Where and how to extract repeated business logic? - laravel

I have certain business logic that repeats throughout my code. Is there a standardized way of separating this out for version 4.2? I know in the newer versions, Commands are used for this type of thing. Example of repeating logic:
// detach tags
$card->tags()->detach();
foreach (Input::get('tags', []) as $tag)
{
// existing tag
if (is_numeric($tag) && Tag::whereId($tag)->exists())
{
$card->tags()->attach($tag);
}
// new tag
else
{
$new_tag = new Tag();
$new_tag->market()->associate($market);
$new_tag->name = $tag;
$new_tag->save();
$card->tags()->attach($new_tag->id);
}
}
The simplest way I could do this is create a new class, like TagManager and add methods for this logic, like createTag, attachTagToCard, etc. However, I'm not sure if there is already a "predefined" way of doing this.

The repeated code problem can be solved by using traits.
For more information on trait go here
Create a file called TagManagerTrait.php inside the folder app/traits
contents of file
<?php
namespace App\Traits;
trait TagManagerTrait {
public function createTag()
{
// your create tag logic
}
public function updateTag()
{
//your update tag logic
}
}
Update your composer.json to autoload this
{
"autoload" : {
"classmap" : [
"app/traits"
]
}
}
In the controllers where you want to use the repeated code
<?php
use App\Traits\TagManagerTrait;
class XyzController extends Controller{
use TagManagerTrait;
}
Now the controller will inherit all the functions of the trait and be used freely.

Related

How can I add extra view component class paths in Laravel?

The problem
The default namespace for view components is App\View\Components with the folder being app/View/Components. I am setting up a DDD file structure and wish to do two things:
Move "shared" view components to a namespace and folder of App\ViewComponents and src/app/ViewComponents respectively
Have view components specific to individual "apps" with their own namespace and folder of App\MyApplication\ViewComponents and /src/app/MyApplication/ViewComponets respectively.
The new App namespace/folder setup is done via composer psr-4 autoload keys and works fine. But Laravel always used the App\View\Components namespace when trying to load components.
My attempt
I have solved the first part of my problem, but I am hoping that there is a better way. For instance when I want to move views, I can just set the view.paths config directive in my AppServiceProvider but I don't see a similar way of, essentially, adding namespaces to where Laravel looks for view components. So what I ended up doing was:
Create a ViewServiceProvider class, extending Illuminate\View\ViewServiceProvider::class and point to it in bootstrap/app.php instead
In there, override the registerBladeEngine method, in there pointing towards my own BladeCompiler class instead of the built-in one
public function registerBladeEngine($resolver)
{
// The Compiler engine requires an instance of the CompilerInterface, which in
// this case will be the Blade compiler, so we'll first create the compiler
// instance to pass into the engine so it can compile the views properly.
$this->app->singleton('blade.compiler', function () {
return new BladeCompiler(
$this->app['files'],
$this->app['config']['view.compiled'],
);
});
$resolver->register('blade', function () {
return new CompilerEngine(
$this->app['blade.compiler']
);
});
}
In my own BladeCompiler class, which extends Illuminate\View\Compilers\BladeCompiler, override the component() and compileComponentTags() methods - basically anywhere that referenced View\\Components - with pretty much a carbon copy but instead using ViewComponents and also made sure that where they return a Illuminate\View\Compilers\ComponentTagCompiler I instead referenced my own ComponentTagCompiler
In my own TagCompiler I override the guessClassName() method, again with essentially a carbon copy, just renaming View\\Components to ViewComponents
As you can see, that's quite a lot of work just to change the path. And I also want to add another path. Multiple "apps" run under the same Laravel codebase, so for instance we might have App\Website\, App\Admin and App\Blog and, depending on which app is currently running, load a different namespace for the running app, i.e. the blog would be App\Blog\ViewComponents pointing to src/app/Blog/ViewComponents.
Is there a way to achieve this without as much overriding as above? If not, can you suggest a way to achieve the second part of the requirement?
Note: I haven't ruled out using sub folders and continuing with everything under the main App\View\Components namespace just yet - I don't want to fight Laravel more than I have to and am willing to concede if there's no better way, but if I can achieve the folder structure I want it would feel a lot tidier.
Update; got a working implementation by using a configuration and php 8 annotations
Follow the steps below to make it possible to add more lookup folders for the blade view components feature, based on your question and details you have provided. It would have helped to have posted that code you already had. But I have added a possible solution to get it to work, using Annotations and using a config with a namespace/path map.
Depending on how you switch between one application and the other, from which the details are not provided in your question, you have to modify the way the configuration is retreived in the MyComponentTagCompiler class.
Blade compiler
In order to change the ComponentTagCompiler we need to change the BladeCompiler class:
namespace App;
class YourBladeCompiler extends \Illuminate\View\Compilers\BladeCompiler
{
protected function compileComponentTags($value)
{
if (! $this->compilesComponentTags) {
return $value;
}
return (new \App\MyComponentTagCompiler( //it is about this line
$this->classComponentAliases, $this->classComponentNamespaces, $this
))->compile($value);
}
}
Service provider
Now register the YourBladeCompiler in YourViewServiceProvider :
class YourViewServiceProvider extends \Illuminate\View\ViewServiceProvider
{
public function registerBladeEngine($resolver)
{
$this->app->singleton('blade.compiler', function () {
return new \App\YourBladeCompiler( //it is about this line
$this->app['files'],
$this->app['config']['view.compiled'],
);
});
$resolver->register('blade', function () {
return new CompilerEngine(
$this->app['blade.compiler']
);
});
}
}
MyComponentTagCompiler
This is an implemention I created that works with PHP 8 Attributes, given below:
namespace App;
#[\Attribute]
class ViewComponentName
{
public string $name;
public string $package;
public function __construct(string $name, string $package)
{
$this->name = $name;
$this->package = $package;
}
}
With this attribute, you can declare the package name and component name on the view component class (see example at the bottom). So during lookup the component can be matched on these parameters.
But you can change it to your own requirements if needed.
What it does:
It first let's Laravel lookup the View Component through it's own mechanisms, in the parent::componentClass method.
If no component is found and an exception (InvalidArgumentException) is thrown, after which my implementation will walk through the given paths and namespaces (from the getLookupPaths method) and see if an attribute matches the component name and package name. If so it returns this class and the view component is loaded accordingly.
namespace App;
use App\View\ViewComponentName;
use Illuminate\View\Compilers\ComponentTagCompiler;
class MyComponentTagCompiler extends ComponentTagCompiler
{
protected function getLookupPaths() : array
{
/*
* add some logic here to get an application specific configuration
* since you have multiple application in one, I cannot know it works in your
* application, since the details are not provided in the question
*/
return config('view_component_paths');
}
private function getFiles(string $dir) : array
{
return scandir($dir);
}
private function isPhpFile(string $file) : bool
{
return strpos($file, ".php");
}
private function getClassNamespace(string $file, string $folderNamespace) : string
{
$class = str_replace(".php", "", $file);
$classNamespace = $folderNamespace . "\\" . $class;
return $classNamespace;
}
private function getComponentName(string $file, string $namespace) : ?ViewComponentName
{
$classNamespace = $this->getClassNamespace($file, $namespace);
$reflection = new \ReflectionClass($classNamespace);
if(method_exists($reflection, 'getAttributes')) {
$attribute = $reflection->getAttributes()[0];
if ($attribute->getName() == ViewComponentName::class) {
return $attribute->newInstance();
}
}
return null;
}
public function componentClass(string $component)
{
try {
parent::componentClass($component);
} catch(\InvalidArgumentException $e) {
list($lookupComponentPackage, $lookupComponentName) = explode("-", $component);
foreach($this->getLookupPaths() as $namespace=>$dir) {
foreach ($this->getFiles($dir) as $file) {
if ($this->isPhpFile($file)) {
if($componentName = $this->getComponentName($file, $namespace)) {
if($componentName->name == $lookupComponentName && $componentName->package == $lookupComponentPackage) {
return $this->getClassNamespace($file, $namespace);
}
}
}
}
}
throw $e;
}
}
}
Where the config contains (config/view_component_paths.php):
return [
"App\\Test"=>__DIR__ . "/Test/"
];
If you wish to replace the default laravel behavior completely or do not like my implementation based on annotations, consider implementing your own version of the method:
public function componentClass(string $component)
{
//return the class name here based the component name
//without calling parent
dd($component);
}
Example view component
namespace App\Test;
use App\View\ViewComponentName;
use Illuminate\View\Component;
#[ViewComponentName('test', 'namespace')]
class MyViewComponent extends Component
{
public function render()
{
return view('components.test');
}
}
In blade:
<x-namespace-test />
It should now be working. I think this is enough information to give you an idea of how to implement this in your own application. There seems to be no other way than to extend some base classes. But looking at this answer, it is possible to create a high level implementation based on a global lookup configuration and php annotations (or some other mechanism you wish, for example converting the class name with namespace to a view component name).
Old answer
Problem 2 as defined in your question
Have view components specific to individual "apps" with their own namespace and folder of App\MyApplication\ViewComponents and /src/app/MyApplication/ViewComponets respectively.
Sadly there seems to be no way of defining multiple class paths for view components in Laravel. But you can however change the application path and namespace prefix. As far as I found out you only have to overwrite the following properties in the Application class.
bootstrap/app.php
Replace the following lines:
$app = new Illuminate\Foundation\Application(
$_ENV['APP_BASE_PATH'] ?? dirname(__DIR__)
);
With:
class YourApplication extends \Illuminate\Foundation\Application
{
protected $namespace = "App\\MyApplication";
protected $appPath = __DIR__ . "/../app/MyApplication";
}
$app = new YourApplication(
$_ENV['APP_BASE_PATH'] ?? dirname(__DIR__)
);
This is enough to change the app folder to another and gives you an idea of how to change it dynamically for having multiple apps in different namespaces. If you now run laravel commands like php artisan make:component Test1234 it is created in your new app folder: app/MyApplication/View/Components/Test1234.php.
Hardcoded paths
Some paths like View/Components are hardcoded in Laravel, and therefor not that easy to change. If you change as defined above, in this case the view components namespace becomes: App\MyApplication\View\Components and the path: app/MyApplication/View/Components.
Problem 1 as defined in your question
Move "shared" view components to a namespace and folder of App\ViewComponents and src/app/ViewComponents respectively
When you change application paths as explained above it is not possible to have a "shared" View Component folder. Laravel, as it seems, has only one default View Components path, which is based on hard coded paths and a dynamic namespace prefix as explained above. But you can of course, create a shared namespace and register the view components manually:
View component (app/ViewComponents/ folder)
namespace App\ViewComponents;
use Illuminate\View\Component;
class Test extends Component
{
public function render()
{
return view('components.test');
}
}
Don't forget the components.test blade view.
ServiceProvider
\Blade::component("shared-test",\App\ViewComponents\Test::class);
Blade
<x-shared-test />

Laravel global function

I have 2 models:
Bill:
id, account_id, descripcion, monto_pagado, saldo
Payment:
id, bill_id, monto
Each time someone insert a new bill to the account or insert a new payment I pretend to calculate the balance of the account.
What would be the best place to accomplish this:
as service
as mutators in the model
as function in the controller
I know i would have to call this in others places of my project. So i would like it to be a global function. What would be the best place to do it?
You could use an event in your models. Use creating if you want to calculate before the model is actually created in the database, or created if you want to calculate after it has been created.
In your App\Providers\AppServiceProvider::boot() method, define the events for both models:
class AppServiceProvider extends ServiceProvider
{
public function boot()
{
Bill::creating(function ($bill) {
// Do something with $bill
});
}
// etc
}
To avoid code repetition, you may use a trait and use it in both classes. Call it PretendCalculationTrait for example and place it in app/Traits (create the directory if needed):
<?php
namespace App\Traits;
trait PretendCalculationTrait
{
public function pretendCalculate()
{
// Do your stuff
}
}
Then in your model, use this trait:
class Bill extends Eloquent
{
use App\Traits\PretendCalculationTrait;
// etc.
}
Finally, in your AppServiceProvider, call the method defined in the trait:
public function boot()
{
Bill::creating(function ($bill) {
return $bill->pretendCalculate();
});
Payment::creating(function ($payment) {
return $payment->pretendCalculate();
});
}
See Laravel Model Events documentation for more details.
One possible solution, since you mentioned wanting it to be a global function, is to use Laravel's autoloading feature.
Create a file that contains the function for your calculation. It can be placed anywhere, and contain other functions, but for brevity we'll place it here: App/Http/customFunctions.php. In your file, create your function:
function pretendCalculation()
{
return $something;
}
Next, tell Laravel to autoload it by adding it to your autoloading list in composer.json:
"autoload": {
"classmap": [
"database"
],
"psr-4": {
"App\\": "app/"
},
"files": [
"app/Http/customFunctions.php" <-- Here is the new file
]
Then just execute a composer dump auto-load -o or the like, and now you'll have access to this file/all functions within the file, anywhere in your application.

Laravel, autoload classes based on an input array of class names

I have various classes, e.g.
<?php
namespace MyApp\Notifications;
class FirstNotification implements NotificationInterface {
public function getMessage() {
return 'first message';
}
}
and
<?php
namespace MyApp\Notifications;
class SecondNotification implements NotificationInterface {
public function getMessage() {
return 'second message';
}
}
I then have an array like: ['First','Second'].
I'm using:
foreach (['First','Second'] as $class_prefix) {
$class = "MyApp\Notifications\\{$class_prefix}Notification";
$object = new $class();
echo $object->getMessage();
}
but it feels a bit hacky - is there a better/more standard way to do this? The array is supplied elsewhere and will be different depending on the user - my aim is to be able to easily create classes that implement my interface and know this loop will be able to show their messages if they exist.
I ideally don't want to have to add a use statement for all the classes upfront, or pass them into a constructor, I just want magic to happen!
I'm assuming you don't actually mean autoload but rather instantiate the class. Autoloading is the process of including all the files in your application so the contents (usually classes) can be used. If you are using Laravel 5 and you follow PSR-4 (namespace matches directory structure) you don't have to do anything to make those classes available.
The code you already have looks fine and probably works. However you could make use of Laravels Service Container to resolve the class. This has quite a few advantages, one being the availability of automatic dependency injection...
foreach (['First','Second'] as $class_prefix) {
$object = app()->make("MyApp\Notifications\\{$class_prefix}Notification");
echo $object->getMessage();
}
Or even this:
foreach (['First','Second'] as $class_prefix) {
echo app()->callClass("MyApp\Notifications\\{$class_prefix}Notification#getMessage");
}
However, both will cause an exception if the class doesn't exist. You can check for that beforehand or just catch the exception:
foreach (['First','Second'] as $class_prefix) {
try{
$object = app()->make("MyApp\Notifications\\{$class_prefix}Notification");
echo $object->getMessage();
}
catch(ReflectionException $e){
// whooops
}
}

Laravel 4 Aliases in custom classes

i want to use the alias classes on laravel 4 "facades" like App::method , Config::method.
Well the thing is that i create a custom class and i have to import the namespaces like
<?php
namespace Face\SocialHandlers;
use Illuminate\Support\Facades\App;
use Illuminate\Support\Facades\Config;
class FacebookHandler implements SocialHandlerInterface {
public function registrar($perfil) {
Config::get('facebook');
}
}
is there any way to use those classes like in controllers or routes files of the framework ?
like
<?php
namespace Face\SocialHandlers;
//use Illuminate\Support\Facades\App;
//use Illuminate\Support\Facades\Config;
class FacebookHandler implements SocialHandlerInterface {
public function registrar($perfil) {
Config::get('facebook');
}
}
Cya
ps: sry for my english
You can use use Config; instead of the more verbose use Illuminate\Support\Facades\Config; and the autoloader should handle it correctly.
Just as a tip, you shouldn't hardcode dependencies in your code. Instead of using the facades, you could create an "ConfigInterface" to get the common dependencies you need. Then create a "LaravelConfig class" (Or Laravel4Config.php) and implement those methods.
For a Quick Fix Answer, "catch the underliying facade instance":
namespace Face\SocialHandlers;
//use Illuminate\Support\Facades\App;
//use Illuminate\Support\Facades\Config;
class FacebookHandler implements SocialHandlerInterface {
protected $config;
protected $app;
public function __construct()
{
$this->config = \Illuminate\Support\Facades\Config::getFacadeRoot();
$this->app = \Illuminate\Support\Facades\App::getFacadeRoot();
}
public function registrar($perfil) {
$this->config->get('facebook');
}
}
For a Real Answer, maybe tedious, but good in the long run, instead of using the facades use an interface.
interface SocialConfigInterface
{
public function getConfigurationByKey($key)
}
Then
class Laravel4Config implements SocialConfigInterface
{
protected $config;
public function __construct()
{
$this->config = \Illuminate\Support\Facades\Config::getFacadeRoot(); //<-- hard coded, but as expected since it's a class to be used with Laravel 4
}
public function getConfigurationByKey($key)
{
return $this->config->get($key);
}
}
And Your Code
namespace Face\SocialHandlers;
//use Illuminate\Support\Facades\App;
//use Illuminate\Support\Facades\Config;
class FacebookHandler implements SocialHandlerInterface {
protected $config;
public function __construct(SocialConfigInterface $config)
{
$this->config = $config;
}
public function registrar($perfil) {
$this->config->get('facebook');
}
}
This way, if you want to change between frameworks you just need to create a SocialConfigInterface Implementation, or imagine the scenario where Laravel 5 wont use Facades, you want your code to be independent of "outsider changes" this is inversion of control IoC
First run,
php artisan dump-autoload
This will add your class namespace to vendor/composer/autoload_classmap.php. Now locate the entry for your class in this classmap array and get the proper namespace from there.
For example, you will get something like,
'Illuminate\\Support\\Facades\\App' => $vendorDir . '/laravel/framework/src/Illuminate/Support/Facades/App.php',
For this particular entry you have an alias in app/config/app.php
'App' => 'Illuminate\Support\Facades\App',
At the same way, locate your entry and use an alias in app/config/app.php.
You just have to create a folder, or place a class wherever already is listed for autoload. Me, for exemple, have this class PDFMaker, that uses a DomPDF Laravel implementation. I created a folder named libraries and put the path to it (under the app folder) in the autoload:classmap key on composer.json
"autoload": {
"classmap": [
"app/commands",
"app/controllers",
"app/libraries",
"app/models",
"app/helpers",
"app/database/migrations"
]
I did the same with commands for artisan commands! When you do that, you only have to declare a new object for any class under that folder, or call it in a static way, if the class has defined static methods. Something like Class::method.
Hope it helps you, have a nice day! :D
EDIT: After that, don't forget the dump-autoload for placing the new class in autoload scope.
EDIT 2: Remember that once you've put the class on autoload, it will be in same scope the others, so you won't have to import it to other, neither others to it!
You can also prefix the class names with a backslash, to use the global namespace: \Config::get('facebook') and \App::someMethod() will work without the need to add a use statement, regardless of the file's namespace.

How to extend laravel 4 core?

I am a newb learning laravel 4. I want to override specific helper functions. Or add new functions to Url, Str etc. How to do this?
Depending on what part of Laravel you want to extend or replace, there are different approaches.
Macros
Adding functions to Str is really easy, because of "macros":
Here's a short example for adding function:
Str::macro('test', function($str) {
return 'Testing: ' . $str . '!';
});
You can then call this function as expected:
echo Str::test('text'); // Outputs "Testing: text!"
Adding functions using macros are supported by Str, Form, HTML and Response.
IOC Based Extension
To extend URL one must use the IOC of Laravel. This is explained in the docs (as mentioned by BenjaminRH). I agree it can be a bit hard to understand. Here's a step-by-step to extend URL:
Create folder app/lib to hold your extension classes.
Add this folder to autoloading:
In app/start/global.php, append the lib path to the class loader:
ClassLoader::addDirectories(array(
app_path().'/commands',
app_path().'/controllers',
app_path().'/models',
app_path().'/database/seeds',
app_path().'/lib'
));
Then add the path to composer.json classmap:
"autoload": {
"classmap": [
"app/commands",
"app/controllers",
"app/models",
"app/database/migrations",
"app/database/seeds",
"app/tests/TestCase.php",
"app/lib"
]
},
Create the custom UrlGenerator app/lib/CustomUrlGenerator.php:
<?php
use \Illuminate\Routing\UrlGenerator;
class CustomUrlGenerator extends UrlGenerator
{
public function test()
{
return $this->to('/test');
}
}
Create a service provider app/lib/CustomRoutingServiceProvider.php:
<?php
use \Illuminate\Routing\RoutingServiceProvider;
class CustomRoutingServiceProvider extends RoutingServiceProvider
{
public function boot()
{
App::bind('url', function()
{
return new CustomUrlGenerator(
App::make('router')->getRoutes(),
App::make('request')
);
});
parent::boot();
}
}
Register the service provider in app/config/app.php:
Add CustomRoutingServiceProvider to the providers array.
For example, right after the Workbench provider:
'Illuminate\Workbench\WorkbenchServiceProvider',
'CustomRoutingServiceProvider',
Run composer dump-autoload from project root folder.
Done. Use like:
URL::test();
NOTE The code is tested, but may contain some errors
Interesting that you should mention this, actually. A whole documentation section was just recently added, which covers this in detail. It's very clear, and easy to understand. If you've been using Laravel at all, it might not even surprise you that Laravel actually provides an extend method for a lot of core components.
Following Fnatte's answer, today's versions of Laravel do some extra processing in the url binding. Redefining the whole binding is no longer a practical option.
Here is how I ended up for extending the URL facade.
First, create your child class using this boilerplate:
use Illuminate\Routing\UrlGenerator;
class YourUrlGenerator extends UrlGenerator {
public function __construct(UrlGenerator $url)
{
parent::__construct($url->routes, $url->request);
}
// redefine or add new methods here
}
Then, add this in a ServiceProvider:
$url = $this->app['url'];
$this->app->singleton('url', function() use ($url)
{
return new YourUrlGenerator($url);
});
The point is simply that the original url binding should be executed at least once before we override it with our own.

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