For example in Java, I can close off a class by declaring it as final.
It will still inherit from its superclass, however:
public abstract class Super {
final boolean test = true;
}
public final class Sub extends Super
{
public static void main(String[] args) {System.out.println(new Sub().test);}
}
However in SHACL this does not seem to work:
#prefix : <http://test.ex/>.
#prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
#prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
#prefix owl: <http://www.w3.org/2002/07/owl#>.
#prefix sh:<http://www.w3.org/ns/shacl#>.
:Super a owl:Class.
:Sub a owl:Class;
rdfs:subClassOf :Super.
:Sub1 a :Sub;
:exampleProperty :TestObject.
:SuperShape a sh:NodeShape;
sh:targetClass :Super;
sh:property [sh:path :exampleProperty].
:SubShape a sh:NodeShape;
sh:targetClass :Sub;
sh:ignoredProperties ( rdf:type );
sh:closed true.
pyshacl -s test.ttl test.ttl
Validation Report
Conforms: False
Results (1):
Constraint Violation in ClosedConstraintComponent (http://www.w3.org/ns/shacl#ClosedConstraintComponent):
Severity: sh:Violation
Source Shape: :SubShape
Focus Node: :Sub1
Value Node: :TestObject
Result Path: :exampleProperty
Message: Node :Sub1 is closed. It cannot have value: :TestObject
Is there any way to use closed shapes in SHACL with inheritance?
The official sh:closed does not handle inheritance. But it can be expressed in SHACL-SPARQL which pySHACL seems to understand, so you could use
https://datashapes.org/constraints.html#ClosedByTypesConstraintComponent
for which you'd only need to owl:import the dash shapes graph.
Related
I am trying to create a class (working as factory class) in my Zend Expressive APP as follows:
declare(strict_types=1);
namespace App\Install\Factory;
use App\Install\Model as Models;
use App\Install\Abstracts\AttributeInterface;
class AttributeEntityFactory{
public static function create($type1 ='Attribute') : AttributeInterface
{
$resolvedClass = "Models\\$type1";
$resolvedClass1 = 'Models\\'.$type1;
//return new $resolvedClass();
//return new $resolvedClass1();
return new Models\Attribute();
}
}
The above code works perfectly for me. However, if try to use any of the other two return statements it shows
Class 'Models\Attribute' not found
How can I achieve dynamic instantiation?
The attribute class code is as follows:
namespace App\Install\Model;
use App\Install\Abstracts\AttributeInterface;
class Attribute implements AttributeInterface
{
protected $attribute;
public function setAttribute($attribute)
{
$this->attribute = $attribute;
}
public function getAttribute()
{
return $this->attribute;
}
}
My PHP version is:
PHP 7.2.13 (cli) (built: Dec 14 2018 04:20:16) ( NTS )
you may need to pass in the full namespace?
"App\Install\Model\" . $type1;
and more...
the model Attribute you have is in the namespace App\Install\Model, and the object you are trying to create is from Models\\ . $type1
maybe you need to change Models to Model
Personally, I would avoid such factory implementation because of several reasons:
It involves magic.
Less predictable code.
Harder to read for both humans and IDE's (E.g: PHPStorm would not find the usages of Attribute class in such code when you need to find it)
Harder to analyze using static analyzers
Instead, I would rewrite this to a more explicit factory, even if I had dozens of different classes in App\Install\Model namespace:
<?php declare(strict_types=1);
namespace App\Install\Factory;
use App\Install\Model as Models;
class AttributeEntityFactory
{
public static function create($type = 'Attribute') : AttributeInterface
{
switch ($type) {
case 'Attribute':
return new Models\Attribute();
case 'SomethingElse':
return new Models\SomethingElse();
default:
throw new \InvalidArgumentException(
sprintf('An unknown type %s requested from %s', $type, __METHOD__)
);
}
}
}
As a rule of thumb:
Never compose classnames / namespaces using strings concatenated with variables / parameters / constants whatever.
Never call methods in such way, too.
You'll thank me when your application/business/codebase grows enough.
I've encountered the following question online.
If we call one constructor from another in a class, what will happen?
Can anyone give me some hints?
in java also its possible with the power of the this keyword. check out the example given below.
public class A {
public A() {
//this("a");
System.out.println("inside default Constructor");
}
public A(String a){
this();
System.out.println("inside Constructor A");
}
}
This concept is called constructor chaining. If it's c# i found this saying it's possible Is nesting constructors (or factory methods) good, or should each do all init work
This example from MSDN clarifies it
To add delegating constructors, constructor (. . .) : constructor (. . .) syntax is used.
class class_a {
public:
class_a() {}
// member initialization here, no delegate
class_a(string str) : m_string{ str } {}
// can’t do member initialization here
// error C3511: a call to a delegating constructor shall be the only member-initializer
class_a(string str, double dbl) : class_a(str) , m_double{ dbl } {}
// only member assignment
class_a(string str, double dbl) : class_a(str) { m_double = dbl; }
double m_double{ 1.0 };
string m_string;
};
Read answers from Can I call a constructor from another constructor (do constructor chaining) in C++? too.
I have a JRuby child class with a Java parent class. I need to override the Java function so that when it is called my JRuby method implementation is called first. The problem is that the java method is private. Any ideas?*
// Java:
public class JavaClass {
private void check(String what) {
System.out.println(what);
}
}
# JRuby:
class RubyClass < JavaClass
def check() # => private above. any way to force it public
super("RubyClass.check was called first")
end
end
*I am aware that this is not generally a good idea. I'm trying to get FXMLLoader to work in JRuby without wholesale reimplementation.
you can call the private method (using Java's reflection) ... but you won't be able to make it public on the original Java class (just on the JRuby side) and thus you can not call it using super ... here's a sample :
>> big_int = Java::JavaMath::BigInteger.new '42'
=> #<Java::JavaMath::BigInteger:0x787faefa>
>> big_int.signInt
NoMethodError: undefined method `signInt' for #<Java::JavaMath::BigInteger:0x787faefa>
from (irb):6:in `evaluate'
now let's do some Java reflection to invoke the (Java) private signInt method :
class Java::JavaMath::BigInteger
def sign_int
signInt = java_class.declared_method :signInt
signInt.accessible = true
signInt.invoke(self)
end
end
and try again :
>> big_int.sign_int
=> 0
I am converting Android 4.x code to use ActionBarSherlock so that our App can be compatible with Gingerbread.
So far so good, but it fails launching a new instance of a fragment.
My MainActivity extends SherlockFragmentActivity implements ActionBar.TabListener.
The code fails here where case is 0:
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
mFragmentProjects = ProjectsFragment.newInstance(position);
return mFragmentProjects;
case 1:
mFragmentContacts = FragmentPeople.newInstance(position, 0);
return mFragmentContacts;
}
return ArrayListFragment.newInstance(position);
}
Where case is 0 it supposed to initialize the fragment but I get this exception:
ClassNotFoundException. The only other clue I have is:
"this" in PathClassLoader and in "name" it says android.app.ActionBar$TabListener
I guess this has something to do with TabListener or libraries not included / loading correctly? I have already cleaned the project.
The fragment ProjectsFragment extends SherlockListFragment.
newInstance is pretty straitforward:
static ProjectsFragment newInstance(int num) {
ProjectsFragment f = new ProjectsFragment();
// Supply num input as an argument.
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
It turns out that although MainActivity has no reference to ActivityY, the mere fact that ActivityY did not have the SherlockFragment code made it fail. To describe this differently:
MainActitivy uses ProjectsFragment which is a list
When you click on a list in ProjectsFragment it calls ListsActivity
ListsActivity references ItemsFragment
I had to change ItemsFragment to Sherlock code before MainActivity would work. It seems Java "looks ahead" in some way when you're working with pagers and tabs and fragments.
I'm currently working with Symfony2 and Doctrine2, but I must override the Doctrine2 EntityManager and add it some "undelete" features (ACLs inside).
So I'm wondering : is there a way to override the EntityManager class and specify Doctrine2 in Symfony2 to use it as implementation of the EntityManager?
Thank you for any help!
After Doctrine 2.4 (Doctrine 2.4 release) you need to use decorator for this. Do not extend EntityManager directly.
First you need to implement you own entity manager decorator that extends Doctrine\ORM\Decorator\EntityManagerDecorator (like #Dana)
But you can't just change doctrine.orm.entity_manager.class to your new decorator because EntityManagerDecorator requires EntityManagerInterface in it's constructor:
public function __construct(EntityManagerInterface $wrapped)
You can't just pass doctrine.orm.entity_manager as a parameter here because it will be a recursion.
And don't do like this:
return new self(\Doctrine\ORM\EntityManager::create(
What you need is to configure your decorator in services like a decorator:
yourcompany_entity_manager:
public: false
class: YourCompany\ORM\EntityManagerDecorator
decorates: doctrine.orm.default_entity_manager
arguments: ["#yourcompany_entity_manager.inner"]
Now you'll have your decorator as a default entity manager for Doctrine. #yourcompany_entity_manager.inner is actually a link to doctrine.orm.default_entity_manager that will be passed to yourcompany_entity_manager constructor.
Symfony docs for configuring decorators: link
Btw this command is very useful to debug your services:
app/console container:debug | grep entity_manager
Yes, it's possible with two steps:
1 - Override the doctrine.orm.entity_manager.class parameter to point to your custom entity manager (which should extend Doctrine\ORM\EntityManager.)
2 - Your custom entity manager must override the create method so that it returns an instance of your class. See my example below, and note the last line regarding MyEntityManager:
public static function create($conn, Configuration $config, EventManager $eventManager = null) {
if (!$config->getMetadataDriverImpl()) {
throw ORMException::missingMappingDriverImpl();
}
if (is_array($conn)) {
$conn = \Doctrine\DBAL\DriverManager::getConnection($conn, $config, ($eventManager ? : new EventManager()));
} else if ($conn instanceof Connection) {
if ($eventManager !== null && $conn->getEventManager() !== $eventManager) {
throw ORMException::mismatchedEventManager();
}
} else {
throw new \InvalidArgumentException("Invalid argument: " . $conn);
}
// This is where you return an instance of your custom class!
return new MyEntityManager($conn, $config, $conn->getEventManager());
}
You'll also need to use the following in your class:
use Doctrine\ORM\EntityManager;
use Doctrine\ORM\Configuration;
use Doctrine\ORM\ORMException;
use Doctrine\Common\EventManager;
use Doctrine\DBAL\Connection;
To be honest, I'm surprised that the 2nd step is required at all, I would think this should be possible to accomplish using only the service container.
At least in Doctrine/ORM 2.4, the doc string of the EntityManager class explicitly discourages inheriting from Doctrine\ORM\EntityManager, instead they suggest inheriting from Doctrine\ORM\Decorator\EntityManagerDecorator:
/**
* The EntityManager is the central access point to ORM functionality.
* ...
* You should never attempt to inherit from the EntityManager: Inheritance
* is not a valid extension point for the EntityManager. Instead you
* should take a look at the {#see \Doctrine\ORM\Decorator\EntityManagerDecorator}
* and wrap your entity manager in a decorator.
* ...
*/
/* final */class EntityManager implements EntityManagerInterface
{
...
So, extend EntityManagerDecorator and make whatever changes you need. You will need to implement the create() factory method, but you don't need to copy EntityManager's implementation now:
use Doctrine\ORM\Decorator\EntityManagerDecorator;
use Doctrine\Common\EventManager;
use Doctrine\ORM\Configuration;
class MyEntityManager extends EntityManagerDecorator
{
/**
* {#inheritDoc}
*/
public function persist($entity)
{
// do something interesting
parent::persist($entity);
}
public function create($conn, Configuration $config, EventManager $eventManager = null)
{
return new self(\Doctrine\ORM\EntityManager::create($conn, $config, $eventManager));
}
}
Then override the doctrine.orm.entity_manager.class parameter to point to your custom entity manager class.
The docs don't cover everything, in many cases you just have to read the code.
I found the process of extending the entity manager extremely counterintuitive,
despite a decent grasp of concepts including dependency injection, service locator, code generation, caching and the decorator pattern.
Hopefully this concise example will paint a clear picture for you (this expands on the answer by #user2563451)
Symfony Version (Mon Aug 20 13:05:58 CEST 2018)
$ composer info | grep -E -e symfony/framework -e 'doctrine/(common|orm|dbal)'
doctrine/common v2.9.0 Common Library for Doctrine projects
doctrine/dbal v2.8.0 Database Abstraction Layer
doctrine/orm v2.6.2 Object-Relational-Mapper for PHP
symfony/framework-bundle v4.1.3 Symfony FrameworkBundle
config/services.yaml
App\Doctrine\ORM\CustomEntityManager:
public: false # optional afaik
decorates: doctrine.orm.original_entity_manager
arguments: [ '#App\Doctrine\ORM\CustomEntityManager.inner' ]
config/packages/doctrine.yaml
doctrine:
orm:
auto_generate_proxy_classes: '%kernel.debug%'
default_entity_manager: original
entity_managers:
original:
connection: from_env
naming_strategy: doctrine.orm.naming_strategy.underscore
auto_mapping: false
mappings:
TimeTracking:
is_bundle: false
type: annotation
dir: '%kernel.project_dir%/src/php/Model'
prefix: TimeTracking\Model
alias: TimeTracking
mapping: true
#mapper_number_5:
# (...)
src/php/App/Doctrine/ORM/CustomEntityManager.php
<?php
namespace App\Doctrine\ORM;
use App\Doctrine\ORM\Proxy\SoggyProxyFactory;
use Doctrine\ORM\Decorator\EntityManagerDecorator;
use Doctrine\ORM\Proxy\ProxyFactory;
/**
* Writes custom proxy-class methods with support for the set-or-get-trait
* #property ProxyFactory soggyProxyFactory
*/
class CustomEntityManager extends EntityManagerDecorator
{
/// SUPER: __construct(EntityManagerInterface $wrapped) { $this->wrapped = $wrapped; }
private $soggyProxyFactory;
public function getProxyFactory() {
$config = $this->getConfiguration();
if (null === $this->soggyProxyFactory) {
$this->soggyProxyFactory = new SoggyProxyFactory(
$this,
$config->getProxyDir(),
$config->getProxyNamespace(),
$config->getAutoGenerateProxyClasses()
);
}
return $this->soggyProxyFactory;
}
}
references
http://symfony.com/doc/current/service_container/service_decoration.html
https://symfony.com/doc/current/doctrine/multiple_entity_managers.html