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coldfusioncoldfusion-9cfc

Using "var this" inside remote CFC methods

I've inherited a project where there are a number of remote CFC's opened up for some Ajax requests and inside most methods in the CFC have the following:

<cfset var this.response = true />

Now I've never seen the var and this scope used together like this so I'm really not sure what to make of it so I guess my questions is:

Are there any issues with how this was coded? If so, are they major enough that I should put in the effort to update all the CFC's to something like <cfset var req.response = true />?

Here is a quick example of what I'm seeing:

<cfcomponent>

    <cffunction name="check_foo" access="remote" returnformat="plain">

        <cfargument
          name     = "isfoo"
          type     = "string"
          required = "false"
          default  = "nope"
          hint     = "I check the string for foo"
          />

        <cfscript>

          /*setup new response*/
          var this.response = false;

          /*check for foo*/
          if( !findnocase( "foo", arguments.isfoo ) ) {

            /*no foo!*/
            this.response = false;

          }

          return this.response;

        </cfscript>

    </cffunction>

</cfcomponent>

.

Updates:

  1. Based on the feedback/answers below I've replace all instances of var this. Thanks again to everyone that helped out!

.

Solution

  • Using var this is the same as using this.

    Dumping the local scope will include local variables as well as the Arguments and This scopes. (Can't find this documented; but I get this result in a bare cfc, and you got it in your screenshots.)

    Because your function is access="remote" you'll be getting a new instance of the cfc on every call, and therefore a bare This scope. So those are "safe", but still a bad idea.

    If there is any use of var this in non-remote functions then you will be getting undesired persistence and may suffer race conditions that result is invalid data.

    Relevant CF documentation:

    "Methods that are executed remotely through Flash Remoting and web services always create a new instance of the CFC before executing the method."

    "Variable values in the This scope last as long as the CFC instance exists and, therefore, can persist between calls to methods of a CFC instance."