is there a way to create an array containing all the public vars from a class without having to add them manually in PHP5?
I am looking for the quickest way to sequentially set a group of vars in a class
Have a look at:
get_class_vars
With this you get the public vars in an array.
get_class_vars() is the obvious one - see get_class_vars docs on the PHP site.
Edit: example of setting using this function:
$foo = new Foo();
$properties = get_class_vars("Foo");
foreach ($vars as $property)
{
$foo->{$property} = "some value";
}
You could also use the Reflection API - from the PHP docs:
<?php
class Foo {
public $foo = 1;
protected $bar = 2;
private $baz = 3;
}
$foo = new Foo();
$reflect = new ReflectionClass($foo);
$props = $reflect->getProperties(ReflectionProperty::IS_PUBLIC);
foreach ($props as $prop) {
print $prop->getName() . "\n";
}
var_dump($props);
?>
...example taken straight from the PHP docs linked above but tweaked for your purpose to only retrieve public properties. You can filter on public, protected etc as required.
This returns an array of ReflectionProperty objects which contain the name and class as appropriate.
Edit: example of setting using the above $props array:
$props = $reflect->getProperties(ReflectionProperty::IS_PUBLIC);
foreach ($props as $prop)
{
$foo->{$prop->getName()} = "some value";
}
Take a look at PHP's Reflection API. You can get the properties with ReflectionClass::getProperties.
To set the properties you do something like this:
$propToSet = 'somePropName';
$obj->{$propToSet} = "newValue";
try get_class_vars($obj);
Related
How can I create a property from a given argument inside a object's method?
class Foo{
public function createProperty($var_name, $val){
// here how can I create a property named "$var_name"
// that takes $val as value?
}
}
And I want to be able to access the property like:
$object = new Foo();
$object->createProperty('hello', 'Hiiiiiiiiiiiiiiii');
echo $object->hello;
Also is it possible that I could make the property public/protected/private ? I know that in this case it should be public, but I may want to add some magik methods to get protected properties and stuff :)
I think I found a solution:
protected $user_properties = array();
public function createProperty($var_name, $val){
$this->user_properties[$var_name] = $val;
}
public function __get($name){
if(isset($this->user_properties[$name])
return $this->user_properties[$name];
}
do you think it's a good idea?
There are two methods to doing it.
One, you can directly create property dynamically from outside the class:
class Foo{
}
$foo = new Foo();
$foo->hello = 'Something';
Or if you wish to create property through your createProperty method:
class Foo{
public function createProperty($name, $value){
$this->{$name} = $value;
}
}
$foo = new Foo();
$foo->createProperty('hello', 'something');
The following example is for those who do not want to declare an entire class.
$test = (object) [];
$prop = 'hello';
$test->{$prop} = 'Hiiiiiiiiiiiiiiii';
echo $test->hello; // prints Hiiiiiiiiiiiiiiii
Property overloading is very slow. If you can, try to avoid it. Also important is to implement the other two magic methods:
__isset();
__unset();
If you don't want to find some common mistakes later on when using these object "attributes"
Here are some examples:
http://www.php.net/manual/en/language.oop5.overloading.php#language.oop5.overloading.members
EDITED after Alex comment:
You can check yourself the differences in time between both solutions (change $REPEAT_PLEASE)
<?php
$REPEAT_PLEASE=500000;
class a {}
$time = time();
$a = new a();
for($i=0;$i<$REPEAT_PLEASE;$i++)
{
$a->data = 'hi';
$a->data = 'bye'.$a->data;
}
echo '"NORMAL" TIME: '.(time()-$time)."\n";
class b
{
function __set($name,$value)
{
$this->d[$name] = $value;
}
function __get($name)
{
return $this->d[$name];
}
}
$time=time();
$a = new b();
for($i=0;$i<$REPEAT_PLEASE;$i++)
{
$a->data = 'hi';
//echo $a->data;
$a->data = 'bye'.$a->data;
}
echo "TIME OVERLOADING: ".(time()-$time)."\n";
Use the syntax: $object->{$property}
where $property is a string variable and
$object can be this if it is inside the class or any instance object
Live example: http://sandbox.onlinephpfunctions.com/code/108f0ca2bef5cf4af8225d6a6ff11dfd0741757f
class Test{
public function createProperty($propertyName, $propertyValue){
$this->{$propertyName} = $propertyValue;
}
}
$test = new Test();
$test->createProperty('property1', '50');
echo $test->property1;
Result: 50
How can I create a property from a given argument inside a object's method?
class Foo{
public function createProperty($var_name, $val){
// here how can I create a property named "$var_name"
// that takes $val as value?
}
}
And I want to be able to access the property like:
$object = new Foo();
$object->createProperty('hello', 'Hiiiiiiiiiiiiiiii');
echo $object->hello;
Also is it possible that I could make the property public/protected/private ? I know that in this case it should be public, but I may want to add some magik methods to get protected properties and stuff :)
I think I found a solution:
protected $user_properties = array();
public function createProperty($var_name, $val){
$this->user_properties[$var_name] = $val;
}
public function __get($name){
if(isset($this->user_properties[$name])
return $this->user_properties[$name];
}
do you think it's a good idea?
There are two methods to doing it.
One, you can directly create property dynamically from outside the class:
class Foo{
}
$foo = new Foo();
$foo->hello = 'Something';
Or if you wish to create property through your createProperty method:
class Foo{
public function createProperty($name, $value){
$this->{$name} = $value;
}
}
$foo = new Foo();
$foo->createProperty('hello', 'something');
The following example is for those who do not want to declare an entire class.
$test = (object) [];
$prop = 'hello';
$test->{$prop} = 'Hiiiiiiiiiiiiiiii';
echo $test->hello; // prints Hiiiiiiiiiiiiiiii
Property overloading is very slow. If you can, try to avoid it. Also important is to implement the other two magic methods:
__isset();
__unset();
If you don't want to find some common mistakes later on when using these object "attributes"
Here are some examples:
http://www.php.net/manual/en/language.oop5.overloading.php#language.oop5.overloading.members
EDITED after Alex comment:
You can check yourself the differences in time between both solutions (change $REPEAT_PLEASE)
<?php
$REPEAT_PLEASE=500000;
class a {}
$time = time();
$a = new a();
for($i=0;$i<$REPEAT_PLEASE;$i++)
{
$a->data = 'hi';
$a->data = 'bye'.$a->data;
}
echo '"NORMAL" TIME: '.(time()-$time)."\n";
class b
{
function __set($name,$value)
{
$this->d[$name] = $value;
}
function __get($name)
{
return $this->d[$name];
}
}
$time=time();
$a = new b();
for($i=0;$i<$REPEAT_PLEASE;$i++)
{
$a->data = 'hi';
//echo $a->data;
$a->data = 'bye'.$a->data;
}
echo "TIME OVERLOADING: ".(time()-$time)."\n";
Use the syntax: $object->{$property}
where $property is a string variable and
$object can be this if it is inside the class or any instance object
Live example: http://sandbox.onlinephpfunctions.com/code/108f0ca2bef5cf4af8225d6a6ff11dfd0741757f
class Test{
public function createProperty($propertyName, $propertyValue){
$this->{$propertyName} = $propertyValue;
}
}
$test = new Test();
$test->createProperty('property1', '50');
echo $test->property1;
Result: 50
Can I freely assign something to non-existent or not-known-existent members in php? Is there any difference between member names and associative array index?
I there any difference beteween
$a = array();
$a['foo'] = 'something';
and
$a->foo = 'something';
If there is a difference, then how can I create "empty" object and add members dynamically to it?
You are mixing Arrays (which are bags/containers for data) and Objects (which are wrappings for data with semantic meaning and functionality).
Array Access
The first is correct since you are using an Array which acts like a HashTable or Dictionary in other languages.
$a = array(); // create an empty "box"
$a['foo'] = 'something'; // add something to this array
Object Access
The second is an Object access. You would use something like this:
class Foo {
public $foo;
}
$a = new Foo();
$a->foo = 'something';
Although the better usage in that case is to use a setter/getter approach like this.
class Foo {
private $foo;
public function setFoo($value) {
$this->foo = $value;
}
public function getFoo() {
return $this->foo;
}
}
$a = new Foo();
$a->setFoo('something');
var_dump($a->getFoo());
PHP Magic
However there is still an option to use PHPs Magic Methods to create a behavior like you describe it. Nevertheless this should be considers not the usual way of storing data to a object since this lead to errors and gives you a much harder time with (unit) testing.
class Foo {
private $data = array();
public function __set($key, $value) {
$this->data[$key] = $value;
}
public function __get($key) {
return $this->data[$key];
}
}
$a = new Foo();
$a->foo = 'something'; // this will call the magic __set() method
var_dump($a->foo) // this will call the magic __get() method
This hopefully did help you solving your problem.
If you want to assign arbitrary members to an object as you do on an associative array, you'll probably want to look into PHP's magic property overloading.
Here's an example class that will let you just assign and retrieve variables (mostly taken from the PHP documentation):
<?php
class PropertyTest
{
/** Location for overloaded data. */
private $data = array();
public function __set($key, $value) {
$this->data[$key] = $value;
}
public function __get($key) {
return $this->data[$key];
}
}
// sample use:
$a = new PropertyTest();
$a->foo = "bar";
echo $a->foo; // will print "bar"
?>
You can create an empty class object and afterwards add properties to it, e.g.:
<?php
$myObject = new StdClass();
$myObject->id = 1;
$myObject->name = "Franky";
$myObject->url = "http://www.google.com";
var_dump($myObject);
...this should produce
object(stdClass)#1 (3) { ["id"]=> int(1) ["name"]=> string(6) "Franky" ["url"]=> string(21) "http://www.google.com" }
Personally, I prefer using object classes instead of arrays.
First, a quote from the ole' manual on ArrayAccess::offsetSet():
This function is not called in assignments by reference and otherwise indirect changes to array dimensions overloaded with ArrayAccess (indirect in the sense they are made not by changing the dimension directly, but by changing a sub-dimension or sub-property or assigning the array dimension by reference to another variable). Instead, ArrayAccess::offsetGet() is called. The operation will only be successful if that method returns by reference, which is only possible since PHP 5.3.4.
I'm a bit confused by this. It appears that this suggests that (as of 5.3.4) one can define offsetGet() to return by reference in an implementing class, thus handling assignments by reference.
So, now a test snippet:
(Disregard the absence of validation and isset() checking)
class Test implements ArrayAccess
{
protected $data = array();
public function &offsetGet($key)
{
return $this->data[$key];
}
public function offsetSet($key, $value)
{
$this->data[$key] = $value;
}
public function offsetExists($key) { /* ... */ }
public function offsetUnset($key) { /* ... */ }
}
$test = new Test();
$test['foo'] = 'bar';
$test['foo'] = &$bar; // Fatal error: Cannot assign by reference to
// overloaded object in
var_dump($test, $bar);
Ok, so that doesn't work. Then what does this manual note refer to?
Reason
I'd like to permit assignment by reference via the array operator to an object implementing ArrayAccess, as the example snippet shows. I've investigated this before, and I didn't think it was possible, but having come back to this due to uncertainty, I (re-)discovered this mention in the manual. Now I'm just confused.
Update: As I hit Post Your Question, I realized that this is likely just referring to assignment by reference to another variable, such as $bar = &$test['foo'];. If that's the case, then apologies; though knowing how, if it is at all possible, to assign by reference to the overloaded object would be great.
Further elaboration: What it all comes down to, is I would like to have the following method aliases:
isset($obj[$key]); // $obj->has_data($key);
$value = $obj[$key]; // $obj->get_data($key);
$obj[$key] = $value; // $obj->set_data($key, $value);
$obj[$key] = &$variable; // $obj->bind_data($key, $variable);
// also, flipping the operands is a syntactic alternative
$variable = &$obj[$key]; // $obj->bind_data($key, $variable);
unset($obj[$key]); // $obj->remove_data($key);
As far as has, get, set, and remove go, they're no problem with the supported methods of ArrayAccess. The binding functionality is where I'm at a loss, and am beginning to accept that the limitations of ArrayAccess and PHP are simply prohibitive of this.
What the manual is referring to are so called "indirect modifications". Consider the following script:
$array = new ArrayObject;
$array['foo'] = array();
$array['foo']['bar'] = 'foobar';
In the above script $array['foo'] = array(); will trigger a offsetSet('foo', array()). $array['foo']['bar'] = 'foobar'; on the other hand will trigger a offsetGet('foo'). Why so? The last line will be evaluated roughly like this under the hood:
$tmp =& $array['foo'];
$tmp['bar'] = 'foobar';
So $array['foo'] is first fetched by ref and then modified. If your offsetGet returns by ref this will succeed. If not you'll get some indirect modification error.
What you want on the other hand is the exact opposite: Not fetch a value by reference, but assign it. This would theoretically require a signature of offsetSet($key, &$value), but practically this is just not possible.
By the way, references are hard to grasp. You'll get lots of non-obvious behavior and this is especially true for array item references (those have some special rules). I'd recommend you to just avoid them altogether.
This does not work with ArrayAccess, you could add yourself a public function that allows you to set a reference to an offset (sure, this looks different to using array syntax, so it's not really a sufficient answer):
class Test implements ArrayAccess{
protected $_data = array();
public function &offsetGet($key){
return $this->_data[$key];
}
...
public function offsetSetReference($key, &$value)
{
$this->_data[$key] = &$value;
}
}
$test = new Test();
$test['foo'] = $var = 'bar';
$test->offsetSetReference('bar', $var);
$var = 'foo';
echo $test['bar']; # foo
$alias = &$test['bar'];
$alias = 'hello :)';
echo $var; # hello :)
Probably such a function was forgotten when ArrayAccess was first implemented.
Edit: Pass it as "a reference assignment":
class ArrayAccessReferenceAssignment
{
private $reference;
public function __construct(&$reference)
{
$this->reference = &$reference;
}
public function &getReference()
{
$reference = &$this->reference;
return $reference;
}
}
class Test implements ArrayAccess{
...
public function offsetSet($key, $value){
if ($value instanceof ArrayAccessReferenceAssignment)
{
$this->offsetSetReference($key, $value->getReference());
}
else
{
$this->_data[$key] = $value;
}
}
Which then works flawlessly because you implemented it. That's probably more nicely interfacing than the more explicit offsetSetReference variant above:
$test = new Test();
$test['foo'] = $var = 'bar';
$test['bar'] = new ArrayAccessReferenceAssignment($var);
$var = 'foo';
echo $test['bar']; # foo
$alias = &$test['bar'];
$alias = 'hello :)';
echo $var; # hello :)
I am trying to perform a backup/restore function for static properties of classes. I can get a list of all of the static properties and their values using the reflection objects getStaticProperties() method. This gets both private and public static properties and their values.
The problem is I do not seem to get the same result when trying to restore the properties with the reflection objects setStaticPropertyValue($key, $value) method. private and protected variables are not visible to this method as they are to getStaticProperties(). Seems inconsistent.
Is there any way to set a private/protected static property using reflection classes, or any other way for that matter?
TRIED
class Foo {
static public $test1 = 1;
static protected $test2 = 2;
public function test () {
echo self::$test1 . '<br>';
echo self::$test2 . '<br><br>';
}
public function change () {
self::$test1 = 3;
self::$test2 = 4;
}
}
$test = new foo();
$test->test();
// Backup
$test2 = new ReflectionObject($test);
$backup = $test2->getStaticProperties();
$test->change();
// Restore
foreach ($backup as $key => $value) {
$property = $test2->getProperty($key);
$property->setAccessible(true);
$test2->setStaticPropertyValue($key, $value);
}
$test->test();
For accessing private/protected properties of a class we may need to set the accessibility of that class first, using reflection. Try the following code:
$obj = new ClassName();
$refObject = new ReflectionObject( $obj );
$refProperty = $refObject->getProperty( 'property' );
$refProperty->setAccessible( true );
$refProperty->setValue(null, 'new value');
For accessing private/protected properties of a class, using reflection, without the need for a ReflectionObject instance:
For static properties:
<?php
$reflection = new \ReflectionProperty('ClassName', 'propertyName');
$reflection->setAccessible(true);
$reflection->setValue(null, 'new property value');
For non-static properties:
<?php
$instance = new SomeClassName();
$reflection = new \ReflectionProperty(get_class($instance), 'propertyName');
$reflection->setAccessible(true);
$reflection->setValue($instance, 'new property value');
You can implement also a class internal method to change the object properties access setting and then set value with $instanve->properyname = .....:
public function makeAllPropertiesPublic(): void
{
$refClass = new ReflectionClass(\get_class($this));
$props = $refClass->getProperties();
foreach ($props as $property) {
$property->setAccessible(true);
}
}