Click here to close now.

Welcome!

AJAX & REA Authors: XebiaLabs Blog, Greg O'Connor, Elizabeth White, Cloud Best Practices Network, Liz McMillan

Related Topics: AJAX & REA, ColdFusion

AJAX & REA: Article

Building a Drag-and-Drop Shopping Cart with AJAX

Creating an interactive shopping experience

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

The rise of AJAX over the past several months has taken over the development world and breathed new life into the Web. Although these techniques have been possible for many years now, the maturity of Web standards like XHTML and CSS now make it a viable alternative that will be viewable by all but the oldest browsers.

It's also been possible to accomplish many of the same things using Flex or Flash, but the development cycle with those applications is typically more involved and the overhead often not justified.

We're going to harness the power of the Scipt.aculo.us JavaScript library to provide our interaction. As their Web site states, this library "provides you with easy-to-use, compatible and, ultimately, totally cool JavaScript libraries to make your web sites and web applications fly, Web 2.0 style." We're also going to utilize the <CF_SRS> library to handle the actual AJAX data piping to our application. Both of these libraries are free for all to use, and they're easier to integrate than you would think.

For this article, we'll create an interactive shopping experience allowing us to add items to our shopping basket by dragging and dropping them onto an icon of a shopping cart. We'll add AJAX functionality, allowing us to update our shopping cart without redrawing the entire screen. To save the trouble of setting up a product database, we'll use Amazon Web Services to search for DVDs and use those to shop from.

Start with a blank index.cfm in your root directory. You'll need to visit http://script.aculo.us/downloads to download the latest distribution (they're nearing a final release for version 1.5 as of this writing). Copy the "lib" and "src" directories into your empty directory. You'll need all of the .js files so just copy over the entire directory in each case. Next, type the following lines into the <head></head> section of your page:

<script src="./lib/prototype.js" type="text/javascript"></script>
<script src="./src/scriptaculous.js" type="text/javascript"></script>

We'll need a search box to submit our query to Amazon:

<form action="index.cfm" method="post">
Search: <input type="text" name="keywords" size="20" />
<input type="submit" name="search" value="Go" />
</form>

The page will look for a form.search variable and run an Amazon search when it is defined. Each item returned will be placed in its own styled div that will be able to be picked up and dragged.

The Scriptaculous library makes it easy to create "draggables" (the only required argument is the ID of the object that you want draggable). Listing 1 contains the code to search Amazon and return the results as draggable divs.

At this point, all of the items returned from the search will be in their own box and should be draggable around the screen. When we created each draggable, we set "revert=true", which will snap each object back to its original location if not placed directly on a drop zone.

Next, we'll add a graphic of a shopping cart to our page, which will become a drop target on which to drag items. The Scriptaculous library also makes it easy to create these "droppables". The syntax is simply:

Droppables.add('id_of_element',[options]);

The code below creates a droppable zone of id "cart1" and also runs a function onDrop() that pops up an alert box letting the user know an item has being added. We then hide the element from view, which allows the other divs to slide over and adjust accordingly.

<img src="shopcart.jpg" id="cart1" style="float:left;">
<script language="javascript" type="text/javascript">
Droppables.add('cart1', { onDrop:function(element) {
alert('Added UPC ' + element.id + ' to your shopping cart.');
Element.hide(element.id);}})
</script>

The items should now be disappearing when dropped onto the shopping cart, but there's nothing going on behind the scenes yet. Now it's time to add some AJAX to process our shopping cart.

Although there are several AJAX libraries to choose from, we're going to use the ColdFusion Simple Remote Scripting <CF_SRS> library made available free of charge by Matthew Walker of ESWsoftware in New Zealand. <CF_SRS> uses an IFRAME for communication and encapsulates all of the dirty work for you. This library was chosen for its ability to handle HTML tables well and for its ability to interact directly with the browser's Document Object Model (DOM) to output our shopping cart rows.

We'll start with an empty cart by including the following code:

<fieldset style="width:400px;">
<legend>Your shopping cart</legend>
<table border="0" cellspacing="0" cellpadding="5" id="tableCart">
<thead></thead><tbody></tbody></table>
<button onclick="emptyCartButton_onClick()" id="emptyCartButton">
Clear Shopping Cart</button>
</fieldset>

(Don't worry about the fact that our table body (<tbody></tbody>) is empty right now - we'll be populating it in just a second through AJAX.)

Next, you'll need to download the <CF_SRS> package from www.eswsoftware.com/products/download/. Copy the srs.cfm file into your Webroot (or you can add it to your CustomTags directory if you plan to do more AJAXing). You'll also need to create a subdirectory to hold the gateway pages that handle our AJAX data passing. Name the directory "SRS" and copy the Application.cfm and OnRequestEnd.cfm files into there from the "serverpages" directory in the zip file. You can use either regular CFM files or CFCs for these gateway pages (the download provides examples of each). The main thing to remember is that these pages should always return their results to "request.response".

Simply adding a <cf_srs> call to your page will handle the creation of the hidden IFRAME for you. Another great feature of the CF_SRS library is the ability to view an inline debugging window right inside the page you are working on. This allows you to see all of the data being passed back and forth through the gateway. You can enable this debugging by calling the tag as <cf_srs trace>. This line can be placed anywhere but we'll add it at the very end of the file.

Next, we'll need to create some JavaScript functions to handle the AJAX interactions. Add an onLoad function to your body tag as such: <body onload="body_onLoad()">. This will execute body_onLoad() when the page loads and we'll use this function to set up our gateway. The function should read as follows:

function body_onLoad() {
// create an SRS gateway to the cart.cfm page
objGateway = new gateway("srs/cart.cfm?");
// update cart in case of return visit
// code for this function is below
updateCart();
}

Once you have created your gateway, you can invoke the methods below to send requests to the server:

  • objGateway.setListener( str ): Use this method to specify the name of the function in your Web page that will handle the server's response. str is a string representing the function's name. The listener defaults to "alert", which will pop up a JavaScript alert() box containing the server's response. Note that while ColdFusion is a case-insensitive language, JavaScript is case-sensitive. If you return a structure to your listener function, all the structure keys will be rendered in JavaScript as lowercase.
  • objGateway.setArguments( obj ): Set the arguments and values to pass to the server. obj is an object literal, which is basically just a set of one or more attribute/value pairs wrapped in curly braces. Here's an example: { name:'Joe', age:30, country:'US' }. You can see that string values need to be wrapped in quotation marks, and colons (:) are used in place of equals signs (=).
  • objGateway.resetArguments(): Remove all the arguments previously set.
  • objGateway.request(): Send the request to the server.

More Stories By Joe Danziger

Joe Danziger is a senior web applications developer with Multimax, Inc., a provider of Enterprise IT Services and Solutions supporting the critical missions of the Air Force, Army, Navy, and other Department of Defense components. He is certified as an Advanced Macromedia ColdFusion MX Developer, and also maintains the Building Blocks site (www.ajaxcf.com) dedicated to AJAX and ColdFusion, as well as DJ Central (www.djcentral.com), a Website serving DJs and the electronic dance music industry.

Comments (22) 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
King 05/21/08 03:33:54 PM EDT

Soon everything will be Ajax, just look how the major websites are adapting to use it.

A 05/07/08 01:02:58 PM EDT

I think your right when you say that Ajax is the way of the future, although its is difficult to program, you can see yahoos and googles implementation of it.

Scott 08/02/07 12:04:03 PM EDT

Hello N,

I had the same problem. Try changing:

to:
<cfif StructKeyExists(xnSearch.Items.Item, "MediumImage")>

N 07/14/07 10:19:57 AM EDT

I'm following this tutorial to the letter as well and I also get this error in the code that retrieves the info from Amazon...

Element ITEMS.TOTALRESULTS.XMLTEXT is undefined in XNSEARCH

Is there a fix available or anything to get this to work. It looks good though.

N

asdf 07/10/07 01:17:36 AM EDT

asdfsafs asdfasf asdfasf

abcd 07/10/07 01:14:52 AM EDT

heloow asdf asdfs asdfasf biuiouer asdfaf boihoi awerew asdf

Wally Kolcz 01/22/07 09:27:35 AM EST

I loved your tutorial on how to make a drag and drop web cart, but I couldn't quite follow on how to put the code into the page to make it work. Do you have any finished files available for download to see how it is constructed?

Thanks

BUses 12/26/06 08:45:23 PM EST

Awesome content: L'augmentation d'AJAX pendant plusieurs mois passés a repris du monde de développement et a donné un second souffle au Web.
Merry Christmas of Poland!

Simone from Italy 12/20/06 10:54:21 AM EST

Hi, please add a link to index.cfm full compliled because It's very hard to have a union of all fragments introduced in your article. Thanks

Danny 10/31/06 04:09:38 AM EST

I'm following this tutorial to the letter and I get this error in the code that retrieves the info from Amazon...

Element ITEMS.TOTALRESULTS.XMLTEXT is undefined in XNSEARCH

Any ideas? Thanks for this tutorial!

j j 09/21/06 02:01:43 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

Student Organization Guy 08/05/06 04:28:22 AM EDT

How is user experience improved with dragging items into a shopping cart? ;) This is just developer feature candy. There are many other site components to focus your time on that will improve your application. Don't work so hard just to remove your 'add to cart' buttons.

CFDJ News Desk 08/04/06 04:20:22 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

AJAXWorld News Desk 08/04/06 03:46:57 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

AJAXWorld News Desk 08/04/06 03:46:48 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

AJAXWorld News Desk 08/04/06 03:35:26 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

AJAXWorld News Desk 08/01/06 04:10:49 PM EDT

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

barb 08/01/06 03:52:54 PM EDT

I also have been struggling to get this example to work. It is not clear to me if I have to have a Coldfusion server running. Currently, I do not. I simply followed the instructions in the article. I'm getting the Javascript error "gateway not defined" from the line of code where I try to instantiate it: objGateway = new gateway("srs/cart.cfm?");. Can you please provide more information or a complete code listing?

Thank you!

bill 02/10/06 11:35:56 PM EST

The app is great but I'm also struggling to get it to work. I'm not giving up!
Hi Joe,
could you please post the full code file or send us by email.
Thanks,
b.

Kenny 02/08/06 07:10:32 PM EST

This is one of the most frustrating examples I've ever tried. I cannot figure out how to assemble this application. It is not well written at all in my opinion. Why is there not a clear list of all the code somewhere? I came to the website to download the code, so I could simply paste it and watch it work. But instead I've been stressing for the last 40 minutes just trying to figure out how to get it all together, and I simply cannot. I give up!

SYS-CON Brazil News Desk 01/27/06 02:28:32 PM EST

Keeping up with the latest Web technologies is tough nowadays. Every week it seems new sites are launched that push the envelope further and further in terms of what can be accomplished using just a Web browser.

Colm Brazel 01/24/06 08:54:51 AM EST

Hi,

I'm reading the online digital edition version
of this article, page 2 ends without giving the complete listings of the code given in the article, so, for example, I don't have the code to search amazon to test. Code listings are invaluable to check article contents with hopefully verified working version.

cheers

Colm

@CloudExpo Stories
SYS-CON Events announced today that robomq.io will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. robomq.io is an interoperable and composable platform that connects any device to any application. It helps systems integrators and the solution providers build new and innovative products and service for industries requiring monitoring or intelligence from devices and sensors.
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding bu...
Today, IT is not just a cost center. IT is an enabler and driver of business. With the emergence of the hybrid cloud paradigm, IT now has increasingly more capabilities to create new strategic opportunities for a business. Hybrid cloud allows an organization to utilize multi-tenant public clouds, dedicated private clouds, bare metal hosting, and the associated support and services for the right use cases through an on-demand, XaaS model. This model of IT creates tremendous opportunities for busi...
Business as usual for IT is evolving into a “Make or Buy” decision on a service-by-service conversation with input from the LOBs. How does your organization move forward with cloud? In his general session at 16th Cloud Expo, Paul Maravei, Regional Sales Manager, Hybrid Cloud and Managed Services at Cisco, discusses how Cisco and its partners offer a market-leading portfolio and ecosystem of cloud infrastructure and application services that allow you to uniquely and securely combine cloud busi...
Businesses are looking to empower employees and departments to do more, go faster, and streamline their processes. For all workers – but mobile workers especially – utilizing the cloud to reconnect documents and improve processes without destructing existing workflows can have a dramatic impact on productivity. In his session at 16th Cloud Expo, Mark Grilli, vice president of Acrobat Solutions marketing at Adobe Systems Incorporated, will outline new ways that the cloud is changing the way peo...
SYS-CON Events announced today that Litmus Automation 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. Litmus Automation’s vision is to provide a solution for companies that are in a rush to embrace the disruptive Internet of Things technology and leverage it for real business challenges. Litmus Automation simplifies the complexity of connected devices applications with Loop, a secure and scalable clou...
As Marc Andreessen says software is eating the world. Everything is rapidly moving toward being software-defined – from our phones and cars through our washing machines to the datacenter. However, there are larger challenges when implementing software defined on a larger scale - when building software defined infrastructure. In his session at 16th Cloud Expo, Boyan Ivanov, CEO of StorPool, will provide some practical insights on what, how and why when implementing "software-defined" in the dat...
With the arrival of the Big Data revolution, a data professional is expected to master a broad spectrum of complex domains including data processing, mathematics, programming languages, machine learning techniques, and business knowledge. While this mastery is undoubtedly important, this narrow focus on tool usage has divorced many from the imagination required to solve real-world problems. As the demand for analysis increases, the data science community must transform from tool experts to "data...
WSM International has launched a DevOps services division that offers assessment, consulting and implementation to large enterprises and organizations with complex infrastructures. The concept of DevOps is to blend information technology (IT) software development with operations to optimize the computing infrastructure according to the specific needs of the organization. According to a recent press release from Gartner, "By 2016, DevOps will evolve from a niche strategy employed by large cloud ...
SYS-CON Events announced today that Solgenia 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, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Solgenia is the global market leader in Cloud Collaboration and Cloud Infrastructure software solutions. Designed to “Bridge the Gap” between Personal and Professional S...
SYS-CON Events announced today that QTS Realty Trust, one of the nation’s largest and fastest-growing providers of data center facilities and cloud services and a leader in security and compliance, 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. QTS Realty Trust, Inc. (NYSE: QTS) is a leading national provider of data center solutions and fully managed services, and a leader in security and compliance...
SYS-CON Events announced today that WSM International (WSM), the world’s leading cloud and server migration services provider, 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. WSM is a solutions integrator with a core focus on cloud and server migration, transformation and DevOps services.
SYS-CON Events announced today that MangoApps 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., and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. MangoApps provides private all-in-one social intranets allowing workers to securely collaborate from anywhere in the world and from any device. Social, mobile, and eas...
SYS-CON Events announced today that Emcien 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. Emcien’s vision is to let anyone use data to know the future. Emcien has built an automated, predictive analysis product that improves the lives of real people. Emcien allows people to automate their data analysis so they can build a better future.
The speed of software changes in growing and large scale rapid-paced DevOps environments presents a challenge for continuous testing. Many organizations struggle to get this right. Practices that work for small scale continuous testing may not be sufficient as the requirements grow. In his session at DevOps Summit, Marc Hornbeek, Sr. Solutions Architect of DevOps continuous test solutions at Spirent Communications, will explain the best practices of continuous testing at high scale, which is r...
Internet of Things (IoT) will be a hybrid ecosystem of diverse devices and sensors collaborating with operational and enterprise systems to create the next big application. In their session at @ThingsExpo, Bramh Gupta, founder and CEO of robomq.io, and Fred Yatzeck, principal architect leading product development at robomq.io, will discuss how choosing the right middleware and integration strategy from the get-go will enable IoT solution developers to adapt and grow with the industry, while at...
One of the hottest areas in cloud right now is DRaaS and related offerings. In his session at 16th Cloud Expo, Dale Levesque, Disaster Recovery Product Manager with Windstream's Cloud and Data Center Marketing team, will discuss the benefits of the cloud model, which far outweigh the traditional approach, and how enterprises need to ensure that their needs are properly being met.
SYS-CON Events announced today that the DevOps Institute has been named “Association Sponsor” of SYS-CON's DevOps Summit, which will take place on June 9–11, 2015, at the Javits Center in New York City, NY. The DevOps Institute provides enterprise level training and certification. Working with thought leaders from the DevOps community, the IT Service Management field and the IT training market, the DevOps Institute is setting the standard in quality for DevOps education and training.
Even though it’s now Microservices Journal, long-time fans of SOA World Magazine can take comfort in the fact that the URL – soa.sys-con.com – remains unchanged. And that’s no mistake, as microservices are really nothing more than a new and improved take on the Service-Oriented Architecture (SOA) best practices we struggled to hammer out over the last decade. Skeptics, however, might say that this change is nothing more than an exercise in buzzword-hopping. SOA is passé, and now that people are ...
Hosted PaaS providers have given independent developers and startups huge advantages in efficiency and reduced time-to-market over their more process-bound counterparts in enterprises. Software frameworks are now available that allow enterprise IT departments to provide these same advantages for developers in their own organization. In his workshop session at DevOps Summit, Troy Topnik, ActiveState’s Technical Product Manager, will show how on-prem or cloud-hosted Private PaaS can enable organ...