What is MVC?

A Primer in 10 Slides

Dominique Gerald M Cimafrancadominique.cimafranca@gmail.comhttp://villageidiotsavant.com

By

Model-View-Controller

an architectural pattern in software engineering

a way of designing and building applications

object-oriented software development

separates application logic from presentation

loose coupling between components

Without MVC

Client

delete.php

update.php

read.php

create.php

database

db=connect(database);

var1=$_POST[data1];var2=$_POST[data2];

db.query(insert into db values var1,var2);

print Success;

http://myapp/create.phphttp://myapp/read.phphttp://myapp/update.phphttp://myapp/delete.php

database

application

presentation

All in one program!

What happens when you...

change the database settings?

change the database design?

change the database?

process more variables?

change the response?

change the look and feel?

How does MVC work?

Client

http://myapp/customer/createhttp://myapp/customer/readhttp://myapp/customer/updatehttp://myapp/customer/delete

customer (controller)

function create() { : :}

function read() { : :}

function update() { : :}

function delete() { : :}

function read($id) {Customer->get($id);$data=Customer->read();::render($data,template.tpl);}

Controller handles application logic

A single controller may have multiple methods

A controller collects all the actions that takes place

Several controllers may comprise an application

How does MVC work?

Client

customer (controller)

function create() { : :}

function read() { : :}

function update() { : :}

function delete() { : :}

function read($id) {Customer->get($id);$data=Customer->read();::render($data,template.tpl);}

Controller invokes models

Controller manipulates model attributes

Controller uses model methods

Models can invoke other models

namecategoryquantity:

read()save():

Customer

http://myapp/customer/createhttp://myapp/customer/readhttp://myapp/customer/updatehttp://myapp/customer/delete

How does MVC work?

Client

customer (controller)

function create() { : :}

function read() { : :}

function update() { : :}

function delete() { : :}

function read($id) {Customer->get($id);$data=Customer->read();::render($data,template.tpl);}

namecategoryquantity:

read()save():

Customer

http://myapp/customer/createhttp://myapp/customer/readhttp://myapp/customer/updatehttp://myapp/customer/delete

$header

$sidebar

for($item in $data) { echo $item;}

Our Customers

: : : :

Charlie BrownLucy Van PeltLinus Van Pelt

Controller combines data with template

Template may perform additional processing

Return combination as HTML

Or we could do it with XML

Client

customer (controller)

function create() { : :}

function read() { : :}

function update() { : :}

function delete() { : :}

function read($id) {Customer->get($id);$data=Customer->read();::render($data,template.tpl);}

namecategoryquantity:

read()save():

Customer

XML request

XML response

$xml->serialize($data)

Whatever...

Java

C / C++

JavaScript

Client does not need to be a web browser

Can be any client that speaks XML

Serialization: conversion of data into bits

With this, we can talk about web services

XML, JSON, YAML, ...

Some MVC web frameworks

Ruby on Rails (www.rubyonrails.org)

CakePHP (www.cakephp.org)

CodeIgniter (www.codeigniter.org)

Yii (www.yiiframework.com)

Django (www.djangoproject.org)

CherryPy (www.cherrypy.org)

Spring MVC (www.springsource.org)

Catalyst (www.catalyst.org)

Mojolicious (www.mojolicio.us)

Frameworks make things easier

BUT

you don't need to use them topractice MVC

License

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