Suppose that I've this class:
class Loader
{
function library($name)
{
require $name . '.php';
}
}
and now I include the class foo ($name) inside my controller, like this:
class Controller
{
function __construct()
{
$this->load = new Loader();
}
}
class Child_Controller extends Controller
{
function __construct()
{
parent::__construct();
$this->load->library('foo');
init();
}
}
is possible, for example, access to the included class inside $this? Like:
class Child_Controller extends Controller
{
//..construct above..
function init()
{
$this->print('some text');
}
}
where print is a method of foo, the class included:
class Foo
{
function print($message)
{
echo "your message: " . $message;
}
}
So, summing, I want include in the child controller, in $this, all the method of the included class by the Loader class extended by the base controller. Is this possible?
Or another idea would be create dynamically in the Child_Controller, a property that take the name of the included class, so, for call the method of foo I can do something like:
$this->Foo->print('some text');
No, you can't do that however you can do something similar in storing Foo in a generic property like this:
class Child_Controller
{
private $lib;
function __construct()
{
parent::__construct();
$this->lib = $this->load->library('Foo');
$this->init();
}
function init()
{
$this->lib->print('Hello World!');
}
}
If you want to instantiate multiple libraries then rather than using a dynamic name for the variable you should use an array with the library name as the key, like this:
class Child_Controller
{
private $libs = [];
function __construct()
{
parent::__construct();
$this->libs['Foo'] = $this->load->library('Foo');
$this->init();
}
function init()
{
$this->libs['Foo']->print('Hello World!');
}
}
If you can't use an array and absolutely must use a variable name you can do that like this:
class Child_Controller
{
function __construct()
{
$var = 'Foo';
$this->{$var} = $this->load->library($var);
$this->init();
}
function init()
{
$this->Foo('Hello World!');
}
}
Related
I want to call a function defined in child class from a function defined in the parent class for some logic. I am getting error of undefined function. How can I call this function. Here is my sample code.
<?php
class First
{
public function __construct()
{
echo "First class is initiated.";
}
public function call_child()
{
$this->get_ouput();
}
}
class Second extends First
{
public function __construct()
{
parent::__construct();
}
public function get_output()
{
echo "Here is your output";
}
}
$obj = new Second();
$obj->call_child();
?>
The issue is spelling mistake in your function call name
<?php
class First
{
public function __construct()
{
echo "First class is initiated.";
}
public function call_child()
{
$this->get_output(); //update the name here
}
}
class Second extends First
{
public function __construct()
{
parent::__construct();
}
public function get_output()
{
echo "Here is your output";
}
}
$obj = new Second();
$obj->call_child();
?>
There is a typo when calling the get_output method. However you should define the First class and get_output method as abstract in order to be extended/implemented by the other classes:
abstract class First
{
public function __construct()
{
echo "First class is initiated.";
}
abstract public function get_output();
public function call_child()
{
$this->get_output();
}
}
class Second extends First
{
public function get_output()
{
echo "Here is your output";
}
}
$obj = new Second();
$obj->call_child();
Note: the Second class may not define the constructor if it only calls the parent constructor.
I have a code structure like this:
class myclass{
use App/classes/Log
public function myfunc1 () {
$log_obj = new Log;
$log_obj->log('something1');
}
public function myfunc2 () {
$log_obj = new Log;
$log_obj->log('something2');
}
public function myfunc3 () {
$log_obj = new Log;
$log_obj->log('something3');
}
}
In reality, I have 12 methods which I need to make a object of Log class in the most of them. Now I want to know, isn't there any better approach to I do that (making an object) once? For example using a static property and setting the object to it or whatever ..
You can assign the Log instance to a property of your myclass using __construct. Here's an example of accessing a method of a class inside another class:
class Test {
public $var = 'test';
public function show_var() {
echo $this->var;
}
}
class Test_2 {
protected $test;
public function __construct() {
$this->test = new Test;
}
public function show_test() {
$this->test->show_var();
}
}
$test_2 = new Test_2;
$test_2->show_test();
See here in action.
I'm a bit rusty with php, I want to know how I can call the function login available in class2, inside class1. This is the example:
<?php
require_once("property2.php");
class Class1
{
public function __construct()
{
$cls2 = new Class2()
}
public function method1()
{
$cls2->login() //cl2 is undefined
}
} ..
//this is the function
...
class Class2
{
public function __construct()
{
}
//This is the function to call
public function login()
{
//Some stuff
}
} ...
Now PHPSTORM say that the variable cls2 is undefined. What I did wrong?
When you are setting your variable youre not setting it as a class property. Define a private variable inside your class, and "set it and get it" using the $this keyword.
class Class1 {
private $cls2;
public function __construct() {
$this->cls2 = new Class2();
}
public function method1() {
$this->cls2->login();
}
}
Another way to achieve this is to use Inheritance, where one class is considered a "parent" class. You would achieve this by using extends
class Class1 {
public function __construct() {
//Some stuff
}
public function login() {
//Some stuff
}
}
class Class2 extends Class1 {
public function __construct() {
parent::__construct();
}
public function method1() {
$this->login();
}
}
class Class1
{
public function __construct()
{
$cls2 = new Class2();
}
public function method1()
{
$cls2->login() //cl2 is undefined
}
}
When you create Class1 and call $cls2 = new Class2();, $cls2 exists only locally. You have to make it a class property:
class Class1
{
public $cls2;
public function __construct()
{
$this->cls2 = new Class2();
}
public function method1()
{
$this->cls2->login();
}
}
And then you'll be able to access it using $this keyword.
Also please watch for semicolons.
<?php
class BaseController extends Controller
{
protected $foo;
public function __construct()
{
$this->foo = '123';
}
protected function setupLayout()
{
if ( ! is_null($this->layout))
{
$this->layout = View::make($this->layout);
}
}
}
Above is the BaseController and I want to declare foo as 123, but can I get the foo variable in the controller which I have extended from this basecontroller, can you help?
public function detail($action)
{
return $this->foo;
}
As per docs:
http://php.net/manual/en/language.oop5.decon.php
Note: Parent constructors are not called implicitly if the child class
defines a constructor. In order to run a parent constructor, a call to
parent::__construct() within the child constructor is required.
As you are doing some work in your parent class constructor, you must invoke it directly in your subclass too (even this would be to only thing you do in child's constructor). I.e.:
class ChildController extends BaseController
{
public function __construct() {
parent::__construct();
}
...
When you extend the controller, I imagine that you're currently doing this:
<?php
class NewController extends BaseController
{
public function __construct()
{
// Do something here.
}
public function detail($action)
{
return $this->foo;
}
}
You see how the __construct method is being overwritten. You can easily fix this by adding parent::__construct() to the beginning of the method, so you'll have this:
<?php
class NewController extends BaseController
{
public function __construct()
{
parent::__construct();
// Do something here.
}
public function detail($action)
{
return $this->foo;
}
}
I try to call getTest() function inside Child class.
First I initialize instance of Ext class so I assume main property $ext should now contain it. But Child class does not inherit it and obtained error message is:
Call to a member function getTest() on a non-object
Where is the issue?
<?php
$A = new Main;
class Main
{
protected $ext = null;
function __construct()
{
$this->ext= new Ext();
new Child;
}
}
class Child extends Main
{
function __construct()
{
echo $this->ext->getTest();
}
}
class Ext extends Main
{
public function getTest()
{
return "cool";
}
}
?>
I know that to solve it other way I can use:
class Child
{
private $Main;
function __construct( &$Main ) { ... }
}
but I would like to understand why that does not work..
At the moment on construct the object the atribute don't have a value yet.
You need call to the parent constructor before use the attribute
function __construct()
{
parent::__construct();
echo $this->ext->getTest();
}