i'd like to know a details about when instantiation happens in CodeIgniter, specifically that of controllers.
Let's say i have a controller called Main which is structured like this:
class Main extends CI_Controller{
public $variable;
public function index(){
$this->load->view('home/body');
$this->variable="TEST";
}
public function run(){
do something with $this->variable;
}
}
Let's say i call on the browser localhost/index.php/main, thus instantiating for the first main the controller Main. Its default method index() simply loads an html page via load->view().
In this page, there's a button which makes an AJAX request to the same controller to use the method run(), using the url localhost/index.php/main/run.
At this point, will $variable be undefined? In other words, will the Main class be re-instantiated, or will the AJAX request use the same instance built before?
I understand your confusion. Often times with the singleton pattern in codeigniter it seems like variables will exist in perpetuity. That is not the case.
The AJAX load on run() is essentially a separate request (think of it as a page refresh). Any variables previously defined in index() or only defined in the request for index() will not be available.
You have 3 options to carry over variables from one call to the next: sessions, cookies, or database.
Related
I have a question more regarding style and organization that anything else. I often find myself having a single page (controller) that requires multiple ajax calls. Rather than creating a separate controller just for the AJAX calls because that would mean more controllers I just do the following:
class Management extends MY_Controller
{
public function __construct()
{
parent::__construct();
$this->protect->protect();
if ($this->uri->segment(2, 0) !== 0 && !$this->input->is_ajax_request()) {
exit('No direct script access allowed');
}
}
public function index()
{
$this->load->model('management_model');
$data['row_config'] = $this->management_model->getConfigRows();
$data['row_users'] = $this->management_model->getUsers();
$data['roles'] = $this->management_model->getRoles();
$this->tpl->head();
$this->load->view('management/scripts');
$this->tpl->body();
if ($this->messages->hasMessages()) {
$this->output->append_output($this->messages->display());
}
$this->load->view('management/manage', $data);
$this->load->view('management/current_users', $data);
$this->load->view('management/modals', $data);
$this->tpl->footer();
}
public function get_user_details()
{
$user = new \Auth\ASUser($_POST['userId']);
echo json_encode($user->getAll());
}
public function delete_user()
{
$user = new \Auth\ASUser($_POST['userId']);
$user->deleteUser(true);
}
As the index is the only page where I actually need to render a proper view, and the rest are ajax calls I just check the URI segment to see if something other than the index exists and then check if its an ajax request.
Is this bad practice? Should I separate the AJAX calls and the view controller?
Honestly, i don't think that there is a pattern on where you should add your ajax functions, especially in Codeigniter which is loosely coupled for most of it's structure.
In my opinion you should ask yourself the below, in order to find where you should place your ajax calls.
Are the returned data from the ajax call, related to the Controller i am already?
Will i ever use again the same method/functionality in another Controller or somewhere else?
Do i need the already defined constructor of the Controller, which i think i should place the ajax call?
Do i count on the DRY principle of software development?
Is my code flexible, reusable, etc.?
Each project has it's own philosophy and workflow. The design pattern and the data structure that you will decide you will follow, will solve most of your questions in your coding-style.
Your question is asking an opinion which is contrary to Stack Overflow's SOP. But I'll offer my opinion anyway.
Is this bad practice? I don't think so. That said, why make a controller larger than it needs to be? If your Ajax is handling the full CRUD functionality for some page then the controller could be quite large. You might be better served by a separate controller.
An Ajax call is a distinct request to the server - essentially the same as directing the browser to a separate page on some other browser tab. Why not make that request to a controller that is dedicated to Ajax? It could be argued that such a controller produces better "Separation of Concerns". That is good practice.
There is one technique to make certain this controller is only used when requested by an ajax call. A couple lines of code in the controller will make the determination.
class Some_ajax_handler extends CI_Controller
{
public function __construct()
{
if(!is_ajax()){
show_404();
}
parent :: __construct();
//if needed, do the rest of your construct here
}
public function get_user_details()
{
$user = new \Auth\ASUser($_POST['userId']);
echo json_encode($user->getAll());
}
}
The call to show_404(); ends with a call to exit() so you don't need a return; statement or else block in the controller. You can be confident that any method that gets called on this controller is indeed an ajax request.
On the other hand, if a controller's view uses Ajax to get the contents for a select input, or some other simple GET call, then creating a separate controller seems like overkill.
BTW, there is a CI library simplifying Ajax calls HERE that you might find interesting.
The one criticism I offer isn't about ajax but about your use of new which is contrary to the "Codeigniter way" for loading and utilizing other classes (libraries). But I guess that's a different topic.
Atm I'm creating this view composer for fun. It is collecting .js filenames and then passing it to the layout to be linked. The filenames used depend on the current page. For example a lower ranked page like Slides, doesn't include ajax requests used in UserManagement. Please don't ask me why I would do this xD. Im planning to validate requests anyway. Just being bored.
Anyways, as I'm quite new to laravel I'm still looking for more efficient ways to do things.
Atm Im accessing the file names staticly. The Controller now looks like this
class Controller extends BaseController
{
public static $js_file_names = [];
use AuthorizesRequests, DispatchesJobs, ValidatesRequests;
}
In the pagecontroller I construct the filenames:
class SlidesController extends Controller
{
public function __construct()
{
parent::$js_file_names = ['ccs', 'ajax-updates'];
}
And finaly I retreive them inside the registered Viewcomposer like this:
(during development $use_filenames has all files as default)
public function __construct()
{
$filenames = Controller::$js_file_names;
if( !empty($filenames) )
$this->use_filenames = $filenames;
var_dump($this->use_filenames);die;
}
It all seems to be working fine, but the big question is, is there a better way to access controller data from inside a viewcomposer? Every time I try to google this, I get results like 'passing data to views' etc, which is not rly the problem.
Update:
Another idea I had is to store all the filenames to be used in an array inside the viewcomposer itself, and check if the current page exists in that array. This would keep the controllers cleaner.
Using a view composer doesn't really make sense in this situation. Since your controllers already 'know' which files they intent to share, you may as well just pass them to the view like so:
class SlidesController extends Controller
{
public function __construct()
{
View::share('user_filenames', ['ccs', 'ajax-updates']);
}
}
A composer is more for sharing concrete elements such as collections of users, a service provider or some other class instance, for example.
im using laravel 5.
I need to call a controller function but this should be done in another controller.
I dont know how to do this
public function examplefunction(){
//stuff
}
And i have a Route for this function, so at
public function otherfunctioninothercontroller(){
// I need examplefunction here
}
how Can i do this?
1) First way
use App\Http\Controllers\OtherController;
class TestController extends Controller
{
public function index()
{
//Calling a method that is from the OtherController
$result = (new OtherController)->method();
}
}
2) Second way
app('App\Http\Controllers\OtherController')->method();
Both way you can get another controller function.
If they are not in the same folder, place use namespace\to\ExampleClass; on top of your file, then you are able to instantiate your controller.
You can simply instantiate the controller and call the desired method as follows
FirstController.php:
namespace App\Http\Controllers;
class FirstController extends Controller {
public function examplefunction() {
// TODO: implement functionality
}
}
SecondController.php:
namespace App\Http\Controllers;
class SecondController extends Controller {
public function test() {
$object = new FirstController();
$object->examplefunction();
}
}
Now, after i've answered the question, i would like to add the following comment:
Controllers are classes, all rules that applies to normal classes can be applied to them
However, instantiating a controller directly inside another controller to call a desired method signifies a problem in your design for the following 2 reasons:
A controller cannot obtain an instance of another controller directly
Controller should contain as little business logic as possible, and if possible none
The closest possible solution to what you want (WITHOUT BREAKING MVC) is to make an HTTP request to the route that points to the desired method (using cURL, for example) and read the response as the returned data
But this still doesn't make much sense in this scenario because after all you're making an HTTP request from a method in a controller in your project on your server to a method in a controller in your project on your server, seems like unnecessary overhead, right ?
As i said earlier, a controller should contain as little business logic as possible because the logic should stay inside specialized classes (commonly known as Service Classes), and when a processing is requested the controller simply delegates the job of processing to the appropriate service class which does the processing and returns the results to the controller which in turn sends it back as a response
Now imagine if you've the following scenario:
We've got an application that consists of 3 functionalities:
A user can register an account from web application
There's a mobile application that talks to an API to register a user
There's an admin panel, which he can use to add new user
Obviously you need to create 3 controllers, but those controllers contains repeated logic, would you copy/paste the code everywhere ?
Why not encapsulate this logic inside a service class and call it from the controller when needed ?
Let's say I have Controller1 and Controller2. I want to call a function of Controller1 from inside a function placed in Controller2.
// Controller1.php
class Controller1 {
public static function f1()
{
}
}
And on the other controller:
// Controller2.php
use App\Http\Controllers\Controller1;
class Controller2 {
public function f2()
{
return Controller1::f1();
}
}
Points to be noted:
f1() is declared static
A call to a controller from inside another controller is a bad idea. There is no sense of meaning of controllers then. You should just redirect to web.php to save safe whole architecture like this:
class MyController {
public function aSwitchCaseFunction(Request $requestPrm){
...
//getting path string from request here
...
switch($myCase){
case CASE_1:
return redirect()->route('/a/route/path');
....
}
}
}
I am attempting to create a route in Laravel for a dynamic URL to load a particular controller action. I am able to get it to route to a controller using the following code:
Route::get('/something.html', array('uses' => 'MyController#getView'));
What I am having trouble figuring out is how I can pass a variable from this route to the controller. In this case I would like to pass along an id value to the controller action.
Is this possible in Laravel? Is there another way to do this?
You are not giving us enough information, so you need to ask yourself two basic questions: where this information coming from? Can you have access to this information inside your controller without passing it via the routes.php file?
If you are about to produce this information somehow in your ´routes.php´ file:
$information = WhateverService::getInformation();
You cannot pass it here to your controller, because your controller is not really being fired in this file, this is just a list of available routes, wich may or may not be hit at some point. When a route is hit, Laravel will fire the route via another internal service.
But you probably will be able to use the very same line of code in your controller:
class MyController extends BaseController {
function getView()
{
$information = WhateverService::getInformation();
return View::make('myview')->with(compact('information'));
}
}
In MVC, Controllers are meant to receive HTTP requests and produce information via Models (or services or repositores) to pass to your Views, which can produce new web pages.
If this information is something you have in your page and you want to sneak it to your something.html route, use a POST method instead of GET:
Route::post('/something.html', array('uses' => 'MyController#getView'));
And inside your controller receive that information via:
class MyController extends BaseController {
function getView()
{
$information = Input::get('information');
return View::make('myview')->with(compact('information'));
}
}
Let's say that I have a website that has 100 different pages. Each page uses a common header and footer. Inside the header is some dynamic content that comes from a database.
I'd like to avoid having to have code in every single controller and action that passes this common code into the view.
function index()
{
// It sucks to have to include this on every controller action.
data['title'] = "This is the index page";
data['currentUserName'] = "John Smith";
$this->load->view("main_view", data);
}
function comments()
{
// It sucks to have to include this on every controller action.
data['title'] = "Comment list";
data['currentUserName'] = "John Smith";
$this->load->view("comment_view", data);
}
I realize that I could refactor the code so that the common parts are in a single function and the function is called by the action. Doing so would reduce SOME of the pain, but it still doesn't feel right since I'd still have to make a call to that function every time.
What's the correct way to handle this?
One way I have been doing this is to extend the default controller class. You can read up on extending classes with MY_Controller in the user guide. Inside this extended class you can include something that you ALWAYS want to do, like render the page header template before the main content, or authorise a users access etc.
class MY_Controller extends Controller {
function __construct()
{
parent::Controller();
//code to always do goes here
echo 'Always print this comment';
$this->load->view('partials/template_start');
}
}
Then you can have your normal controller class extend THIS class by using
class MyControllerNameHere extends MY_Controller {
function __construct()
{
//setup here
}
function index()
{
echo 'Only print this bit when this method is called';
$this->load->view('partials/MYPAGENAMEHERE');
}
}
There are other ways of doing this, I use a mixture of the above and William's Concepts Codeigniter Template library. Do a bit of searching - there are a few solutions for you.
I had a similar situation. I created an 'includes' folder, and in there put a file that had the repetitive code from my controllers. Then in the controllers just include('/path/to/includeFile.php');
Don't know if it's the "correct" way, but it works well for me.
I ran across this after a search of their site. http://codeigniter.com/wiki/Header_and_footer_and_menu_on_every_page/ I'll review this page and its links, then post my thoughts.