After call static method from another controller, it showing error message
$shipprice = CartController::calcshipping();
Error:
Using $this when not in object context
You don't call controllers from other controllers - ever.
You either put your code into components or models. This way you can share the functionality between different controllers without such hacks as above.
And then there is also no need to do any static stuff here.
It can simply be a normal object call.
$this->MyComponent->calc();
or
$this->MyModel->calc();
etc
Related
In a custom validation function in my model class. I need to use javascript code. for that i used registerJs function but i am getting error:-
Calling to undefined function registerJs()
I also tried calling it by including View class i.e., View::registerJs() but it is also giving error called
Non-static method yii\web\View::registerJs() should not be called statically, assuming $this from incompatible context
How can i user Javascript in Yii2 model class.
Edit:
I have created a custom function for mobile number validation and calling that function from rules section of model. Now i want to use javascript code in that function. is there any other way to achive it?
Thanks in advance
That method is not static. If you open the view.php of the framework you can check out the implementation.
public function registerJs($js, $position = self::POS_READY, $key = null){..
}
Exception clearly mentions that should not be called statically because it is not declared static.
I have seen few of the implementations which call this method as:
$view->registerJs($js, $view::POS_END);
Basically loading a particular JS file in one of the functions.
It is not a good idea using Javascript with a model. If you go that way then probably after some time you will find you heading into big problems with the architecture of the app.
The best way is to call the model inside a controller and then interact with the controller through the Javascript code.
I am working on an MVC framework in PHP.
I have several controller classes called "index" with methods called "index" within them. The classes do not have __construct() methods.
Inevitably, this is resulting in PHP calling the "index" method as the constructor instead, using the old PHP4 convention of the constructor being the method with the same name as the class.
Is there any way to disable this behaviour or do I have to define an empty __construct() to prevent it? (Or just change my own coding style so I don't have methods with the same name as their classes.)
I want PHP5 to stop parsing for the PHP4 constructors essentially.
Ilmiont
I have been down the same road with MVC frameworks before and I have never heard of an index() function being called like this. Upon instanciation it will call the __constructor if present or do nothing. When calling your controller you should be geting the class and method name and checking if they exist and if they do then instantiate it. However if you have the same general setup as me you should have a registry storing all of your variables being passed to the controller when you create an instance, then when/if the view is called from index it should pass the altered registry to the view
I'm confused about an aspect of OOP/Laravel.
I'm following an OOP tutorial (nothing to do with Laravel) that states that you can only use the Scope Resolution Operator when the method you are calling is static.
So I created a quick script;
class Student {
function welcome_students($var="Hello") {
echo "{$var} students.";
}
}
echo Student::welcome_students("Greetings") ."<br />";
And I get the error;
Strict Standards: Non-static method Student::welcome_students() should
not be called statically in /static_modifier.php on line 11 Greetings students.
But in Laravel 5, I've noticed that I've been using calls like
`ClassName::whereIn($var = `
in quite a few of my Controllers. I've checked the package where the whereIn method is stored and it's not static. It's just a public function.
So how is Laravel 5 allowing me to get away with it? I'm in development mode so I don't know why I'm not seeing that same message.
There are some fairly advanced concepts here that need to be understood in order to fully grasp how this is happening.
First, this would only work for the facades in Laravel. These can be found in the app.php config file in the aliases array. Each of these facades can be thought of as entry points for their real classes which are in the Laravel core. So even though the syntax is telling you that you are calling static methods, what's really happening is Laravel is resolving the underlying classes to these proxy classes and calling methods non-statically on those.
You can see this better if you go to some of those facade classes where you will see the methods you are calling are not actually present on those classes.
To really understand how this is happening, read up on Laravel's inversion of control container (IoC), its use of Facades, and the php magic method __callStatic, and the php method class_alias which is what Laravel is using to setup the aliases.
Again, these are fairly complex concepts so don't get discouraged if they seem confusing or the purpose eludes you.
Basically, the workflow looks like this...
You call Config::get()
Laravel looks up the alias for Config which is a facade.
Using the __callStatic magic method, the facade figures out the underlying class to instantiate and calls the appropriate method on that non-statically.
http://laravel.com/docs/5.0/facades#explanation
http://laravel.com/docs/4.2/ioc#introduction
http://php.net/manual/en/language.oop5.overloading.php#object.callstatic
First of all, your function is not static, you need change it if you want to call it like Student::welcome_students()
public static function welcome_students($var="Hello") {
echo "{$var} students.";
}
I don't usually call methods statically but since working with the Yii framework I have started to more.
I'm experiencing an issue which I haven't come across before, I am doing this from a SignupForm class:
$send = mail::sendMail($email_data);
..inside the sendMail method which is obviously inside the mail class I have this line:
$email_data['message'] = $this->sanitizeMsg($email_data['message']);
The sanitizeMsg is a method of the mail class and hence that's why I thought referencing it via $this should work.
However I am getting the error:
Calling unknown method: app\models\SignupForm::sanitizeMsg()
Why is it looking for it in the SignupForm class? Does this have something to do with me calling it statically? Do I need to revert to using self:: instead or should I stop calling it statically?
Using $this only works for member methods. I.e. you can only use it from an instance of the class and I believe also only to access instance members.
To access static members, you should use self::.
Not familiar with the Yii framework, but what someone does is to use static methods as factory methods. Maybe that's what you're confused by. The static method then creates a new instance of itself and returns it, and inside that instance you can of course use $this, but not in the static method. Static methods have no $this.
I'm very new to codeigniter ,
I wanted to know what is the meaning of a constructor in a controller . I saw the following code in a codeigniter tutorial -
class upload extends CI_Controller {
function __construct() {
parent::__construct();
$this->load->helper(form);
}
// rest of the class...
My question is when is the constructor invoked - is it called every time the controller serves a request (e.g the controller class is instantiated for each request it receives?)
Well, that's a more general PHP question. Anyway, yes, the magic method __construct() is called (automatically) upon each instantiation of the class, as you can see in the manual: http://www.php.net/manual/en/language.oop5.decon.php
Usually, in CI is not necessary to call a constructor, unless you actually want one. In the example you posted, the code loads the helper on every instantiation of the class - which is the same as loading the helper in every method, just saves a lot of typing and ensures it's not forgotten. You can alternatively put the library/helper/model you want to have alywas loaded in the respective autoload array in config/autoload.php (check "autoloading" in CI's manual)
Once you define a constructor in your child Controller you're compelled to call the parent constructor (of the mail CI_Controller class), because there is where the main CI object is created and all the classes are loaded, and you need those in your child controller too; if fail to do so your child class will construct separately and won't inherit.
I hope I made myself clear, english is not my mothertongue :)
the constructor is magic Literally its called a magic method.
what makes the constructor cool is that it will do things for you BEFORE any of the methods. So if you have an admin class, and someone should be logged in in order to access it - you can check for login in the constructor and bounce them out if they are not authorized.
in the constructor you can load the models, libraries, helpers, etc that your class needs, and they will be available for any method in the class.
you can load in variables that are used by methods. this is really useful for models.
Don't use _construct() function in latest apache & codeigniter
Use helperlin in index() function
That's a general question. Constructor is a function that is automatically called when instantiated. this function helps us to intialize the things that we are going to need frequently in our code like when we have to load the models of helpers like form e.t.c.
$this->load->model('Model_name');
now when you write this line in your constructor you don't need to load this model again and again in your methods of that class.