03 Interfaces and Technology

Question 1

JavaScript

Answer 1

Client-side programming language

• manipulate DOM
• change HTML
• change CSS

communicate with server

• send / receive data

Question 2

Ajax - Whats New?

Answer 2

changes the fundamental interaction model of the web

Question 3

Sessions

Answer 3

• HTTP is a stateless protocol
• user identifiable only on application layer
• cookies store token that is resent with every call
• server looks up token and assigns resources (e.g. shopping basket)
• token validity period is called “session”

Question 4

What are web services?

Answer 4

• technology that allows applications to communicate with each other in a platform- and programming lanuage-independet manner
• software interface that describes a collection of operations that can be accessed over the network through stnadardized XML messaging
• protocols based on XML to describe an operation or data to exchange with another web service

Question 5

Roles in web service infrastructures

Answer 5

service provider

• provides service and service description
• responsible for implementation, operation and maintenance

service consumer

• uses service, requests service description
• searches for descriptions

service trader

• saves and categorizes descriptions
• provides search functionality

Question 6

Web services: Different implentations

Answer 6

Web Services

• Query address for each application: http://domain.com/weather
• XML request contains functionality
• XML response

REST

• Query address contains functionality and parameters
• http://domain.com/weather/city/5
• JSON