How to define custom autoloader in composer? - php

I am using Nette Framework which uses its own autoloader. How can I define custom autoloader or just exclude the standard one from composer so I can use my own?

Alternatively, if you want an additional autoloader, you can update composer.json with:
{
"autoload": {
"files": ["src/extra/autoloader.php"]
}
}
Then run composer dump-autoload to rebuild it. Now when you include vendor/autoload.php it will also load your autoloader.

Simply don't include it if you don't want to use it. Keep in mind you'll have to handle autoloading on your own.
If your autoloader can work with it, you can use namespaces file generated by composer:
Composer provides its own autoloader. If you don't want to use that one, you can just include vendor/composer/autoload_namespaces.php, which returns an associative array mapping namespaces to directories.
Reference: Autoloading in the composer docs.

Related

How to check if composer's autoloader is being used?

I'm developing a certain PHP framework for WordPress, and I want to give my users the option to use composer to install it as a package, or to install it manually. If composer is used, then a psr-4 class autoloader handles everything. If not, then all files must be loaded manually during the framework's bootstrapping process.
Is there a safe way to check whether composer's autoloader is being used in a given WordPress environment?
Currently i'm using:
if( !class_exists('Composer\\Autoload\\ClassLoader') )
{
// Manually include files if composer is not used.
require_once 'some/files.php';
}
However, if in a given WordPress environment there is a plugin that uses composer internally, then the above if statement will return true even though other plugins have no access to it.
The solution, as it turns out, is quite simple. You need to create 2 different bootstrapping files, say manual-bootstrap.php and composer-bootstrap.php. Then add the following lines to composer.json:
"autoload": {
"files": ["composer-bootstrap.php"]
}
composer-bootstrap.php will only be called if composer is used to load the framework as a dependency. Users that want to load the framework manually will use manual-bootstrap.php instead.
if(class_exists("\Composer\Autoload\ClassLoader"))
{
// a composer autoload.php has already been included/required
}

Autoload My Classes with Sub-Namespaces (Composer.json)

I've added the following to my composer.json file. This works fine but I have a long list of sub-namespaces (eg. Apple, Orange, Lemon, Pear, Banana... etc) that I want to include.
1) Do I have to indicate each sub-namespace or is there a shortcut eg. "Pure\\*": "pure"
composer.json:
"autoload": {
"psr-4": {
"Pure\\": "pure",
"Pure\\Apple\\": "pure/src/Pure/Apple",
"Pure\\Orange\\": "pure/src/Pure/Orange",
"Pure\\Lemon\\": "pure/src/Pure/Lemon"
}
}
2) Is it better to include a custom autoload file instead:
composer.json:
"autoload": {
"files": [
"pure/src/Pure/autoload.php"
]
}
autoload.php:
spl_autoload_register(function ($class) {
//etc...
}
Do I have to indicate each sub-namespace or is there a shortcut
When declaring the autoloading, you should use the longest possible or reasonable prefix.
If this example package is the only one you are ever creating, and it is the only one using Pure as the namespace, go with that if the number of longer prefixes in several subdirectories is too high. However, this assumes that any other package in the world that you are using should avoid doing the same thing with the same namespace.
Composer will be able to search for sub namespaces in all available directories, i.e. if you have two packages, and one says Pure is to be found in pure/src/Pure, and the other says Pure is in code/stuff, Composer will try to find a class Pure\Something\Class in one of these directories first, then has to try the second one if it does not find it. Composer will remember whether the pure/src/Pure/Something directory exists and avoid looking for anything starting with Pure\Something there if a second class in that namespace has to be loaded.
But from a code organization standpoint, one package should only ever provide a defined set of namespaces, and no other package should provide classes in the same namespace. You could accidentially add the same class into two packages and get interesting problems that may be hard to debug if the two files are different.
Is it better to include a custom autoload file instead:
No, avoid it at all cost. You won't get any benefit from this because the file always has to be loaded, and it is duplicate code that occupies some memory - you already have the autoloader from Composer. If you have code that does not conform to PSR-4 or PSR-0, you can use a classmap. For new code: Use PSR-4 only!
Also, your custom autoloader cannot be optimized by Composer. Although any optimization should be measured for effectiveness (read my detailed answer on this: Why use a PSR-0 or PSR-4 autoload in composer if classmap is actually faster?), using your own autoloader will entirely prevent your code from being optimized if it would be beneficial.

Composer - Autoloading an API / Custom Installer

How do I autoload a set of library API functions with a composer installed library?
I have a library with a function API used to interface the libraries internal objects and want composer to automatically load the API and make it available after install without requiring the end-developer to include a file.
Currently the library is loaded by just including the __init__.php and it includes the API functions and an autoloader if required.
Thanks!
Composer always will require the end-developer to include one file, which is vendor/autoload.php. You cannot make it easier that that.
But what you can do is make including __init__.php optional because the integration of Composer allows you to use that autoloader instead. This will also work for functions, which could not really be autoloaded - Composer offers to always include a file if being told so.
So in the end your Composer configuration of that API library would look like this:
{
"name": "yourvendorname/yourfancylibraryname",
"license": "any open source identifier",
"autoload": {
"psr-0": {
"Foo_Api": "src/files"
},
"classmap": [
"extra/folders_with_any_other_class_not_conforming_to_psr0_or_psr4"
],
"files": [
"functions/file_with_your_function_definitions.php"
]
}
}
I don't know about whether your classes conform to PSR-0 or even PSR-4, but if they do, you and everyone would benefit if you can declare the autoloader with these standards. If not: Classmap will help you.
Your function definition will be loaded by the file or files mentioned in "files".
You don't need your own autoloader anymore for Composer.
Of course you could also simply mention the old __init__.php as the file to be included in "files", but this would separate your library from all the other classes, would probably be less performant (Composer already has a very good autoloader - there is no need to have two of them) and would definitely exclude all your classes from being dumped into an even faster Composer classmap autoloader.

Own project via composer

I've got some libraries loaded through composer, and I'm wondering if it's possible to add my own library in the /vendor map, and then to have the composer autoloader load it? The structure would be something like /vendor/mylibrary/ and then a namespace mylibrary.
Would this be possible? Also would it be possible to add a different map to the composer autoloader? Like for example /app/src/ and then to have it load all the classes in that folder? Or do I have to make my own loader for that?
Thanks
Reading the composer documentation:
You can even add your own code to the autoloader by adding an autoload field to composer.json.
{
"autoload": {
"psr-0": {"Acme": "src/"}
}
}
Composer will register a PSR-0 autoloader for the Acme namespace.
You define a mapping from namespaces to directories. The src directory would be in your project root, on the same level as vendor directory is. An example filename would be src/Acme/Foo.php containing an Acme\Foo class.
After adding the autoload field, you have to re-run install to
re-generate the vendor/autoload.php file.
So basically, you just need to follow PSR-0, and tell composer where to find your library, by adding that line to your composer.json
Yes.You can achieve it. Configure your composer.json file as following:
{
"autoload": {
"classmap": [ "classes" ]
}
Here classes is the name of the directory where you have all your application related classes.Vendor related class should be auto detected as well. Just add the following line to achieve both at the same time:
require 'vendor/autoload.php';
And you can use the namesapce to reference your class like the following:
use classes\Model\Article;
Yes, of course it is possible to add own libraries and you should feel highly encouraged to do so. If your library is available publicly, you can simply register it at packagist.org. If not, it's a bit more complicated, but not impossible.
If your project does not follow the PSR-0 standard, composer will create a classmap for you. A custom autoloader is not supported.
I'd recommend you to read the (really excellent) documentation about all this and come back, if you're running into problems.
http://getcomposer.org/doc/

Custom code management with the Composer auto loader?

I've started a new project, where I use Composer to handle some dependencies, as well as their auto-loading.
I only keep the composer.json file in the VCS, instead of the entire vendor directory, so I don't want to start adding my code in there.
How should I handle my own project specific code, so that it auto loads as well?
This is actually very simple. Excluding vendors directory from your repository is the right approach. Your code should be stored in a separate place (like src).
Use the autoload property to make that composer recognizes your namespace(s):
{
"autoload": {
"psr-4": {
"Acme\\": "src/"
}
}
}
Assuming you have class names following the psr-4 standard, it should work. Below some example of class names and their locations on the file system:
Acme\Command\HelloCommand -> src/Command/HelloCommand.php
Acme\Form\Type\EmployeeType -> src/Form/Type/EmployeeType.php
Remember to define a namespace for each class. Here's an example of Acme\Command\HelloCommand:
<?php
namespace Acme\Command;
class HelloCommand
{
}
Don't forget to include the autoloader in your PHP controllers:
<?php
require 'vendor/autoload.php';
Read more on PSR-4 standard on PHP Framework Interoperability Group.
Note that if you edit composer.json, you need to either run install, update or dump-autoload to refresh the autoloader class paths.

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