Navigation Framework using CF Architecture for a Client-Server Application using the open standards of the Web presented by Kedar Desai Differential Technologies, Fairfax, VA

Navigation… a new paradigm Non URL (menu based) navigation Non URL (menu based) navigation ‘FORM’ based application control ‘FORM’ based application control ‘Queue’ and ‘Keys’ philosophy ‘Queue’ and ‘Keys’ philosophy

What is Navigation? User’s perspective User’s perspective –Ability to use the system in the most effective manner. Designer’s perspective Designer’s perspective –Ability to manage or direct the course of the user using the system.

What is this ‘Client-Server’ application? Two – tier application Two – tier application Rich GUI Rich GUI Thick client built using tools like, PowerBuilder or Visual Basic Thick client built using tools like, PowerBuilder or Visual Basic MDI interface MDI interface Interacts with a database at the backend Interacts with a database at the backend Deployed using executables Deployed using executables

Associated problems Maintaining a code base Maintaining a code base DLL hell DLL hell Distributing an exe Distributing an exe Maintaining help files Maintaining help files Difficulties in adding new functionality Difficulties in adding new functionality

About the Application Justice Information System Justice Information System Psuedo three tier architecture Psuedo three tier architecture Has a look and feel of a standard windows application Has a look and feel of a standard windows application

Application architecture Database Application Server IE5.0, HTML, JS, CSS Sybase database ColdFusion 4.5

Challenges 200+ database tables 200+ database tables 500+ functions 500+ functions Database driven Database driven Transaction intensive Transaction intensive

Application frameworks Two main frameworks Two main frameworks –Navigation »Navigation »Error handler »Business Rules engine –Security Each framework is an independent unit. Each framework is an independent unit.

What is so great? Uses ColdFusion. Uses ColdFusion. Enables parallel development of user interface and application logic. Enables parallel development of user interface and application logic. Gives a look and feel of a standard windows application. Gives a look and feel of a standard windows application. Extends ColdFusion’s error handler. Extends ColdFusion’s error handler. Separates the GUI from the business logic. Separates the GUI from the business logic.

Features of the Framework Driven by keys. Driven by keys. Works on a queue architecture. Works on a queue architecture. Maintains state in Session variables and allows multiple sessions from one client machine. Maintains state in Session variables and allows multiple sessions from one client machine.

Message Module Provides the ability to maintain messages in the database. Provides the ability to maintain messages in the database. Functions include: Functions include: –Search for messages –Add, Modify and Delete messages –View specific details about messages

Demo

Function Architecture Five ‘.cfm’ files per function Five ‘.cfm’ files per function –Form page »Main cfm »OnError cfm »CFForm cfm »Presentation cfm –Action page »Action cfm Hidden fields –Function Id –Page Id –Target Function Id –Main cfm file name –OnError cfm file name –Action cfm file name

Navigation Controllers Form controller Form controller –Opens the page Action controller Action controller –Fires the action Error controller –Handles errors Business Rules Engine –Handles business rule validations Keys/Queue controller –Maintains the keys and queues

What are keys? Every function has a set of input and output keys Every function has a set of input and output keys A key is a value that fetches data to be displayed on the page A key is a value that fetches data to be displayed on the page If no keys exists, the default function is opened. If no keys exists, the default function is opened.

What is a queue? Maintain information about the activities that the user wants to perform. Maintain information about the activities that the user wants to perform. Works on FIFO logic. Works on FIFO logic. Two types Two types –Function queues »store the function id’s in a queue. –Data queues »store the keys in a queue.

Page loading process Error propagation is FORM ControllerMain cfm file

Action processing logic Action Controller Error propagation is or 3-0

Features Secure access Secure access Centralized action and form pages Centralized action and form pages Centralized error handler Centralized error handler Everything is a custom tag Everything is a custom tag Complete isolation of logic & presentation Complete isolation of logic & presentation Supports version control and independent development Supports version control and independent development F5 (refresh) works as in a browser F5 (refresh) works as in a browser

Points to ponder Browser back and forward buttons a problem Browser back and forward buttons a problem Custom tag directory cannot be used Custom tag directory cannot be used Not much use for Application.cfm Not much use for Application.cfm

Productivity metrics Built in under three months Built in under three months A team of five and churning out a function every two days. A team of five and churning out a function every two days.

Visit us on line at or write to me at