Reading-Notes

Class 13 Summary:

THE PAST, PRESENT & FUTURE OF LOCAL STORAGE FOR WEB APPLICATIONS :

• Cookies were invented early in the web’s history to be used for presistent local storage of small amount of data . But the negative aspects are:
  1. Cookies included with every HTTP request : slowly down the web application by transmitting the same data over needlessly.
  2. Cookies included with every HTTP request :sending data unencrypted over the internet.
  3. Cookies limited at about 4 KB data, this slow the application.
• We need :
  1. a lot of storage space.
  2. on the client.
  3. isn’t transmitted to server.

Breif History Of Local Storage:

• Microsoft invented DHTML Brhaviors , one of them is (userData) which allws web pages to store up to 64 KB of data per domain.

• In 2002 Adobe introduced Flash 6 (Flash cookies) to store up to 100 KB of data per domain.

• In 2007 Google launched Gears which can store unlimited amounts of data per domain in SQL database tables.

HTML5 Storage:

• It’s a way for web pages to store named key/value pairs locally, within the client web browser.

• From Java Script code , we will access HTML5 storage through the local storage object on the global window object.

Using HTML5 Storage:

• With web storage, web applications can store data locally within the user’s browser.
• HTML5 Storage is based on named key/value pairs.
• We will need to use functions like: parseInt() , parseFloat() , Calling getItem() , setItem()
• example:

Tracking Changes To HTML5 Storage Area:

*example:

HTML Web Storage Objects:

• HTML provides two objects for storing data :
  1. Windows.localStorage (stores data with no expiration date)
  2. windows.sessionStorage (stores data for one session)

** this information from web

Sukina AbuHammad