|By Sam Farmer||
|April 13, 2005 12:00 AM EDT||
In any membership organization with many in-house applications, the ability to share members' data among applications is vital. Previously, applications would duplicate functionality or make members leave one application to update their new address. This didn't work well for members, nor was it easy to maintain by developers.
Using a new framework, CFMVC, allowed us to make improvements. Our new membership system will allow our paper submission application to let members change their institution with the same front and back end code the membership application uses.
In developing a new framework we needed it to handle the integration of over twenty different databases and applications, work with multiple developers, have low processing and be straightforward. We achieved it by utilizing the benefits of ColdFusion and the Model-View-Controller (MVC) architecture.
ColdFusionThough it's arguable whether or not ColdFusion is an object-oriented development environment, it does support many object-oriented features and has many constructs that allow developers to reuse code and functionality. ColdFusion Components (CFCs) are ideal for all data interactions and business logic while normal ColdFusion pages, User Defined Functions (UDFs) and Custom Tags are ideal for handling display portions.
All applications, regardless of size, contain the following pieces:
- There will be some way of displaying information to a user - most likely, for ColdFusion developers, via a Web browser.
- Another piece will process any changes the user makes generally by writing to a database.
- A third piece will direct the user to a new item to be displayed.
Model-View-ControllerThe Model-View-Controller (MVC) architecture was designed over 25 years ago by Trygve Reenskaug. Originally designed for Smalltalk programmers, it has been used in many languages from Visual Basic to Java, and is especially common among Object Oriented programmers. Companies embracing it include Apple and IBM.
MVC separates an application into the three pieces or tiers mentioned earlier. What exactly does MVC consist of?
- The model layer handles all core data interaction whether with a database, XML files or any other data store along with other business interactions.
- The view layer displays data to the user.
- Any action the user takes goes through the controller layer, which calls the needed parts of the model layer before calling the next view layer to display.
By combining ColdFusion's best practices and the proven architecture of MVC, a framework emerges that modulizes code and allows for it to be used in multiple applications. (Benoit Hediard also has a similar idea for merging together MVC and CF, see www.benorama.com.)
Tying Together CF and MVCWhere does ColdFusion code live and where does it use components, pages and custom tags?
Most applications use at least one database. The model tier retrieves data from the database, stores this data, and provides functionality for interacting with the database. If your application uses text files or some other data storage mechanism, then your model tier will interact with that entity. My MVC implementation involved creating an entity CFC for each table in the database (for example, PeopleEntity.cfc) that handles select (get), update and insert statements (set) and delete if required. A utility CFC is used when returning multiple records, joining other tables and processing functions that require more than one entity, like adding a new member - which requires inserts into a members and an addresses table. All code in the model layer must be written so it can be reused in other applications and should not use session, application or request variables; rather, values should be passed in via attributes. Other CFCs, to be shared, are also added in the model layer for e-mail, SOAP calls, LDAP, and so on.
Each CFC should be a object and contain only functions (methods) that relate to it. Functions should either perform one action only or be a wrapper function and call other functions.
The view tier is where all display files reside. Custom tags are used extensively for presentation code and can be called from any application if needed. Like the model layer, they must not include session, application or request variables. For some presentation purposes UDFs may also be needed.
We did two things that are not part of MVC but were needed for ColdFusion implementation. First, all forms use the post method and custom tags that contain a form accept two attributes: formAction and formMethod, which are placed in the form to pass data to the correct controller. This allows for calls from anywhere and the capability to post to anywhere. Second, all applications have at least one applicationSkin file (see membershipSkin.cfm) in the view layer to allow for an application appearance to be set. Multiple skins can then be used if, say, an admin version is intended to look different to a normal version.
The controller tier is on the web root and has no pretense of being reused. Indeed they should only be used by the application. There are two types of controller files: view-controller and model-controller. View-controller files call code in the view tier and sometimes add customization themselves. Model-controller, as the name suggests, handle all interaction with the model layer but it's important to remember that code here is not intended for reuse and extra features for this application can be added for example an e-mail or calling a web service.
As part of the ColdFusion implementation, view-controller files are standard cfm files that call custom tags. Model-controller files are CFCs, are accessed remotely but as are below an Application.cfm (or Application.cfc) file fit into whatever security system an application deploys. Once a model-controller file has finished processing, it uses cflocation to call the next view-controller file to ensure that data is processed only once if a user reloads.
If you have trouble separating your files into their appropriate areas of the MVC framework, the code in that file is probably doing too much. Try breaking it down into smaller parts.
Folder StructureWhere does all this code sit? As controller files are used only by the application they all belong in the application web root, i.e. webroot/membership/. View-controller files, one for each area of the application, sit in this folder (see Figure 1). This allows for freedom in naming and short URL's. Features that apply to that area only, such as navigation, can also be added easily. Model-controller files are all placed in a controller folder i.e. webroot/membership/controller/.
The rest of our code, in the model and view tiers, is intended to be shared. Below the webroot we set up a folder called cfshare and within that a CFC, tag, and UDF folder (see Figure 2). A merging of ColdFusion, MVC and our desire to share code amongst applications led to such a folder set up. All model files are CFCs leading to a natural home for them, so beneath the CFC folder an additional folder is created for each application to store Entity, Utility and other components.
A similar set-up occurs for view files, all of which are custom tags. Likewise within the tag folder is an additional folder for each application. For the times when UDFs are used they follow the exact same structure under the UDF folder.
To make accessing easier in our code, a ColdFusion mapping is set up to the cfshare folder. Once achieved to access the peopleEntity in the model tier simply call the component:
<cfinvoke component="cfshare.cfc.membership.peopleEntity" method="init"></cfinvoke>
And to access the applicationSkin (using CFMX 6.1):
<cfimport prefix="/cfshare/tag/membership/ " taglib="view"> <view:membershipSkin> </view:membershipSkin>
Or for 6 and backwards:
CodeLet's look at two code examples, which can be downloaded from www.sys-con.com/coldfusion/sourcec.cfm; first the display page for a member to join and second the processing of the collected data.
Code Example One: index.cfm
The first example uses a view-controller called index.cfm.
We start by importing a taglib and giving the prefix of view to enable the calling of custom tags (such a method shows future developers exactly where the custom tag is). Then we param the URL display to a default value of "join". Next we open up the membershipSkin call inside of which is a cfswitch statement which will call the desired display. The default value of join is picked and the "people" custom tag is called with some variables passed in. The cfswitch statement and membershipSkin custom tags are then closed.
Let's step back and look at the people custom tag. First it performs a check to see if it has already been called and if so exits, to prevent duplicate output. Then it calls the peopleEntity cfc and outputs a simple form to allow for the collecting or editing of data. The three attributes it accepts are important: nextAction and nextMethod work in tandem - nextAction contains the path to the processing controller ("controller/membershipController.cfc" in this case) and nextMethod is the name of the function that will be called in the controller file. Passing in a value of -1 for peopleID allows for blank values to be created, but if a value of a real member had been passed in then those values would have been displayed.
Code Example Two: process-controller
How does this get processed? This is an example of a process-controller with the membershipController.cfc being called.
The nextMethod attribute in the people custom tag was set to a hidden field called method which when passed to a cfc remotely will trigger that a function of the provided name. For this example it is join. The access attribute in join function is set to remote to allow for it to be called over the web. The function creates an object to the peopleEntity in the model layer and then calls the set function with the passed in values. The peopleEntity then either runs an update if a valid peopleID is passed or an insert. Just like that, we have a new member! The join function then uses cflocation to relocate the user to the next page.
SummaryThe CFMVC framework discussed above is based on a proven, successful architecture in MVC and has a low processing overhead for ColdFusion. The effect of splitting an application into tiers - model, view and controller - allows us to write applications that can share both data and functionality easily. But the benefits will also extend to completely standalone applications.
|David Hardwick 05/12/05 12:00:44 PM EDT|
Have you investigated the other MVC frameworks before coming up with your own? Mach-II and Tartan for example? I'm using Mach-II on a project right now, and it is very solid. I've worked with Java-based MVC frameworks prior to this project, and I am very impressed with the thought that went into this architecture.
While it is admirable that you put together your own MVC framework, I would rather the CF community do a better job than say the PHP community in putting our efforts behind one or two horses instead of fragmenting our time across multiple 're-inventing the wheel' efforts.
|Sridhar Loka 05/12/05 11:53:07 AM EDT|
I have implemented MVC architecture for ColdFusion application using different approach.
|Jim Davis 05/12/05 07:20:35 AM EDT|
I like this approach and its clear division between layers. Will definitely keep it in mind when picking a methodology for a new project.
|Brian Kotek 05/11/05 07:04:17 PM EDT|
While it is always great to spread the word about best practices and patterns like MVC, I have to point out that using MVC with ColdFusion has been around for years. There are several widely-used frameworks with established communities that support MVC development. Fusebox 4, Mach-II, and Model-Glue are among the most popular. These have the added benefit of a built-in system to handle content elements and layouts without having to resort to custom tags. I would urge anyone interested in this topic to investigate these popular frameworks.
The Internet of Things is a misnomer. That implies that everything is on the Internet, and that simply should not be - especially for things that are blurring the line between medical devices that stimulate like a pacemaker and quantified self-sensors like a pedometer or pulse tracker. The mesh of things that we manage must be segmented into zones of trust for sensing data, transmitting data, receiving command and control administrative changes, and peer-to-peer mesh messaging. In his session at @ThingsExpo, Ryan Bagnulo, Solution Architect / Software Engineer at SOA Software, focused on desi...
Dec. 17, 2014 11:15 PM EST Reads: 1,210
"At our booth we are showing how to provide trust in the Internet of Things. Trust is where everything starts to become secure and trustworthy. Now with the scaling of the Internet of Things it becomes an interesting question – I've heard numbers from 200 billion devices next year up to a trillion in the next 10 to 15 years," explained Johannes Lintzen, Vice President of Sales at Utimaco, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 17, 2014 11:00 PM EST Reads: 1,285
"For over 25 years we have been working with a lot of enterprise customers and we have seen how companies create applications. And now that we have moved to cloud computing, mobile, social and the Internet of Things, we see that the market needs a new way of creating applications," stated Jesse Shiah, CEO, President and Co-Founder of AgilePoint Inc., in this SYS-CON.tv interview at 15th Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 17, 2014 08:00 PM EST Reads: 1,255
SYS-CON Events announced today that Gridstore™, the leader in hyper-converged infrastructure purpose-built to optimize Microsoft workloads, 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. Gridstore™ is the leader in hyper-converged infrastructure purpose-built for Microsoft workloads and designed to accelerate applications in virtualized environments. Gridstore’s hyper-converged infrastructure is the industry’s first all flash version of HyperConverged Appliances that include both compute and storag...
Dec. 17, 2014 06:30 PM EST Reads: 1,144
"People are a lot more knowledgeable about APIs now. There are two types of people who work with APIs - IT people who want to use APIs for something internal and the product managers who want to do something outside APIs for people to connect to them," explained Roberto Medrano, Executive Vice President at SOA Software, in this SYS-CON.tv interview at Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Dec. 17, 2014 06:00 PM EST Reads: 1,109
Today’s enterprise is being driven by disruptive competitive and human capital requirements to provide enterprise application access through not only desktops, but also mobile devices. To retrofit existing programs across all these devices using traditional programming methods is very costly and time consuming – often prohibitively so. In his session at @ThingsExpo, Jesse Shiah, CEO, President, and Co-Founder of AgilePoint Inc., discussed how you can create applications that run on all mobile devices as well as laptops and desktops using a visual drag-and-drop application – and eForms-buildi...
Dec. 17, 2014 11:45 AM EST Reads: 1,398
We certainly live in interesting technological times. And no more interesting than the current competing IoT standards for connectivity. Various standards bodies, approaches, and ecosystems are vying for mindshare and positioning for a competitive edge. It is clear that when the dust settles, we will have new protocols, evolved protocols, that will change the way we interact with devices and infrastructure. We will also have evolved web protocols, like HTTP/2, that will be changing the very core of our infrastructures. At the same time, we have old approaches made new again like micro-services...
Dec. 16, 2014 11:45 PM EST Reads: 1,231
Code Halos - aka "digital fingerprints" - are the key organizing principle to understand a) how dumb things become smart and b) how to monetize this dynamic. In his session at @ThingsExpo, Robert Brown, AVP, Center for the Future of Work at Cognizant Technology Solutions, outlined research, analysis and recommendations from his recently published book on this phenomena on the way leading edge organizations like GE and Disney are unlocking the Internet of Things opportunity and what steps your organization should be taking to position itself for the next platform of digital competition.
Dec. 15, 2014 11:45 PM EST Reads: 1,612
The 3rd International Internet of @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 its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
Dec. 15, 2014 10:30 AM EST Reads: 6,842
As the Internet of Things unfolds, mobile and wearable devices are blurring the line between physical and digital, integrating ever more closely with our interests, our routines, our daily lives. Contextual computing and smart, sensor-equipped spaces bring the potential to walk through a world that recognizes us and responds accordingly. We become continuous transmitters and receivers of data. In his session at @ThingsExpo, Andrew Bolwell, Director of Innovation for HP's Printing and Personal Systems Group, discussed how key attributes of mobile technology – touch input, sensors, social, and ...
Dec. 15, 2014 10:00 AM EST Reads: 1,931
In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect at GE, and Ibrahim Gokcen, who leads GE's advanced IoT analytics, focused on the Internet of Things / Industrial Internet and how to make it operational for business end-users. Learn about the challenges posed by machine and sensor data and how to marry it with enterprise data. They also discussed the tips and tricks to provide the Industrial Internet as an end-user consumable service using Big Data Analytics and Industrial Cloud.
Dec. 15, 2014 10:00 AM EST Reads: 1,598
Building low-cost wearable devices can enhance the quality of our lives. In his session at Internet of @ThingsExpo, Sai Yamanoor, Embedded Software Engineer at Altschool, provided an example of putting together a small keychain within a $50 budget that educates the user about the air quality in their surroundings. He also provided examples such as building a wearable device that provides transit or recreational information. He then reviewed the resources available to build wearable devices at home including open source hardware, the raw materials required and the options available to power s...
Dec. 15, 2014 09:00 AM EST Reads: 1,600
Things are being built upon cloud foundations to transform organizations. This CEO Power Panel at 15th Cloud Expo, moderated by Roger Strukhoff, Cloud Expo and @ThingsExpo conference chair, addressed the big issues involving these technologies and, more important, the results they will achieve. Rodney Rogers, chairman and CEO of Virtustream; Brendan O'Brien, co-founder of Aria Systems, Bart Copeland, president and CEO of ActiveState Software; Jim Cowie, chief scientist at Dyn; Dave Wagstaff, VP and chief architect at BSQUARE Corporation; Seth Proctor, CTO of NuoDB, Inc.; and Andris Gailitis, C...
Dec. 15, 2014 09:00 AM EST Reads: 1,419
There's Big Data, then there's really Big Data from the Internet of Things. IoT is evolving to include many data possibilities like new types of event, log and network data. The volumes are enormous, generating tens of billions of logs per day, which raise data challenges. Early IoT deployments are relying heavily on both the cloud and managed service providers to navigate these challenges. In her session at Big Data Expo®, Hannah Smalltree, Director at Treasure Data, discussed how IoT, Big Data and deployments are processing massive data volumes from wearables, utilities and other machines...
Dec. 15, 2014 08:45 AM EST Reads: 2,007
"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.
Dec. 15, 2014 08:15 AM EST Reads: 2,697
SYS-CON Media announced that Splunk, a provider of the leading software platform for real-time Operational Intelligence, has launched an ad campaign on Big Data Journal. Splunk software and cloud services enable organizations to search, monitor, analyze and visualize machine-generated big data coming from websites, applications, servers, networks, sensors and mobile devices. The ads focus on delivering ROI - how improved uptime delivered $6M in annual ROI, improving customer operations by mining large volumes of unstructured data, and how data tracking delivers uptime when it matters most.
Dec. 15, 2014 06:45 AM EST Reads: 2,144
In this Women in Technology Power Panel at 15th Cloud Expo, moderated by Anne Plese, Senior Consultant, Cloud Product Marketing at Verizon Enterprise, Esmeralda Swartz, CMO at MetraTech; Evelyn de Souza, Data Privacy and Compliance Strategy Leader at Cisco Systems; Seema Jethani, Director of Product Management at Basho Technologies; Victoria Livschitz, CEO of Qubell Inc.; Anne Hungate, Senior Director of Software Quality at DIRECTV, discussed what path they took to find their spot within the technology industry and how do they see opportunities for other women in their area of expertise.
Dec. 15, 2014 04:00 AM EST Reads: 1,384
While great strides have been made relative to the video aspects of remote collaboration, audio technology has basically stagnated. Typically all audio is mixed to a single monaural stream and emanates from a single point, such as a speakerphone or a speaker associated with a video monitor. This leads to confusion and lack of understanding among participants especially regarding who is actually speaking. Spatial teleconferencing introduces the concept of acoustic spatial separation between conference participants in three dimensional space. This has been shown to significantly improve comprehe...
Dec. 12, 2014 05:00 PM EST Reads: 1,251
The Industrial Internet revolution is now underway, enabled by connected machines and billions of devices that communicate and collaborate. The massive amounts of Big Data requiring real-time analysis is flooding legacy IT systems and giving way to cloud environments that can handle the unpredictable workloads. Yet many barriers remain until we can fully realize the opportunities and benefits from the convergence of machines and devices with Big Data and the cloud, including interoperability, data security and privacy.
Dec. 11, 2014 06:00 PM EST Reads: 1,452
Performance is the intersection of power, agility, control, and choice. If you value performance, and more specifically consistent performance, you need to look beyond simple virtualized compute. Many factors need to be considered to create a truly performant environment. In his General Session at 15th Cloud Expo, Harold Hannon, Sr. Software Architect at SoftLayer, discussed how to take advantage of a multitude of compute options and platform features to make cloud the cornerstone of your online presence.
Dec. 11, 2014 03:15 PM EST Reads: 1,914