Home > Articles > Mobile Application Development & Programming > HTML5 & Web Standards

  • Print
  • + Share This
Like this article? We recommend

Like this article? We recommend

Using the URL Scope to Pass Parameters

Forms are an excellent way to pass parameters from one template to another when you require user input. There are many times when you need to pass nonsecure variables from one page to another without requiring user input. In this case, you can pass parameters within the URL scope.

Just as it sounds, the URL scope is the set of variables available from the URL of a given template. URL variables, or parameters, are similar to form variables in one respect: They are not available to the page on which they are set—they are available only to the page that they get passed to.

Setting a URL Variable

URL parameters are passed in the query string of a given URL. You create a query string by appending a question mark (?) to your link. They take the form parameter=value. Let's say that you have a page called SomePage.cfm. You want to pass a value to SomeActionPage.cfm. You structure your link as follows:


In the above example, SomeActionPage.cfm will receive the parameter value when the link on SomePage.cfm is clicked. Your URL variable will be available for further processing or display on SomeActionPage.cfm, but not on SomePage.cfm.

An example should quickly elucidate. Let's create these two pages and populate them with real values. In Studio, type the code in Listing 3, and save your file as SetURLParam.cfm.

Listing 3: Setting Parameters in the URL




   Choose your favorite color:
   <a href="URLAction.cfm?favecolor=Green">Green</a>
   <a href="URLAction.cfm?favecolor=Red">Red</a>
   <a href="URLAction.cfm?favecolor=Blue">Blue</a>


You now have three links that all point to the same action page but have different parameters. Let's make an action page, URLAction.cfm, that accepts your passed URL parameter and displays it. Type the code from Listing 4 into Studio.

Listing 4: Outputting the Value of a Parameter Passed in the URL


<title>URL Fave</title>


Your favorite color is 



When you click on a link in SetURLParam.cfm, the favecolor parameter is passed in the query string of the link to URLAction.cfm. The value of that parameter is then available to the action page as favecolor. When you reference that parameter, its value is displayed (or is available for further processing). Just like we did with form variables, we put the scoped variable inside a block of <cfoutput> tags. ColdFusion interprets the variable and assigns it the value passed.

Notice that you can reference URL parameters in the title of your document as well. Your browser will display dynamic output from ColdFusion here just as well as any other place.


Just as a reminder that it is possible to reference your variables without their scope. We could also write <cfoutput>#favecolor#</cfoutput> in the above code, and it would work. However, because ColdFusion will look for a parameter within each scope in a predetermined order until it finds one, forgetting the scope may lead to unpredictable results. Your code will process a bit faster, too, because ColdFusion doesn't have to go looking for a variable's scope.

URL Encoded Format

URLs may not contain spaces or any nonalphanumeric characters. If you are going to pass variables through a URL, you must define your parameter string to be acceptable for use in a URL. ColdFusion provides an easy way to do this: the URLEncodedFormat function.

The URLEncodedFormat function encodes the special characters and spaces within a string into a percent sign, followed by hexadecimal (16-bit) code. Nonalphanumeric characters are replaced with equivalent hexadecimal escape sequences. Spaces are replaced with plus signs.

URL variables are browser-independent, which means that they will work on any platform. However, they sometimes work slightly differently, depending on how forgiving your browser is. For instance, Microsoft Internet Explorer will account for incorrectly formed URL query strings, if it can, and will insert the proper base 16 codes.

Netscape, on the other hand, is far stricter in its interpretation of URL parameters. I recommend that you consider using Netscape as your development browser for just this reason. If it works in Netscape, you can be usually be confident that it will work in Internet Explorer. Of course, it is prudent to test your code in a wide variety of browsers. I've just found that this practice keeps me careful about working with URL parameters.

The URLEncodedFormat function takes one argument—the string to be encoded. You can therefore use it this way:


Let's say that we wanted to pass a parameter whose value contained spaces or special characters. We'll write some code very similar to the favorite color code that we wrote before. However, this time we are going to choose our favorite cook. Because all of the choices of favorite cooks are first and last names, they need to contain spaces in the URL parameters in order to display correctly (with one space between the first and last names) on the action page. So, let's quickly modify our favorite color code from above as shown in Listing 5, and save it as favecook.cfm. (Note: This code will not perform reliably; we need to view it to make the point.)

Listing 5: Setting URL Parameters with Spaces in the String

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

   <title>Favorite Cooks</title>


Choose your favorite cook:<br>
<a href="Action2.cfm?cook=Julia Child">Julia Child</a>
<a href="Action2.cfm?cook=Martha Stewart">Martha Stewart</a>
<a href="Action2.cfm?cook=My Dad">My Dad</a>


We now need to create Action2.cfm to accept the cook parameter. You can easily modify URLAction to output the value of the #URL.cook# parameter, as in Listing 6.

Listing 6: You Can Sometimes Output the Value of Unencoded Parameters, Depending on Your Browser

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">

<title>Fave Cooks</title>

Your favorite cook is <b><cfoutput>#URL.cook#</cfoutput></b>.


Netscape would return an error stating the "the parameter is incorrect." Let's really make it tough. We'll change our code to include not only spaces, but also two special characters: ' and &.

Create a file, FaveCookBook.cfm, with the code in Listing 7.

Listing 7: Using the URLEncoded Format Function Handles the Problem

Choose your favorite cook book:<br>

<cfset cookbook1 = "Julia Child & Friends">
<cfset cookbook2 = "Martha Stewart's">

<a href="Action2.cfm?book=#URLEncodedFormat(cookbook1)#">Julia Child & Friends</a>
<a href="Action2.cfm?book=#URLEncodedFormat(cookbook2)#">Martha Stewart's</a>

Then create a simple action page to accept these values:

Your favorite cook book is <b><cfoutput>#URL.book#</cfoutput></b>.


Now, using the URLEncodedFormat function, we will pass these difficult parameters with ease to our action page. If you load this page and look in the address bar of your browser, you notice that the spaces have been replaced with %20 and the ampersand (&) has been replaced with %26. These are hexadecimal representations that your browser can read.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020