a php christmas miracle - 3 frameworks, 1 app
DESCRIPTION
In this presentation, we walk take a flat PHP4-style application and gently migrate it into our own "framework", that uses components from Symfony2, Lithium, Zend Framework and a library called Pimple. By the end, you'll see how any ugly application can take advantage of the many wonderful tools available to PHP developers.TRANSCRIPT
A PHP Christmas Miracle
Ryan Weaver@weaverryan
A story of deception, wisdom, and finding our common interface
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/enhttp://www.github.com/weaverryan
@weaverryanSaturday, December 3, 11
Act 1:
A History of modern PHP
@weaverryanSaturday, December 3, 11
First, the facts
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To put it politely...
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We have a surplus of PHP frameworks
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To put it honestly...
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We have a sh*tload
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‣ Symfony‣ Zend Framework‣ Lithium‣ Aura (formerly Solar)‣ Code Igniter‣ Yii‣ Cake‣ Fuel‣ Akelos‣ Kohana‣ Flow3‣ ...
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And we solve common problems
@weaverryanSaturday, December 3, 11
‣ HTTP classes (e.g. request, response)‣ Routing‣ Controllers‣ Templates‣ Loggers‣ Database tools‣ Service containers‣ Security‣ Serialization
‣ Forms‣ Events‣ Mailing‣ Validation‣ Pagination‣ Menus‣ Search
Common Problems
@weaverryanSaturday, December 3, 11
Lack of sharing means duplicated efforts
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But, there is some hope...
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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
@weaverryanSaturday, December 3, 11
PSR-0 with namespaces
class: Symfony\Component\HttpFoundation\Request
path: vendor/src/Symfony/Component/HttpFoundation/Request.php
Namespace your classes and have the namespaces follow the directory structure
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PSR-0 with underscores
class: Twig_Extension_Core
path: vendor/twig/lib/Twig/Extension/Core.php
Use underscores in your classes and follow the directory structure
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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
@weaverryanSaturday, December 3, 11
What else can we agree on?
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So far, not much
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But we’ll see how all the libraries can still work
together
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And we can always hope for a Christmas miracle
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Act 2:
Starting with a Horrible App
@weaverryanSaturday, December 3, 11
How many of you use a framework on a regular
basis?
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How many of you have been told that it's a bad idea to not
use a framework?
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Was I the one who told you that?
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Today we’re going to break the rules...
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... build a framework from “scratch” ...
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... and see why that’s no longer necessarily a bad
thing.
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• 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...
Today’s 2 goals:
@weaverryanSaturday, December 3, 11
Our starting point
• Our app is a single file that fuels two pages
http://bit.ly/php-xmas
• Following along with the code of our app at:
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• Shucks, we even have a database connection
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Open our Database connection
try { $dbPath = __DIR__.'/data/database.sqlite'; $dbh = new PDO('sqlite:'.$dbPath);} catch(PDOException $e) { die('Panic! '.$e->getMessage());}
// index.php
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Try to get a clean URI
$uri = $_SERVER['REQUEST_URI'];if ($pos = strpos($uri, '?')) { $uri = substr($uri, 0, $pos);}
// index.php
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Render the homepage
if ($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>', $_GET['name'] ); }}
// index.php
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Print out some lettersif ($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'], $row['received_at'] ); } echo '</ul>';}
// index.php
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Got it?
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Great, let’s clean this mess up
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Act 3:
Symfony's HTTP Foundation
@weaverryanSaturday, December 3, 11
• Our code for trying to get a clean URL is a bit archaic and probably error prone
• We're echoing content from our controllers, maybe we can evolve
Problems
@weaverryanSaturday, December 3, 11
• Symfony’s HttpFoundation Component
• Gives us (among other things) a solid Request and Response class
Solution
@weaverryanSaturday, December 3, 11
Bring in HttpFoundation
mkdir -p vendors/Symfony/Component
git submodule add \ git://github.com/symfony/HttpFoundation.git \ vendors/Symfony/Component/HttpFoundation/
git submodule add \ git://github.com/symfony/ClassLoader.git \ vendors/Symfony/Component/ClassLoader
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Current Status
@weaverryanSaturday, December 3, 11
• No matter what framework or libraries you use, you’ll need an autoloader
• We’ll use Symfony’s “ClassLoader”
• Each PSR-0 autoloader is very similar
Autoloading
@weaverryanSaturday, December 3, 11
Create a bootstrap file<?php// bootstrap.php
require __DIR__.'/vendors/Symfony/Component/ClassLoader/UniversalClassLoader.php';use Symfony\Component\ClassLoader\UniversalClassLoader;
// setup the autoloader$loader = new UniversalClassLoader();$loader->registerNamespace( 'Symfony', __DIR__.'/vendors');$loader->register();
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... and include it
<?php// index.phprequire 'bootstrap.php';
// ...
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So how does this help?
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$uri = $_SERVER['REQUEST_URI'];if ($pos = strpos($uri, '?')) { $uri = substr($uri, 0, $pos);}
use Symfony\Component\HttpFoundation\Request;$request = Request::createFromGlobals();
// the clean URI - a lot of logic behind it!!!$uri = $request->getPathInfo();
... becomes ...
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if (isset($_GET['name'])) { echo sprintf( '<p>Oh, and hello %s!</p>', $_GET['name'] );}
if ($name = $request->query->get('name')) { echo sprintf(
'<p>Oh, and hello %s!</p>',$name
);}
... becomes ...
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• Normalizes server variables across systems
• Shortcut methods to common things like getClientIp(), getHost(), getContent(), etc
• Nice object-oriented interface
The “Request” object
@weaverryanSaturday, December 3, 11
• We also have a Response object
• Instead of echoing out content, we populate this fluid object
The “Response” object
@weaverryanSaturday, December 3, 11
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>';
$content = '<h1>404 Page not Found</h1>';$content .= '<p>This is most certainly *not* an xmas miracle</p>';
$response = new Response($content);$response->setStatusCode(404);$response->send();
... becomes ...
Saturday, December 3, 11
Act 4:
Routing
@weaverryanSaturday, December 3, 11
• Our app is a giant gross “if” statementProblems
if ($uri == '/' || $uri == '') { // ...} elseif ($uri == '/letters') { // ...} else { // ...}
• Grabbing a piece from the URL like /blog/my-blog-post will take some work
@weaverryanSaturday, December 3, 11
• 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
Solution
@weaverryanSaturday, December 3, 11
3 Steps to Bringing in an external tool
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git submodule add git://github.com/UnionOfRAD/lithium.git vendors/lithium
#1 Download the library
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// bootstrap.php// ...
$loader = new UniversalClassLoader();$loader->registerNamespace('Symfony', __DIR__.'/vendors');$loader->registerNamespace('lithium', __DIR__.'/vendors');
$loader->register();
#2 Configure the autoloader
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use lithium\net\http\Router;$router = new Router();// ...
#3 Celebrate!
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@weaverryan
Current Status
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So how do we use the router?
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Full disclosure: “use” statements I’m hiding from the
next page
use Symfony\Component\HttpFoundation\Request;use lithium\net\http\Router;use lithium\action\Request as Li3Request;
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$request = Request::createFromGlobals();$li3Request = new Li3Request();// get the URL from Symfony's request, give it to lithium$li3Request->url = $request->getPathInfo();
a) Map URI to “controller”
// create a router, build the routes, and then execute it$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 { $controller = 'error404';}
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// execute the controller, send the request, get the response$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();
b) Execute the controller*
* each controller is a flat function Saturday, December 3, 11
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( '<p>Oh, and hello %s!</p>', $name ); }
return new Response($content);}
The Controllers
Saturday, December 3, 11
function letters(Request $request){ global $dbh;
$sql = 'SELECT * FROM php_santa_letters'; $content = '<h1>Read the letters to PHP Santa</h1>'; $content .= '<ul>'; foreach ($dbh->query($sql) as $row) { $content .= sprintf( '<li>%s - dated %s</li>', $row['content'], $row['received_at'] ); } $content .= '</ul>';
return new Response($content);}
The Controllers$kitten--
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function error404(Request $request){ $content = '<h1>404 Page not Found</h1>'; $content .= 'This is most certainly *not* an xmas miracle';
$response = new Response($content); $response->setStatusCode(404);
return $response;}
The Controllers
Saturday, December 3, 11
1. Request cleans the URI2. Router matches the URI to a route, returns a “controller” string3. We execute the controller function4. The controller creates a Response object5. We send the Response headers and content
The Big Picture
@weaverryanSaturday, December 3, 11
Your 20 line framework
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Act 5:
Pimple!
@weaverryanSaturday, December 3, 11
• We’ve got lots of random, disorganized objects floating around
Problems
• And we can’t easily access them from within our controllers
@weaverryan
function letters(Request $request){ global $dbh;
// .... }
Saturday, December 3, 11
• Pimple! - a Dependency Injection Container
• Dependency Injection Container:
the scariest word we could think of todescribe an array of objects on steroids
Solution
@weaverryanSaturday, December 3, 11
Remember: 3 Steps to bringing in an external tool
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git submodule add git://github.com/fabpot/Pimple.git vendors/Pimple
#1 Download the library
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// bootstrap.php// ...
require __DIR__.'/vendors/Pimple/lib/Pimple.php';
#2 Configure the autoloader
actually, it’s only one file - so just require it!
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$c = new Pimple();
#3 Celebrate!
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• 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
Pimple Creates Objects
@weaverryanSaturday, December 3, 11
$c = new Pimple();
$c['connection'] = $c->share(function() { $dsn = 'sqlite:'.__DIR__.'/data/database.sqlite'; return new PDO($dsn);});
Centralize the db connection
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Centralize the db connection
$c1 = $c['connection'];$c2 = $c['connection'];
// they are the same - only one object is created!$c1 === $c2
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Centralize the db connection
$c1 = $c['connection'];$c2 = $c['connection'];
// they are the same - only one object is created!$c1 === $c2
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• 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
Access to what we need
@weaverryanSaturday, December 3, 11
Pass the container to the controller
$c = new Pimple();
// ...
$response = call_user_func_array( $controller, array($request, $c));
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function letters(Request $request, Pimple $c){ $dbh = $c['connection'];
$sql = 'SELECT * FROM php_santa_letters'; $content = '<h1>Read the letters to PHP Santa</h1>'; $content .= '<ul>'; foreach ($dbh->query($sql) as $row) { // ... } // ...}
$kitten++
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What else?
How about configuration?
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$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']);});
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Further?
What about dependencies?
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$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 = $c['li3_request'];
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With everything in the container, our “framework”
just got skinny
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$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();Saturday, December 3, 11
Logging with ZF2
@weaverryanSaturday, December 3, 11
• I don’t have enough frameworks in my framework
Problems
• Oh yeah, and we need logging...
@weaverryanSaturday, December 3, 11
• Zend Framework2
• ZF2 has a ton of components, including a logger
Solution
@weaverryanSaturday, December 3, 11
3 Steps to bringing in an external tool
Saturday, December 3, 11
git submodule add git://github.com/zendframework/zf2.git vendors/zf2
#1 Download the library
Saturday, December 3, 11
// bootstrap.php// ...
$loader = new UniversalClassLoader();$loader->registerNamespace('Symfony', __DIR__.'/vendors');$loader->registerNamespace('lithium', __DIR__.'/vendors');$loader->registerNamespace( 'Zend', __DIR__.'/vendors/zf2/library');
$loader->register();
#2 Configure the autoloader
Saturday, December 3, 11
use Zend\Log\Logger;use Zend\Log\Writer\Stream;
$logger = Logger($pimple['logger_writer']);
#3 Celebrate!
Yes we did just bring in a 100k+ lines of code for a simple logger :)
Saturday, December 3, 11
Current Status
@weaverryanSaturday, December 3, 11
use Zend\Log\Logger;use Zend\Log\Writer\Stream;
$c['log_path'] = __DIR__.'/data/web.log';$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']);});
Create the Logger in our Fancy Container
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function error404(Request $request, Pimple $c){ $c['logger']->log( 'Crap, 404 for '.$request->getPathInfo(), Logger::ERR ); $content = '<h1>404 Page not Found</h1>'; // ...}
And use it anywhere
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Getting kinda easy, right?
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What other libraries can you think to integrate?
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Getting Organized
@weaverryanSaturday, December 3, 11
• Our application has 4 major parts:1) autoloading setup2) Creation of container3) Definition of routes4) Definition of controllers5) The code that executes everything
• For our business, only #3 and #4 are important
• ... but it’s all jammed together
Problems
@weaverryanSaturday, December 3, 11
• Some definitions
“Application” - the code that makes you money
“Framework” - under-the-hood code that impresses your geek friends
• To be productive, let’s “hide” the framework
Solution
@weaverryanSaturday, December 3, 11
• Our app basically has 2 files
‣ bootstrap.php: holds autoloading‣ index.php: holds
- container setup- definition of routes- definition of controllers- the code that executes it all
Starting point
@weaverryanSaturday, December 3, 11
‣ bootstrap.php: holds- autoloading- container setup- the code that executes it all
(as a function called _run_application())‣ controllers.php: holds controllers‣ routes.php: holds routes
‣ index.php: pulls it all together
Ending point
@weaverryanSaturday, December 3, 11
<?php
// index.php$c = require 'bootstrap.php';require 'routing.php';require 'controllers.php';
$response = _run_application($c);$response->send();
Nothing to see here...
Saturday, December 3, 11
// bootstrap.phpfunction _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'], $c) );}
“Framework” hidden away...
Saturday, December 3, 11
// routing.php$c['router']->connect( '/letters', array('controller' => 'letters'));
$c['router']->connect( '/{:name}', array( 'controller' => 'homepage', 'name' => null ));
Routes have a home
Saturday, December 3, 11
// controllers.phpuse Symfony\Component\HttpFoundation\Request;use Symfony\Component\HttpFoundation\Response;
function homepage(Request $request) { // ...}
function letters(Request $request, $c){ // ...}
function error404(Request $request){ // ...}
Controllers have a home
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To make $$$, work in routes.php and controllers.php
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Final Thoughts
@weaverryanSaturday, December 3, 11
It doesn’t matter if you use a framework...
Saturday, December 3, 11
... inherited a legacy spaghetti system...
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... or practice “not-invented-here” development
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...an innumerable number of tools are available...
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... so you can stop writing your framework ...
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... and start writing your application
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What’s available? Search GitHub
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Thanks!Questions?
Ryan Weaver@weaverryan
Saturday, December 3, 11
• http://bit.ly/php-xmas• http://github.com/symfony• https://github.com/UnionOfRAD/lithium• https://github.com/zendframework/zf2• http://pimple.sensiolabs.org/
References
@weaverryan
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
Saturday, December 3, 11