Adobe flex  is an umbrella term for a group of technologies initially realeased in March of 2004 by macromedia to support the development and deployment of Rich Internet Applications based on their proprietary macromedia Flash Platform.

Traditional application programmers found it challenging to adapt to the animation metaphor upon which the Flash platform was originally built. Flex seeks to minimize this problem by providing a workflow and programming model that is fimiliar to application developers.

The goal of flex is to allow web application developers to quickly and easily build rich internet applications. In a Multi-tiered model. Flex applications serve as the presentation tier.

Flex features development of graphic user interfaces using an XML- based language called MXML.

Flex come with various components and features that make capabilities such as web services, remote objects, darg and drop, sortable columns, charting/graphing, built in animation effects, and other interfaces interactions simple. Since the client only loads once, application workflow is significantly improved versus HTML based applicationsIeg, JSP, PHP, ASP) which requirs executing templates on the server with every action.

Flex’s Language and file structure are seeking to decouple application logic from design.

Web 2.0 refers to the second generation of web development and web design that facilitites information sharing and colloboration on the world wide web.

The development and evolution of web based communities, hosted services and web applications.

Examples:

social networking sites

video sharing sites

wikis

blogs

Design Pattern

1. Abstract

2.control structure templete

3. OOP

4. Flexible

5. architecture

Algorithm:

1. concrete

2. set of actions

3. structured/oo programming

4. deterministic

5. recipe

A framework is a reusable, ’semi-complete application that can be specialized to produce custom application. A framework is a semi complete application, for e.g. we have struts framework which is used as a base for many custom applications.

A Design pattern is not an application but is a solution to a commonly occuring design problem. we can use a pattern to avoid some of the possible design draw backs in the application as being designed. These patterns can be used by all applications.

The struts framework which is based on MVC model uses patterns like ‘front controller’ in its design.

Architecture – set which functionality the system should perform, split the functionality between components, set how components should behave and communicate in the system context, set the physical location of components and finally choose the tools in order to create components.

Design Pattern – while architecture deals more with the wide picture, design should drill down into the details relating to implementing certain components. designing of components endup with classes, interfaces, abstruct classes and oo features in order to fulfill the given component tasks.

Architecture:  It is a logical view. it means doesnot have any implementation(Java Classes), just have an idea where to put each components(Jsp, servlet) and model component for MVC architecture. we can called as Design Pattern.

Architecture is abstruct.

Architecture is an idea about how to structure you appliaction possibly shared through natural language documentation and structured methods, like UML.

Architecture is definig a strategy to meet a set of design objectives and identifying a set of components and their components that satisfy those objectives.

Framwork- It is an implementation of an architecture like spring(application architecture), struts(MVS web application architecture are some framework.)

Framework are classes and interfaces

Framework is an implementation of an architecture that some one can use as the basis for a working application.

Frameworks are architecture independent. you can do architecture for an application, not a framework. Frameworks are factored out logic that are reusable across architecture.

Methods are functions that are part of a class definition, once an instance of the class is created, a method is bound to that instance. Unlike a function declared outside a class, a method cannot be used apart from the instance to which it is attached.

Reason:

1. Function statements are more concise and easier to read.

2. Function statements allow you to use the override and final keywords.

3. Function statements create a stronger bond between the identifierm, that is the name of the function and the code within the method body.

An interfaces is a collection of method declarations that allows unrelated objects to communicate with one another.

Interfaces are based on the distinction between a methods interface and its implementation. A methods interface include all the information necesary to invoke that method, including the name of the method, all of its parameters, and it return type.

A Methods implementation include not only the interface information but also the executable statements that carryout the methods behaviour.

An interface definition contains only method interfaces and any class that implements the interface is responsible for defing the method implementation.

Definiton An Interface:

   The structure of an interface definition is similar to that of a class definiton, except that an interface can contain only methods with no method bodies. Interfaces cannot include variables or constants but can inlude getters and setters. Use the interface keyword.

Implementing an Interface in a class:

  A class is the only Actionscript 3.0 language element that can implenent an interface. Use the implemtnts kehyword in a class to implement one or more Interface.

In a calss that implements an interface , implemented method  must do the following:

1. Use the public acces control identifier.

2. Use the same name as the interface method.

3. Have the same number of parameters, each with data types that match the interface method parameter data types

4. Use the same return type.

Deployed flex applications typically make several types of requests to services within your firewall, as the following example shows:

Most of the deployment issures that customers report are related to network security and routing, and fall into one of the following scenario.

1.  Direct access to resources on a web server.

2. Direct access to resources on your application server.

3. Webservices requests through a proxy. A proxy redirects a request to the server that handles the webservices.

4. Direct access of a web service.

common uses of  data binding includes the following:

—> To bind properties of user interface controls to other user interface controls.

—> To bind properties of user interface controls to a middle tier data model, and to data models fields bound a data service request( a Three tier system).

—> To bind properties of user interface controls to a data service requests.

—> To bind data service results to properties of user interface controls.

—>To bind data service results to a middle tier data model, and to bind the data models  fields of user interface controls.

—> To bind An array collection or XML collection object to the data provider property of a list based control.

—>To bind individual part of complex properties to properties of user interface controls.

—> To bind XML data to user interface control by using ECMA Script for XML expressions in binding expressions.