A PHP Christmas Miracle - 3 Frameworks, 1 app

A PHP Christmas Miracle
A story of deception, wisdom, and ﬁnding our
common interface

Ryan Weaver
@weaverryan

Saturday, December 3, 11

Who is this dude?
• Co-author of the Symfony2 Docs
• Core Symfony2 contributor
• Co-owner of KnpLabs US
• Fiancee of the much more
talented @leannapelham

http://www.knplabs.com/en
http://www.github.com/weaverryan
@weaverryan

Act 1:

A History of modern PHP

@weaverryan

First, the facts


To put it politely...


We have a surplus of PHP
frameworks


To put it honestly...


We have a sh*tload


‣ Symfony
‣ Zend Framework
‣ Lithium
‣ Aura (formerly Solar)
‣ Code Igniter
‣ Yii
‣ Cake
‣ Fuel
‣ Akelos
‣ Kohana
‣ Flow3
‣ ...

And we solve common problems

@weaverryan

Common Problems
‣ HTTP classes (e.g. request, response)
‣ Routing
‣ Controllers ‣ Forms
‣ Templates ‣ Events
‣ Loggers ‣ Mailing
‣ Database tools ‣ Validation
‣ Service containers ‣ Pagination
‣ Security ‣ Menus
‣ Serialization ‣ Search
@weaverryan

Lack of sharing means
duplicated efforts


But, there is some hope...


PSR-0

• The PHP community came together, sang
Kumbaya and wrote up some class-naming
standards

• PSR-0 isn’t a library, it’s just an agreement to
name your classes in one of two ways

@weaverryan

PSR-0 with namespaces
Namespace your classes and have the namespaces
follow the directory structure

class: SymfonyComponentHttpFoundationRequest

path: vendor/src/Symfony/Component/HttpFoundation/Request.php


PSR-0 with underscores
Use underscores in your classes and follow the
directory structure

class: Twig_Extension_Core

path: vendor/twig/lib/Twig/Extension/Core.php


But what does this mean?
• An "autoloader" is a tool you can use so that
you don't have to worry about “including”
classes before you use them

• Use anyone’s autoloader

• We're all still duplicating each other's work,
but at least everyone’s autoloader does the
same thing

@weaverryan

What else can we agree on?


So far, not much


But we’ll see how all the
libraries can still work
together


And we can always hope for
a Christmas miracle


Act 2:

Starting with a Horrible App

@weaverryan

How many of you use a
framework on a regular
basis?


How many of you have been
told that it's a bad idea to not
use a framework?


Was I the one who told you
that?


Today we’re going to break
the rules...


... build a framework from
“scratch” ...


... and see why that’s no
longer necessarily a bad
thing.


Today’s 2 goals:
• Refactor a crappy ﬂat PHP application into a
framework that makes sense

• Use as many libraries from as many quarreling
PHP tribes as possible
‣ Symfony
‣ Zend Framework
‣ Lithium
‣ ... only lack of time prevents more...

@weaverryan

Our starting point

• Following along with the code of our app at:
http://bit.ly/php-xmas

• Our app is a single ﬁle that fuels two pages


• Shucks, we even have a database connection


Open our Database connection

// index.php

try {
$dbPath = __DIR__.'/data/database.sqlite';
$dbh = new PDO('sqlite:'.$dbPath);
} catch(PDOException $e) {
die('Panic! '.$e->getMessage());
}


Try to get a clean URI

// index.php

$uri = $_SERVER['REQUEST_URI'];
if ($pos = strpos($uri, '?')) {
$uri = substr($uri, 0, $pos);
}


Render the homepage

// index.php
if ($uri == '/' || $uri == '') {
echo '<h1>Welcome to PHP Santa</h1>';
echo '<a href="/letters">Readletters</a>';
if (isset($_GET['name'])) {
echo sprintf(
'<p>Oh, and hello %s!</p>',
$_GET['name']
);
}
}

Print out some letters
// index.php
if ($uri == '/letters') {

$sql = 'SELECT * FROM php_santa_letters';
echo '<h1>Read the letters to PHP Santa</h1>';
echo '<ul>';
foreach ($dbh->query($sql) as $row) {
echo sprintf(
'<li>%s - dated %s</li>',
$row['content'],
$row['received_at']
);
}
echo '</ul>';
}

Got it?


Great, let’s clean this mess up


Act 3:

Symfony's HTTP Foundation

@weaverryan

Problems
• Our code for trying to get a clean URL is a bit
archaic and probably error prone

• We're echoing content from our controllers,
maybe we can evolve

@weaverryan

Solution
• Symfony’s HttpFoundation Component

• Gives us (among other things) a solid Request
and Response class

@weaverryan

Bring in HttpFoundation

mkdir -p vendors/Symfony/Component

git submodule add
git://github.com/symfony/HttpFoundation.git
vendors/Symfony/Component/HttpFoundation/

git submodule add
git://github.com/symfony/ClassLoader.git
vendors/Symfony/Component/ClassLoader


Current Status

@weaverryan

Autoloading
• No matter what framework or libraries you use,
you’ll need an autoloader

• We’ll use Symfony’s “ClassLoader”

• Each PSR-0 autoloader is very similar

@weaverryan

Create a bootstrap file
<?php
// bootstrap.php

require __DIR__.'/vendors/Symfony/Component/
ClassLoader/UniversalClassLoader.php';
use SymfonyComponentClassLoaderUniversalClassLoader;

// setup the autoloader
$loader = new UniversalClassLoader();
$loader->registerNamespace(
'Symfony', __DIR__.'/vendors'
);
$loader->register();


... and include it

<?php
// index.php
require 'bootstrap.php';

// ...


So how does this help?


$uri = $_SERVER['REQUEST_URI'];
if ($pos = strpos($uri, '?')) {
$uri = substr($uri, 0, $pos);
}

... becomes ...
use SymfonyComponentHttpFoundationRequest;
$request = Request::createFromGlobals();

// the clean URI - a lot of logic behind it!!!
$uri = $request->getPathInfo();


if (isset($_GET['name'])) {
echo sprintf(
$_GET['name']
);
}
... becomes ...
if ($name = $request->query->get('name')) {
echo sprintf(
$name
);
}


The “Request” object
• Normalizes server variables across systems

• Shortcut methods to common things like
getClientIp(), getHost(), getContent(), etc

• Nice object-oriented interface

@weaverryan

The “Response” object
• We also have a Response object

• Instead of echoing out content, we populate
this ﬂuid object

@weaverryan

header("HTTP/1.1 404 Not Found");
echo '<h1>404 Page not Found</h1>';
echo '<p>This is most certainly *not* an xmas
miracle</p>';

... becomes ...
$content = '<h1>404 Page not Found</h1>';
$content .= '<p>This is most certainly *not*
an xmas miracle</p>';

$response = new Response($content);
$response->setStatusCode(404);
$response->send();


Act 4:

Routing

@weaverryan

Problems
• Our app is a giant gross “if” statement
if ($uri == '/' || $uri == '') {
// ...
} elseif ($uri == '/letters') {
// ...
} else {
// ...
}

• Grabbing a piece from the URL like
/blog/my-blog-post will take some work
@weaverryan

Solution
• Lithium’s Routing library

• Routing matches URIs (e.g. /foo) and returns
information we attached to that URI pattern

• All the nasty regex matching is out-of-sight

@weaverryan

3 Steps to Bringing in an
external tool


#1 Download the library

git submodule add git://github.com/UnionOfRAD/
lithium.git vendors/lithium


#2 Conﬁgure the autoloader
// bootstrap.php
// ...

$loader->registerNamespace('Symfony', __DIR__.'/vendors');
$loader->registerNamespace('lithium', __DIR__.'/vendors');



#3 Celebrate!

use lithiumnethttpRouter;
$router = new Router();
// ...


So how do we use the router?


Full disclosure: “use”
statements I’m hiding from the
next page

use lithiumnethttpRouter;
use lithiumactionRequest as Li3Request;


a) Map URI to “controller”
$request = Request::createFromGlobals();
$li3Request = new Li3Request();
// get the URL from Symfony's request, give it to lithium
$li3Request->url = $request->getPathInfo();

// create a router, build the routes, and then execute it
$router = new Router();
$router->connect('/letters', array('controller' => 'letters'));
$router->connect('/', array('controller' => 'homepage'));
$router->parse($li3Request);

if (isset($li3Request->params['controller'])) {
$controller = $li3Request->params['controller'];
} else {
$controller = 'error404';
}

b) Execute the controller*

// execute the controller, send the request, get the response
$response = call_user_func_array($controller, array($request));
if (!$response instanceof Response) {
throw new Exception(sprintf(
'WTF! Your controller "%s" didn't return a response!!',
$controller
));
}

$response->send();

* each controller is a ﬂat function

The Controllers
function homepage(Request $request) {
$content = '<h1>Welcome to PHP Santa</h1>';
$content .= '<a href="/letters">Read the letters</a>';
if ($name = $request->query->get('name')) {
$content .= sprintf(
$name
);
}

return new Response($content);
}


The Controllers
function letters(Request $request)
{
global $dbh; $kitten--
$content = '<h1>Read the letters to PHP Santa</h1>';
$content .= '<ul>';
$content .= sprintf(
'<li>%s - dated %s</li>',
$row['content'],
$row['received_at']
);
}
$content .= '</ul>';

return new Response($content);
}

The Controllers

function error404(Request $request)
{
$content .= 'This is most certainly *not* an xmas miracle';

$response = new Response($content);
$response->setStatusCode(404);

return $response;
}


The Big Picture
1. Request cleans the URI
2. Router matches the URI to a route, returns a
“controller” string
3. We execute the controller function
4. The controller creates a Response object
5. We send the Response headers and content

@weaverryan

Your 20 line framework


Act 5:

Pimple!

@weaverryan

Problems
• We’ve got lots of random, disorganized
objects ﬂoating around

• And we can’t easily access them from within
our controllers
function letters(Request $request)
{
global $dbh;

// ....
}
@weaverryan

Solution
• Pimple! - a Dependency Injection Container

• Dependency Injection Container:
the scariest word we could think of to
describe an array of objects on steroids

@weaverryan

Remember: 3 Steps to
bringing in an external tool



git submodule add git://github.com/fabpot/
Pimple.git vendors/Pimple



// bootstrap.php
// ...

require __DIR__.'/vendors/Pimple/lib/Pimple.php';

actually, it’s only one ﬁle - so just require it!


#3 Celebrate!

$c = new Pimple();


Pimple Creates Objects
• Use Pimple to create and store your objects in
a central place

• If you have the Pimple container object, then
you have access to every other object in your
application

@weaverryan

Centralize the db connection

$c = new Pimple();

$c['connection'] = $c->share(function() {
$dsn = 'sqlite:'.__DIR__.'/data/database.sqlite';
return new PDO($dsn);
});


Centralize the db connection

$c1 = $c['connection'];
$c2 = $c['connection'];

// they are the same - only one object is created!
$c1 === $c2


Access to what we need
• So far, we’re using a “global” keyword to
access our database connection

• But if we pass around our Pimple container,
we always have access to anything we need -
including the database connection

@weaverryan

Pass the container to the
controller
$c = new Pimple();

// ...

$response = call_user_func_array(
$controller,
array($request, $c)
);


function letters(Request $request, Pimple $c)
{
$dbh = $c['connection']; $kitten++
$content = '<h1>Read the letters to PHP Santa</h1>';
$content .= '<ul>';
// ...
}
// ...
}


What else?

How about conﬁguration?


$c = new Pimple();

// configuration
$c['connection_string'] = 'sqlite:'.__DIR__
.'/data/database.sqlite';

$c['connection'] = $c->share(function(Pimple $c) {
return new PDO($c['connection_string']);
});


Further?

What about dependencies?


$c['request'] = $c->share(function() {
return Request::createFromGlobals();
});

$c['li3_request'] = $c->share(function($c) {
$li3Request = new Li3Request();
$li3Request->url = $c['request']->getPathInfo();

return $li3Request;
});

// ...
$li3Request = $c['li3_request'];


With everything in the
container, our “framework”
just got skinny


$c = new Pimple();
// create objects in Pimple

// execute our routing, merge attributes to request
$result = $c['router']->parse($c['li3_request']);
$c['request']->attributes
->add($c['li3_request']->params);

// get controller and execute!
$controller = $c['request']->attributes
->get('controller', 'error404');
$response = call_user_func_array(
$controller,
array($c['request'], $c)
);

$response->send();

Logging with ZF2

@weaverryan

Problems
• I don’t have enough frameworks in my
framework

• Oh yeah, and we need logging...

@weaverryan

Solution
• Zend Framework2

• ZF2 has a ton of components, including a
logger

@weaverryan

3 Steps to bringing in an
external tool



git submodule add git://github.com/
zendframework/zf2.git vendors/zf2


// bootstrap.php
// ...

$loader->registerNamespace('Symfony', __DIR__.'/vendors');
$loader->registerNamespace('lithium', __DIR__.'/vendors');
$loader->registerNamespace(
'Zend',
__DIR__.'/vendors/zf2/library'
);



#3 Celebrate!

use ZendLogLogger;
use ZendLogWriterStream;

$logger = Logger($pimple['logger_writer']);

Yes we did just bring in a 100k+ lines of
code for a simple logger :)


Create the Logger in our
Fancy Container
use ZendLogLogger;
use ZendLogWriterStream;

$c['log_path'] = __DIR__.'/data/web.log';
$c['logger_writer'] = $c->share(function($pimple) {
return new Stream($pimple['log_path']);
});

$c['logger'] = $c->share(function($pimple) {
return new Logger($pimple['logger_writer']);
});


And use it anywhere
function error404(Request $request, Pimple $c)
{
$c['logger']->log(
'Crap, 404 for '.$request->getPathInfo(),
Logger::ERR
);

// ...
}


Getting kinda easy, right?


What other libraries can you
think to integrate?


Getting Organized

@weaverryan

Problems
• Our application has 4 major parts:
1) autoloading setup
2) Creation of container
3) Deﬁnition of routes
4) Deﬁnition of controllers
5) The code that executes everything

• For our business, only #3 and #4 are important

• ... but it’s all jammed together
@weaverryan

Solution
• Some deﬁnitions

“Application” - the code that makes you money

“Framework” - under-the-hood code that
impresses your geek friends

• To be productive, let’s “hide” the framework

@weaverryan

Starting point
• Our app basically has 2 files

‣ bootstrap.php: holds autoloading
‣ index.php: holds
- container setup
- definition of routes
- definition of controllers
- the code that executes it all

@weaverryan

Ending point
‣ bootstrap.php: holds
- autoloading
- container setup
- the code that executes it all
(as a function called _run_application())
‣ controllers.php: holds controllers
‣ routes.php: holds routes

‣ index.php: pulls it all together
@weaverryan

Nothing to see here...
<?php

// index.php
$c = require 'bootstrap.php';
require 'routing.php';
require 'controllers.php';

$response = _run_application($c);
$response->send();


“Framework” hidden away...
// bootstrap.php
function _run_application(Pimple $c)
{
$c['router']->parse($c['li3_request']);
$c['request']->attributes
->add($c['li3_request']->params);

$controller = $c['request']->attributes
->get('controller', 'error404');

return call_user_func_array(
$controller,
array($c['request'], $c)
);
}

Routes have a home
// routing.php
$c['router']->connect(
'/letters',
array('controller' => 'letters')
);

$c['router']->connect(
'/{:name}',
array(
'controller' => 'homepage',
'name' => null
)
);

Controllers have a home
// controllers.php
use SymfonyComponentHttpFoundationResponse;

function homepage(Request $request) {
// ...
}

function letters(Request $request, $c)
{
// ...
}

function error404(Request $request)
{
// ...
}

To make $$$, work in
routes.php and controllers.php


Final Thoughts

@weaverryan

It doesn’t matter if you use a
framework...


... inherited a legacy spaghetti
system...


... or practice “not-invented-
here” development


...an innumerable number of
tools are available...


... so you can stop writing
your framework ...


... and start writing your
application


What’s available? Search GitHub


Thanks!
Questions?

Ryan Weaver
@weaverryan


References
• http://bit.ly/php-xmas
• http://github.com/symfony
• https://github.com/UnionOfRAD/lithium
• https://github.com/zendframework/zf2
• http://pimple.sensiolabs.org/
And if we had more time...
• http://twig.sensiolabs.org/
• https://github.com/knplabs/KnpMenu
• https://github.com/Seldaek/monolog
• https://github.com/avalanche123/Imagine
@weaverryan

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