Click here to close now.


You will be redirected in 30 seconds or close now.

ColdFusion Authors: Yakov Fain, Maureen O'Gara, Nancy Y. Nee, Tad Anderson, Daniel Kaar

Related Topics: ColdFusion

ColdFusion: Article

A Closer Look at CFScript

A Closer Look at CFScript

Allaire's esteemed guru Ben Forta introduced CFSCRIPT to CFDJ readers last year with his article "Stick to the Script" (CFDJ, Vol. 2, issue 7). Hopefully, some of you absorbed the words of wisdom from our evangelist and gave CFSCRIPT a shot, but I suspect for most of you the lesson fell to the wayside when it came time to hit the code again. I can't blame you. Paltry documentation by Allaire on CFSCRIPT coupled with most CF developers' inexperience in scripting languages makes it easy to ignore.

Most ColdFusion developers don't have a scripting background. So why take up CFSCRIPT? It can't replace conventional CF tag structure. Although a modest performance gain can be seen in some circumstances, its exclusion of CF tags significantly limits its potential functionality. What does it offer most developers who are not seasoned scripters?

I believe it can make three compelling contributions to your repertoire. First, CFSCRIPT simplifies concatenation of strings and basic mathematical manipulation, even if you know little about scripting.

Second, and perhaps most important, CFSCRIPT offers an easy way to encapsulate business logic in a single location at the top of your page. Studio's coloring of scripting helps differentiate business logic from output, making it easy to find and address. It also rests in a more native state, devoid of some of the visual overhead tags create.

The third and rarely discussed reason, at least in my opinion, is that it serves as a great introduction to scripting languages. While most of us enjoy the ease of ColdFusion, we limit ourselves by not employing JavaScript, JSP, or other scripting languages. Indeed, next year Allaire will allow the cohabitation of JSP and ColdFusion in their NEO release (sixth generation ColdFusion). Future ColdFusion developers will really need to know JSP to extract the full potential of future CF applications, and what better way to cut their teeth than inside ColdFusion.

I must confess, jumping into CFSCRIPT may be a bit intimidating. Gone are meaningful plain English tags (CFSET, CFLOOP, etc.) that made developing so easy. Also, as I mentioned earlier, Allaire's normally strong documentation provides woeful coverage of CFSCRIPT. To help you along your daunting journey into the scary forest of scripting, I've prepared a large block of CFSCRIPT employing many of the basic constructs you'll want to use. I've chosen a credit card validation routine for a shopping cart. This doesn't expose all of CFSCRIPT's operations, but should provide enough examples to give you a jump start on your own projects. (Source code for this article can be found on the CFDJ Web site,

To start the process I open with a CFSCRIPT tag. There are no attributes for the tag, but I don't leave the Script block empty (ColdFusion doesn't like this and returns an error). Before I even get to the credit card validation, I'm taking advantage of the fact that I've started a CFSCRIPT block and set defaults for a page that would normally have been accomplished with CFSET or CFPARAM. By moving these sets into the CFSCRIPT, I'm reducing some visual and performance overhead. I identify the section with a comment that I start with two back slashes. These comment markers only comment out a line at a time and have no ending markers to stop the commenting (a bit weird for CF developers, but old hat for scripters).

The first three events are simple sets:

j=0; local.errM = ""; check = "";
(see Figure 1).

Note: Other than comment lines, CFSCRIPT ignores carriage returns. After making each assignment you must place a semicolon before addressing another operation. CFSCRIPT doesn't require any special word to make an assignment (like var or set); simply place a variable on the left, some expression on the right, and end it with a semicolon. Missing semicolons will be the primary cause of errors when you begin CFSCRIPTing, and they're generally not obvious. This single line of code replaces the following three conventional ColdFusion tags:

<CFSET local.errM = "">
<CFSET check = "">
Hopefully, you can recognize the "visual" advantage of making these settings inside of CFSCRIPT in conventional tags.

The next block of code drives navigation links on the page, and again bears no relation to the credit card routine. As I mentioned, you can't use ColdFusion tags inside CFSCRIPT. We can, however, re-create the functionality of some tags using ColdFusion functions. In this case I need to parameterize a form variable, which may or may not have been passed. Since I can't use CFPARAM, I'll have to mimic it with the IsDefined function and a simple assignment if the formfield doesn't exist:

if (Not IsDefined("form.carType")) form.carType = "Mondial t";
This introduces our first conditional statement, a simple if. JavaScripters take note, your favorite operators (!, ==, >=, etcŠ) are not available. You have to use ColdFusion operators (such as "NOT," "IS," "GTE," etc.), which can be a bit frustrating but are necessary nonetheless. To begin the "CFIF" simply type if, followed by the condition you wish to check enclosed in parentheses. In a simple conditional check, place the assignment or action right after the check and end it with a semicolon. In this case, if the condition is met (i.e., there's no form variable), I'd like to set it to a default of "Mondial t". We'll cover the if statements in more detail later, but I wanted to demonstrate that there are workarounds for some ColdFusion tags (although in this case, CFPARAM would have been easier).

Next, I moved some of the logic I employed in the navigation scheme into the CFSCRIPT block. This specific chunk of code occupied eight lines of code in my original template, so it was a prime candidate for moving into this block of CFSCRIPT. Again, we haven't hit the credit card validation yet, I'm just moving logic normally found throughout my page into a clean and more concise environment. This particular snippet peeks at the path to see if we're looking at Ferraris, Maseratis, or Ducatis (see Figure 2). For whichever one the script will set a nav count that will position one of those silly arrows the client absolutely must have:

if (cgi.Script_name CONTAINS "Fer") {local.navCount = 1; local.title = "Ferrari";}
else {if (cgi.Script_Name CONTAINS "Mas") {local.navCount = 16; local.title = "Maserati";}
else {local.navCount = 32; local.title = "Ducati";}}
In CFSCRIPT the braces allow you to perform multiple actions instead of a single set (much the same way parentheses work in ColdFusion or mathematics). Without the braces the if statement would end with the first semicolon. After the first set of braces, we have an else statement (just like CFELSE). I actually needed a CFELSEIF, but that's not directly available in CFSCRIPT so I simply embed another if statement inside the else. This block could have been accomplished with a switch statement (very similar to CFSWITCH), which Ben Forta covered in his CFSCRIPT article.

The final block of code I want to discuss prior to launching into the credit card validation is a simple banner rotator. Again, this logic would normally appear elsewhere on my template, but I'm moving it into the CFSCRIPT block to clean up my page. This gives us an opportunity to witness a simple concatenation and arithmetic operation, which CFSCRIPT performs so well. The snippet takes the title I set in the last section of code and appends a number (from 1 to 6) based on what minute it is. This essentially rotates through six different banners (named, for example, Ferrari1.gif, Ferrari2. gif, etc.) and will be used in the content after the CFSCRIPT block.

variables.mod = local.title & (Minute(now()) MOD 6) & ".gif";
You could extend this to create a string with the link and other HTML features as well. Whenever you have to assemble long strings (such as interaction with a COM object or other third-party software), always consider CFSCRIPT as an alternative to conventional CFSETs. JavaScripters should notice that ampersands, not the addition sign, concatenate strings.

Finally we're ready to play with the credit card validation. The first thing I must do is set some defaults that I'll manipulate further downstream. I could have separated these assignments with a carriage return, but I prefer keeping the simple ones in a single line for cleanliness. Next we see a new comment tag, this time in a multiline format. This comment resembles traditional ColdFusion REM statements in that content contained between the symbols is not executed (versus the single-line comments). To begin a multiline comment we employ a backslash and an asterisk /*; to end we reverse the order and employ an asterisk and a backslash */.

/* Required: local.CardNum, local.expYear, local.expMonth. PASSED: local.errM on exception */
As the comment suggests, we're now going to step through the card number and strip out any nonintegers the client may have provided us. This event gives us our first loop. Scripters will welcome CFSCRIPT's loops, but regular Cold-Fusion developers will probably find these a tad confusing. The looping syntax in CFSCRIPT bears no resemblance to its big brother, CFLOOP, and due to the requirement that CFSCRIPT employs ColdFusion operators, it's not a direct match with JavaScript or Java loops (but is familiarly close).

Loops come in a variety of flavors in CFSCRIPT; the while loop is the first one we'll discuss. It's not the most common loop (which is the for loop), but it's the first we see in this application. The while loop inspects the conditions specified in its parentheses and executes the operations inside its braces as long as the condition is met. This is very similar, yet distinct from a do..while loop, which checks for the condition only after executing each loop, allowing a minimum of one run through the loop. In this scenario we're going to progress through each element of the credit card string the client submitted and discard any characters that are not integers.

while (Len(trim(local.CardNum)) GT 0) { if(IsNumeric(mid(local.CardNum, 1, 1))) check = check & mid(local.CardNum, 1, 1); local.CardNum = RemoveChars(local.CardNum, 1, 1);}

The condition in this situation is the length of the variable we're manipulating. It'll shrink by one position each time through the loop. The trim function discards accidental spaces the client may have provided. As mentioned earlier, the operator must be a ColdFusion operator (in this case "GT") instead of a mathematical or JavaScript one. I have a simple if inquiry that, when true, appends that integer to a new string, cryptically named check. Subsequently, the RemoveChars function strips out the character we had just checked. The same snippet could have been accomplished with a conventional for loop, which I'll discuss soon, or through an REReplace() with regular expressions (a better idea, but it doesn't afford me the opportunity to talk about loops).

The next lines of script build error messages if the card number fails to meet certain basic criteria, specifically length, expiration, and whether the first digit is appropriate for the card type specified. The only thing worth noting here is the compound conditions for the first if statement.

if((Len(local.CardNum) LT 13) OR (Len(local.CardNum) GT 16)) local.errM = local.errM & "<li>Your credit card number must be between 13 and 16 characters long, and should only contain numbers.";
As with its elder brother the CFIF tag, if statements can check for multiple conditions (ranges of values, exclusion of ranges, or different strings).

Before the template evaluates the specifics of the number, it offers an opportunity to short-circuit if any of the earlier conditions uncovers an error. This prevents unnecessary processing of a card we won't accept anyway. To do this I simply wrap the remaining logic in an if statement.

First I perform some quick math and set a couple of defaults. These numbers will be used in the loop that follows.

local.lngth = Len(local.CardNum) - 1; tempCard = Left(local.CardNum,local.lngth); newNum = "";
The local.lngth is one less than the number of integers in the card, and tempCard is the card number stripped of the last digit. CFSCRIPT's variables are case insensitive, but minding case only helps build the coding discipline required in JSP or Java. Many developers prefer to employ more descriptive variables, but I've chosen to err on the side of brevity, due to the math I want to perform. For the same reason I've left the scope off tempCard, newNum, and Step1. In production I'd scope these variables to prevent possible problems.

The i=1; establishes the variable "i" as the index or incrementing variable. The second expression defines the condition under which the loop should continue (see Figure 3). In this case, as long as "i" is less than or equal to the value of local.lngth, the loop will process its contents. The last expression increments the variable. I need to step by two through the loop, thus I set "i" equal to itself plus 2. If I didn't want the step, I'd use the expression i=i+1. The CFLOOP equivalent of this for loop would be:

<CFLOOP from="1" to="#local.lngth#" step="2">
Since some credit cards are 16 digits while others are 15, I need two different operations with an if..else operation to direct each loop iteration. In the case of Visa, Discover, and MasterCard, I need to double the digit I'm currently viewing (specifically in the "i" position) and concatenate it with the next digit in line.
newNum = newNum & (2 * Mid(tempCard,i,1)) & (Mid(tempCard,nextNum,1));
For the American Express card the next digit in line must be doubled and concatenated to the first digit:
newNum = newNum & Mid(tempCard,i,1) & (2 * Mid(tempCard,nextNum,1));

Once I've built the new number I must sum all of its digits. For this a simple for loop can iterate through each number and add it to a variable I'll call sumNum:

for(j=1; j LTE Len(newNum); j=j+1) sumNum = sumNum + Int(Mid(newNum,j,1));
Given the simplicity of the operation, I've left the braces out of this for loop. If you perform more than one operation, however, you'll need braces (just as with if..else statements).

The final step compares the last digit of the credit card against the difference of the right-most digit of sumNum from 10. If it's not a match, I create an error message to display in the content.

In a real application this template would allow the client an opportunity to correct a mistaken entry before sending the card to a financial institution for verification. This template doesn't guarantee that the card submitted is valid, but that it conforms to industry standards. Performing such checks before interacting with third-party agents not only en-hances server performance (by preventing HTTP interaction for an event that was bound to fail), it also improves your chances of completing the transaction by providing the client with an opportunity to immediately correct a mistake. For best results this should be combined with a similar routine in JavaScript, providing instant feedback (if the client has JavaScript turned on) when the client has made a faulty entry.

This same application logic in traditional ColdFusion tags occupies more than twice the number of lines as its CFSCRIPT counterpart and is more difficult to read. By translating the functionality into CFSCRIPT I've made the business logic more transparent, transportable, and refined. Indeed, when I translated this logic, I uncovered several unnecessary redundancies and found a better progression for the logic simply because the operations were unencumbered by tags.

For those ColdFusion developers without scripting experience, I'd highly recommend some experimentation with CFSCRIPT in your next application. As a rule of thumb, anytime more than three consecutive CFSETs lie in a row, you'll benefit from moving them into a CFSCRIPT block. Start slow, making simple assignments in your templates. Next, for giggles, move a loop into CFSCRIPT. Finally, go back to some old business logic module and translate it into CFSCRIPT. Not only will your code be improved, you'll have gained invaluable experience in an important language family: scripting.


More Stories By Christopher Graves

Christopher Graves is president of RapidCF, a ColdFusion development
shop in Connecticut. In his prior "life" he was a Marine Corps
officer and graduate of the U.S. Naval Academy.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
NHK, Japan Broadcasting will feature upcoming @ThingsExpo Silicon Valley in a special IoT documentary which will be filmed on the expo floor November 3 to 5, 2015 in Santa Clara. NHK is the sole public TV network in Japan equivalent to BBC in UK and the largest in Asia with many award winning science and technology programs. Japanese TV is producing a documentary about IoT and Smart technology covering @ThingsExpo Silicon Valley. The program will be aired during the highest viewership season of the year that it will have a high impact in the industry through this documentary in Japan. The film...
SYS-CON Events announced today that Luxoft Holding, Inc., a leading provider of software development services and innovative IT solutions, has been named “Bronze Sponsor” of SYS-CON's @ThingsExpo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Luxoft’s software development services consist of core and mission-critical custom software development and support, product engineering and testing, and technology consulting.
The broad selection of hardware, the rapid evolution of operating systems and the time-to-market for mobile apps has been so rapid that new challenges for developers and engineers arise every day. Security, testing, hosting, and other metrics have to be considered through the process. In his session at Big Data Expo, Walter Maguire, Chief Field Technologist, HP Big Data Group, at Hewlett-Packard, will discuss the challenges faced by developers and a composite Big Data applications builder, focusing on how to help solve the problems that developers are continuously battling.
Nowadays, a large number of sensors and devices are connected to the network. Leading-edge IoT technologies integrate various types of sensor data to create a new value for several business decision scenarios. The transparent cloud is a model of a new IoT emergence service platform. Many service providers store and access various types of sensor data in order to create and find out new business values by integrating such data.
Developing software for the Internet of Things (IoT) comes with its own set of challenges. Security, privacy, and unified standards are a few key issues. In addition, each IoT product is comprised of at least three separate application components: the software embedded in the device, the backend big-data service, and the mobile application for the end user's controls. Each component is developed by a different team, using different technologies and practices, and deployed to a different stack/target - this makes the integration of these separate pipelines and the coordination of software upd...
SYS-CON Events announced today that IBM Cloud Data Services has been named “Bronze Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. IBM Cloud Data Services offers a portfolio of integrated, best-of-breed cloud data services for developers focused on mobile computing and analytics use cases.
In his session at @ThingsExpo, Tony Shan, Chief Architect at CTS, will explore the synergy of Big Data and IoT. First he will take a closer look at the Internet of Things and Big Data individually, in terms of what, which, why, where, when, who, how and how much. Then he will explore the relationship between IoT and Big Data. Specifically, he will drill down to how the 4Vs aspects intersect with IoT: Volume, Variety, Velocity and Value. In turn, Tony will analyze how the key components of IoT influence Big Data: Device, Connectivity, Context, and Intelligence. He will dive deep to the matrix...
When it comes to IoT in the enterprise, namely the commercial building and hospitality markets, a benefit not getting the attention it deserves is energy efficiency, and IoT’s direct impact on a cleaner, greener environment when installed in smart buildings. Until now clean technology was offered piecemeal and led with point solutions that require significant systems integration to orchestrate and deploy. There didn't exist a 'top down' approach that can manage and monitor the way a Smart Building actually breathes - immediately flagging overheating in a closet or over cooling in unoccupied ho...
SYS-CON Events announced today that Cloud Raxak has been named “Media & Session Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Raxak Protect automates security compliance across private and public clouds. Using the SaaS tool or managed service, developers can deploy cloud apps quickly, cost-effectively, and without error.
Scott Guthrie's keynote presentation "Journey to the intelligent cloud" is a must view video. This is from AzureCon 2015, September 29, 2015 I have reproduced some screen shots in case you are unable to view this long video for one reason or another. One of the highlights is 3 datacenters coming on line in India.
“The Internet of Things transforms the way organizations leverage machine data and gain insights from it,” noted Splunk’s CTO Snehal Antani, as Splunk announced accelerated momentum in Industrial Data and the IoT. The trend is driven by Splunk’s continued investment in its products and partner ecosystem as well as the creativity of customers and the flexibility to deploy Splunk IoT solutions as software, cloud services or in a hybrid environment. Customers are using Splunk® solutions to collect and correlate data from control systems, sensors, mobile devices and IT systems for a variety of Ind...
SYS-CON Events announced today that ProfitBricks, the provider of painless cloud infrastructure, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. ProfitBricks is the IaaS provider that offers a painless cloud experience for all IT users, with no learning curve. ProfitBricks boasts flexible cloud servers and networking, an integrated Data Center Designer tool for visual control over the cloud and the best price/performance value available. ProfitBricks was named one of the coolest Clo...
You have your devices and your data, but what about the rest of your Internet of Things story? Two popular classes of technologies that nicely handle the Big Data analytics for Internet of Things are Apache Hadoop and NoSQL. Hadoop is designed for parallelizing analytical work across many servers and is ideal for the massive data volumes you create with IoT devices. NoSQL databases such as Apache HBase are ideal for storing and retrieving IoT data as “time series data.”
Clearly the way forward is to move to cloud be it bare metal, VMs or containers. One aspect of the current public clouds that is slowing this cloud migration is cloud lock-in. Every cloud vendor is trying to make it very difficult to move out once a customer has chosen their cloud. In his session at 17th Cloud Expo, Naveen Nimmu, CEO of Clouber, Inc., will advocate that making the inter-cloud migration as simple as changing airlines would help the entire industry to quickly adopt the cloud without worrying about any lock-in fears. In fact by having standard APIs for IaaS would help PaaS expl...
Organizations already struggle with the simple collection of data resulting from the proliferation of IoT, lacking the right infrastructure to manage it. They can't only rely on the cloud to collect and utilize this data because many applications still require dedicated infrastructure for security, redundancy, performance, etc. In his session at 17th Cloud Expo, Emil Sayegh, CEO of Codero Hosting, will discuss how in order to resolve the inherent issues, companies need to combine dedicated and cloud solutions through hybrid hosting – a sustainable solution for the data required to manage I...
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Bradley Holt, Developer Advocate at IBM Cloud Data Services, will demonstrate techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user experience, both offline and online. The focus of this talk will be on IBM Cloudant, Apa...
Mobile messaging has been a popular communication channel for more than 20 years. Finnish engineer Matti Makkonen invented the idea for SMS (Short Message Service) in 1984, making his vision a reality on December 3, 1992 by sending the first message ("Happy Christmas") from a PC to a cell phone. Since then, the technology has evolved immensely, from both a technology standpoint, and in our everyday uses for it. Originally used for person-to-person (P2P) communication, i.e., Sally sends a text message to Betty – mobile messaging now offers tremendous value to businesses for customer and empl...
As more and more data is generated from a variety of connected devices, the need to get insights from this data and predict future behavior and trends is increasingly essential for businesses. Real-time stream processing is needed in a variety of different industries such as Manufacturing, Oil and Gas, Automobile, Finance, Online Retail, Smart Grids, and Healthcare. Azure Stream Analytics is a fully managed distributed stream computation service that provides low latency, scalable processing of streaming data in the cloud with an enterprise grade SLA. It features built-in integration with Azur...
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
The enterprise is being consumerized, and the consumer is being enterprised. Moore's Law does not matter anymore, the future belongs to business virtualization powered by invisible service architecture, powered by hyperscale and hyperconvergence, and facilitated by vertical streaming and horizontal scaling and consolidation. Both buyers and sellers want instant results, and from paperwork to paperless to mindless is the ultimate goal for any seamless transaction. The sweetest sweet spot in innovation is automation. The most painful pain point for any business is the mismatch between supplies a...