|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 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. 1, 2015 04:45 PM EDT Reads: 479
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. 1, 2015 03:15 PM EDT Reads: 321
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: 292
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 @ThingsExpo, James Kirkland, Red Hat's Chief Architect for the Internet of Things and Intelligent Systems, described how to revolutionize your archit...
Jul. 30, 2015 07:30 PM EDT Reads: 1,411
MuleSoft has announced the findings of its 2015 Connectivity Benchmark Report on the adoption and business impact of APIs. The findings suggest traditional businesses are quickly evolving into "composable enterprises" built out of hundreds of connected software services, applications and devices. Most are embracing the Internet of Things (IoT) and microservices technologies like Docker. A majority are integrating wearables, like smart watches, and more than half plan to generate revenue with APIs within the next year.
Jul. 30, 2015 02:30 PM EDT Reads: 123
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Opening Keynote at 16th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, d...
Jul. 30, 2015 12:00 PM EDT Reads: 2,066
In his keynote at 16th Cloud Expo, Rodney Rogers, CEO of Virtustream, discussed the evolution of the company from inception to its recent acquisition by EMC – including personal insights, lessons learned (and some WTF moments) along the way. Learn how Virtustream’s unique approach of combining the economics and elasticity of the consumer cloud model with proper performance, application automation and security into a platform became a breakout success with enterprise customers and a natural fit for the EMC Federation.
Jul. 30, 2015 09:00 AM EDT Reads: 2,168
The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists addressed this very serious issue of profound change in the industry.
Jul. 29, 2015 03:00 PM EDT Reads: 1,285
Discussions about cloud computing are evolving into discussions about enterprise IT in general. As enterprises increasingly migrate toward their own unique clouds, new issues such as the use of containers and microservices emerge to keep things interesting. In this Power Panel at 16th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the state of cloud computing today, and what enterprise IT professionals need to know about how the latest topics and trends affect their organization.
Jul. 29, 2015 02:00 PM EDT Reads: 1,192
It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society-changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his session at @ThingsExpo, Jason Mondanaro, Director, Product Management at Metanga, discussed how you can plan to cooperate, partner, and form lasting all-star teams to change the world and it starts with business models and monetization strategies.
Jul. 28, 2015 04:30 PM EDT Reads: 1,769
Converging digital disruptions is creating a major sea change - Cisco calls this the Internet of Everything (IoE). IoE is the network connection of People, Process, Data and Things, fueled by Cloud, Mobile, Social, Analytics and Security, and it represents a $19Trillion value-at-stake over the next 10 years. In her keynote at @ThingsExpo, Manjula Talreja, VP of Cisco Consulting Services, discussed IoE and the enormous opportunities it provides to public and private firms alike. She will share what businesses must do to thrive in the IoE economy, citing examples from several industry sectors.
Jul. 28, 2015 11:00 AM EDT Reads: 2,046
There will be 150 billion connected devices by 2020. New digital businesses have already disrupted value chains across every industry. APIs are at the center of the digital business. You need to understand what assets you have that can be exposed digitally, what their digital value chain is, and how to create an effective business model around that value chain to compete in this economy. No enterprise can be complacent and not engage in the digital economy. Learn how to be the disruptor and not the disruptee.
Jul. 27, 2015 10:00 AM EDT Reads: 2,036
Akana has released Envision, an enhanced API analytics platform that helps enterprises mine critical insights across their digital eco-systems, understand their customers and partners and offer value-added personalized services. “In today’s digital economy, data-driven insights are proving to be a key differentiator for businesses. Understanding the data that is being tunneled through their APIs and how it can be used to optimize their business and operations is of paramount importance,” said Alistair Farquharson, CTO of Akana.
Jul. 27, 2015 09:00 AM EDT Reads: 328
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 business applications and services across multiple cloud delivery models.
Jul. 27, 2015 08:00 AM EDT Reads: 1,907
The enterprise market will drive IoT device adoption over the next five years. In his session at @ThingsExpo, John Greenough, an analyst at BI Intelligence, division of Business Insider, analyzed how companies will adopt IoT products and the associated cost of adopting those products. John Greenough is the lead analyst covering the Internet of Things for BI Intelligence- Business Insider’s paid research service. Numerous IoT companies have cited his analysis of the IoT. Prior to joining BI Intelligence, he worked analyzing bank technology for Corporate Insight and The Clearing House Payment...
Jul. 26, 2015 09:00 PM EDT Reads: 1,578
"Optimal Design is a technology integration and product development firm that specializes in connecting devices to the cloud," stated Joe Wascow, Co-Founder & CMO of Optimal Design, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
Jul. 25, 2015 02:00 PM EDT Reads: 399
SYS-CON Events announced today that CommVault has been named “Bronze Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular Information Management® solutions for high-performance data protection, universal availability and simplified management of data on complex storage networks. CommVault's exclusive single-platform architecture gives companies unp...
Jul. 25, 2015 01:00 PM EDT Reads: 1,964
Electric Cloud and Arynga have announced a product integration partnership that will bring Continuous Delivery solutions to the automotive Internet-of-Things (IoT) market. The joint solution will help automotive manufacturers, OEMs and system integrators adopt DevOps automation and Continuous Delivery practices that reduce software build and release cycle times within the complex and specific parameters of embedded and IoT software systems.
Jul. 25, 2015 12:15 PM EDT Reads: 480
"ciqada is a combined platform of hardware modules and server products that lets people take their existing devices or new devices and lets them be accessible over the Internet for their users," noted Geoff Engelstein of ciqada, a division of Mars International, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
Jul. 25, 2015 12:00 PM EDT Reads: 1,543
Internet of Things is moving from being a hype to a reality. Experts estimate that internet connected cars will grow to 152 million, while over 100 million internet connected wireless light bulbs and lamps will be operational by 2020. These and many other intriguing statistics highlight the importance of Internet powered devices and how market penetration is going to multiply many times over in the next few years.
Jul. 25, 2015 09:00 AM EDT Reads: 1,493