext().getRequest().getParameterMap())>
<cfset quasiArray = []>
<cfif structKeyExists(params, "foo")>
<!--- note: this is not a *true* CF array --->
<!--- you can do most things with it, but you cannot append data to it --->
<cfset quasiArray = params["foo"]>
</cfif>
<cfdump var="#quasiArray#">

Answer 2

Well, if you're OK with parsing the URL, following "raw" method may work for you:
<cffunction name="myArrayTest" access="remote" output="false">
<cfset var local = {} />
<!--- parse raw query --->
<cfset local.args = ListToArray(cgi.QUERY_STRING, "&") />
<!--- grab only foo's values --->
<cfset local.foo = [] />
<cfloop array="#local.args#" index="local.a">
<cfif Left(local.a, 3) EQ "foo">
<cfset ArrayAppend(local.foo, ListLast(local.a, "=")) />
</cfif>
</cfloop>
<cfreturn SerializeJSON(local.foo) />
</cffunction>
I've tested it with this query: ?method=myArrayTest&foo=1&foo=2&foo=3,3, looks to work as expected.
Bonus. Railo's top tip: if you format the query as follows, this array will be created automatically in URL scope ?method=myArrayTest&foo[]=1&foo[]=2&foo[]=3,3.

Answer 3

listToArray( arguments.foo ) should give you what you want.