When should the Controller get instantiated? - php

I am building an AJAX web app, using PHP for my back end. I am trying to design a routing system that will let me easily drop new pages in, and let me focus on the Javascript. The actual pages that PHP will be serving up are simple, just views that are essentially containers for Javascript charts (built with d3.js). Thus, my controller won't even have to interact with my model until I start making AJAX calls.
I am new to OOP, especially in back end. I've been doing a bit with Javascript, but I am brand new to incorporating OOP with MVC & solving the issue of routing. I know there are modules/plugins out there that have Routing classes written, but as the back end part of this project is very straight-forward - essentially, how best to serve up an 'About' page on a blog - I'd like to take this opportunity to learn it thoroughly myself.
I have one controller:
<?php
//controller.php
include 'views/view.php';
class Controller
{
public function homeAction() {
$view = new View();
$view->setTemplate('views/home.php');
$view->render();
}
public function categoryAction($category) {
$view = new View();
$view->setTemplate("views/Monitor/{$category}/{$category}.php");
$view->setCategory($category);
$view->render();
}
public function monitorAction($category, $monitor) {
$view = new View();
$view->setTemplate("views/Monitor/{$category}/{$monitor}.php");
$view->setCategory($category);
$view->setMonitor($monitor);
$view->render();
}
}
?>
Right now, I instantiate my controller at the beginning of index.php:
<?php
// Load libraries
require_once 'model.php';
require_once 'controller.php';
$controller = new Controller();
$uri = str_replace('?'.$_SERVER['QUERY_STRING'], '', $_SERVER['REQUEST_URI']);
// home action
if ($uri == '/') {
$controller->homeAction();
// /{category}/{monitor}
} elseif (preg_match("#/(.+)/(.+)#", $uri, $matches) ) {
$category = $matches[1];
$monitor = $matches[2];
$controller->monitorAction($category, $monitor);
// /{category}
} elseif (preg_match("#/([^/.]+)#", $uri, $matches) ) {
$category = $matches[1];
$controller->categoryAction($category);
// 404
} else {
header('Status: 404 Not Found');
echo '<html><body><h1>Page Not Found</h1></body></html>';
}
if (isset($_SERVER['HTTP_X_REQUESTED_WITH']) && (!empty($_GET)) && $_GET['action'] == 'get_data') {
$function = $_GET['chart'] . "_data";
$dataJSON = call_user_func($function);
header('Content-type: application/json');
echo $dataJSON;
}
?>
I have read a bit about PHP's autoloader, but I'd like to get it down manually first, because I want to make sure and understand the fundamentals.
Is this the appropriate place to instantiate my Controller object?

First, your architecture is facing some major problems. You need a router to take care of your requested URIs by the users and next you need an initialization state for your system. The usual way to create Controllers is to extend a parent class, then in your parent class __construct method you can initialize your children controllers, however, your system isn't in a good shape.
This is a gold link that I never delete:
http://johnsquibb.com/tutorials/mvc-framework-in-1-hour-part-one

Related

How are controller actions and views rendered through a single entry script in php frameworks?

For example in a Yii Framework application the url is in this format
www.example.com/index.php?r=foo/bar
Which renders the script inside the actionBar() method of class FooController. Further, this class (or its parent class) implements a render() method which can render a view file.
All the url's are handled through the entry script index.php.
I would like to write my own class which can handle url's through this way.
Can someone give me a very basic 'hello world' example of writing such a script ?
I'll give it a shot:
// index.php
$r = $_REQUEST['r']; // 'foo/bar'
$rParts = explode('/',$r);
$foo = $rParts[0];
$bar = $rParts[1];
$controller = new $foo; // foo
echo $controller->$bar();
Here is what I did for a friend recently, when teaching him how frameworks works. This is a basic example, but it demonstrates how a container works, how to handle the router, giving the controller a request and a response and handling redirects and the like.
<?php
require 'autoload.php';
$container = [];
$container['controller.elephant'] = function() {
return new Controller\Elephant();
};
$routes = [];
$routes['/babar'] = 'controller.elephant:babar';
$routes['/celeste'] = 'controller.elephant:celeste';
$request = new Request();
if (!isset($routes[$request->path()])) {
http_response_code(404);
exit;
}
$route = $routes[$request->path()];
list($class, $method) = explode(':', $route);
$controller = $container[$class]();
$response = $controller->{$method}($request, new Response());
if ($response->isRedirect()) {
http_response_code($response->status());
header('Location: '.$response->destination());
} else {
echo $response->content();
}
exit;
I won't include anything more than that (albeit there is other files) because it would bloat the answer needlessly (I can send them to you by other means if you want to).
I highly advise you to look at the Slim Framework code, as it is a micro framework that basically do just that.
Well in the Symfony documentation you have this page: http://symfony.com/doc/current/components/http_kernel/introduction.html
where it explains how is the life cycle of a request, it's just a flow diagram.
But it will give you a really good idea on how you should build yours
If you are more interested in how based on a url you get the controller you should read the RoutingComponent in symfony
http://symfony.com/doc/current/components/routing/introduction.html
http://symfony.com/doc/current/components/routing/hostname_pattern.html
But if you want to write your own class, you should use something like regex expression groups where you can detect the url parts separated by i.e: '/' then you somehow map the url to the controller i.e associative array 'Hash'
someurl.com/someController/someAction
$mappings = [
...
'someController' => 'The\Controller\Class'
]
$controller = new $mappings[$urlControllerPart]();
$response = $controller->{$urlActionPart}($request);
return $response;

Phalcon PHP framework not passing parameters to controller

Just started development in the Phalcon PHP framework and am also pretty new to PHP in general. My question is on how to create a request with a route, which I believe I have done, and pass the parameters of the route to the controller action that is linked to the said route. Below I have included the three files that I have been working on and summarize what each one is supposed to do. I also have the end result and where my problem lies directly.
The first file is the index.php file that takes in all route requests for my site.
<?php
//Include all routes on site
foreach (glob("../app/routes/*.php") as $filename)
{
include $filename;
}
foreach (glob("../app/controllers/*.php") as $filename)
{
include $filename;
}
//Create routes and initialize routes
$router = new \Phalcon\Mvc\Router();
$router->mount(new PublicRoutes());
$router->mount(new ApiRoutes());
$router->mount(new AdminRoutes());
$router->handle();
$controller = $router->getControllerName();
$action = $router->getActionName();
$params = $router->getParams();
$di = new \Phalcon\DI\FactoryDefault();
$d = new Phalcon\Mvc\Dispatcher();
$d->setDI($di);
$d->setControllerName($router->getControllerName());
$d->setActionName($router->getActionName());
$d->setParams($router->getParams());
$controller = $d->dispatch();
The second file is the actual routes mounted in for my API call which I am testing everything out with.
<?php
class ApiRoutes extends Phalcon\Mvc\Router\Group
{
public function initialize()
{
//Basic api route for pixelpusher
$this->add(
"/addhawk/api/:action/:model/:params",
array(
"controller" => "api",
"action" => 1,
"model" => 2,
"params" => 3,
)
);
}
}
The third, and final file is the controller class for the API with the only action I am testing right now.
<?php
class ApiController extends \Phalcon\Mvc\Controller
{
public function handlerAction()
{
//Pull in parameters
echo "<h1>API Handler Entered</h1>";
$model = $this->dispatcher->getParam("model");
echo $model;
//Choose correct api based off of api param
if( $model == "grid" ) {
echo 'grid';
}
else if ( $model == "admin" ) {
echo 'admin';
}
else {
//No valid api must have been found for request
}
//Return result from api call
return true;
}
}
So, the url is "localhost/addhawk/api/handler/grate/view" which results in the following output in html courtesy of line 9 in the ApiController.
There is no print out of the $model variable as it should do. There is also no error so I have no idea why it's not printing. According to the documentation and every resource I have read online, all parameters should be available directly from each controller action thanks to the dispatcher and $di class or something similar. So my question is why can I not access the parameters if everything seems to be saying I should be able to?

Managing different output formats or device-types

I have to display different views for mobile devices and I want to provide a simple JSON-API.
I wrote a little module for the Kohana Framework which loads different views depending on some circumstances, which should help me in this case: https://github.com/ClaudioAlbertin/Kohana-View-Factory
However, I'm not very happy with this solution because I can't set different assets for different device-types. Also, when I'd output JSON with a JSON-view, it's still wrapped in all the HTML-templates.
Now, I'm looking for a better solution. How do you handle different output formats or device-types in your MVC-applications?
I had an idea: just split the controller into two controllers: a data-controller and an output-controller.
The data-controller gets and sets data with help of the models, does
all the validating etc. It gets the data from the models and write it to a data-object
which is later passed to the view.
The output-controller loads the views and give them the data-object from the data-controller. There is an output-controller for each format or device-type: an output-controller for mobile-devices could load the mobile-views and add all the mobile-versions of stylesheets and scripts. A JSON-output-controller could load a view without all the html-template stuff and convert the data into JSON.
A little example:
<?php
class Controller_Data_User extends Controller_Data // Controller_Data defines a data-object $this->data
{
public function action_index()
{
$this->request->redirect('user/list');
}
public function action_list()
{
$this->data->users = ORM::factory('user')->find_all();
}
public function action_show($id)
{
$user = new Model_User((int) $id);
if (!$user->loaded()) {
throw new HTTP_Exception_404('User not found.');
}
$this->data->user = $user;
}
}
class Controller_Output_Desktop extends Controller_Output_HTML // Controller_Output_HTML loads a HTML-template
{
public function action_list($data)
{
$view = new View('user/list.desktop');
$view->set($data->as_array());
$this->template->body = $view;
}
public function action_show($data)
{
$view = new View('user/show.desktop');
$view->set($data->as_array());
$this->template->body = $view;
}
}
class Controller_Output_JSON extends Controller_Output // Controller_Output doesn't load a template
{
public function action_list($data)
{
$view = new View('user/list.json');
$view->users = json_encode($data->users->as_array());
$this->template = $view;
}
public function action_show($data)
{
$view = new View('user/show.json');
$view->user = json_encode($data->user);
$this->template = $view;
}
}
What do you think?
Hmm... From the 1st view it loooks strange, and somehow like fractal -- we are breaking on MVC one of our MVC -- C.
But why is this app returns so different results, based on point-of-entry (or device)?
The task of the controller is only to get the data and choose the view -- why do we need standalone logic for choosing something based on point-of-entry (device)?
I think these questions should be answered first. Somewhere could be some problem.
Also the cotroller should select only one view ideally, and dont' do "encode" or else with data, based on current output. I think all this should be in some kind of "layouts" or else. As data always the same and even different views should be the same -- only some aspects changes.

Dynamic PHP website with MVC - What navigation pattern is this?

All,
I am studying some sample code given in my web dev class as an example of MVC (again, for the web). In this code, there's a system to navigate from the index.php page to the various controllers (which then call the Model and View modules), and then back into index.php.
I understand how the MVC works.
What I'm grappling with is the navigation mechanism. I am having difficulties understanding how all the pieces work together.
Could anyone take a look at the code below and tell me if this matches a well known method / pattern to deal with dynamic website navigation? (Maybe the Front Controller?) If it does, then my hope is that I can more easily do some more research on it.
Many thanks!
JDelage
Index.php
<?php
require_once("User.php");
session_start();
if (isset($_GET['action']))
$action= $_GET['action'];
else
$action="";
switch ($action) {
case 'login':
require_once('Login.php');
$command= new LoginControler();
break;
case 'logoff':
require_once('Logoff.php');
$command= new LogoffControler();
break;
// Several other cases
default:
require_once('Unknown.php');
$command= new UnknownControle();
}
$command->execute();
require_once('EntryMenu.php'); // Those are objects that represent both the
// menu label and the links.
$menu= array(
new EntryMenu("Login", "index.php", array("action" => "logon")),
new EntryMenu("Logoff", "index.php", array("action" => "logoff")),
new EntryMenu("Write", "index.php", array("action" => "write")),
new EntryMenu("Read", "index.php", array("action" => "read"))
);
if ($command->redirect) {
header('Location: ' . $command->redirect);
} else if ($command->page) {
include("ui/header.php");
include("ui/menu.php");
echo "<div class='content'>";
include("ui/". $command->page);
echo "</div>";
include("ui/footer.php");
}
?>
Controler.php
<?php
class Controler {
public $page= "problem.php";
function execute() {}
}
?>
LogoffControler.php
<?php
require_once('Controler.php');
class LogoffControler extends Controler {
function execute() {
$this->redirect= "index.php";
unset($_SESSION['user']);
}
}
?>
LoginControler.php
<?php
require_once('LoginModel.php'); // This manages the exchanges with the user db
require_once('Controler.php');
class ConnexionControle extends Controler {
public $page= "LoginForm.php";
function execute() {
// More code to deal with incorrectly filled login forms
$login = new LoginModel();
$login->loginUser($_POST['login'], $_POST['password']);
if ($login->userLogedIn()) {
$_SESSION['user']= $login->user;
$this->redirect= "index.php";
}
// More code to deal with invalid logins
}
}
?>
I am assuming you understand the controller part, and is asking about the switch..case statements. I haven't come across an official name for that yet,but most MVC frameworks for PHP (Kohana, CakePHP, CodeIgniter, Fat Free and etc.) calls that 'routing'. It's mapping of a URL to a controller.
Using a switch..case sets of statement is one of the easier ways. More sophisticated solutions use RegEx to match pre-defined URL patterns to resolve what controller to invoke, and what are its parameters (usually bundled as a 'request')
Other methods include using URL rewriting to come up with pretty urls, such as /articles/month/nov/article-id/3
which in 'ugly url form' is :
action=articles&month=nov&article-id=3
If you would like an easy-to-dissect verion of a MVC system you could try the 1kb PHP MVC which handles everything you are attempting in a much cleaner fashion. Though you might have to break up the code if you really want to read it as it is in compressed form.
With this system you simply place a controller in /classes/controller/ named somthing.php and you can then access it from the URL like http://site.com/something.
Loading Models is also easy and doesn't require any include or require calls.
class Controller_Something
{
public function index()
{
$model = new Model_User();
}
}

A Generic, catch-all action in Zend Framework... can it be done?

This situation arises from someone wanting to create their own "pages" in their web site without having to get into creating the corresponding actions.
So say they have a URL like mysite.com/index/books... they want to be able to create mysite.com/index/booksmore or mysite.com/index/pancakes but not have to create any actions in the index controller. They (a non-technical person who can do simple html) basically want to create a simple, static page without having to use an action.
Like there would be some generic action in the index controller that handles requests for a non-existent action. How do you do this or is it even possible?
edit: One problem with using __call is the lack of a view file. The lack of an action becomes moot but now you have to deal with the missing view file. The framework will throw an exception if it cannot find one (though if there were a way to get it to redirect to a 404 on a missing view file __call would be doable.)
Using the magic __call method works fine, all you have to do is check if the view file exists and throw the right exception (or do enything else) if not.
public function __call($methodName, $params)
{
// An action method is called
if ('Action' == substr($methodName, -6)) {
$action = substr($methodName, 0, -6);
// We want to render scripts in the index directory, right?
$script = 'index/' . $action . '.' . $this->viewSuffix;
// Script file does not exist, throw exception that will render /error/error.phtml in 404 context
if (false === $this->view->getScriptPath($script)) {
require_once 'Zend/Controller/Action/Exception.php';
throw new Zend_Controller_Action_Exception(
sprintf('Page "%s" does not exist.', $action), 404);
}
$this->renderScript($script);
}
// no action is called? Let the parent __call handle things.
else {
parent::__call($methodName, $params);
}
}
You have to play with the router
http://framework.zend.com/manual/en/zend.controller.router.html
I think you can specify a wildcard to catch every action on a specific module (the default one to reduce the url) and define an action that will take care of render the view according to the url (or even action called)
new Zend_Controller_Router_Route('index/*',
array('controller' => 'index', 'action' => 'custom', 'module'=>'index')
in you customAction function just retrieve the params and display the right block.
I haven't tried so you might have to hack the code a little bit
If you want to use gabriel1836's _call() method you should be able to disable the layout and view and then render whatever you want.
$this->_helper->layout()->disableLayout();
$this->_helper->viewRenderer->setNoRender(true);
I needed to have existing module/controller/actions working as normal in a Zend Framework app, but then have a catchall route that sent anything unknown to a PageController that could pick user specified urls out of a database table and display the page. I didn't want to have a controller name in front of the user specified urls. I wanted /my/custom/url not /page/my/custom/url to go via the PageController. So none of the above solutions worked for me.
I ended up extending Zend_Controller_Router_Route_Module: using almost all the default behaviour, and just tweaking the controller name a little so if the controller file exists, we route to it as normal. If it does not exist then the url must be a weird custom one, so it gets sent to the PageController with the whole url intact as a parameter.
class UDC_Controller_Router_Route_Catchall extends Zend_Controller_Router_Route_Module
{
private $_catchallController = 'page';
private $_catchallAction = 'index';
private $_paramName = 'name';
//-------------------------------------------------------------------------
/*! \brief takes most of the default behaviour from Zend_Controller_Router_Route_Module
with the following changes:
- if the path includes a valid module, then use it
- if the path includes a valid controller (file_exists) then use that
- otherwise use the catchall
*/
public function match($path, $partial = false)
{
$this->_setRequestKeys();
$values = array();
$params = array();
if (!$partial) {
$path = trim($path, self::URI_DELIMITER);
} else {
$matchedPath = $path;
}
if ($path != '') {
$path = explode(self::URI_DELIMITER, $path);
if ($this->_dispatcher && $this->_dispatcher->isValidModule($path[0])) {
$values[$this->_moduleKey] = array_shift($path);
$this->_moduleValid = true;
}
if (count($path) && !empty($path[0])) {
$module = $this->_moduleValid ? $values[$this->_moduleKey] : $this->_defaults[$this->_moduleKey];
$file = $this->_dispatcher->getControllerDirectory( $module ) . '/' . $this->_dispatcher->formatControllerName( $path[0] ) . '.php';
if (file_exists( $file ))
{
$values[$this->_controllerKey] = array_shift($path);
}
else
{
$values[$this->_controllerKey] = $this->_catchallController;
$values[$this->_actionKey] = $this->_catchallAction;
$params[$this->_paramName] = join( self::URI_DELIMITER, $path );
$path = array();
}
}
if (count($path) && !empty($path[0])) {
$values[$this->_actionKey] = array_shift($path);
}
if ($numSegs = count($path)) {
for ($i = 0; $i < $numSegs; $i = $i + 2) {
$key = urldecode($path[$i]);
$val = isset($path[$i + 1]) ? urldecode($path[$i + 1]) : null;
$params[$key] = (isset($params[$key]) ? (array_merge((array) $params[$key], array($val))): $val);
}
}
}
if ($partial) {
$this->setMatchedPath($matchedPath);
}
$this->_values = $values + $params;
return $this->_values + $this->_defaults;
}
}
So my MemberController will work fine as /member/login, /member/preferences etc, and other controllers can be added at will. The ErrorController is still needed: it catches invalid actions on existing controllers.
I implemented a catch-all by overriding the dispatch method and handling the exception that is thrown when the action is not found:
public function dispatch($action)
{
try {
parent::dispatch($action);
}
catch (Zend_Controller_Action_Exception $e) {
$uristub = $this->getRequest()->getActionName();
$this->getRequest()->setActionName('index');
$this->getRequest()->setParam('uristub', $uristub);
parent::dispatch('indexAction');
}
}
You could use the magic __call() function. For example:
public function __call($name, $arguments)
{
// Render Simple HTML View
}
stunti's suggestion was the way I went with this. My particular solution is as follows (this uses indexAction() of whichever controller you specify. In my case every action was using indexAction and pulling content from a database based on the url):
Get an instance of the router (everything is in your bootstrap file, btw):
$router = $frontController->getRouter();
Create the custom route:
$router->addRoute('controllername', new Zend_Controller_Router_Route('controllername/*', array('controller'=>'controllername')));
Pass the new route to the front controller:
$frontController->setRouter($router);
I did not go with gabriel's __call method (which does work for missing methods as long as you don't need a view file) because that still throws an error about the missing corresponding view file.
For future reference, building on gabriel1836 & ejunker's thoughts, I dug up an option that gets more to the point (and upholds the MVC paradigm). Besides, it makes more sense to read "use specialized view" than "don't use any view".
// 1. Catch & process overloaded actions.
public function __call($name, $arguments)
{
// 2. Provide an appropriate renderer.
$this->_helper->viewRenderer->setRender('overload');
// 3. Bonus: give your view script a clue about what "action" was requested.
$this->view->action = $this->getFrontController()->getRequest()->getActionName();
}
#Steve as above - your solution sounds ideal for me but I am unsure how you implmeented it in the bootstrap?

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