Verify if a method of an object exists - coldfusion

Question

I'm calling a web service through ColdFusion which returns an object, and I want to verify if one of the methods of this object exists as it won't always exist.
I found this source which seemed promising however based on my tests I can see the results are always negative and the method is never found when it's clearly there.
<cfif structKeyExists("#Result.getNotifications().getValidationResult(0)#","getField")>
Result is my underlying object, and my end goal is to verify if the method getField() exists.
Is there a clean way to do this as opposed to a try/catch?

Answer 1

Update:
Unfortunately, I am not sure IsInstanceOf() works with web services, due to the fact that CF uses a Proxy object to "wrap" the underlying web service class. If not, another simple option is to check class name. That avoids the ambiguity of checking for method name only (which could potentially exist in many different classes). Plus I suspect it may be more light-weight than IsInstanceOf() anyway.
<cfif compare(yourObject.getClass().name, "org.tempuri.ValidationResultField") eq 0>
Found ValidationResultField. do something
</cfif>
It looks like the dump contains several different types of objects/classes: ArrayOfValidationResult, ValidationResultField, etecetera. It sounds like what you are really trying to determine is which of those classes you are working with, so you know exactly what fields and methods will be available, per the web service definitions. Given that, I think IsInstanceOf() would be a more appropriate test, than checking for method names. More accurate as well. Nothing prevents two different classes from having the same method name. So even if method X or Y exists, there is still a possibility it may be a different class than expected.
<cfif IsInstanceOf(yourObject, "org.tempuri.ValidationResultField")>
do something
</cfif>

Answer 2

As far as I know, the mentioned structKeyExists approach only works if CF wraps the class internally, e.g. all instances of cfcomponent.
The only option left is to actually reflect the class:
<cftry>
<cfset Result.getNotifications().getValidationResult(0).getClass().getMethod("getField", javaCast("null", ""))>
<!--- method does exist --->
<cfcatch type="coldfusion.runtime.CfJspPage$UnsupportedBaseTypeException">
<!--- method does not exist --->
</cfcatch>
</cftry>
If the method doesn't exist, it throws UnsupportedBaseTypeException, which seems to be a follow-up of NoSuchMethodException.
Honestly, you might as well just invoke the method and catch it. Reflection comes with an additional overhead and you have to catch it anyway.

Answer 3

Like Miguel-F, I think this is something for getMetadata(). The following should return an array containing the respective functions of the object:
<cfset funcs = getmetadata(nameOfObj).functions>
The names of the functions are then funcs[1].name, funcs[2].name, and so on.

Answer 4

In general, you may obtain the metadata of all the functions of a webservice, given the URL of the WSDL, with something like
<cfhttp method="get" url="http://www.webservicex.net/globalweather.asmx?WSDL" result="res">
<cfset wsXml=xmlparse(res.filecontent)>
<cfset wsOperations = xmlsearch(wsXml,"//wsdl:operation")>
<cfdump var="#wsOperations#">
Another method you could look at (perhaps undocumented) is to get the method names from the class names in the stubs directory.
The code to run is:
<cfscript>
wsargs = structnew();
wsargs.savejava="yes";
</cfscript>
<cfset convert=createobject("webservice","url_of_wsdl",wsargs)>
Then figure out how to fish out the names from the stubs directory, {CF_INSTALL}/stubs. In my case, CF_INSTALL is C:/ColdFusion2016/cfusion/