Debugging ajax calls with ColdFusion part deux
A few days ago I wrote a post about debugging ajax calls with ColdFusion. My approach was to basically write every remote method within a cftry/cfcatch block. Ray suggested I use the new onCFCRequest() method built in to CF9, unfortunately I am not running CF9.
However it did get me to thinking about ways I could create a wrapper for handling errors in my remote methods. I tried several different ways based on onRequestStart and onRequest, but nothing really came of it. Next I tried setting up my error handling strangely enough in the onError method. This method works, but I am still not quite sure how I feel about it. Here is what I worked out:
<cffunction name="onError" access="public" returntype="void" output="true"> <cfargument name="Exception" type="any" required="true"/> <cfargument name="EventName" type="string" required="false" default="" /> <cfset var result = structNew()/> <cfif arrayLen(arguments.exception.tagContext) and lcase(listLast(listLast(arguments.exception.tagContext.template, '/'), '.')) EQ "cfc"> <cfset result['svrStatus'] = "-1"/> <cfset result['svrMessage'] = arguments.exception.message/> <cfoutput>#serializeJSON(result)#</cfoutput> <cfelse> <cfdump var="#arguments#"/> </cfif> </cffunction>
This actually works out fairly well. When fired, the onError method checks to see if it was called from a CFC or a CFM page. If it was called from a CFC it sets up the default return values for an error and then returns the data as a JSON object. What I do not like about this method is, every CFC returns the dump as a JSON object, whether it is a remote remote method or not. I would rather have a hard error if an application-scoped CFC failed, but I guess we cannot have it all. I would have to say it makes a lot more sense to handle things this way instead of writing every CFC method in a try/catch block.