|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.
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies leverage disruptive technologies to optimize revenue-generating systems, 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. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advanced analytics, and DevOps to advance innovation and increase agility. Specializing in designing, imple...
Sep. 1, 2015 11:45 AM EDT Reads: 314
Through WebRTC, audio and video communications are being embedded more easily than ever into applications, helping carriers, enterprises and independent software vendors deliver greater functionality to their end users. With today’s business world increasingly focused on outcomes, users’ growing calls for ease of use, and businesses craving smarter, tighter integration, what’s the next step in delivering a richer, more immersive experience? That richer, more fully integrated experience comes about through a Communications Platform as a Service which allows for messaging, screen sharing, video...
Sep. 1, 2015 11:45 AM EDT Reads: 668
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...
Sep. 1, 2015 11:15 AM EDT Reads: 225
SYS-CON Events announced today that Micron Technology, Inc., a global leader in advanced semiconductor systems, 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. Micron’s broad portfolio of high-performance memory technologies – including DRAM, NAND and NOR Flash – is the basis for solid state drives, modules, multichip packages and other system solutions. Backed by more than 35 years of technology leadership, Micron's memory solutions enable the world's most innovative computing, consumer,...
Sep. 1, 2015 09:45 AM EDT Reads: 237
Contrary to mainstream media attention, the multiple possibilities of how consumer IoT will transform our everyday lives aren’t the only angle of this headline-gaining trend. There’s a huge opportunity for “industrial IoT” and “Smart Cities” to impact the world in the same capacity – especially during critical situations. For example, a community water dam that needs to release water can leverage embedded critical communications logic to alert the appropriate individuals, on the right device, as soon as they are needed to take action.
Sep. 1, 2015 09:00 AM EDT
As more intelligent IoT applications shift into gear, they’re merging into the ever-increasing traffic flow of the Internet. It won’t be long before we experience bottlenecks, as IoT traffic peaks during rush hours. Organizations that are unprepared will find themselves by the side of the road unable to cross back into the fast lane. As billions of new devices begin to communicate and exchange data – will your infrastructure be scalable enough to handle this new interconnected world?
Sep. 1, 2015 08:00 AM EDT Reads: 166
While many app developers are comfortable building apps for the smartphone, there is a whole new world out there. In his session at @ThingsExpo, Narayan Sainaney, Co-founder and CTO of Mojio, will discuss how the business case for connected car apps is growing and, with open platform companies having already done the heavy lifting, there really is no barrier to entry.
Sep. 1, 2015 08:00 AM EDT Reads: 146
With the Apple Watch making its way onto wrists all over the world, it’s only a matter of time before it becomes a staple in the workplace. In fact, Forrester reported that 68 percent of technology and business decision-makers characterize wearables as a top priority for 2015. Recognizing their business value early on, FinancialForce.com was the first to bring ERP to wearables, helping streamline communication across front and back office functions. In his session at @ThingsExpo, Kevin Roberts, GM of Platform at FinancialForce.com, will discuss the value of business applications on wearable ...
Sep. 1, 2015 08:00 AM EDT
WebRTC has had a real tough three or four years, and so have those working with it. Only a few short years ago, the development world were excited about WebRTC and proclaiming how awesome it was. You might have played with the technology a couple of years ago, only to find the extra infrastructure requirements were painful to implement and poorly documented. This probably left a bitter taste in your mouth, especially when things went wrong.
Sep. 1, 2015 03:00 AM EDT Reads: 463
Too often with compelling new technologies market participants become overly enamored with that attractiveness of the technology and neglect underlying business drivers. This tendency, what some call the “newest shiny object syndrome,” is understandable given that virtually all of us are heavily engaged in technology. But it is also mistaken. Without concrete business cases driving its deployment, IoT, like many other technologies before it, will fade into obscurity.
Aug. 31, 2015 09:00 PM EDT Reads: 374
The Internet of Things is in the early stages of mainstream deployment but it promises to unlock value and rapidly transform how organizations manage, operationalize, and monetize their assets. IoT is a complex structure of hardware, sensors, applications, analytics and devices that need to be able to communicate geographically and across all functions. Once the data is collected from numerous endpoints, the challenge then becomes converting it into actionable insight.
Aug. 31, 2015 07:00 PM EDT
Consumer IoT applications provide data about the user that just doesn’t exist in traditional PC or mobile web applications. This rich data, or “context,” enables the highly personalized consumer experiences that characterize many consumer IoT apps. This same data is also providing brands with unprecedented insight into how their connected products are being used, while, at the same time, powering highly targeted engagement and marketing opportunities. In his session at @ThingsExpo, Nathan Treloar, President and COO of Bebaio, will explore examples of brands transforming their businesses by t...
Aug. 31, 2015 06:00 PM EDT Reads: 247
With the proliferation of connected devices underpinning new Internet of Things systems, Brandon Schulz, Director of Luxoft IoT – Retail, will be looking at the transformation of the retail customer experience in brick and mortar stores in his session at @ThingsExpo. Questions he will address include: Will beacons drop to the wayside like QR codes, or be a proximity-based profit driver? How will the customer experience change in stores of all types when everything can be instrumented and analyzed? As an area of investment, how might a retail company move towards an innovation methodolo...
Aug. 31, 2015 02:30 PM EDT Reads: 467
The Internet of Things (IoT) is about the digitization of physical assets including sensors, devices, machines, gateways, and the network. It creates possibilities for significant value creation and new revenue generating business models via data democratization and ubiquitous analytics across IoT networks. The explosion of data in all forms in IoT requires a more robust and broader lens in order to enable smarter timely actions and better outcomes. Business operations become the key driver of IoT applications and projects. Business operations, IT, and data scientists need advanced analytics t...
Aug. 31, 2015 02:30 PM EDT Reads: 423
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.
Aug. 31, 2015 11:30 AM EDT Reads: 904
In his session at @ThingsExpo, Lee Williams, a producer of the first smartphones and tablets, will talk about how he is now applying his experience in mobile technology to the design and development of the next generation of Environmental and Sustainability Services at ETwater. He will explain how M2M controllers work through wirelessly connected remote controls; and specifically delve into a retrofit option that reverse-engineers control codes of existing conventional controller systems so they don't have to be replaced and are instantly converted to become smart, connected devices.
Aug. 31, 2015 09:30 AM EDT Reads: 125
SYS-CON Events announced today that IceWarp 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. IceWarp, the leader of cloud and on-premise messaging, delivers secured email, chat, documents, conferencing and collaboration to today's mobile workforce, all in one unified interface
Aug. 31, 2015 04:00 AM EDT Reads: 430
Akana has announced the availability of the new Akana Healthcare Solution. The API-driven solution helps healthcare organizations accelerate their transition to being secure, digitally interoperable businesses. It leverages the Health Level Seven International Fast Healthcare Interoperability Resources (HL7 FHIR) standard to enable broader business use of medical data. Akana developed the Healthcare Solution in response to healthcare businesses that want to increase electronic, multi-device access to health records while reducing operating costs and complying with government regulations.
Aug. 26, 2015 07:00 AM EDT Reads: 197
For IoT to grow as quickly as analyst firms’ project, a lot is going to fall on developers to quickly bring applications to market. But the lack of a standard development platform threatens to slow growth and make application development more time consuming and costly, much like we’ve seen in the mobile space. In his session at @ThingsExpo, Mike Weiner, Product Manager of the Omega DevCloud with KORE Telematics Inc., discussed the evolving requirements for developers as IoT matures and conducted a live demonstration of how quickly application development can happen when the need to comply wit...
Aug. 2, 2015 11:15 AM EDT Reads: 559
The Internet of Everything (IoE) brings together people, process, data and things to make networked connections more relevant and valuable than ever before – transforming information into knowledge and knowledge into wisdom. IoE creates new capabilities, richer experiences, and unprecedented opportunities to improve business and government operations, decision making and mission support capabilities.
Aug. 1, 2015 10:00 AM EDT Reads: 490