API PSR-11 compliance (fixes #6594) (#6931)

Note that our usage of `$asSingleton` in `get()` is fine. Quote from the PSR:

> Two successive calls to get with the same identifier SHOULD return the same value. However, depending on the implementor design and/or user configuration, different values might be returned, so user SHOULD NOT rely on getting the same value on 2 successive calls.

composer.json

@@ -39,7 +39,8 @@
     "ext-tokenizer": "*",
     "ext-ctype": "*",
     "ext-hash": "*",
-    "ext-session": "*"
+    "ext-session": "*",
+    "psr/container-implementation": "1.0.0"
   },
   "require-dev": {
     "phpunit/phpunit": "^5.7",
@@ -48,6 +49,9 @@
     "silverstripe/serve": "dev-master",
     "se/selenium-server-standalone": "2.41.0"
   },
+  "provide": {
+    "psr/container-implementation": "1.0.0"
+  },
   "extra": {
     "branch-alias": {
       "dev-master": "4.0.x-dev"

docs/en/04_Changelogs/4.0.0.md

@@ -1292,6 +1292,9 @@ After (`mysite/_config/config.yml`):
 * Removed `CreditCardField`, `CountryDropdownField`, `PhoneNumberField`, `MemberDatetimeOptionsetField`, `InlineFormAction`.
   Use custom code instead
 * Removed `ResetFormAction`, use `FormAction::create()->setAttribute('type', 'reset')` instead
+* `Injector` now complies with [PSR-11](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-11-container.md).
+  Accordingly, `hasService()` has been renamed to `has()`, and `get()` will throw
+  `SilverStripe\Core\Injector\InjectorNotFoundException` when the service can't be found.
 
 #### <a name="overview-general-deprecated"></a>General and Core Deprecated API
 

src/Core/Injector/InjectionCreator.php

@@ -3,6 +3,7 @@
 namespace SilverStripe\Core\Injector;
 
 use ReflectionClass;
+use ReflectionException;
 
 /**
  * A class for creating new objects by the injector.
@@ -12,7 +13,11 @@ class InjectionCreator implements Factory
 
     public function create($class, array $params = array())
     {
-        $reflector = new ReflectionClass($class);
+        try {
+            $reflector = new ReflectionClass($class);
+        } catch (ReflectionException $e) {
+            throw new InjectorNotFoundException($e);
+        }
 
         if (count($params)) {
             return $reflector->newInstanceArgs($params);

src/Core/Injector/Injector.php

@@ -2,11 +2,14 @@
 
 namespace SilverStripe\Core\Injector;
 
+use Psr\Container\NotFoundExceptionInterface;
 use SilverStripe\Core\Config\Config;
 use ReflectionProperty;
 use ArrayObject;
 use ReflectionObject;
 use ReflectionMethod;
+use Psr\Container\ContainerInterface;
+use SilverStripe\Dev\Deprecation;
 
 /**
  * A simple injection manager that manages creating objects and injecting
@@ -122,7 +125,7 @@ use ReflectionMethod;
  * @author marcus@silverstripe.com.au
  * @license BSD License http://silverstripe.org/bsd-license/
  */
-class Injector
+class Injector implements ContainerInterface
 {
 
     /**
@@ -233,7 +236,7 @@ class Injector
      * If a user wants to use the injector as a static reference
      *
      * @param array $config
-     * @return Injector
+     * @return ContainerInterface
      */
     public static function inst($config = null)
     {
@@ -246,10 +249,10 @@ class Injector
     /**
      * Sets the default global injector instance.
      *
-     * @param Injector $instance
+     * @param ContainerInterface $instance
      * @return Injector Reference to new active Injector instance
      */
-    public static function set_inst(Injector $instance)
+    public static function set_inst(ContainerInterface $instance)
     {
         return self::$instance = $instance;
     }
@@ -693,7 +696,7 @@ class Injector
                     if ($propertyObject->isPublic() && !$propertyObject->getValue($object)) {
                         $origName = $propertyObject->getName();
                         $name = ucfirst($origName);
-                        if ($this->hasService($name)) {
+                        if ($this->has($name)) {
                             // Pull the name out of the registry
                             $value = $this->get($name);
                             $propertyObject->setValue($object, $value);
@@ -710,7 +713,7 @@ class Injector
                     $methName = $methodObj->getName();
                     if (strpos($methName, 'set') === 0) {
                         $pname = substr($methName, 3);
-                        if ($this->hasService($pname)) {
+                        if ($this->has($pname)) {
                             // Pull the name out of the registry
                             $value = $this->get($pname);
                             $methodObj->invoke($object, $value);
@@ -782,6 +785,35 @@ class Injector
         }
     }
 
+    /**
+     * @deprecated 4.0.0:5.0.0 Use Injector::has() instead
+     * @param $name
+     * @return string
+     */
+    public function hasService($name)
+    {
+        Deprecation::notice('5.0', 'Use Injector::has() instead');
+
+        return $this->has($name);
+    }
+
+    /**
+     * Does the given service exist?
+     *
+     * We do a special check here for services that are using compound names. For example,
+     * we might want to say that a property should be injected with Log.File or Log.Memory,
+     * but have only registered a 'Log' service, we'll instead return that.
+     *
+     * Will recursively call itself for each depth of dotting.
+     *
+     * @param string $name
+     * @return boolean
+     */
+    public function has($name)
+    {
+        return (bool)$this->getServiceName($name);
+    }
+
     /**
      * Does the given service exist, and if so, what's the stored name for it?
      *
@@ -789,15 +821,14 @@ class Injector
      * we might want to say that a property should be injected with Log.File or Log.Memory,
      * but have only registered a 'Log' service, we'll instead return that.
      *
-     * Will recursively call hasService for each depth of dotting
+     * Will recursively call itself for each depth of dotting.
      *
      * @param string $name
-     * @return string The name of the service (as it might be different from the one passed in)
+     * @return string|null The name of the service (as it might be different from the one passed in)
-     * The name of the service (as it might be different from the one passed in)
      */
-    public function hasService($name)
+    public function getServiceName($name)
     {
-        // common case, get it overwith first
+        // common case, get it over with first
         if (isset($this->specs[$name])) {
             return $name;
         }
@@ -808,7 +839,7 @@ class Injector
             return null;
         }
 
-        return $this->hasService(substr($name, 0, strrpos($name, '.')));
+        return $this->getServiceName(substr($name, 0, strrpos($name, '.')));
     }
 
     /**
@@ -859,30 +890,45 @@ class Injector
      * Next, will check to see if there's any registered configuration for the given type
      * and will then try and load that
      *
-     * Failing all of that, will just return a new instance of the
+     * Failing all of that, will just return a new instance of the specified object.
-     * specificied object.
      *
-     * @param string $name
+     * @throws NotFoundExceptionInterface  No entry was found for **this** identifier.
-     *              the name of the service to retrieve. If not a registered
+     *
-     *              service, then a class of the given name is instantiated
+     * @param string $name The name of the service to retrieve. If not a registered
-     * @param boolean $asSingleton
+     * service, then a class of the given name is instantiated
-     *              Whether to register the created object as a singleton
+     * @param boolean $asSingleton Whether to register the created object as a singleton
-     *              if no other configuration is found
+     * if no other configuration is found
-     * @param array $constructorArgs
+     * @param array $constructorArgs Optional set of arguments to pass as constructor arguments
-     *              Optional set of arguments to pass as constructor arguments
+     * if this object is to be created from scratch (with $asSingleton = false)
-     *              if this object is to be created from scratch
+     * @return mixed Instance of the specified object
-     *              (ie asSingleton = false)
-     * @return mixed the instance of the specified object
      */
     public function get($name, $asSingleton = true, $constructorArgs = null)
+    {
+        $object = $this->getNamedService($name, $asSingleton, $constructorArgs);
+
+        if (!$object) {
+            throw new InjectorNotFoundException("The '{$name}' service could not be found");
+        }
+
+        return $object;
+    }
+
+    /**
+     * Returns the service, or `null` if it doesnt' exist. See {@link get()} for main usage.
+     *
+     * @param string $name
+     * @param boolean $asSingleton
+     * @param array $constructorArgs
+     * @return mixed|null Instance of the specified object (if it exists)
+     */
+    protected function getNamedService($name, $asSingleton = true, $constructorArgs = null)
     {
         // reassign the name as it might actually be a compound name
-        if ($serviceName = $this->hasService($name)) {
+        if ($serviceName = $this->getServiceName($name)) {
             // check to see what the type of bean is. If it's a prototype,
             // we don't want to return the singleton version of it.
             $spec = $this->specs[$serviceName];
             $type = isset($spec['type']) ? $spec['type'] : null;
-
             // if we're explicitly a prototype OR we're not wanting a singleton
             if (($type && $type == 'prototype') || !$asSingleton) {
                 if ($spec && $constructorArgs) {
@@ -903,7 +949,6 @@ class Injector
                 return $this->serviceCache[$serviceName];
             }
         }
-
         $config = $this->configLocator->locateConfigFor($name);
         if ($config) {
             $this->load(array($name => $config));
@@ -916,7 +961,6 @@ class Injector
                 return $this->instantiate($spec, $name);
             }
         }
-
         // If we've got this far, we're dealing with a case of a user wanting
         // to create an object based on its name. So, we need to fake its config
         // if the user wants it managed as a singleton service style object

src/Core/Injector/InjectorNotFoundException.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace SilverStripe\Core\Injector;
+
+use Psr\Container\NotFoundExceptionInterface;
+
+class InjectorNotFoundException extends \Exception implements NotFoundExceptionInterface
+{
+}

tests/php/Core/Injector/InjectorTest.php

@@ -6,6 +6,7 @@ use InvalidArgumentException;
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Core\Injector\Factory;
 use SilverStripe\Core\Injector\Injector;
+use SilverStripe\Core\Injector\InjectorNotFoundException;
 use SilverStripe\Core\Injector\SilverStripeServiceConfigurationLocator;
 use SilverStripe\Core\Tests\Injector\AopProxyServiceTest\AnotherService;
 use SilverStripe\Core\Tests\Injector\AopProxyServiceTest\SampleService;
@@ -80,9 +81,15 @@ class InjectorTest extends SapphireTest
         );
 
         $injector->load($config);
+
+
+        $this->assertFalse($injector->has('UnknownService'));
+        $this->assertNull($injector->getServiceName('UnknownService'));
+
+        $this->assertTrue($injector->has('SampleService'));
         $this->assertEquals(
             'SampleService',
-            $injector->hasService('SampleService')
+            $injector->getServiceName('SampleService')
         );
 
         $myObject = new TestObject();
@@ -110,15 +117,17 @@ class InjectorTest extends SapphireTest
         );
 
         $injector->load($services);
+        $this->assertTrue($injector->has('SampleService'));
         $this->assertEquals(
             'SampleService',
-            $injector->hasService('SampleService')
+            $injector->getServiceName('SampleService')
         );
         // We expect a false because the AnotherService::class is actually
         // just a replacement of the SilverStripe\Core\Tests\Injector\AopProxyServiceTest\SampleService
+        $this->assertTrue($injector->has('SampleService'));
         $this->assertEquals(
             'AnotherService',
-            $injector->hasService('AnotherService')
+            $injector->getServiceName('AnotherService')
         );
 
         $item = $injector->get('AnotherService');
@@ -136,8 +145,11 @@ class InjectorTest extends SapphireTest
 
         $injector->load($services);
 
-        $this->assertTrue($injector->hasService('FirstId') == 'FirstId');
+        $this->assertTrue($injector->has('FirstId'));
-        $this->assertTrue($injector->hasService('SecondId') == 'SecondId');
+        $this->assertEquals($injector->getServiceName('FirstId'), 'FirstId');
+
+        $this->assertTrue($injector->has('SecondId'));
+        $this->assertEquals($injector->getServiceName('SecondId'), 'SecondId');
 
         $this->assertTrue($injector->get('FirstId') instanceof AnotherService);
         $this->assertTrue($injector->get('SecondId') instanceof SampleService);
@@ -251,9 +263,10 @@ class InjectorTest extends SapphireTest
         );
         $injector->load($config);
 
+        $this->assertTrue($injector->has('SampleService'));
         $this->assertEquals(
             'SampleService',
-            $injector->hasService('SampleService')
+            $injector->getServiceName('SampleService')
         );
         // We expect a false because the AnotherService::class is actually
         // just a replacement of the SilverStripe\Core\Tests\Injector\AopProxyServiceTest\SampleService
@@ -419,7 +432,8 @@ class InjectorTest extends SapphireTest
         );
 
         $injector->load($config);
-        $this->assertEquals('SampleService', $injector->hasService('SampleService'));
+        $this->assertTrue($injector->has('SampleService'));
+        $this->assertEquals('SampleService', $injector->getServiceName('SampleService'));
 
         $myObject = new InjectorTest\OtherTestObject();
         $injector->inject($myObject);
@@ -453,7 +467,8 @@ class InjectorTest extends SapphireTest
         );
 
         $injector->load($config);
-        $this->assertEquals('SampleService', $injector->hasService('SampleService'));
+        $this->assertTrue($injector->has('SampleService'));
+        $this->assertEquals('SampleService', $injector->getServiceName('SampleService'));
 
         $myObject = $injector->get(OtherTestObject::class);
         $this->assertInstanceOf(
@@ -919,7 +934,14 @@ class InjectorTest extends SapphireTest
         $item = $injector->get('TestService');
     }
 
-
+    /**
+     * @expectedException \SilverStripe\Core\Injector\InjectorNotFoundException
+     */
+    public function testGetThrowsOnNotFound()
+    {
+        $injector = new Injector();
+        $injector->get('UnknownService');
+    }
 
     /**
      * Test nesting of injector

tests/php/ORM/DataListTest.php

@@ -3,6 +3,7 @@
 namespace SilverStripe\ORM\Tests;
 
 use SilverStripe\Core\Convert;
+use SilverStripe\Core\Injector\InjectorNotFoundException;
 use SilverStripe\ORM\DataList;
 use SilverStripe\ORM\DB;
 use SilverStripe\ORM\Filterable;
@@ -744,7 +745,7 @@ class DataListTest extends SapphireTest
     public function testSimpleFilterWithNonExistingComparisator()
     {
         $this->setExpectedException(
-            'ReflectionException',
+            InjectorNotFoundException::class,
             'Class DataListFilter.Bogus does not exist'
         );
         $list = TeamComment::get();
@@ -755,7 +756,7 @@ class DataListTest extends SapphireTest
     {
         // Invalid modifiers are treated as failed filter construction
         $this->setExpectedException(
-            'ReflectionException',
+            InjectorNotFoundException::class,
             'Class DataListFilter.invalidmodifier does not exist'
         );
         $list = TeamComment::get();