I have this in my controller:
if (!defined('BASEPATH'))
exit('No direct script access allowed');
use xampp\htdocs\client\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Spreadsheet;
use xampp\htdocs\client\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx;
But here is the error I am seeing after running the code
Message: Class 'xampp\htdocs\client\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Spreadsheet' not found
Filename: C:\xampp\htdocs\client\application\controllers\admin\Home.php
You appear to have confused use and include/require.
A use statement is for namespace importing and aliasing. It says "when I use the class name Foo, what I actually mean is Something\Something\Foo. That full name may look like a Windows file path, but the \ here is actually PHP's namespace separator, and doesn't directly relate to the location on disk.
In this case, you would write:
// Alias these class name so I don't have to write them in full in this file
use PhpSpreadsheet\Spreadsheet;
use PhpSpreadsheet\Writer\Xlsx;
If you want to reference the code in a particular file, you need the include and require family of keywords. Those say "load this PHP file, and execute the code in it, including class and function definitions.
So the following would make sense:
// Load the file
require_once 'xampp\htdocs\client\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Spreadsheet.php';
require_once 'xampp\htdocs\client\vendor\phpoffice\phpspreadsheet\src\PhpSpreadsheet\Writer\Xlsx.php';
However, most PHP libraries are built to be autoloaded, so you don't have to name each file manually. Generally, you don't even need to configure the autoloading itself, instead you'd use Composer to install them, and it would set up the autoloader for you.
You would then write, in the main entry point of your code:
require_once 'vendor/autoload.php';
And the classes would be loaded automatically when referenced. Note that you probably still want the use lines, though, and those do have to be in each file (because each file can use the same alias to reference different classes).
Related
I am trying to call my model file from another folder. I have provided both of these file structure.
I am getting this error:
Uncaught Error: Class 'App\Models\Providers' not found in /Applications/XAMPP/xamppfiles/htdocs/pro/app/Scripts/Providers/1/Scrape.php:17
I am calling the model file from a script folder located :
app/Scripts/Providers/1/Scrape.php
In this class I have the below :
namespace App\Scripts\Providers\1;
use App\Models;
Model file is located :
app/Models/Providers.php
Within this file I have the below:
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
I have not shared the full content that I have in both of these files. If you would like to see the full content of these files please let me know.
This is how the Scrape.php looks like
<?php
namespace App\Scripts\Providers\1;
use App\Models\Providers;
class Scrape {
public function __construct() {
$test = new \App\Models\Providers();
die(print_r($test, true));
}
}
$obj = new Scrape();
You can't have a namespace that starts with a number.
Namespaces follow the same basic rules for variable names:
A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores
(Emphasis mine).
Thus, your declaration
namespace App\Scripts\Providers\1
is basically invalid.
From that point forward, all bets are off.
First, change your namespace to a valid identifier (and I would advise choosing something more reasonable and recognizable than numbers, you can have descriptive names and there is simply no reason not to):
namespace App\Scripts\Providers\GroupWhatever
Logically, you'll have to rename the folder where this file resides. It used to be
app/Scripts/Providers/1/Scrape.php
so rename that directory to
app/Scripts/Providers/GroupWhatever/Scrape.php
(In both cases, replace GroupWhatever with something that makes sense for your application and domain).
From that point forward, if the class \App\Models\Providers exists at app/Models/Providers.php, it should work.
Important:
Another problem that there could exist, is that is not very clear what Scripts/Scrape.php is or how is it called.
This should work if you are executing Scrape.php from within Laravel, by calling a Laravel controller or console application.
If you are calling this script directly (e.g. by executing php app/Scripts/Providers/1/Scrape.php (or the corrected app/Scripts/Providers/GroupWhatever/Scrape.php) this simply won't work, since the autoloading logic is not run at all.
If you are executing your script manually, on top of the above changes you need to include composer autoload script, which is located at vendor/autoload.php.
Basically, add this line close to the top of your Scrape.php:
require_once dirname( __DIR__ ) . '/../../../vendor/autoload.php';
(I think I put the appropriate amount of go-up-one-dir path-segments, but you make sure it matches the correct path in your installation).
Once that is in place, the autoloader will be run, and classes will be found.
In your Scrape.php, change your namespace to:
<?php
namespace App\Scripts\Providers\p1;
From PHP manual comment,
namespace (even nested or sub-namespace) cannot be just a number, it
must start with a letter. For example, lets say you want to use
namespace for versioning of your packages or versioning of your API:
namespace Mynamespace\1; // Illegal
Instead use this: namespace
Mynamespace\v1; // OK
This is what I have at hand:
//Person.php
namespace Entity;
class Person{
}
User file:
//User.php
use Entity\Person;
$person = new Person;
Here, it fails if I don't include the Person.php file. If I include it, the everything works fine. Do I absolutely require to include the file even when using namespaces? If at all we need to include/require files, then how can namespaces be effectively used? Also, can we maintain folder structure by nesting namespaces?
The answer to your question is "yes and no".
Indeed the code implementing class Person has to be included, otherwise the class is not defined and cannot be used. Where should the definition come from, when the code is not included? The php interpreter cannot guess the classes implementation. That is the same in all programming languages, by the way.
However there is something called Autoloading in php. It allows to automatically include certain files. The mechanism is based on a mapping of class names to file names. So in the end it boils down to php searching through a folder structure to find a file whos name suggests that it implements a class currently required in the code it executes.
But don't get this wrong: that still means the file has to be included. The only difference is: the including is done automatically, so without you specifying an explicit include or require statement.
Yes, you need to include every file.
A very good example can be found here on effective usage of namespaces.
With PSR-0 autoloading, the namespace has to be the same as the folder in which the class is, file the filename has to be the same as the classname. This gives you very simple and effective autoloading with composer for example.
I've been reading a lot of posts on StackOverflow but I'm not really sure I'm using namespaces, autoloading, and aliasing correctly. This is functioning fine, but I'm not sure I'm properly using these concepts. I've listed some reasons why I think this setup is incorrect at the bottom of the post.
Imagine the following directory structure:
\public_html
- index.php
\Classes
\A
- One.php
\B
- Two.php
One.php is structured like:
<?php
namespace Classes\A;
class A { ....
Two.php is structured like:
<?php
namespace Classes\B;
class B { ....
Then, in index.php I do something like:
<?php
use Classes\A\One as One;
use Classes\B\Two as Two;
spl_autoload_register(function ($className) {
...
});
... ?>
So, a couple things that bug me about this:
If I am doing aliasing (the "use" statements) I still need to list out all of the files. Aren't we trying to avoid doing this by using autoload?
If I want to use internal classes, I need to add a line such as "use \mysqli;" into the class that uses this and do things like "new \mysqli()". Seems kind of messy?
If a class extends a class from another namespace (say Two.php extends One.php for example) then I need to include "use \Classes\A\One as One;" in One.php which seems to be what we want to avoid in the first place
You don't have to reference all of your namespaced classes via a use statement. You can use partial namespaces.
use Classes\A;
new A\One();
So you can see if you had another class in the A namespace it could be instantiated with
new A\Three();
There are many things in the global namespace, you don't need to define them with use. You can just call them \mysqli(). Yes it's a bit unsightly but it allows you to make a function called mysqli in your own code without worrying about collisions with globally namespaced functions.
I'm not sure I follow you on this one. You don't need to do a use in the base class which references itself.
Ultimately it kinda seems like you view use almost like include when they are very different, use, in this context, is a convenience thing so you don't have to type out full namespaces every time.
Your Autoloader also doesn't need to know about your namespaces. The autoloader just tells PHP how to load a class. So if it sees a class come in with the name Classes\A\One you can make it look in the directory /Classes/A for a file called One.php and include it. PHP will make sure that the class is allocated in the proper namespace. The autoloader is just a convenience thing to keep you from having to do includes and requires in each of your PHP files.
I think this is very simple for many of you, but in the moment I got stuck with this. I have the following part of code:
header.php
include "facebook/autoload.php";
use Facebook\FacebookRedirectLoginHelper;
test.php
include "header.php";
$helper = new FacebookRedirectLoginHelper($redirect_url);
Why do I always get this error:
Fatal error: Class 'FacebookRedirectLoginHelper' not found in test.php on line
I thought when I include a PHP file, classes can also be used. But in this case not, why? I think I do not understand how this autoload and use works, so I would be happy for some explanation.
PHP does not inherit the namespaces nor the use statements of included/required files. This is intentional as otherwise if you include 2 files using a class aliased the same way you will get errors and you might not need all those classes in firs place.
If a class requires a namespace it has to have use statement defined with the full namespace to the particular class they need. Except in the cases where there might be aliasing. For example if you have:
// file1.php
use \My\Cool\LogWriter as Writer;
and
// file2.php
use \My\Cool\FileWriter as Writer;
Now both classes are accessible as Writer.
// test.php
require 'file1.php';
require 'file2.php';
In which case if you don't declare which class from which space you want this will give nasty error that class Writer is defined, which is true, but it is also true that the two classes are 2 separate ones.
For more information on namespaces in PHP5 see (http://php.net/manual/en/language.namespaces.php).
As a side note:
Every file, if not namespace declaration is provided is considered in the global namespace.
If a use is without leading slash the namespace might be considered relative to the current. (unsure but I think it depends on the autoloader?) (Reference here: https://stackoverflow.com/a/4879615/1747193)
This is what I have at hand:
//Person.php
namespace Entity;
class Person{
}
User file:
//User.php
use Entity\Person;
$person = new Person;
Here, it fails if I don't include the Person.php file. If I include it, the everything works fine. Do I absolutely require to include the file even when using namespaces? If at all we need to include/require files, then how can namespaces be effectively used? Also, can we maintain folder structure by nesting namespaces?
The answer to your question is "yes and no".
Indeed the code implementing class Person has to be included, otherwise the class is not defined and cannot be used. Where should the definition come from, when the code is not included? The php interpreter cannot guess the classes implementation. That is the same in all programming languages, by the way.
However there is something called Autoloading in php. It allows to automatically include certain files. The mechanism is based on a mapping of class names to file names. So in the end it boils down to php searching through a folder structure to find a file whos name suggests that it implements a class currently required in the code it executes.
But don't get this wrong: that still means the file has to be included. The only difference is: the including is done automatically, so without you specifying an explicit include or require statement.
Yes, you need to include every file.
A very good example can be found here on effective usage of namespaces.
With PSR-0 autoloading, the namespace has to be the same as the folder in which the class is, file the filename has to be the same as the classname. This gives you very simple and effective autoloading with composer for example.