Credit: Pumpkin icon by Good Ware, https://www.flaticon.com/authors/good-ware, from www.flaticon.com, used with permission.

 

 

 

Processing Forms on a Server Vs. by the Client

 

The data must be processed somehow

 

 That means software to do it must be somewhere

 

 On a server:

 

                   Can run complex software

 

                   Like databases

 

Can be important!

 

                   Server must be running properly

 

                   Server must permit software to run

 

      Not the case for e.g. wordpress

 

      Nor other typical content management systems

 

                   IFSC 4365 Web Server Applications explains more

 

                   Key concept: persistence

 

Servers can persist data

 

To persist data:

    To save data across sessions

 

 

 On a client

 

          Client:

Usually that means browser

A server-using local app

 

          Server details don’t matter

 

          Server can permit extra software or not

 

          Coder needs no server access

 

          Can even run without a server

 

      Browsers work on local files too

 

          Browsers can process form data too

 

      Typically using JavaScript

 

          Problem: databases

 

      Web pages don’t contain DBs

 

          General problem: persistence

 

      Browsers can’t remember things

 

 But… browsers can persist some data!

 

 Not databases though

 

That’s an important limitation

        

 Cookies exist to enable browsers to persist data

 

    We cover cookies in a future session

        

          There is limited local storage

 

    window.localStorage.setItem("lastname", "Smith");

    window.localStorage.getItem("lastname");

      For short:

    localStorage.setItem("lastname", "Smith");

    localStorage.getItem("lastname");

 

     That’s DB-like, actually

 

          It is user, browser, computer, and protocol-specific

 

      Won’t work across computers, etc.