A platform-enabled website is a website in which additional functionality can be seamlessly integrated by means of an external application programming interface

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

 (API). The platform should provide integration points. These integration points are places in the application where new functionality can be plugged in.

Platform

The Platform is the website on which new functionality is added via an external API

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

. Often the platform provides client libraries for writing platform Applications (also known as Plug-ins)

Application

Application refers to the external module that integrates with the platform via an external API

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

. The term application is a bit ambiguous since the platform itself is also an application. However, for convenience, this article will typically refer to the plug-ins as applications.

Plug-in

Same as Application. This article typically refers to Plug-ins as Applications.

Architecture

A platform-enabled web application exchanges data with plug-in applications. When designing a platform, it is necessary to determine what data is exposed by the platform and under what conditions. This exchange of data is fundamental to the design of a platform-enabled website. Designed correctly, the platform and the applications that extend it are loosely coupled, yet maintain a seamless look and feel.

A loosely coupled relationship between the platform and a plug-in application exists when:

• the platform does not depend on the plug-in application (i.e., the platform will still operate even if a plug-in is removed);
• plug-in applications can be added and removed easily;
• there is a well-defined interface for communication between the platform and the plug-in application;
• unexpected termination or errors in a plug-in application will not be detrimental to the platform;
• there are minimal expectations about the internal operation of each component (i.e., the platform and the plug-in application are black boxes).

Execution

• In what environment will plug-in applications be executed?
• Will plug-in applications execute in a protected sandbox
  Sandbox (computer security)
  In computer security, a sandbox is a security mechanism for separating running programs. It is often used to execute untested code, or untrusted programs from unverified third-parties, suppliers, untrusted users and untrusted websites....
  
  ?
• Will plug-in applications be hosted on servers external to the platform?

Security

• Will your platform run trusted and approved plug-ins only?
• Will your platform protect the end-user from malicious code?
• How will you authenticate and authorize plug-in applications?

Privacy

• Will your platform protect the company's proprietary data?
• Will your application protect sensitive end-user data?

Installation

• Can users add and remove plug-in applications (this might not always be necessary)?
• How can users find new plug-in applications?

Communication

• What mechanism will the platform and plug-in applications use to communicate (REST
  Representational State Transfer
  Representational state transfer is a style of software architecture for distributed hypermedia systems such as the World Wide Web. The term representational state transfer was introduced and defined in 2000 by Roy Fielding in his doctoral dissertation...
  
  , JSON
  JSON
  JSON , or JavaScript Object Notation, is a lightweight text-based open standard designed for human-readable data interchange. It is derived from the JavaScript scripting language for representing simple data structures and associative arrays, called objects...
  
  , XML
  XML
  Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
  
  , JavaScript
  JavaScript
  JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
  
  , etc.)?

Presentation

• How will the plug-in be displayed?
• Will you need an IFRAME canvas?
• Will the platform serve as proxy for data exchange between the plug-in canvas and remote web application?

Agility

• How will the platform handle changes to the Application Programming Interface (API)?
• Will the platform support deprecation of older versions of the API?
• Will multiple revisions of the API be supported simultaneously?

Standards

• Will your platform's external API conform to any industry standards (e.g., OpenSocial
  OpenSocial
  OpenSocial is a set of common application programming interfaces for web-based social network applications, developed by Google along with MySpace and a number of other social networks.It was released November 1, 2007....
  
  ).

Standards

Certain social networking websites are attempting to create external APIs that conform to the OpenSocial

OpenSocial

OpenSocial is a set of common application programming interfaces for web-based social network applications, developed by Google along with MySpace and a number of other social networks.It was released November 1, 2007....

specification. Participants include MySpace, Orkut, Bebo, and LinkedIn.