I would like to typecast PHP exceptions. Consider the following code:
class myException extends Exception {
function __construct( $mOrigin = "", $iCode = 0, Exception $oPrevious = null){
if(is_string($mOrigin)){
parent::__construct($mOrigin, $iCode, $oPrevious);
} elseif ($mOrigin instanceof Exception) {
parent::__construct($mOrigin->getMessage(),$mOrigin->getCode(),$mOrigin->getPrevious());
$this->file = $mOrigin->getFile();
$this->line = $mOrigin->getLine();
} else {
parent::__construct("\$mOrigin has wrong type", self::eFatal, $oPrevious);
}
}
The idea is to turn a standard Exception into a myException preserving the original stack trace. Since the variables holding the trace are private I cannot copy these values immediately and the CTOR produces a new one for myException.
The first idea was of course to use clone, but I can hardly re-assign $this, can I?
So what I'm trying to do is a C++ style typecast CTOR. Is there a sensible paradigm in PHP to do this?
Why not just set trace & previous the same way as file & line?
class myException extends Exception {
function __construct( $mOrigin = "", $iCode = 0, Exception $oPrevious = null){
if(is_string($mOrigin)){
parent::__construct($mOrigin, $iCode, $oPrevious);
} elseif ($mOrigin instanceof Exception) {
parent::__construct($mOrigin->getMessage(),$mOrigin->getCode(),$mOrigin->getPrevious());
$this->file = $mOrigin->getFile();
$this->line = $mOrigin->getLine();
$this->trace = $mOrigin->getTrace();
$this->previous = $mOrigin->getPrevious();
} else {
parent::__construct("\$mOrigin has wrong type", self::eFatal, $oPrevious);
}
}
EDIT:
See comments below regarding why I got away w/ this code earlier.
Why not turn your myException class into a decorator:
class myException extends Exception {
private $_oException;
function __construct( $mOrigin = "", $iCode = 0, Exception $oPrevious = null){
if(is_string($mOrigin)){
parent::__construct($mOrigin, $iCode, $oPrevious);
} elseif ($mOrigin instanceof Exception) {
$this->_oException = $mOrigin;
parent::__construct($mOrigin->getMessage(),$mOrigin->getCode(),$mOrigin->getPrevious());
$this->file = $mOrigin->getFile();
$this->line = $mOrigin->getLine();
} else {
parent::__construct("\$mOrigin has wrong type", self::eFatal, $oPrevious);
}
}
function getTrace()
{
return $this->_oException->getTrace();
}
function getPrevious()
{
return $this->_oException->getPrevious();
}
}
FUTHER INFO:
I've followed up on php-general and it turns out this is the intended behavior and it works the same in Java et al as well. You can override the member variable in child classes and have a separate store with the same name. This compiles just fine in java
public class PrivateAccess
{
private Boolean isAccessible = true;
public Boolean getAccessible()
{
return isAccessible;
}
}
class PrivateAccessChild extends PrivateAccess
{
private Boolean isAccessible = false;
public Boolean getAccessible()
{
return isAccessible;
}
public Boolean getParentAccessible()
{
return super.getAccessible();
}
public static void main(String[] args)
{
PrivateAccessChild pAccess = new PrivateAccessChild();
if(!pAccess.getAccessible())
System.out.println("we're hitting the child here...");
if(pAccess.getParentAccessible())
System.out.println("we're hitting the parent here...");
System.out.println("we're done here...");
}
}
Related
I have a class that handles errors with exceptions, like
class fooException extends Exception{}
class foo {
public function bar($x){
if(!$x){
throw new fooException ("x can not be false value");
}
}
}
Now, what I am trying to do, is allow user of the class to make choices whether an exception should be thrown, or not just like the PDO class.
PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
So, I was to give flexibility to the class not to throw exceptions all the time.
You could extend the Exception in a better way
class MyException extends Exception
{
static public $enable = true;
public function __construct($message = null, $code = 0)
{
if (self::$enable) {
parent::__construct($message, $code);
}
}
}
the you could call
throw new MyException("x can not be false value");
MyException::enable = false; //for disable
Note this is really very basic implementation and you have the problem to handle the false state in some way.
Another better solution is to use an ExceptionHandler
class ExceptionHanlder
{
static public $enable = true;
function __construct($message = null,$code = null) {
if (self::$enable) {
throw new Exception($message,$code);
}
}
}
ExceptionHandler::$enable = false;
new ExceptionHandler('test');
Consider the following class
class myClass {
private $model;
public function update($input) {
return $this->model->update($input);
}
public function find($id) {
$this->model = ORMfind($id);
}
}
How do I prevent
$myClass = new myClass;
$myClass->update($input);
The problem isn't HOW to use the above code but how to make update() a method only callable after find().
EDIT: I changed what my method does so it was more clearly understood that I need to do one method (find()) before another (update())
You could add a flag to your code like so:
class myClass {
private $model;
private $canUpdate = 0;
public function update($input) {
if ($canUpdate === 0) return; // or throw an exception here
return $this->model->update($input);
}
public function find($id) {
$this->model = ORMfind($id);
$canUpdate = 1;
}
}
Setting the flag $canUpdate will caution the update() method to react accordingly. If update() is called, you can throw an exception or exit out of the method if the flag is still 0.
To prevent from returning null value by get :
public function get() {
if (isset($this->value)) return $this->value;
else echo "please give me a value ";
}
You can also create a construct:
function __construct($val){
$this->value=$val;
}
and then give a value to your $value without using set() method:
$myClass=new myClass(10);
Outputting text, returning void, I think all of this is wrong. When you do not expect something to happen, you should throw an exception:
class MyClass {
private $canUpdate = false;
public function find($id) {
// some code...
$this->canUpdate = true;
}
public function canUpdate() {
return $this->canUpdate;
}
private function testCanUpdate() {
if (!$this->canUpdate()) {
throw new Exception('You cannot update');
}
}
public function update($inpjut) {
$this->testCanUpdate();
// ... some code
}
}
Now you can do:
$obj = new MyClass();
try {
$obj->update($input);
} catch (Exception $e) {
$obj->find($id);
$obj->update($input);
}
The proper way to make sure ->update() can only be called when the model has been initialized is to turn it into a dependency:
class myClass
{
private $model;
public function __construct($id)
{
$this->model = ORMfind($id);
}
public function update($input) {
return $this->model->update($input);
}
}
$x = new myClass('123');
Alternatively, if you have multiple find operations, you could introduce them as static constructor methods:
class myClass
{
private $model;
private function __construct($model)
{
$this->model = $model;
}
public function update($input) {
return $this->model->update($input);
}
public static function find($id)
{
return new self(ORMfind($id));
}
}
$x = myClass::find('123');
Update
Tackling your immediate problem can be done by a simple check:
public function update($input) {
return $this->model ? $this->model->update($input) : null;
}
PHP calls private method in parent class instead of method define in current class called by call_user_func
class Car {
public function run() {
return call_user_func(array('Toyota','getName')); // should call toyota
}
private static function getName() {
return 'Car';
}
}
class Toyota extends Car {
public static function getName() {
return 'Toyota';
}
}
$car = new Car();
echo $car->run(); //Car instead of Toyota
$toyota = new Toyota();
echo $toyota->run(); //Car instead of Toyota
I have found a solution with a different approach..
<?php
class Car {
public static function run() {
return static::getName();
}
private static function getName() {
return 'Car';
}
}
class Toyota extends Car {
public static function getName() {
return 'Toyota';
}
}
echo Car::run();
echo Toyota::run();
?>
Using Late Static Binding..
You might use something like this:
<?php
class Car {
public function run() {
return static::getName();
}
private static function getName(){
return 'Car';
}
}
class Toyota extends Car {
public static function getName(){
return 'Toyota';
}
}
$car = new Car();
echo $car->run();
echo PHP_EOL;
$toyota = new Toyota();
echo $toyota->run();
?>
Output:
Car
Toyota
PHP 5.4.5
This is a bug that appears to have fluctuated in and out of existence for a long time (see #deceze's tests in comments on the question). It is possible to "fix" this issue - that is, give consistent behaviour across PHP versions - using reflection:
Works in PHP 5.3.2 and later due to a dependency on ReflectionMethod::setAccessible() to invoke private/protected methods. I will add further explanation for this code, what it can and can't do and how it works very shortly.
Unfortunately it's not possible to test this directly on 3v4l.org because the code is too large, however this is the first ever real use case for minifying PHP code - it does work on 3v4l if you do this, so feel free to play around and see if you can break it. The only issue I'm aware of is that it doesn't currently understand parent. It is also restricted by the lack of $this support in closures before 5.4, there's not really anything that can be done about this though.
<?php
function call_user_func_fixed()
{
$args = func_get_args();
$callable = array_shift($args);
return call_user_func_array_fixed($callable, $args);
}
function call_user_func_array_fixed($callable, $args)
{
$isStaticMethod = false;
$expr = '/^([a-z_\x7f-\xff][\w\x7f-\xff]*)::([a-z_\x7f-\xff][\w\x7f-\xff]*)$/i';
// Extract the callable normalized to an array if it looks like a method call
if (is_string($callable) && preg_match($expr, $callable, $matches)) {
$func = array($matches[1], $matches[2]);
} else if (is_array($callable)
&& count($callable) === 2
&& isset($callable[0], $callable[1])
&& (is_string($callable[0]) || is_object($callable[0]))
&& is_string($callable[1])) {
$func = $callable;
}
// If we're not interested in it use the regular mechanism
if (!isset($func)) {
return call_user_func_array($func, $args);
}
$backtrace = debug_backtrace(); // passing args here is fraught with complications for backwards compat :-(
if ($backtrace[1]['function'] === 'call_user_func_fixed') {
$called = 'call_user_func_fixed';
$contextKey = 2;
} else {
$called = 'call_user_func_array_fixed';
$contextKey = 1;
}
try {
// Get a reference to the target static method if possible
switch (true) {
case $func[0] === 'self':
case $func[0] === 'static':
if (!isset($backtrace[$contextKey]['object'])) {
throw new Exception('Use of self:: in an invalid context');
}
$contextClass = new ReflectionClass($backtrace[$contextKey][$func[0] === 'self' ? 'class' : 'object']);
$contextClassName = $contextClass->getName();
$method = $contextClass->getMethod($func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if (!$method->isStatic()) {
throw new Exception('Attempting to call instance method in a static context');
}
$invokeContext = null;
if ($method->isPrivate()) {
if ($ownerClassName !== $contextClassName
|| !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
if (!method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method in an invalid context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
break;
case is_object($func[0]):
$contextClass = new ReflectionClass($func[0]);
$contextClassName = $contextClass->getName();
$method = $contextClass->getMethod($func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if ($method->isStatic()) {
$invokeContext = null;
if ($method->isPrivate()) {
if ($ownerClassName !== $contextClassName || !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
if (!method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method in an invalid context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
} else {
$invokeContext = $func[0];
}
break;
default:
$contextClass = new ReflectionClass($backtrace[$contextKey]['object']);
$method = new ReflectionMethod($func[0], $func[1]);
$ownerClassName = $method->getDeclaringClass()->getName();
if (!$method->isStatic()) {
throw new Exception('Attempting to call instance method in a static context');
}
$invokeContext = null;
if ($method->isPrivate()) {
if (empty($backtrace[$contextKey]['object'])
|| $func[0] !== $contextClass->getName()
|| !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call private method in an invalid context');
}
$method->setAccessible(true);
} else if ($method->isProtected()) {
$contextClass = new ReflectionClass($backtrace[$contextKey]['object']);
if (empty($backtrace[$contextKey]['object']) || !method_exists($method, 'setAccessible')) {
throw new Exception('Attempting to call protected method outside a class context');
}
while ($contextClass->getName() !== $ownerClassName) {
$contextClass = $contextClass->getParentClass();
}
if ($contextClass->getName() !== $ownerClassName) {
throw new Exception('Attempting to call protected method in an invalid context');
}
$method->setAccessible(true);
}
break;
}
// Invoke the method with the passed arguments and return the result
return $method->invokeArgs($invokeContext, $args);
} catch (Exception $e) {
trigger_error($called . '() expects parameter 1 to be a valid callback: ' . $e->getMessage(), E_USER_ERROR);
return null;
}
}
Use "protected" modifier if you want to get access from parent and descendants only. IMO, it's obvious. For example:
<?php
class Car {
public function run() {
return call_user_func(array('static','getName'));
}
protected static function getName() {
return 'Car';
}
}
class Toyota extends Car {
protected static function getName() {
return 'Toyota';
}
}
$car = new Car();
echo $car->run(); // "Car"
$toyota = new Toyota();
echo $toyota->run(); // "Toyota"
You can use get_called_class() instead of 'static'.
The problem is, I think, with the different access levels of the two getname functions. If you make the base class version of getname() public (the same as the derived class version), then in php 5.3.15 (on my Mac), you get Toyota. I think that, because of the different access levels, you end up with two different versions of the getname() function in the Toyota class, rather than the derived class version overriding the base class version. In other words, you have overloading rather than overriding. Therefore, when the run() function looks for a getname() function in the Toyota class to execute, it finds two and takes the first one, which would be the first to be declared (from the base class).
Granted this is just supposition on my part, but it sounds plausible.
use the get_called_called function todo this
public function run() {
$self = get_called_class();
return $self::getName();
}
I believe you're functions are overriding each other and by default going to the first one. Unless you change the parameters of one function, or rename the function it will always default to the parent class function.
In a lot of my PHP classes, I have this code:
private $strError = "";
private $intErrorCode = NULL;
private $blnError = FALSE;
public function isError() {
return $this->blnError;
}
public function getErrorCode() {
return $this->intErrorCode;
}
private function setError( $strError, $intErrorCode = NULL ) {
$this->blnError = TRUE;
$this->intErrorCode = $intErrorCode;
$this->strError = $strError;
}
The point is so that outside code can know if an object has an error state, what the string of the error is, etc. But to have this exact code in a bunch of different classes is repetitious!
I'd love to have a dual-extension where I could do
class childClass extends parentClass, error {
...
}
And have those properties and methods inborn, But PHP doesn't support multiple inheritances. What I'm thinking about doing is creating an error class that exists inside each class. If I make it public, I can call it directly through the object
if ( $myObject->error->isError() ) {...}
but wouldn't that also make its error status settable from outside the containing class,
$myObject->error->setError("I shouldn't be doing this here");
which I would rather avoid?
Or I could write 'gateway' functions in the containing class, which do the appropriate calls on the error object, and prevent setting the error status from outside,
class childClass extends parentClass {
private $error;
public function __construct(...) {
...
$error = & new error();
...
}
public function isError() {...}
public function getError() {...}
public function getErrorCode() {...}
private function setError() {...}
...
}
but that leads to (some of) the code duplication that I'm trying to avoid.
What's the optimal solution here? I'm trying to have functionality for error statuses for a number of objects, so that the outside world can see their error state, with minimal repetition.
Use composition instead of inheritance.
class Errors {
private $strError = "";
private $intErrorCode = NULL;
private $blnError = FALSE;
public function isError() {
return $this->blnError;
}
public function getErrorCode() {
return $this->intErrorCode;
}
private function setError( $strError, $intErrorCode = NULL ) {
$this->blnError = TRUE;
$this->intErrorCode = $intErrorCode;
$this->strError = $strError;
}
}
And now use a private instance variable to refer to it:
class childClass extends parentClass {
private $errors = new Errors();
...
}
The private visibility prevents you from referencing $errors outside of the class.
There's also no need to create isError(), getError(), etc. inside childClass (and therefore no need to worry about code duplication). Simply call $this->errors->isError(), $this->errors->getError(), etc. If you still wanted to require those methods to be implemented though, as suggested below, you could specify an interface.
You could also abuse the __call magic method to do the same thing:
public function __call($name, array $arguments) {
$name = strtolower($name);
if (isset($this->methods[$name])) {
array_unshift($arguments, $this);
return call_user_func_array($this->methods[$name], $arguments);
}
throw new BadMethodCallException('Method does not exist');
}
Note that I said abuse... Ideally, I'd think of a different architecture rather than having all these "common methods" everywhere. Why not use an exception instead of checking $foo->isError? If that's not appropriate, why not decorate a class?
class Errors
protected $object = null;
public function __construct($object) {
$this->object = $object;
}
public function __call($method, array $arguments) {
$callback = array($this->object, $method);
if (is_callable($callback)) {
return call_user_func_array($callback, $arguments);
}
throw new BadMethodCallException('Method does not exist');
}
public function __get($name) { return $this->object->$name; }
public function __set($name, $value) { $this->object->$name = $value; }
// Your methods here
public function isInstance($name) { return $this->object instanceof $name; }
}
Then just "wrap" your existing object in that class:
$obj = new Errors($obj);
$obj->foo();
As of PHP 5.4, you can use Traits.
For example you could make Trait called ErrorTrait like this:
trait ErrorTrait {
private $strError = "";
private $intErrorCode = NULL;
private $blnError = FALSE;
public function isError() {
return $this->blnError;
}
public function getErrorCode() {
return $this->intErrorCode;
}
private function setError( $strError, $intErrorCode = NULL ) {
$this->blnError = TRUE;
$this->intErrorCode = $intErrorCode;
$this->strError = $strError;
}
}
Then you would define your child class like this:
class childClass extends parentClass {
use ErrorTrait;
...
}
Traits work basically like copy/paste so all of the code in the trait would be available within the class (without the code duplication).
I have a class implementing ArrayAccess and I'm trying to get it to work with a multidimensional array. exists and get work. set and unset are giving me a problem though.
class ArrayTest implements ArrayAccess {
private $_arr = array(
'test' => array(
'bar' => 1,
'baz' => 2
)
);
public function offsetExists($name) {
return isset($this->_arr[$name]);
}
public function offsetSet($name, $value) {
$this->_arr[$name] = $value;
}
public function offsetGet($name) {
return $this->_arr[$name];
}
public function offsetUnset($name) {
unset($this->_arr[$name]);
}
}
$arrTest = new ArrayTest();
isset($arrTest['test']['bar']); // Returns TRUE
echo $arrTest['test']['baz']; // Echo's 2
unset($arrTest['test']['bar']); // Error
$arrTest['test']['bar'] = 5; // Error
I know $_arr could just be made public so you could access it directly, but for my implementation it's not desired and is private.
The last 2 lines throw an error: Notice: Indirect modification of overloaded element.
I know ArrayAccess just generally doesn't work with multidimensional arrays, but is there anyway around this or any somewhat clean implementation that will allow the desired functionality?
The best idea I could come up with is using a character as a separator and testing for it in set and unset and acting accordingly. Though this gets really ugly really fast if you're dealing with a variable depth.
Does anyone know why exists and get work so as to maybe copy over the functionality?
Thanks for any help anyone can offer.
The problem could be resolved by changing public function offsetGet($name) to public function &offsetGet($name) (by adding return by reference), but it will cause Fatal Error ("Declaration of ArrayTest::offsetGet() must be compatible with that of ArrayAccess::offsetGet()").
PHP authors screwed up with this class some time ago and now they won't change it in sake of backwards compatibility:
We found out that this is not solvable
without blowing up the interface and
creating a BC or providing an
additional interface to support
references and thereby creating an
internal nightmare - actually i don't
see a way we can make that work ever.
Thus we decided to enforce the
original design and disallow
references completley.
Edit: If you still need that functionality, I'd suggest using magic method instead (__get(), __set(), etc.), because __get() returns value by reference. This will change syntax to something like this:
$arrTest->test['bar'] = 5;
Not an ideal solution of course, but I can't think of a better one.
Update: This problem was fixed in PHP 5.3.4 and ArrayAccess now works as expected:
Starting with PHP 5.3.4, the prototype checks were relaxed and it's possible for implementations of this method to return by reference. This makes indirect modifications to the overloaded array dimensions of ArrayAccess objects possible.
This issue is actually solvable, entirely functional how it should be.
From a comment on the ArrayAccess documentation here:
<?php
// sanity and error checking omitted for brevity
// note: it's a good idea to implement arrayaccess + countable + an
// iterator interface (like iteratoraggregate) as a triplet
class RecursiveArrayAccess implements ArrayAccess {
private $data = array();
// necessary for deep copies
public function __clone() {
foreach ($this->data as $key => $value) if ($value instanceof self) $this[$key] = clone $value;
}
public function __construct(array $data = array()) {
foreach ($data as $key => $value) $this[$key] = $value;
}
public function offsetSet($offset, $data) {
if (is_array($data)) $data = new self($data);
if ($offset === null) { // don't forget this!
$this->data[] = $data;
} else {
$this->data[$offset] = $data;
}
}
public function toArray() {
$data = $this->data;
foreach ($data as $key => $value) if ($value instanceof self) $data[$key] = $value->toArray();
return $data;
}
// as normal
public function offsetGet($offset) { return $this->data[$offset]; }
public function offsetExists($offset) { return isset($this->data[$offset]); }
public function offsetUnset($offset) { unset($this->data); }
}
$a = new RecursiveArrayAccess();
$a[0] = array(1=>"foo", 2=>array(3=>"bar", 4=>array(5=>"bz")));
// oops. typo
$a[0][2][4][5] = "baz";
//var_dump($a);
//var_dump($a->toArray());
// isset and unset work too
//var_dump(isset($a[0][2][4][5])); // equivalent to $a[0][2][4]->offsetExists(5)
//unset($a[0][2][4][5]); // equivalent to $a[0][2][4]->offsetUnset(5);
// if __clone wasn't implemented then cloning would produce a shallow copy, and
$b = clone $a;
$b[0][2][4][5] = "xyzzy";
// would affect $a's data too
//echo $a[0][2][4][5]; // still "baz"
?>
You can then extend that class, like so:
<?php
class Example extends RecursiveArrayAccess {
function __construct($data = array()) {
parent::__construct($data);
}
}
$ex = new Example(array('foo' => array('bar' => 'baz')));
print_r($ex);
$ex['foo']['bar'] = 'pong';
print_r($ex);
?>
This will give you an object that can be treated like an array (mostly, see note in code), which supports multi-dimensional array set/get/unset.
EDIT: See the response of Alexander Konstantinov. I was thinking of the __get magic method, which is analogous, but was actually implemented correctly. So you cannot do that without an internal implementation of your class.
EDIT2: Internal implementation:
NOTE: You might argue this is purely masturbatory, but anyway here it goes:
static zend_object_handlers object_handlers;
static zend_object_value ce_create_object(zend_class_entry *class_type TSRMLS_DC)
{
zend_object_value zov;
zend_object *zobj;
zobj = emalloc(sizeof *zobj);
zend_object_std_init(zobj, class_type TSRMLS_CC);
zend_hash_copy(zobj->properties, &(class_type->default_properties),
(copy_ctor_func_t) zval_add_ref, NULL, sizeof(zval*));
zov.handle = zend_objects_store_put(zobj,
(zend_objects_store_dtor_t) zend_objects_destroy_object,
(zend_objects_free_object_storage_t) zend_objects_free_object_storage,
NULL TSRMLS_CC);
zov.handlers = &object_handlers;
return zov;
}
/* modification of zend_std_read_dimension */
zval *read_dimension(zval *object, zval *offset, int type TSRMLS_DC) /* {{{ */
{
zend_class_entry *ce = Z_OBJCE_P(object);
zval *retval;
void *dummy;
if (zend_hash_find(&ce->function_table, "offsetgetref",
sizeof("offsetgetref"), &dummy) == SUCCESS) {
if(offset == NULL) {
/* [] construct */
ALLOC_INIT_ZVAL(offset);
} else {
SEPARATE_ARG_IF_REF(offset);
}
zend_call_method_with_1_params(&object, ce, NULL, "offsetgetref",
&retval, offset);
zval_ptr_dtor(&offset);
if (!retval) {
if (!EG(exception)) {
/* ought to use php_error_docref* instead */
zend_error(E_ERROR,
"Undefined offset for object of type %s used as array",
ce->name);
}
return 0;
}
/* Undo PZVAL_LOCK() */
Z_DELREF_P(retval);
return retval;
} else {
zend_error(E_ERROR, "Cannot use object of type %s as array", ce->name);
return 0;
}
}
ZEND_MODULE_STARTUP_D(testext)
{
zend_class_entry ce;
zend_class_entry *ce_ptr;
memcpy(&object_handlers, zend_get_std_object_handlers(),
sizeof object_handlers);
object_handlers.read_dimension = read_dimension;
INIT_CLASS_ENTRY(ce, "TestClass", NULL);
ce_ptr = zend_register_internal_class(&ce TSRMLS_CC);
ce_ptr->create_object = ce_create_object;
return SUCCESS;
}
now this script:
<?php
class ArrayTest extends TestClass implements ArrayAccess {
private $_arr = array(
'test' => array(
'bar' => 1,
'baz' => 2
)
);
public function offsetExists($name) {
return isset($this->_arr[$name]);
}
public function offsetSet($name, $value) {
$this->_arr[$name] = $value;
}
public function offsetGet($name) {
throw new RuntimeException("This method should never be called");
}
public function &offsetGetRef($name) {
return $this->_arr[$name];
}
public function offsetUnset($name) {
unset($this->_arr[$name]);
}
}
$arrTest = new ArrayTest();
echo (isset($arrTest['test']['bar'])?"test/bar is set":"error") . "\n";
echo $arrTest['test']['baz']; // Echoes 2
echo "\n";
unset($arrTest['test']['baz']);
echo (isset($arrTest['test']['baz'])?"error":"test/baz is not set") . "\n";
$arrTest['test']['baz'] = 5;
echo $arrTest['test']['baz']; // Echoes 5
gives:
test/bar is set
2
test/baz is not set
5
ORIGINAL follows -- this is incorrect:
Your offsetGet implementation must return a reference for it to work.
public function &offsetGet($name) {
return $this->_arr[$name];
}
For the internal equivalent, see here.
Since there's no analogous to get_property_ptr_ptr, you ought to return a reference (in the sense of Z_ISREF) or a proxy object (see the get handler) in write-like contexts (types BP_VAR_W, BP_VAR_RW and BP_VAR_UNSET), though it's not mandatory. If read_dimension is being called in a write-like context such as in $val =& $obj['prop'], and you return neither a reference nor an object, the engine emit a notice. Obviously, returning a reference is not enough for those operations to work correctly, it is necessary that modifying the returned zval actually has some effect. Note that assignments such as $obj['key'] = &$a are still not possible – for that one would need the dimensions to actually be storable as zvals (which may or may not be the case) and two levels of indirection.
In sum, operations that involve writing or unseting a sub-dimension of sub-property call offsetGet, not offsetSet, offsetExists or offsetUnset.
Solution:
<?php
/**
* Cube PHP Framework
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* #author Dillen / Steffen
*/
namespace Library;
/**
* The application
*
* #package Library
*/
class ArrayObject implements \ArrayAccess
{
protected $_storage = array();
// necessary for deep copies
public function __clone()
{
foreach ($this->_storage as $key => $value)
{
if ($value instanceof self)
{
$this->_storage[$key] = clone $value;
}
}
}
public function __construct(array $_storage = array())
{
foreach ($_storage as $key => $value)
{
$this->_storage[$key] = $value;
}
}
public function offsetSet($offset, $_storage)
{
if (is_array($_storage))
{
$_storage = new self($_storage);
}
if ($offset === null)
{
$this->_storage[] = $_storage;
}
else
{
$this->_storage[$offset] = $_storage;
}
}
public function toArray()
{
$_storage = $this -> _storage;
foreach ($_storage as $key => $value)
{
if ($value instanceof self)
{
$_storage[$key] = $value -> toArray();
}
}
return $_storage;
}
// as normal
public function offsetGet($offset)
{
if (isset($this->_storage[$offset]))
{
return $this->_storage[$offset];
}
if (!isset($this->_storage[$offset]))
{
$this->_storage[$offset] = new self;
}
return $this->_storage[$offset];
}
public function offsetExists($offset)
{
return isset($this->_storage[$offset]);
}
public function offsetUnset($offset)
{
unset($this->_storage);
}
}
I solved it using this:
class Colunas implements ArrayAccess {
public $cols = array();
public function offsetSet($offset, $value) {
$coluna = new Coluna($value);
if (!is_array($offset)) {
$this->cols[$offset] = $coluna;
} else {
if (!isset($this->cols[$offset[0]])) $this->cols[$offset[0]] = array();
$col = &$this->cols[$offset[0]];
for ($i = 1; $i < sizeof($offset); $i++) {
if (!isset($col[$offset[$i]])) $col[$offset[$i]] = array();
$col = &$col[$offset[$i]];
}
$col = $coluna;
}
}
public function offsetExists($offset) {
if (!is_array($offset)) {
return isset($this->cols[$offset]);
} else {
$key = array_shift($offset);
if (!isset($this->cols[$key])) return FALSE;
$col = &$this->cols[$key];
while ($key = array_shift($offset)) {
if (!isset($col[$key])) return FALSE;
$col = &$col[$key];
}
return TRUE;
}
}
public function offsetUnset($offset) {
if (!is_array($offset)) {
unset($this->cols[$offset]);
} else {
$col = &$this->cols[array_shift($offset)];
while (sizeof($offset) > 1) $col = &$col[array_shift($offset)];
unset($col[array_shift($offset)]);
}
}
public function offsetGet($offset) {
if (!is_array($offset)) {
return $this->cols[$offset];
} else {
$col = &$this->cols[array_shift($offset)];
while (sizeof($offset) > 0) $col = &$col[array_shift($offset)];
return $col;
}
}
}
So you can use it with:
$colunas = new Colunas();
$colunas['foo'] = 'Foo';
$colunas[array('bar', 'a')] = 'Bar A';
$colunas[array('bar', 'b')] = 'Bar B';
echo $colunas[array('bar', 'a')];
unset($colunas[array('bar', 'a')]);
isset($colunas[array('bar', 'a')]);
unset($colunas['bar']);
Please note that I don't check if offset is null, and if it's an array, it must be of size > 1.
Mainly according to Dakota's solution* I want to share my simplification of it.
*) Dakota's was the most understandable one to me and the outcome is quite great (- the others seem quite similar great).
So, for the ones like me, who have their difficulties in understanding what's going on here:
class DimensionalArrayAccess implements ArrayAccess {
private $_arr;
public function __construct(array $arr = array()) {
foreach ($arr as $key => $value)
{
$this[$key] = $value;
}
}
public function offsetSet($offset, $val) {
if (is_array($val)) $val = new self($val);
if ($offset === null) {
$this->_arr[] = $val;
} else {
$this->_arr[$offset] = $val;
}
}
// as normal
public function offsetGet($offset) {
return $this->_arr[$offset];
}
public function offsetExists($offset) {
return isset($this->_arr[$offset]);
}
public function offsetUnset($offset) {
unset($this->_arr);
}
}
class Example extends DimensionalArrayAccess {
function __construct() {
parent::__construct([[["foo"]]]);
}
}
$ex = new Example();
echo $ex[0][0][0];
$ex[0][0][0] = 'bar';
echo $ex[0][0][0];
I did some changes:
deleted the toArray-function, as it has no immediate purpose as long as you don't want to convert your object into an real (in Dakota's case associative) array.
deleted the clone-thing, as it has no immediate purpose as long as you don't want to clone your object.
renamed the extended class and same vars: seems more understandable to me. especially I want to emphasize, that the DimensionalArrayAccess-class gives array-like access to your object even for 3- or more-dimensional (and of course also non-associative) 'arrays' - at least as long as you instanciate it with an array counting the number of dimensions you need.
last it seems important to me to emphasize, that as you can see the Example-class itself is not dependent on a constructor variable, whereas the DimensionalArrayAccess-class is (as it calls itself in the offsetSet-function recursively.
As I introduced, this post is rather for the not so advanced ones like me.
EDIT: this only works for cells which are set during instantiation, whereas it is not possible to add new cells afterwards.
class Test implements \ArrayAccess {
private
$input = [];
public function __construct () {
$this->input = ['foo' => ['bar' => 'qux']];
}
public function offsetExists ($offset) {}
public function offsetGet ($offset) {}
public function offsetSet ($offset, $value) {}
public function offsetUnset ($offset) {}
}
runkit_method_redefine ('Test', 'offsetGet', '&$offset', 'return $this->input[$offset];');
$ui = new Test;
var_dump($ui['foo']['bar']); // string(3) "qux"