Welcome!

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

Related Topics: ColdFusion

ColdFusion: Article

A Cure for Arachnophobia

A Cure for Arachnophobia

Barely a week goes by without someone asking me about ColdFusion and search engine-friendly URLs. This is one of those topics that ColdFusion developers have been discussing for a long time - I first started a thread on this subject on the Allaire Developer's Forum close to five years ago. As this topic keeps coming up (and because three of you e-mailed me to ask about it this morning), I decided to scrap the column I was writing in favor of an explanation of all this once and for all.

Search Engines and ColdFusion
Here's the problem. Many search engines index sites by spidering them - starting at a known point, indexing that retrieved page, parsing it for embedded URLs, and then retrieving and indexing them too. They keep doing this until they have retrieved and indexed all linked pages in a site.

At least that's how it's supposed to work. Where things get complicated is when dynamic pages are indexed, or rather, when they're not. Some spiders won't index URLs that are dynamic, the theory being that since the content changes all the time there's no point in indexing it - after all, it may not even be the same content on subsequent accesses. So this link would be followed and indexed:

<A HREF="catalog.cfm">Catalog</A>

but this one may not:

<A HREF="catalog.cfm?dept=10">Catalog</A>

You can see the problem: ColdFusion developers (as well as ASP, PHP, Perl, Python, and JSP developers, among others) build dynamic pages. That's why we use ColdFusion - if all content was static we'd use plain old HTML without any server-side processing at all. We use ColdFusion because we want and need dynamic content - content that spiders may choose to ignore. If search engine indexing is a requirement for you, that can pose a real problem.

The Basic Solution
The solution to this problem is actually quite simple. What is it that tips off the spider, telling it that the page is dynamic? It's the query string portion of the URL, starting with the question mark. That question mark separates the URL (the file to be retrieved or the script to be executed) from any passed parameters (usually in name=value pairs).

The solution is to simply not have a query string - no question mark, no values passed after it, and no name=value pairs. Simple, eh? Yep, until you actually need passed parameters. Then what?

Well, look at this URL:

http://host/path/catalog.cfm/10

What happens when this is processed? catalog.cfm is the file to be executed and anything after the file name is ignored altogether. Even though the Web server and ColdFusion ignore it, that doesn't mean you have to. Using CGI variables (like PATH_INFO) you can access the complete URL - even parts of it that may be ignored by other processes or applications. The following snippet will display the complete path (minus any host and protocol information, although that's available in another CGI variable if needed).

<CFOUTPUT>#CGI.PATH_INFO#</CFOUTPUT>

Using the above URL this will display:

/path/catalog.cfm/10

We now know how to get the passed information. Next you need to remove the path and script name. You could do this by searching for the CFM file, but there's an easier way using yet another CGI variable, this time SCRIPT_NAME, which contains the name of the script being executed (here /path/catalog.cfm):

<CFSET query_string_length=Len(CGI.PATH_INFO)-Len(CGI.SCRIPT_NAME)>
<CFSET query_string=Right(CGI.PATH_INFO, query_string_length)>

The first <CFSET> gets the length of PATH_INFO and subtracts the length of SCRIPT_NAME from it, giving us the length of the section at the end (the data we want). The second <CFSET> uses Right() to extract the desired data, saving it in a variable named query_string. Displaying query_string would result in this output:

/10

That's how you get the data off the end of the URL.

Note: Depending on the Web server and OS being used you may find different CGI variables or different values in them. You can use <CFDUMP VAR="#CGI#"> to see all the CGI variables available to you (and you'll be able to adapt the code here accordingly).

Making It All Work
Now that the basic concept is clear, let's take this one step further. How can you pass multiple parameters? Well, you could pass three parameters, each separated by a /:

http://host/path/catalog.cfm/10/0/B12

But you would have no way of knowing which was which, what their names should be, and they'd always have to be in order (something you typically don't worry about when working with URL parameters).

While the technique is sound, the implementation can be improved by simulating name=value pairs. Look at this example:

http://host/path/catalog.cfm/dept/10/user/0/item/B12

There are now six values passed to the URL; each set of two is a name and value pair. Here it's dept=10, user=0, and item=B12. The advantage of this enhancement is that the variable name is known, the order of pairs is irrelevant, and the URL is easy to construct.

All that is required now is a simple way to extract these values and turn them into real URL values (after all, your application code shouldn't have to worry about manipulating this data; as far as it's concerned these are URL parameters plain and simple). This is where ColdFusion's list functions come in handy:

<!--- Extract "query_string" from full path --->
<CFSET query_string_length=Len(CGI.PATH_INFO)-Len(CGI.SCRIPT_NAME)>
<CFSET query_string=Right(CGI.PATH_
INFO, query_string_length)>

<!--- How many items in "query_string? --->
<CFSET items=ListLen(query_string, "/")>

<!--- Loop through list, pair of items at a time --->
<CFLOOP FROM="1" TO="#items#" STEP="2" INDEX="i">
<!--- Save this URL parameter --->
<CFPARAM NAME="URL.#ListGetAt(query_string, i, "/")#"
DEFAULT="#ListGetAt(query_string, i+1, "/")#">

</CFLOOP>

The first two <CFSET> statements simply extract the virtual query_string (as we saw earlier). Next we need to know how many items query_string contains. All ColdFusion list functions take an optional delimiter as a parameter, and so ListLen(query_string, "/") returns the number of items delimited by / (in this case, six).

Next, a <CFLOOP> is used to loop through the items, from one to however many there are, stepping two at a time (because every two is a set). Within the loop <CFPARAM> is used to create the variables. The value passed to NAME is the first of the pair (i) and the value passed to DEFAULT is the second (i+1). For the first set of values (/dept/10) the <CFPARAM> would be:

<CFPARAM NAME="URL.dept" DEFAULT="10">

There you have it. By the time the </CFLOOP> is reached, a set of URL parameters would have been created. This code could be placed once at the top of a page, and all other code could refer to URL parameters without knowing they were actually faked. In addition, as <CFPARAM> was used (instead of <CFSET>), you wouldn't overwrite variables if URL parameters actually did exist.

Clean, safe, and spider friendly, too.

Custom Tags to the Rescue
Of course, you wouldn't want all that code in every page - this type of processing is ideally suited for custom tags - thus my <CF_FakeURL> tag. Listing 1 shows the complete code.

Let's take a quick look at the tag. It starts with comments and a description, as all code should. Then a <CFPARAM> is used to define the default delimiter (a slash). Next the virtual query string is extracted using two <CFSET> tags (as we did earlier).

For this code to work there must always be an even number of elements (there are two for every parameter, one for name and one for value). The next <CFIF> statement uses the MOD operator to make sure the number of items in the list is a multiple of two - if this is not the case the list is not processed.

Within the <CFLOOP> the two values (current and next) are extracted, and then <CFPARAM> creates the URL variable.

Now all you need to do is call <CF_FakeURL> in your page and any faked URL parameters will be available for you to use. When you create your URLs just change this:

file.cfm?LName=Ben&FName=Forta

to this:

file.cfm/LName/Ben/FName/Forta

Simple as that.

Summary
Arachnophobia is the irrational fear of spiders - a fear that many ColdFusion developers seem to be suffering from. As you can see, with a little ingenuity and some good old CFML, there's a very workable solution to help you overcome this fear. Enjoy!

More Stories By Ben Forta

Ben Forta is Adobe's Senior Technical Evangelist. In that capacity he spends a considerable amount of time talking and writing about Adobe products (with an emphasis on ColdFusion and Flex), and providing feedback to help shape the future direction of the products. By the way, if you are not yet a ColdFusion user, you should be. It is an incredible product, and is truly deserving of all the praise it has been receiving. In a prior life he was a ColdFusion customer (he wrote one of the first large high visibility web sites using the product) and was so impressed he ended up working for the company that created it (Allaire). Ben is also the author of books on ColdFusion, SQL, Windows 2000, JSP, WAP, Regular Expressions, and more. Before joining Adobe (well, Allaire actually, and then Macromedia and Allaire merged, and then Adobe bought Macromedia) he helped found a company called Car.com which provides automotive services (buy a car, sell a car, etc) over the Web. Car.com (including Stoneage) is one of the largest automotive web sites out there, was written entirely in ColdFusion, and is now owned by Auto-By-Tel.

Comments (6) View Comments

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.


Most Recent Comments
Daniel Leroux 12/16/03 02:09:53 PM EST
Vikas Tailor 07/26/03 04:18:00 PM EDT

Hey all,

I used this great strategy and all of a sudden it stopped working! Could it be possible that the web server administrator no longer allows this? For example, go to http://www.linkexchanged.com/directory.cfm/Arts

This use to work, but no longer does.

Thoughts?

Laura Schneiderman 04/23/03 11:01:00 AM EDT

We've noticed that Norton firewall scrambles CGI variables. This CF_FakeURL tag relies on CGI variables. Has anyone else mentioned this problem?

Stephen Cassady 07/08/02 11:39:00 AM EDT

MX has many undocumented changes for 5.0 to MX.

One includes the new wal URLs are examined. I have a similiar script I picked up from the developers excange which allowed me to do http://www.site.com/page.cfm/var1.value1/var2.value2/var3.value3

And it also doesn't work now. Massive blow to the way everyting works, and, ironically, to the now indexed - but non-functional pages in all the search engines.

Arrgh. And there are other undocumented changes too (part of the CFIDE directory beeing in the site map - something we removed for security issues - for auto JavaScript from things like CFFrom, and a CFFILE problem).

Stephen Cassady
[email protected]
http://www.lopedia.com

Seth Aaronsen 06/30/02 06:30:00 PM EDT

We have successfully used CF_FakeURL on CF 5.0

We are having problems getting CF_FakeURL to work with CFMX standalone. This has been documented in the latest allaire message boards with the similar tag from Fusebox -- CF_FormUrl2AttributesSearch. CFMX will not process the strings http://www.mysite.com/page.cfm/variableid/value -- Please try this and you'll see.

We have tried to tweak the settings in the C:\CFusionMX\wwwroot\WEB-INF\web.xml doc by adding,

CfmServlet
*

but this does not work for us.

Do you have some suggestions?

Jill Crawford 02/22/02 09:51:00 AM EST

Thank you for the continued information that proves to be invaluable.

I have created URLs like http://www.yoursite.com/index.cfm/productID=item similiar to what you have suggested but and have lost the query string (everything after .cfm) in the log files for IIS since doing.

Apparently ColdFusion no longer believes these are URL parameters and does not return them to IIS to write as the cs-uri-query. Is there some way to capture the paramaters to the log file?

I would greatly appreciate any assistance you can give or point me towards.

@ThingsExpo Stories
"There is a natural synchronization between the business models, the IoT is there to support ,” explained Brendan O'Brien, Co-founder and Chief Architect of Aria Systems, in this SYS-CON.tv interview at the 15th International Cloud Expo®, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
The major cloud platforms defy a simple, side-by-side analysis. Each of the major IaaS public-cloud platforms offers their own unique strengths and functionality. Options for on-site private cloud are diverse as well, and must be designed and deployed while taking existing legacy architecture and infrastructure into account. Then the reality is that most enterprises are embarking on a hybrid cloud strategy and programs. In this Power Panel at 15th Cloud Expo (http://www.CloudComputingExpo.com), moderated by Ashar Baig, Research Director, Cloud, at Gigaom Research, Nate Gordon, Director of T...
The definition of IoT is not new, in fact it’s been around for over a decade. What has changed is the public's awareness that the technology we use on a daily basis has caught up on the vision of an always on, always connected world. If you look into the details of what comprises the IoT, you’ll see that it includes everything from cloud computing, Big Data analytics, “Things,” Web communication, applications, network, storage, etc. It is essentially including everything connected online from hardware to software, or as we like to say, it’s an Internet of many different things. The difference ...

ARMONK, N.Y., Nov. 20, 2014 /PRNewswire/ --  IBM (NYSE: IBM) today announced that it is bringing a greater level of control, security and flexibility to cloud-based application development and delivery with a single-tenant version of Bluemix, IBM's platform-as-a-service. The new platform enables developers to build ap...

Cloud Expo 2014 TV commercials will feature @ThingsExpo, which was launched in June, 2014 at New York City's Javits Center as the largest 'Internet of Things' event in the world.
An entirely new security model is needed for the Internet of Things, or is it? Can we save some old and tested controls for this new and different environment? In his session at @ThingsExpo, New York's at the Javits Center, Davi Ottenheimer, EMC Senior Director of Trust, reviewed hands-on lessons with IoT devices and reveal a new risk balance you might not expect. Davi Ottenheimer, EMC Senior Director of Trust, has more than nineteen years' experience managing global security operations and assessments, including a decade of leading incident response and digital forensics. He is co-author of t...
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Architect for the Internet of Things and Intelligent Systems at Red Hat, described how to revolutioniz...
Technology is enabling a new approach to collecting and using data. This approach, commonly referred to as the "Internet of Things" (IoT), enables businesses to use real-time data from all sorts of things including machines, devices and sensors to make better decisions, improve customer service, and lower the risk in the creation of new revenue opportunities. In his General Session at Internet of @ThingsExpo, Dave Wagstaff, Vice President and Chief Architect at BSQUARE Corporation, discuss the real benefits to focus on, how to understand the requirements of a successful solution, the flow of ...
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, and physical persons. In the IoT vision, every new "thing" - sensor, actuator, data source, data con...
"BSQUARE is in the business of selling software solutions for smart connected devices. It's obvious that IoT has moved from being a technology to being a fundamental part of business, and in the last 18 months people have said let's figure out how to do it and let's put some focus on it, " explained Dave Wagstaff, VP & Chief Architect, at BSQUARE Corporation, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Focused on this fast-growing market’s needs, Vitesse Semiconductor Corporation (Nasdaq: VTSS), a leading provider of IC solutions to advance "Ethernet Everywhere" in Carrier, Enterprise and Internet of Things (IoT) networks, introduced its IStaX™ software (VSC6815SDK), a robust protocol stack to simplify deployment and management of Industrial-IoT network applications such as Industrial Ethernet switching, surveillance, video distribution, LCD signage, intelligent sensors, and metering equipment. Leveraging technologies proven in the Carrier and Enterprise markets, IStaX is designed to work ac...
C-Labs LLC, a leading provider of remote and mobile access for the Internet of Things (IoT), announced the appointment of John Traynor to the position of chief operating officer. Previously a strategic advisor to the firm, Mr. Traynor will now oversee sales, marketing, finance, and operations. Mr. Traynor is based out of the C-Labs office in Redmond, Washington. He reports to Chris Muench, Chief Executive Officer. Mr. Traynor brings valuable business leadership and technology industry expertise to C-Labs. With over 30 years' experience in the high-tech sector, John Traynor has held numerous...
Bit6 today issued a challenge to the technology community implementing Web Real Time Communication (WebRTC). To leap beyond WebRTC’s significant limitations and fully leverage its underlying value to accelerate innovation, application developers need to consider the entire communications ecosystem.
The 3rd International @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - computers, smartphones, tablets, and sensors - connected to the Internet by 2020. This number will continue to grow at a rapid pace for the next several decades.
The Internet of Things is not new. Historically, smart businesses have used its basic concept of leveraging data to drive better decision making and have capitalized on those insights to realize additional revenue opportunities. So, what has changed to make the Internet of Things one of the hottest topics in tech? In his session at @ThingsExpo, Chris Gray, Director, Embedded and Internet of Things, discussed the underlying factors that are driving the economics of intelligent systems. Discover how hardware commoditization, the ubiquitous nature of connectivity, and the emergence of Big Data a...
Almost everyone sees the potential of Internet of Things but how can businesses truly unlock that potential. The key will be in the ability to discover business insight in the midst of an ocean of Big Data generated from billions of embedded devices via Systems of Discover. Businesses will also need to ensure that they can sustain that insight by leveraging the cloud for global reach, scale and elasticity.
SYS-CON Events announced today that Windstream, a leading provider of advanced network and cloud communications, has been named “Silver Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. Windstream (Nasdaq: WIN), a FORTUNE 500 and S&P 500 company, is a leading provider of advanced network communications, including cloud computing and managed services, to businesses nationwide. The company also offers broadband, phone and digital TV services to consumers primarily in rural areas.
SYS-CON Events announced today that IDenticard will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. IDenticard™ is the security division of Brady Corp (NYSE: BRC), a $1.5 billion manufacturer of identification products. We have small-company values with the strength and stability of a major corporation. IDenticard offers local sales, support and service to our customers across the United States and Canada. Our partner network encompasses some 300 of the world's leading systems integrators and security s...
IoT is still a vague buzzword for many people. In his session at @ThingsExpo, Mike Kavis, Vice President & Principal Cloud Architect at Cloud Technology Partners, discussed the business value of IoT that goes far beyond the general public's perception that IoT is all about wearables and home consumer services. He also discussed how IoT is perceived by investors and how venture capitalist access this space. Other topics discussed were barriers to success, what is new, what is old, and what the future may hold. Mike Kavis is Vice President & Principal Cloud Architect at Cloud Technology Pa...
Cloud Expo 2014 TV commercials will feature @ThingsExpo, which was launched in June, 2014 at New York City's Javits Center as the largest 'Internet of Things' event in the world. The next @ThingsExpo will take place November 4-6, 2014, at the Santa Clara Convention Center, in Santa Clara, California. Since its launch in 2008, Cloud Expo TV commercials have been aired and CNBC, Fox News Network, and Bloomberg TV. Please enjoy our 2014 commercial.