Monolog implementation with common class - php

I succeeded in implementing a Monolog logger for test purposes. And now I'm trying to use it in a project. This project doesn't use any MVC framework.
I'm trying to write a common class file to wrap access to the Monolog instance.
Common class file: File: app_log.php
require 'autoload.php';
use Monolog\Logger;
use Monolog\Handler\RotatingFileHandler;
use Monolog\Processor\UidProcessor;
use Monolog\Processor\WebProcessor;
use Monolog\Processor\MemoryUsageProcessor;
use Monolog\Processor\ProcessIdProcessor;
use Monolog\Formatter\LineFormatter;
class app_log {
public function info(){
$logger = new Logger('applog');
$handler = new RotatingFileHandler('useractivity.log', 0, Logger::INFO);
$handler->setFormatter(new LineFormatter("[%datetime%] %extra.process_id% %channel%.%level_name%: %message% %extra% %context% \n"));
$logger->pushHandler($handler);
$logger->pushProcessor(new WebProcessor);
}
}
Other File: users.php
include_once 'app_log.php';
class users extends dbconnector{
function login(){
// Some project code.
$logger = new app_log();
$logger->info('User logged successfully');
}
}
Up to this works well and i want to include filename, method name, request parameters. But i am getting app_log.php file name instead users.php and Method name is 'info' instead 'login' in the logs.
Example:
[2018-06-07 20:55:50] 4410 applog.INFO: User logged successfully {"file":"/var/www/portal/lib/app_log.php","line":59,"class":"app_log","function":"info"} []
Could you guys help on this part?

I'm afraid your whole design is simply wrong.
Instead of instantiating a new Logger every time you need to log, you should be creating a single $logger to use as a service around your application.
Without knowing more about your application (and having to rewrite your application would make the question too broad anyway), it's hard to guess how to implement dependency injection here.
But a simplistic and naive approach would be:
class users extends dbconnector {
protected $logger;
public function _construct(Logger $logger) {
$this->logger = $logger;
}
function login() {
$this->logger->info('User logged successfully');
}
}
And then:
$logger = new Logger('applog');
$handler = new RotatingFileHandler('useractivity.log', 0, Logger::INFO);
$handler->setFormatter(new LineFormatter("[%datetime%] %extra.process_id% %channel%.%level_name%: %message% %extra% %context% \n"));
$logger->pushHandler($handler);
$logger->pushProcessor(new WebProcessor);
$logger->pushProcessor(new IntrospectionProcessor);
$users = new users($logger);
If you inject that Logger instance in the objects that need it, you can use it directly without having to create your own "wrapper" (which in your example was poorly designed), and the output in the log files will match your expectations.
Notice that you are not using the IntrospectionProcessor, which you'd need to capture the filename and file line number. In the above example I'm also pushing it in $logger, the Logger instance.
(And also note that simply adding this processor to your code won't solve your issue, since the call to Logger::info() would always happen in app_log::info()).
Remember that you'll need to add the corresponding use statement: use Monolog\Processor\IntrospectionProcessor;
I do not know all the details of your system, and can't build it all for you anyway, but if dependency injection is still too much for you, you could just cheat temporarily with a global-state approach.
E.g.:
function get_logger() {
static $logger;
if ($logger !== null) {
return $logger;
}
$logger = new Logger('applog');
$handler = new RotatingFileHandler('useractivity.log', 0, Logger::INFO);
$handler->setFormatter(new LineFormatter("[%datetime%] %extra.process_id% %channel%.%level_name%: %message% %extra% %context% \n"));
$logger->pushHandler($handler);
$logger->pushProcessor(new WebProcessor);
$logger->pushProcessor(new IntrospectionProcessor);
return $logger;
}
You could put this in a file that you require_once, and in each of these places where you need access to the logger you can simply do:
get_logger()->info('write to the log!');
This is not something I'd endorse, but a crummy workaround for you to get moving until you advance somewhat in your understanding of other OOP topics. This is nothing else than a poor's man singleton, which more often than not is a pattern to avoid anyway; but that could help you right now..

WebProcessor will not add data you need, I mean file and line.
IntrospectionProcessor does what you need, try
$logger->pushProcessor(new IntrospectionProcessor());

Related

How do I mock an object I can't pass to a method to trigger an exception?

Consider the following method:
function m1()
{
$ent = new Entity;
...
try {
$ent->save();
} catch (QueryException $e) {
...
}
I've got to trigger an exception. Preferably with mockery. How do I do that?
P.S. I can't pass $ent into the method.
UPD Let me describe my particular case to confirm if I do need to trigger an exception. Here I'm trying to test controller's action that is triggered by payment system to notify that user has made a payment. In it I, among other things, store in database all the data coming from payment system in PaymentSystemCallback model, and link it to Order model, which is created before redirecting user to the payment system. So, it goes like this:
function callback(Request $request)
{
$c = new PaymentSystemCallback;
$c->remote_addr = $request->ip();
$c->post_data = ...;
$c->headers = ...;
...
$c->save();
$c->order_id = $request->request->get('order_id');
$c->save();
}
But if incorrect order_id comes in, foreign constraint fails, so I change it this way:
try {
$c->save();
} catch (QueryException $e) {
return response('', 400);
}
But it doesn't look good to handle any database exception this way, so I'm seeking for a way to rethrow the exception unless $e->errorInfo[1] == 1452.
And here's what I came up with:
/**
* #runInSeparateProcess
* #preserveGlobalState disabled
*/
function testExceptionOnSave()
{
$this->setUpState();
Mockery::mock('overload:App\PaymentSystemCallback')
->shouldReceive('save')
->andReturnUsing(function() {}, function() {
throw new QueryException('', [], new Exception);
});
$this->doRequest();
$this->assertBalanceDidntChange();
$this->assertNotProcessed();
$this->seeStatusCode(500);
}
I use #runInSeparateProcess because preceding tests trigger the same action, and therefore the class is loaded before mockery has a chance to mock it.
As for #preserveGlobalState disabled it doesn't work without it. As phpunit's documentation put it:
Note: By default, PHPUnit will attempt to preserve the global state from the parent process by serializing all globals in the parent process and unserializing them in the child process. This can cause problems if the parent process contains globals that are not serializable. See the section called “#preserveGlobalState” for information on how to fix this.
I deviate a little from what mockery's documentation says when I'm marking only one test to run in a separate process, since I need it only for one test. Not the whole class.
Constrictive criticism is welcome.
The easiest way around this is to call a factory method that creates a mock instance of your Entity. Something like:
function testSomething()
{
$ent = $this->getEntity();
...
try {
$ent->save();
} catch (QueryException $e) {
...
}
}
function getEntity()
{
$mock = $this->createMock(Entity::class);
$mock
->method('save')
->will($this->throwException(new QueryException));
return $mock;
}
Your method is not designed for test. Fix that. If you can't, then you have to monkey patch, which PHP does not support natively.
My recommended approach would be to have your test suite install its own priority autoloader. Have your test case register a mock class into that autoloader, associated with class name Entity. Your mock class will do its magic to throw an exception. If you're using PHP 7, you have access to anonymous classes, which makes fixtures easier: new class Entity {}.
Per the accepted answer, Mockery supports this autoloading trick using the overload: quantifier on mocked classes. This saves a lot of work on your part!

Init another class in construct method?

I am looking into trying to simplify my PHP code some more, and I have yet to find an answer with this methodology one of my team members are using. Nor, have I ever saw this done before anywhere on the web.
Here is the code example from our web application which he is working on with me.
<?php
class ArticlesHandler {
public function __construct() {
require 'Articles.php';
$articles = new Articles;
}
}
?>
Is this proper to init one class within another class?
For me, this just seems not proper standard to init classes to work together.
Yes and no. It works, but this particular code can lead to a number of problems.
You should be using require_once instead of require to avoid possible errors of including the same file twice. As it is this code here will bring your app to a complete stop:
new ArticlesHandler;
new ArticlesHandler;
This creates a hard coupling to the Articles class. You should probably rather be using dependency injection and pass an instance of Article to the constructor of ArticlesHandler. See How Not To Kill Your Testability Using Statics.
Yes, it is proper and normal to call constructors in a constructor. There is nothing weird/bad about it.
This is what I normally do.
class Repository {
protected $_models = array();
public function getModel($model, array $params = array()){
require_once $model.'.php'; //Replace this with an autoloader
if(empty($this->_models[$model])){
if(!empty($params)){
$this->_models[$model] = new $model($params);
} else {
$this->_models[$model] = new $model();
}
}
return $this->_models[$model];
}
}
And call the other class like this.
class ArticlesHandler extends Repository {
public function __construct() {
$articles = $this->getModel('Articles');
}
}
it seem's right.
For me, this just seems not proper standard to init classes to work together.
you can extend Articles class if you want to use Articles class inside the ArticlesHandler

How to call methods that I'm not sure are available? (optional dependencies)

Let's say you have a class which is compliant to the PSR logger interface standard, but you want it to be usable also by people who don't need logging or don't bother having a PSR logger. It's clear to me to use method injection for the logger(something like function setLogger(Psr\Log\LoggerInterface $logger){...}). Now I wonder how to call logger's methods if I can't be sure if a logger class was specified. One of the solutions would be to create a class that would act as a proxy to the logger, but I'm not sure that's the appropriate solution.
You could implement a "NullLogger" and have it as default logger:
class NullLogger implement LoggerInterface
{
public function error($message, $context = [])
{
// do nothing
}
// ...
}
class MyClass
{
private $logger;
public function __construct(LoggerInterface $logger = null)
{
$this->logger = $logger ?: new NullLogger();
}
public function doSomething()
{
$this->logger->info('');
// ...
}
public function setLogger(LoggerInterface $logger)
{
$this->logger = $logger;
}
}
I would also seriously consider the good old:
if ($this->logger) {
$this->logger->...
}
(if it's not used everywhere) since it's more lightweight.
But the first solution is definitely valid IMO.
Finally, you can also decide that logging has nothing to do directly with your class, and that's behavior that could be left to the responsiblity of the user. You can provide extension points using Events, or the Template Method Pattern (see my question about that if you are interested: Should I use events or the "template method" pattern for an open source library?).
To sum up, I'd say it depends on the use case: do you log a lot? is "logging" part of the functionality you provide? or is it cleary a separate concern?
As it turns out, PSR standard defines a null logger, that can be used for this purpose.
<?php
use \PSR\Log\NullLogger

Alternatives to static methods in a framework PHP

Lately I have been trying to create my own PHP framework, just to learn from it (As we may look into some bigger and more robust framework for production). One design concept I currently have, is that most core classes mainly work on static functions within classes.
Now a few days ago, I've seen a few articles about "Static methods are death to testability". This concerned me as.. yeah.. my classes contain mostly static methods.. The main reason I was using static methods is that a lot of classes would never need more than one instance, and static methods are easy to approach in the global scope. Now I'm aware that static methods aren't actually the best way to do things, I'm looking for a better alternative.
Imagine the following code to get a config item:
$testcfg = Config::get("test"); // Gets config from "test"
echo $testcfg->foo; // Would output what "foo" contains ofcourse.
/*
* We cache the newly created instance of the "test" config,
* so if we need to use it again anywhere in the application,
* the Config::get() method simply returns that instance.
*/
This is an example of what I currently have. But according to some articles, this is bad.
Now, I could do this the way how, for example, CodeIgniter does this, using:
$testcfg = $this->config->get("test");
echo $testcfg->foo;
Personally, I find this harder to read. That's why I would prefer another way.
So in short, I guess I need a better approach to my classes. I would not want more than one instance to the config class, maintain readability and have easy access to the class. Any ideas?
Note that I'm looking for some best practice or something including a code sample, not some random ideas. Also, if I'm bound to a $this->class->method style pattern, then would I implement this efficiently?
In response to Sébastien Renauld's comments: here's an article on Dependency Injection (DI) and Inversion of Control (IoC) with some examples, and a few extra words on the Hollywood principle (quite important when working on a framework).
Saying your classes won't ever need more than a single instance doesn't mean that statics are a must. Far from it, actually. If you browse this site, and read through PHP questions that deal with the singleton "pattern", you'll soon find out why singletons are a bit of a no-no.
I won't go into the details, but testing and singletons don't mix. Dependency injection is definitely worth a closer look. I'll leave it at that for now.
To answer your question:
Your exaple (Config::get('test')) implies you have a static property in the Config class somewhere. Now if you've done this, as you say, to facilitate access to given data, imagine what a nightmare it would be to debug your code, if that value were to change somewhere... It's a static, so change it once, and it's changed everywhere. Finding out where it was changed might be harder than you anticipated. Even so, that's nothing compared to the issues someone who uses your code will have in the same situation.
And yet, the real problems will only start when that person using your code wants to test whatever it is he/she made: If you want to have access to an instance in a given object, that has been instantiated in some class, there are plenty of ways to do so (especially in a framework):
class Application
{//base class of your framework
private $defaulDB = null;
public $env = null;
public function __construct($env = 'test')
{
$this->env = $env;
}
private function connectDB(PDO $connection = null)
{
if ($connection === null)
{
$connection = new PDO();//you know the deal...
}
$this->defaultDB = $connection;
}
public function getDB(PDO $conn = null)
{//get connection
if ($this->defaultDB === null)
{
$this->connectDB($conn);
}
return $this->defaultDB;
}
public function registerController(MyConstroller $controller)
{//<== magic!
$controller->registerApplication($this);
return $this;
}
}
As you can see, the Application class has a method that passes the Application instance to your controller, or whatever part of your framework you want to grant access to scope of the Application class.
Note that I've declared the defaultDB property as a private property, so I'm using a getter. I can, if I wanted to, pass a connection to that getter. There's a lot more you can do with that connection, of course, but I can't be bothered writing a full framework to show you everything you can do here :).
Basically, all your controllers will extend the MyController class, which could be an abstract class that looks like this:
abstract class MyController
{
private $app = null;
protected $db = null;
public function __construct(Application $app = null)
{
if ($app !== null)
{
return $this->registerApplication($app);
}
}
public function registerApplication(Application $app)
{
$this->app = $app;
return $this;
}
public function getApplication()
{
return $this->app;
}
}
So in your code, you can easily do something along the lines of:
$controller = new MyController($this);//assuming the instance is created in the Application class
$controller = new MyController();
$controller->registerApplication($appInstance);
In both cases, you can get that single DB instance like so:
$controller->getApplication()->getDB();
You can test your framework with easily by passing a different DB connection to the getDB method, if the defaultDB property hasn't been set in this case. With some extra work you can register multiple DB connections at the same time and access those at will, too:
$controller->getApplication->getDB(new PDO());//pass test connection here...
This is, by no means, the full explanation, but I wanted to get this answer in quite quickly before you end up with a huge static (and thus useless) codebase.
In response to comments from OP:
On how I'd tackle the Config class. Honestly, I'd pretty much do the same thing as I'd do with the defaultDB property as shown above. But I'd probably allow for more targeted control on what class gets access to what part of the config:
class Application
{
private $config = null;
public function __construct($env = 'test', $config = null)
{//get default config path or use path passed as argument
$this->config = new Config(parse_ini_file($config));
}
public function registerController(MyController $controller)
{
$controller->setApplication($this);
}
public function registerDB(MyDB $wrapper, $connect = true)
{//assume MyDB is a wrapper class, that gets the connection data from the config
$wrapper->setConfig(new Config($this->config->getSection('DB')));
$this->defaultDB = $wrapper;
return $this;
}
}
class MyController
{
private $app = null;
public function getApplication()
{
return $this->app;
}
public function setApplication(Application $app)
{
$this->app = $app;
return $this;
}
//Optional:
public function getConfig()
{
return $this->app->getConfig();
}
public function getDB()
{
return $this->app->getDB();
}
}
Those last two methods aren't really required, you could just as well write something like:
$controller->getApplication()->getConfig();
Again, this snippet is all a bit messy and incomplete, but it does go to show you that you can "expose" certain properties of one class, by passing a reference to that class to another. Even if the properties are private, you can use getters to access them all the same. You can also use various register-methods to control what it is the registered object is allowed to see, as I've done with the DB-wrapper in my snippet. A DB class shouldn't deal with viewscripts and namespaces, or autoloaders. That's why I'm only registering the DB section of the config.
Basically, a lot of your main components will end up sharing a number of methods. In other words, they'll end up implementing a given interface. For each main component (assuming the classic MVC pattern), you'll have one abstract base-class, and an inheritance chain of 1 or 2 levels of child classes: Abstract Controller > DefaultController > ProjectSpecificController.
At the same time, all of these classes will probably expect another instance to be passed to them when constructed. Just look at the index.php of any ZendFW project:
$application = new Zend_Application(APPLICATION_ENV);
$application->bootstrap()->run();
That's all you can see, but inside the application, all other classes are being instantiated. That's why you can access neigh on everything from anywhere: all classes have been instantiated inside another class along these lines:
public function initController(Request $request)
{
$this->currentController = $request->getController();
$this->currentController = new $this->currentController($this);
return $this->currentController->init($request)
->{$request->getAction().'Action'}();
}
By passing $this to the constructor of a controller class, that class can use various getters and setters to get to whatever it needs... Look at the examples above, it could use getDB, or getConfig and use that data if that's what it needs.
That's how most frameworks I've tinkered or worked with function: The application is kicks into action and determines what needs to be done. That's the Hollywood-principle, or Inversion of Control: the Application is started, and the application determines what classes it needs when. In the link I provided I believe this is compared to a store creating its own customers: the store is built, and decides what it wants to sell. In order to sell it, it will create the clients it wants, and provide them with the means they need to purchase the goods...
And, before I forget: Yes, all this can be done without a single static variable, let alone function, coming into play. I've built my own framework, and I've never felt there was no other way than to "go static". I did use the Factory pattern at first, but ditched it pretty quickly.
IMHO, a good framework is modular: you should be able to use bits of it (like Symfony's components), without issues. Using the Factory pattern makes you assume too much. You assume class X will be available, which isn't a given.
Registering those classes that are available makes for far more portable components. Consider this:
class AssumeFactory
{
private $db = null;
public function getDB(PDO $db = null)
{
if ($db === null)
{
$config = Factory::getConfig();//assumes Config class
$db = new PDO($config->getDBString());
}
$this->db = $db;
return $this->db;
}
}
As opposed to:
class RegisteredApplication
{//assume this is registered to current Application
public function getDB(PDO $fallback = null, $setToApplication = false)
{
if ($this->getApplication()->getDB() === null)
{//defensive
if ($setToApplication === true && $fallback !== null)
{
$this->getApplication()->setDB($fallback);
return $fallback;//this is current connection
}
if ($fallback === null && $this->getApplication()->getConfig() !== null)
{//if DB is not set #app, check config:
$fallback = $this->getApplication()->getConfig()->getSection('DB');
$fallback = new PDO($fallback->connString, $fallback->user, $fallback->pass);
return $fallback;
}
throw new RuntimeException('No DB connection set #app, no fallback');
}
if ($setToApplication === true && $fallback !== null)
{
$this->getApplication()->setDB($fallback);
}
return $this->getApplication()->getDB();
}
}
Though the latter version is slightly more work to write, it's quite clear which of the two is the better bet. The first version just assumes too much, and doesn't allow for safety-nets. It's also quite dictatorial: suppose I've written a test, and I need the results to go to another DB. I therefore need to change the DB connection, for the entire application (user input, errors, stats... they're all likely to be stored in a DB).
For those two reasons alone, the second snippet is the better candidate: I can pass another DB connection, that overwrites the application default, or, if I don't want to do that, I can either use the default connection, or attempt to create the default connection. Store the connection I just made, or not... the choice is entirely mine. If nothing works, I just get a RuntimeException thrown at me, but that's not the point.
Magic methods would help you: see the examples about __get() and __set()
You should also take a look at namespaces: it may help you to get rid of some classes with static methods only.

Micro-Dependencies, Avoiding Coupling, and Objects Creating Objects [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Dependency Hell — how does one pass dependencies to deeply nested objects?
In a system built around strong dependency injection, I'm wondering how to deal with a contrived situation like this:
<?php
class LogWriter
{
public function write(Log $log)
{
echo $log->getMessage();
}
}
class Log
{
private $message;
public function setMessage($message)
{
$this->message = $message;
}
public function getMessage()
{
return $this->message;
}
}
class Logger
{
private $writer;
public function __construct(LogWriter $writer)
{
$this->writer = $writer;
}
public function write($message)
{
// Here is the dependency
$log = new Log();
$log->setMessage($message);
$this->writer->write($log);
}
}
The Logger::write() method creates an instance of Log, and passes it to the log writer. My gut tells me that's a bad approach, and a month from now I'm going to be tracking down a bug related to it, and I might want to switch the Log class for something else during testing.
But how to avoid it? The only thing that comes to mind is passing a Log type to the Logger constructor, and changing my Logger class to this:
class Logger
{
private $writer;
private $log_type;
public function __construct(LogWriter $writer, $log_type)
{
$this->writer = $writer;
$this->log_type = $log_type;
}
public function write($message)
{
$log = new $this->log_type();
$log->setMessage($message);
$this->writer->write($log);
}
}
And then creating a new Logger instance like this:
$log_writer = new LogWriter();
$logger = new Logger($log_writer, "Log");
But that feels a bit hackish. So how do you deal with micro-dependencies like this?
Note: I'm using the logging classes as an example, and I'm not looking for a solution to this exact problem. I would probably just use an array instead of the Log class.
Edit: In a more complex situation, I might pass a dependency injection container to the Logger class, and use that to create an instance of Log, but that seems overly complicated for a simple logger class.
Since your Log object is really just a Data Transfer Object or Value Object, you can create it inside the Logger class. It's okay to do so in this case. You dont need to pass anything to the Logger. But you are right in that you wont be able to mock/stub this easily then.
As an alternative, you could also inject a Factory if you want to decouple the Log class from the Logger:
$logger = new Logger($logWriter, new LogFactory);
and then create the Log Type from there:
public function write($message)
{
$log = $this->logFactory->createNew();
…
This capsules the creation logic inside the Factory class. The Factory will still have the Log type hardcoded inside, but it's okay for Factories to have that. You then just test that it returns the right type when you call createNew. And in your consumers, you can stub that call.
If you dont feel like creating a full-blown Factory class for this, you can also use a Lambda instead of a Factory. Since it captures the essential creation logic, it's effectively the same as a Factory, just without a class:
$logger = new Logger($logWriter, function() { return new Log; });
And then
public function write($message)
{
$log = call_user_func($this->createLogCallback);
…
Both, the Factoy and the Lambda approach allow for substituting the Log type in your Unit-Test. Then again, substituting the Log type doesn't seem that necessary in your scenario. The Log type doesn't have any dependencies of it's own, so you can pretty much use the real deal here. You can easily verify your write method by simply looking at what gets written by the LogWriter. You won't have an explicit assertion on a Log Mock, but if the writer produces the expected output for the given input to write, you can safely assume that the Log type collaborates as expected.
Also see http://misko.hevery.com/2008/09/30/to-new-or-not-to-new for more details.

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