CF: Scripting amidst the tags

Recently I had to do a quick "utility" page where I needed to see how many files from a directory listing had been recorded into a database. I've been writing about 98% of my CF code in script syntax but, since it was quick and easy, I did this quickly in tags because it was outputting directly to the browser. In doing so, I made an interesting discovery in that, when you use closures, even in tag based pages, you can write cfscript. Here's the example

1. Get the directory listing: 
   
   

   <cfset alljs = directoryList(expandpath('/src'),true,"path","*.js")>

   
   
2. Get the database listings and convert it to an array
   
   

   <cfquery name="alljsQ" datasource="blah">
       select * from sitefiles where filename like '%.js%'
   </cfquery>
   <cfset recordedFiles = valuelist(alljsQ.filename).listToArray()>
   
   

3. Use a filter function to weed out the files I'd already recorded
   

   <cfset missingFiles = alljs.filter(function(item){
       var foundFile=item.replacenocase(expandpath('/src\'),'','all').replace("\","/","all");
       return recordedFiles.find(foundFile) eq 0;
   })>

4. Use a map function to do what I needed to do with the files not recorded
   
   

   <cfset missingFiles.map(function(item){
           var foundFile=item.replacenocase(expandpath('/src\'),'','all').replace("\","/","all");
       writeOutput("<li>#foundFile#</li>");
    })>
    

A couple of notes about this:

1. 1. Using the filter and map functions make the code more "functional". If you're looking for a reason to experiment with the idea of functional code, here are two good reasons:
1.  It really diminishes the number of things you can screw up. 
2. You can do it, even using tag based code which might ease the process of moving into script
   
   
2. In the filter function in step 3, I used the member function ".find()". This is the equivalent of ArrayFind(recordedFiles,foundFile) but is more readable. Incidentally, I actually used ".indexOf" but then was a bit thrown when I had to use "eq -1" until I remembered that the CF version is ".find" and therefore starts counting at 1 with 0 being "not found". The Java version is ".indexOf" which means it starts counting at 0 and therefore -1 is the "not found".
   
   
3. In the map function, the "callback" or "closure" function that is passed in, can be written in cfscript without worrying about the <cfscript> tag and so on. 

Perhaps obvious to everyone but I did this mostly without thinking and then was pleasantly surprised when it worked.