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Fusion Authority Fusion Authority
The House of Fusion Technical Magazine 		Issue: 18

April 10, 2000
April 16, 2000
This is an opt-in magazine. To join, leave or change subscription mode, please visit the signup page. All content of this magazine is copyright Fusion Authority, Inc. It may not be reproduced without permission.
Community
Allaire Events: Coming to a Venue Near YOU
Allaire Price List
CFUG Changes
 
News
Allaire/Cisco Team-Up Continues in the News
Allaire Uses Live WebCast to Announce 1Q2000 Earnings, Tuesday, April 18th, 2000
Allaire Announces Open License Program
Yahoo! Clubs Include ColdFusion and HomeSite
Allaire's Third-Party Reference Desk
Sys-Con's XML Journal.com Interviews Jeremy Allaire
Allaire Discussed on RadioWallStreet.com
 
Tech and Tags
What's New in the Tag Gallery
JSP Pages Stop Working After Upgrading to JRun Build 157
JRun 2.3.3: Too Many Concurrent JRun Requests Error Message
Allaire's Spectra Installation Documentation Update
JRun 2.3.x: System Changes Made when Installing JRun on Windows NT
File Upload Problems with IE 4.01
 
Techniques
Making Full Use of the Tools at Hand (Part I)
Think Like the Server
 

Community

Allaire Events: Coming to a Venue Near YOU

This URL contains a comprehensive listing of Allaire-related events. One is surely near your home or office.

Allaire Events Listing

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Allaire Price List

Allaire's posted price list includes discounts on CF for Linux and HPUX. Discounts and promotion prices expire June 30th, so think ahead!

Allaire Price List

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CFUG Changes

The following CFUGS have been updated or added to the Fusion Authority CFUG page: Ramstein CFUG, Charlotte CFUG.

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News

Allaire/Cisco Team-Up Continues in the News

CAMBRIDGE, Mass., April 11 /PRNewswire/ -- Allaire Corporation announced earlier this month that it is shipping technology that integrates with Cisco Systems' load balancing solutions. As discussed in an earlier FA News Alert, Allaire has integrated the high availability clustering features of its industry-leading Internet business platform with Cisco's LocalDirector load balancing solutions to deliver increased website reliability and performance.

Newsalert.com Article

Allaire Article

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Allaire Uses Live WebCast to Announce 1Q2000 Earnings, Tuesday, April 18th, 2000

CAMBRIDGE, Mass., April 13 /PRNewswire/ -- Allaire Corporation's First Quarter Fiscal Year 2000 earnings call was broadcast live over the Internet on Tuesday, April 18th at 4:30 p.m. EST. David Orfao, president and CEO, David Gerth, chief financial officer and Jeremy Allaire, chief technology officer of Allaire Corporation, presented the company's first quarter earnings results at that time.

Company Sleuth Article

Allaire Article

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Allaire Announces Open License Program

Allaire's Open License Program (OLP) offers a "more efficient method of software procurement and delivery", with "favorable pricing and flexible purchasing options" for U.S. customers interested in obtaining Allaire licenses and media.

Allaire Announces Open License Program

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Yahoo! Clubs Include ColdFusion and HomeSite

Yahoo!'s ubiquitous club program has had a ColdFusion Club for nearly two years. Now, HomeSite's widespread use has led to the creation of a club for its users, too. Membership growth in its first three months has been steady, although not much is being posted yet.

Yahoo HomeSite Club

Yahoo ColdFusion Club

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Allaire's Third-Party Reference Desk

Allaire's convenient "all-in-one-place" reference desk has been updated to strengthen coverage of Java and WAP. For more info on ColdFusion and WAP, try the CF_WAP List.

Allaire Reference Desk

CF Wap List

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Sys-Con's XML Journal.com Interviews Jeremy Allaire

In addition to XMLJ's usual in-depth coverage of CF issues, they recently did a follow-up interview with Jeremy Allaire on Allaire's recent focus on acquisition and partnership mode. The interview offers a brief history of the events over the last couple of years and the rationale behind these decisions. (Registration Required.)

http://www.sys-con.com/xml/archives

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Allaire Discussed on RadioWallStreet.com

PHILADELPHIA--(BUSINESS WIRE)--April 12, 2000--Allaire was one of the key companies focused on by Banc of America Securities Analyst, Greg Vogel in his RadioWallStreet.com talk show, Today. Others discussed were Intraware, Inc., Vignette Corporation, BroadVision, Inc. and Macromedia, Inc.

Yahoo Report on RadioWallStreet.com Broadcast

RadioWallStreet.com Broadcast

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Tech and Tags

What's New in the Tag Gallery

CF_ClientCacheControl
Use this tag to set client cache directives in the HTTP header and HTML page. Useful in dealing with the problems many have with IE caching pages unexpectedly. See the comments in the tag for additional information.
CF_CopyRow
Copy / move one or more rows from one database table to another. The tables may or may not reside in different datasources. All fields in the source table must exist in the destination, with identical name and datatype. Use for creating archives and history tables, for checking in and out of production tables, etc.

Requires a separate database-specific custom tag (sample version supplied)to determine the datatypes of table columns.

Project & Task Manager r1.2
This is an update for the Project & Task Manager application that fixes some display issues with the Calendar and cross-browser JavaScripting. The database included in the ZIP is Access 2K, but Access 97 and the SQL to create the database structure are available on the Epic site.
fuseAds
fuseAds is a powerful, fully customizable banner rotation solution that allows websites to properly track and report on banners and advertising campaigns. fuseAds offers administrators scalable features to manage and properly identify banners. A powerful reporting engine lets administrators or clients view their impression and click through statistics for individual pages, web sites, banner sizes and categories. Key Features: Expire banners by Click Throughs, Impressions or Date. Categorize banners by categories and/or banner sizes. Login for clients. Banner reporting by date, Categories, clients and web server. Export and print reports. Supports local and external banners. Supports HTML, DHTML, Javascript banners. Web interface for banner and client management. Multi-Database Support.
CF_CheckSSN
CF_CheckSSN is based on CF_phonemat by Michael R. Yeary. CF_CheckSSN strips all non-numeric (0-9) characters from a Social Security Number submitted to it. CF_CheckSSN validates the number of digits submitted. As long as 9 digits are entered, CF_CheckSSN passes it as a valid Social Security Number. CF_CheckSSN returns a formatted SSN (123-45-6789) and a numeric SSN (123456789).
CFX_ResolveDNS
Resolves DNS name based on IPAddress submitted. Normally CGI.Remote_Addr.
RapidDiet
RapidDiet 1.0 puts your code on a fast diet or, in technical terms, it strips ALL unnecessary whitespace, line feeds and carriage returns. It uses a Java library to achieve this very quickly, having almost zero performance impact.
Ariba CF Punchout Example
Ariba CF Punchout Example. Non-Supported Example of Punchout. Work around for CF's inability to read/access http headers. Parses cXML using MSDOM. PunchoutSetupRequest PunchoutSetupResponce
CF_VARIABLEISNULL
Combines the functionality of the "isdefined" function and a 'CFIF trim(variablename) is not ""' statement to decide if the named variable isdefined, and if it is, if it is null or not null. Returns 3 response codes based on results: tells if the variable is defined, and if it is null or not. Does not work on variables set with CFPARAM, CFSET (on the same page or on the application page). Application, session, & local variables will not be detected with this tag.
CF_LessWhiteSpace
Custom Tag based on Nate Weiss' CF_StripWhiteSpace. Strips out extraneous whitespace generated by CF templates. MUCH easier than using CFSETTING! Preserves indentation by default, but takes a JUSTIFY attribute ("y" or "yes") to completely left justify everything). Checks for PRE or CODE tags, and does NOTHING AT ALL to the output if found. VERY simple.
CF_PREVNEXT
Browse Records. Allows user to be returned to the exact page where the user has just added or edited a record. Comes with help file, images and vtm file.
CF_WebBody
CF_WebBody allows you to get any Web page using CFFILE or CFHTTP, while stripping away the HTML Header information and the HTML Footer information. CF_WebBody delivers a variable that contains only the HTML that exists between the and tags. You can then include only the contents of the retrieved Web page into your Web page.
CF_CheckTIN
CF_CheckTIN strips all non-numeric (0-9) characters from an input Tax ID Number and validates the number of digits submitted. As long as 9 digits are entered, CheckTIN passes it as a valid Tax ID Number. Adapted from "CF_phonemat."
BUCalendar v2.1
Calendar Event and Scheduling System. Wrapped up in a single command line. Integrate it into your own applications.
CF_download.cfm
Have you ever wanted to create a download page, but didn't want your visitors to know where the download files live on the server? This Custom ColdFusion tag will allow you to do just that!!!
CF_Filter
A flexible ColdFusion custom tag to replace characters in illegal words passed as form field values with defined symbols. It also gives the user the ability to either destroy HTML and ColdFusion tags passed as form field values or just replace the angled brackets with round ones to neutralize their possible effect.
Realist - Realestate Application
Complete solution for REAL estate agencies which requires control of their own internet presence. Seamless integration with the look and feel of an existing website. Separate user accounts for agents within an agency permit the upload and maintenance of properties information and property photos.

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JSP Pages Stop Working After Upgrading to JRun Build 157

Problem: Changes made to the JSP engine in Build 157 may cause existing JSP pages to fail.

Solution: Workaround available at http://www.allaire.com/handlers/index.cfm?ID=15274.

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JRun 2.3.3: Too Many Concurrent JRun Requests Error Message

Come here to see what can trigger this error message, and what you can do about it.

JRun 2.3.3: Too Many Concurrent JRun Requests Error Message

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Allaire's Spectra Installation Documentation Update

Use the information at this URL to replace Chapter 2 of your Spectra Installation documentation.

Spectra Documentation Update

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JRun 2.3.x: System Changes Made when Installing JRun on Windows NT

When installing JRun on Windows NT, certain system changes are, of course, made by the installation program. This Note outlines the registry changes made and discusses why some are needed.

JRun 2.3.x: System Changes Made when Installing JRun on Windows NT

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File Upload Problems with IE 4.01

Problem: When uploading a file to IIS Web server using Microsoft's NTLM authentication and IE 4.01, you may receive a CFFILE error message: "The multi-part boundary marker is not present in the posted data". There is a bug in IE 4.01 where the file form variable doesn't get passed in the header information.

Solution: This URL leads to a workaround.

File Upload Problems with IE 4.01

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Techniques

Making Full Use of the Tools at Hand (Part I)

Maximizing code re-use because we hate typing!

(The Layman's Fusebox)

Written / Researched By:
Fred T. Sanders and Nat Papovich

The Tools We Never Think Of

This is the first of a three part series covering the importance of various types of snippets or templates in ColdFusion application development. Many ColdFusion programmers are not aware of tools that can save them a large amount of time and provide them with a large library of reusable code. By the end of this series, you should be aware of three types of tools available to all ColdFusion programmers that will make your job much easier.

In Part I, we will be dealing with "Document Templates," which are stored in the "New Document" section of the File menu in Studio. By the end of this article, we will have several starter templates for you to start off your collection of generic, reusable code. The author uses the Fusebox method, and as these examples are taken from his collection, most will conform to that methodology. This is in no way an attempt to sell you on the Fusebox method and is just a matter of personal taste. Hopefully, with a better understanding of Document Templates, they will become an integral part of your development style and increase the speed, accuracy, and consistency of the coding of your applications.

Why Do We Want To Use Document Templates?

Well, we all have full-page starter templates that we use on regular basis. Some good examples would be our "Application.cfm" (despite the Fusebox controversy on the matter in currently published specs, we should have one. Read the next article by Michael Dinowitz as to why), "app_globals.cfm," "app_locals.cfm," and any commonly used design layouts or stylesheets. Aside from some setting changes from application to application, these templates rarely change in overall construction. Instead of keeping them in a directory somewhere, which is what most mortals do, let's let Studio do the work for us. We'll save each of these "universal" application templates as write-protected "Document Templates," and we won't have to worry about accidentally over-writing our masters.

A Little Planning Goes a Long Way These Days

By default, all Allaire gives us is a "Custom" tab under the "New Documents" window. Since the whole purpose of creating the master templates is to make our lives and jobs easier, we need a better way to organize our newly rediscovered resource. The problem is that just having a "Custom" tab isn't good enough. We need more organization and we'll want to categorize our templates. Allaire was thoughtful enough to keep these tabs as actual sub-directories and adding new tabs is as simple as adding a new sub-directory. We'll need to use Windows Explorer to add our own tabs, or alternately we can do this from the "Local Files" Resource tab. Unfortunately, after creating our templates, we'll have to move them from the "Custom" folder to the folders we've created for them, but I guess you can't have everything.

You can make your own template directories under:

(Studio 4.0.1) "C:\Program Files\Allaire\ColdFusion Studio4\Wizards"
or
(Studio 4.5) " C:\Program Files\Allaire\ColdFusion Studio45\Wizards."

Once you "Save as Template," you will need to move them from the "Custom" folder into the subdirectory you have chosen. Hopefully, you can now see the importance of this tool, and will begin using it to its full potential.

Some Starter Templates

Application.cfm
All applications should have an Application.cfm file. You will want one whether you use it or not, simply because your application will run faster. A common misconception among Fuseboxers is that we shouldn't have one, when actually what the Fusebox specs say is not to use the Application.cfm file for starting application management or to set application variables. We will, however, want the file to exist, even if it's just there with a commented line (blank Application.cfm files will crash some Application Servers).

We will be using the Application.cfm template for the speed benefit, initial application documentation, and a little extra Fusebox-specific template security. You will need to define two things in this template.

The first variable you will need to define is "request.root." This is the root of the application, not necessarily of the entire site. Since Application.cfm is not used for session management, we will actually assign a separate request.root value for each sub-application (smaller applications that are called from parent applications) as well. As an example, if you have a fusebox application in its own subdirectory (i.e., www.my-site.com/myapp), then you'll want ("request.root") to be "myapp."

Request.root is used for, but not limited to, site security. For instance, one of the Fusebox conventions is to have all applications called through the index.cfm. Let's say someone was trying to call a template directly, rather than going through index.cfm. With code using this variable, you can tell the application to redirect this user in the following ways:

1. Find an index.cfm in the directory of the template being called.

2. If there isn't one, then find an index.cfm in the immediate parent directory (which is supposed to be defined by #request.root#.)

3. If there isn't one, then go to the absolute root of the website and call that index.cfm.

Now this code has a problem, in that it will redirect while you're in development and you may not want this. Therefore, we've encapsulated all this code in a few <CFIF> statements that are based on a variable we set called "#attributes.published#." This is set by default to "NO". When we are ready to publish the application to its permanent home, we will set this to "YES" to enable the template security. If you are not using the Fusebox application framework, you'll need to modify this a bit before saving it as a "Document Template."

<!--- Application.cfm --->
<!-----------------------------------------------------------
NAME: Application.cfm
PURPOSE:
DATE CREATED:
AUTHOR:
CHANGE HISTORY:
----------------------------------------------------------->

<!--- Is this application published or still in development.
"NO" = we are developing. "YES" = we are published. --->
<CFSET ATTRIBUTES.PUBLISHED = "NO">
<CFIF NOT ISDEFINED("request.domain")>
<CFSET REQUEST.DOMAIN="#CGI.SERVER_NAME#">
</CFIF>

<!--- Set Application's Root Directory Default --->
<CFIF #ATTRIBUTES.PUBLISHED# EQ "NO">
<!--- Do nothing; we are developing. --->
<CFELSE>
<CFIF NOT ISDEFINED("request.root")>
<!--- Insert Published Application's Root/Sub Directory Name, or leave blank.--->
<CFSET REQUEST.ROOT = "">
</CFIF>
</CFIF>
<CFIF #ATTRIBUTES.PUBLISHED# EQ "NO">
<!--- Do nothing we are developing. --->
<CFELSE>
<!---
Prevents someone from directly calling a template without going through our Fusebox. This will redirect them to the first page of the application, or to an index.cfm in the directory they're sticking their nose in. If that fails, it will redirect them to the main page of our application.
--->
<CFIF FINDNOCASE("cfm",CGI.CF_TEMPLATE_PATH) AND NOT
FINDNOCASE("index.cfm",CGI.CF_TEMPLATE_PATH)>
<CFSET THISPATH = EXPANDPATH("*.*")>
<CFSET THISDIRECTORY = GETDIRECTORYFROMPATH(THISPATH)>
<CFIF FILEEXISTS(EXPANDPATH("index.cfm"))>
<CFLOCATION URL = "index.cfm?badfile=yes">
<CFELSE>
<CFIF REQUEST.ROOT IS NOT "">
<CFLOCATION URL = "/#request.root#/index.cfm?badfile=yes">
<CFELSE>
<CFLOCATION URL = "/index.cfm?badfile=yes">
</CFIF>
</CFIF>
</CFIF>
</CFIF>
<!--- end Application.cfm --->
app_globals.cfm
In Fusebox, this template is where you define all global application settings and initialize your Session and/or Client Management. You will need to define the following in this template. The Application Name. This is for your Client and Session Management. We leave client cookies off, as they aren't very efficient, users don't always have them turned on, and are generally scared of them. You will also define your Data Source Names, mail server (optional), and webmaster email address. You will want to add any other generic global settings that you commonly use for your applications. We are providing the ones that are common to almost every application. 

<!--- app_globals.cfm --->

<CFSETTING ENABLECFOUTPUTONLY="Yes">

<!--- Change form and URL variables to attributes variables. --->
<!--- This is to keep with the Fusebox Standard --->
<CFIF NOT ISDEFINED("attributes.fuseaction")>
   <CF_FORMURL2ATTRIBUTES>
</CFIF>


<!--- Define Application name and turn on client and
      session management settings --->
<CFAPPLICATION NAME = "" <!--- Application Name --->
 CLIENTMANAGEMENT = "YES"
 SESSIONMANAGEMENT = "YES" 
 SETCLIENTCOOKIES = "NO">

<!--- Set some global variables --->
<CFSCRIPT>
   request.MainDSN        = ""; // Define Data Source Name
   request.MailServer      = ""; // Define Mail Server (optional)
   request.sysAdmin        = "<A HREF='MAILTO:WEBMASTER@THIS-SITE.COM'>Webmaster</A>"; // Define Administrator Email
   attributes.headerfile     = "dsp_header.cfm"; // Define our Application Header File
   attributes.footerfile      = "dsp_footer.cfm"; // Define our Application Footer File


   request.WeeklyCache    = CreateTimeSpan(7,0,0,0); // Define Cache time for queries that need updating weekly
   request.DailyCache     = CreateTimeSpan(0,1,0,0); // Define Cache time for queries that need updating daily
   request.HourlyCache    = CreateTimeSpan(0,0,1,0); // Define Cache time for queries that need updating hourly
</CFSCRIPT>

<!--- Fusebox tag for CFID and CFTOKEN in Search Engine Friendly URLs--->
<CF_FUSETOKEN>
<CFSETTING ENABLECFOUTPUTONLY="No">
<!--- end global variables --->

app_locals.cfm
This template is used for defining our application's local variables. You will have one for each application and one for each of (if any) sub applications. A good analogy for this template and the app_globals.cfm template would be to compare the differences between your driver's license and the owner's manual for your car. You need your driver's license to operate any car. This is like your "app_globals.cfm" template, which affects every application and sub-application. The owner's manual is what you need to know to drive a specific car. This is like the "app_locals.cfm" template, which is specific to only one application. In this template, we'll define our application's stylesheet. If you do not wish to do so, just delete or comment out the include. I've named it "app_style.cfm" in the template code below. If you have several stylesheets, I would just include them from "app_style.cfm," or if you have only one stylesheet, then store it there. The other four parameters to define will be the default values for your site's page title, keywords associated with the site, page description for, and possibly the search engine robot directives. We will change these settings dynamically within our fuseactions (located in our "index.cfm" template). 

<!--- app_locals.cfm --->

<!--- Include Global Application Settings--->
<CFINCLUDE TEMPLATE = "app_globals.cfm">

<!--- Get Our Stylesheet --->
<!--- Optional --->
<CFINCLUDE TEMPLATE = "app_style.cfm"> 

<!--- Set Any Local Application Variables --->
<CFPARAM NAME = "request.title" DEFAULT = ""> <!--- Set Default Application Title--->
<CFPARAM NAME = "request.keywords" DEFAULT = ""> <!--- Application Keywords--->
<CFPARAM NAME = "request.description" DEFAULT = ""> <!--- Set Default Application Description--->
<CFPARAM NAME = "request.robots" DEFAULT="index,follow"> <!---(index, noindex; follow, nofollow)--->

<!--- end app_locals.cfm --->

app_layout.cfm
This is the default template used by the Fusebox BODYCONTENT tag. No changes need to be made to this template. It is simply added to the collection for convenience when starting a new project. 

<!--- app_layout --->
<!--- Used In Conjuction With The Fusebox BODYCONTENT Custom Tag. --->

<CFPARAM NAME="attributes.headerfile">
<CFPARAM NAME="attributes.footerfile">
<CFPARAM NAME="request.bodycontent">
<CFPARAM NAME="attributes.showbody" DEFAULT="yes">
<CFIF LEN(ATTRIBUTES.HEADERFILE)><CFINCLUDE TEMPLATE = "#attributes.headerfile#"> </CFIF>
<CFIF ATTRIBUTES.SHOWBODY><CFOUTPUT>#request.bodycontent#</CFOUTPUT></CFIF>
<CFIF LEN(ATTRIBUTES.FOOTERFILE)><CFINCLUDE TEMPLATE = "#attributes.footerfile#"> </CFIF>

<!--- end app_layout--->

dsp_header.cfm
This template is just a header template. The only things you may want to change are the Meta Tags. You may also want to go ahead and fill out the HTML comment provided at the bottom with author information, etc. Remember: Only fill out what is unlikely to change. Leave all "#request.?????#" variable references alone, as we will change these dynamically within our fuseactions. 

<!--- dsp_header.cfm --->
<!--- This template is used in conjunction with the BODYCONTENT Fusebox Custom Tag. --->
<CFOUTPUT>
 <!DOCTYPE HTML PUBLIC "<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN">
 <META HTTP-EQUIV = "Content-type" CONTENT = "text/html; charset = US-ASCII">
 <!--- Help prevent Page Caching --->
 <META HTTP-EQUIV = "Expires" CONTENT = "Sun, 12 May 1996 00:36:05 GMT">
 <HTML>
 <HEAD>
 <TITLE>#request.title#</TITLE>
 <META NAME = "robots" CONTENT = "#request.robots#"> 
 <META NAME = "revisit-after" CONTENT = "5 days">
 <META NAME = "rating" CONTENT = "General">
 <META NAME = "DC.Language" SCHEME="RFC1766" CONTENT="EN">
 <META NAME = "Description" CONTENT="#request.description#">
 <META NAME = "Keywords" CONTENT="#request.keywords#">
 <LINK REL = "SHORTCUT ICON" HREF = "http://#request.domain#/favicon.ico">
 </HEAD>
 
<!-- 
Title: 
Company: 
Coded by: 
Web Address: http://www.your-site.com   <!--- replace --->
Email: webmaster@your-site.com  <!--- replace --->
-->
</CFOUTPUT>

<!--- end dsp_header.cfm --->

dsp_footer.cfm
This template, like the header template above, shouldn't really need changing, and this is the bare minimum required in it. What I will often do (once I've decided on a page layout) is to include everything from the end of the page body that isn't going to change, as well as the closing HTML tags for the entire document. I'm providing bare minimum here; modify any way you like. 

<!--- dsp_footer.cfm --->
</HTML>
<!--- end dsp_footer.cfm--->

Index.cfm

This is probably one of the most important templates in this set. This is where everything comes together. All of the links in a Fusebox application point here. Other than defining your fuseactions, there is not much extra that needs to be done here. In Part II, we will build a "Fuseaction" Code Template (among others) to help speed this along. 

<!--- index.cfm --->

<CFTRY>

<!--- Call Local Application Variables.--->
<CFINCLUDE TEMPLATE="app_locals.cfm">

<!--- Set our Default Fuseaction. --->
<CFPARAM NAME="attributes.fuseaction" DEFAULT="Main">

<!--- Call BODYCONTENT Fusebox Tag to define page layout. --->
<CF_BODYCONTENT>
	
<!--- 
      Set Allowable Fuseactions.
      The following CFSWITCH expression defines what fuseactions
      are allowed and what procedures to follow when a fuse-
      action is called. 
  --->
  
<CFSWITCH EXPRESSION="#attributes.fuseaction#">

  <CFCASE VALUE="Main">
     <!--- Be sure to change the following to call page layout template. We're using dsp_body.cfm. --->

     <CFINCLUDE TEMPLATE="dsp_body.cfm">
  </CFCASE>
  
  <!--- Insert Additional Fuseactions Here. --->  

<!--- Define What to do if an invalid action is called. --->  
  <CFDEFAULTCASE>
     <CFMODULE TEMPLATE="/#request.root#/index.cfm" FUSEACTION="#attributes.defaultfuseaction#">
  </CFDEFAULTCASE>

</CFSWITCH>
<!--- end of fuseaction definitions --->
</CF_BODYCONTENT>
<CFINCLUDE TEMPLATE="app_layout.cfm">
    <!--- Catch Page Errors and Display Message --->
	<CFCATCH TYPE="Any">
		<!--- You can have this do whatever you want it to do
			when an error occurs.--->
		<CFOUTPUT>#cfcatch.message#</CFOUTPUT>
	</CFCATCH>	
</CFTRY>
<!--- end of index.cfm --->

That's it for our Document Templates. Please stay tuned for Part II, "Code Templates," for another exciting but under-valued tool to help you on your way to faster application coding.

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Think Like the Server

by Michael Dinowitz

When I have a problem with my code, I like to debug by 'thinking as the server.' This means walking through the code step by step as if I was the ColdFusion server and seeing what is actually happening. I'll actually talk more about this in another article, but this time I'd like to talk about two things I've discovered in one of these 'walks'.

The first thing is that Application.cfm and OnRequestEnd.cfm are required by the ColdFusion server. When I say required, I don't mean that a template will not work without them but that the ColdFusion server expects them to always exist.

Let's imagine we're the ColdFusion server and we've just been asked to process a page. The first thing we do is to see if an Application.cfm exists in memory for this directory. If not, we'll look at the directory to see if one is there. If we still can't find it, we'll go to the parent directory and do the operation again (check memory and then check disk). This process will continue until we have checked all the way up to the drive root (Yes, the ColdFusion server looks all the way to the drive root rather than to the web or ColdFusion root.) At this point, if we haven't found any Application.cfm files, we simply assume that none exist and start to process the template that was actually requested. Once we're done with the template, we'll do the exact same search for the OnRequestEnd.cfm template.

These searches are actually rather fast and probably don't even show up on the resource monitors, but they do exist. For this reason, I suggest every application has an Application.cfm and an OnRequestEnd.cfm file, even if it simply contains a space character (Template must contain at least one character or an error will occur).

The second thing I found is that the way most people set their variables inside Application.cfm templates is wrong. Again, let's act as the ColdFusion server and process a page, but this time let's just focus on the Application.cfm file.

Someone requests the template index.cfm. Before that template is run, the Application.cfm template is processed. The first line is a CFAPPLICATION tag, which says that index.cfm is part of an application. The next line is a CFSET with a variable of Application.DSN and a value of "datasource". A few more CFSETs are used for different application variables and by the time we're ready to process index.cfm, four variables have been written to memory for this application. So far, so good. The next minute, someone (the same person or someone else, it doesn't matter) asks for a template called outdex.cfm in the same directory. Again, we start with the Application.cfm. The first line is the CFAPPLICATION tag that says that outdex.cfm is part of an application, the same application as index.cfm. This means that it can share the same memory-based variables. The next line is a CFSET with a variable of Application.DSN and a value of "datasource". A few more CFSETs are used for different application variables and, by the time we're ready to process index.cfm, four variables have been written to memory for this application.

Can you see what's wrong here?

If an application variable was set once, why are we setting it again? Why are we setting application.DSN on EVERY template call we make? There's no reason and, in some cases, this can run into variable overwrite errors (in CF 4.0x especially). Instead, what we should be doing is setting the application variables once and never again. This avoids extra work on every page and avoids the potential for errors. This method should be used for Session variables as well.

Old Way
    <CFSET Application.DSN = "DataSource">
    <CFSET Application.Path = "/">
    <CFSET Application.Images = "/images/">
    <CFSET Application.Attachments = "c:\cfusion\attachments\">

New Way
  <CFIF Not IsDefined('Application.DSN')>
    <CFSET Application.DSN = "DataSource">
    <CFSET Application.Path = "/">
    <CFSET Application.Images = "/images/">
    <CFSET Application.Attachments = "c:\cfusion\attachments\">
  </CFIF>

The application variables will only be created if they don't already exist. I use Application.DSN as the 'key' value as most programmers use this to dynamically set their data source names. Finally, you can add a CFLOCK inside the CFIF statment if you are using CF 4.0x.

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