PHP: How to use dynamic variable name with a class' setter - php

I have a class with a private member "description" but that proposes a setter :
class Foo {
private $description;
public function setDescription($description) {
$this->description = $description;
}
}
I have the name of the member in a variable. I would like to access the field dynamically. If the field was simply public I could do :
$bar = "description";
$f = new Foo();
$f->$bar = "asdf";
but I don't know how to do in the case I have only a setter.

<?php
$bar = "description";
$f = new Foo();
$func="set"+ucwords($bar);
$f->$func("asdf");
?>

Try this:
$bar = 'description';
$f = new Foo();
$f->{'set'.ucwords($bar)}('test');

This function come do the job:
private function bindEntityValues(Product $entity, array $data) {
foreach ($data as $key => $value){
$funcName = 'set'+ucwords($key);
if(method_exists($entity, $funcName)) $entity->$funcName($value);
}
}

Use magic setter
class Foo {
private $description;
function __set($name,$value)
{
$this->$name = $value;
}
/*public function setDescription($description) {
$this->description = $description;
}*/
}
but by this way your all private properties will act as public ones if you want it for just description use this
class Foo {
private $description;
function __set($name,$value)
{
if($name == 'description')
{ $this->$name = $value;
return true;
}
else
return false
}
/*public function setDescription($description) {
$this->description = $description;
}*/
}

Related

PHP: Get Acces To Private Variable In Class

I've been doing a project in PHP for the last few hours and I have encountered into a problem.
The problem is I don't know how to access private variables in a class and I can't find it online.
Example:
<?php
class Example{
private $age;
public function __construct() {
$age = 14;
$this->checkAge();
}
private function checkAge() {
if($this->$age > 12)
echo "welcome!";
}
}
$boy = new Example();
?>
As far as I know, I should be able to access the variable with $this->$age but it isn't working.
Thank you.
EDIT: Got it working with help of the awesome stackoverflooooooooow community, this is how a working one looks.
<?php
class Example{
private $age;
public function __construct() {
$this->age = 14;
$this->checkAge();
}
private function checkAge() {
if($this->age > 12)
echo "welcome!";
}
}
$boy = new Example();
?>
Look at this approach.
first: create Entity that stores and retrieves data inside of private $attributes array, and with magic __set(), __get() You can also do like: $object->variable = 123
second: extend Entity with Human class and add some function specific to child class (for example hasValidAge()):
<?php
class Entity {
private $attributes;
public function __construct($attributes = []) {
$this->setAttributes($attributes);
}
public function setAttribute($key, $value) {
$this->attributes[$key] = $value;
return $this;
}
public function setAttributes($attributes = []) {
foreach($attributes AS $key => $value) {
$this->setAttribute($key, $value);
}
}
public function getAttribute($key, $fallback = null) {
return (isset($this->attributes[$key]))?
$this->attributes[$key] : $fallback;
}
public function __get($key) {
return $this->getAttribute($key);
}
public function __set($key, $value) {
$this->setAttribute($key, $value);
}
}
class Human extends Entity {
public function __construct($attributes = []) {
$this->setAttributes($attributes);
$this->checkAge();
}
public function hasValidAge() {
return ($this->getAttribute('age') > 12)? true : false;
}
}
$boy = new Human(['name' => 'Mark', 'age' => 14]);
if($boy->hasValidAge()) {
echo "Welcome ".$boy->name."!";
}
?>
p.s. I've removed echo "Welcome!" part from constructor because it's not cool to do echo from model object, in our example Human is model of Entity.

Special class value in PHP

Some code:
class MyClass
{
public function __get($key)
{
return $this[$key];
}
public function __set($key, $value)
{
$this[$key] = $value;
}
}
$m = new MyClass();
$m->name = 'This is my class.';
OR
$m['name'] = 'This is my class.';
But not working. Somebody can help me?
In order to be able to access values in your class using array access, you have to implement the ArrayAccess interface. In order to also arbitrary property names dynamically, copy the sample code from that page. Once you've implemented the ArrayAccess methods your __get and __set will work as-is.
<?php
class obj implements arrayaccess {
private $container = array();
public function __construct() {
$this->container = array(
"one" => 1,
"two" => 2,
"three" => 3,
);
}
public function offsetSet($offset, $value) {
if (is_null($offset)) {
$this->container[] = $value;
} else {
$this->container[$offset] = $value;
}
}
public function offsetExists($offset) {
return isset($this->container[$offset]);
}
public function offsetUnset($offset) {
unset($this->container[$offset]);
}
public function offsetGet($offset) {
return isset($this->container[$offset]) ? $this->container[$offset] : null;
}
public function __get($key) {
return $this[$key];
}
public function __set($key, $value) {
$this[$key] = $value;
}
}
$foo = new obj();
$foo->pill = 123;
var_dump($foo->pill);
The problem you are having is that inside the __get and __set methods, you are accessing the properties as an array. You need to use $this->$key instead of $this[$key].
class MyClass
{
public function __get($key)
{
return $this->$key;
}
public function __set($key, $value)
{
$this->$key = $value;
}
}
$m = new MyClass();
echo "before set: \n";
var_dump($m);
$m->foo = "bar";
echo "after set: \n";
var_dump($m);
Example: http://codepad.viper-7.com/oNLbzq
Try this approach
class MyClass
{
private $m_var_data = array();
public function __set($p_name, $p_value)
{
$this->m_var_data[$p_name] = $p_value;
}
public function __get($p_name)
{
if (array_key_exists($p_name, $this->m_var_data))
{
return $this->m_var_data[$p_name];
}
}
}
$m = new MyClass();
$m->name = 'This is my class.';
In order to create a new property, you should do this:
class MyClass
{
private $data = array();
public function __set($name, $value)
{
echo "Setting '$name' to '$value'\n";
$this->data[$name] = $value;
}
public function __get($name)
{
echo "Getting '$name'\n";
if (array_key_exists($name, $this->data)) {
return $this->data[$name];
}
}
}
Then you can overload properties as you want in your example.
This link can give you more references:
http://www.php.net/manual/pt_BR/language.oop5.overloading.php#language.oop5.overloading.members

return class properties as JSON

I'm trying to encode some properties in a class in php to JSON but all my method is returning is {}
Here's my code, where am I going wrong?
Thanks.
<?php
class Person
{
private $_photo;
private $_name;
private $_email;
public function __construct($photo, $name, $email)
{
$this->_photo = $photo;
$this->_name = $name;
$this->_email = $email;
}
public function getJsonData() {
$json = new stdClass;
foreach (get_object_vars($this) as $name => $value) {
$this->$name = $value;
}
return json_encode($json);
}
}
$person1 = new Person("mypicture.jpg", "john doe", "doeman#gmail.com");
print_r( $person1->getJsonData() );
That's is because you are not using the $json variable but instead you are using $this->$name. Which $this are you refering too? You aren't using the $json variable from what I am seeing.
class Person
{
private $_photo;
private $_name;
private $_email;
public function __construct($photo, $name, $email)
{
$this->_photo = $photo;
$this->_name = $name;
$this->_email = $email;
}
public function getJsonData() {
//I'd make this an array
//$json = new stdClass;
$json = array();
foreach (get_object_vars($this) as $name => $value) {
//Here is my change
//$this->$name = $value;
$json[$name] = $value
}
return json_encode($json);
}
}
$person1 = new Person("mypicture.jpg", "john doe", "doeman#gmail.com");
print_r( $person1->getJsonData() );
Hope it solves you problem. That's how I would do it.
Implement the JsonSerializable interface in your class, starting with PHP 5.4.

GEt data from array object

Hi i'm new to PHP and have below problem. i have written below codes to add data in to the array, now i need to see the added data, please tell me how to do it.
class ShoppingCart
{
private $items = array();
private $n_items = 0;
function addItem( Item $item )
{
$this->items[] = $item;
$this->n_items = $this->n_items + 1;
//print_r (array_values($this->items));
echo "item $this->items added sussesfully";
}
}
and
class Item {
protected $name;
protected $price;
public function __construct($name, $price) {
$this->name = $name;
$this->price = $price;
}
public function getName() {
echo "item is $this->name";
return $this->name;
}
public function getPrice() {
return $this->price;
}
}
and
require_once('AddingMachine.php');
require_once('item.php');
//$arrayofnumbers = array(100,200);
$objectname = new ShoppingCart();
$objectname->addItem(new Item('My Super Cool Toy', 10.99));
Thanks
Since $items is a private property you will need to create a new method on the ShoppingCart class
public function getItems()
{
return $this->items;
}
And then retrieve the $items array by calling the new method
$objectname = new ShoppingCart();
$items = $objectname->getItems();
var_dump($items);

get set properties in php

I'm from the C# environment and I'm starting to learn PHP in school.
I'm used to set my properties in C# like this.
public int ID { get; set; }
What's the equivalent to this in php?
Thanks.
There is none, although there are some proposals for implementing that in future versions.
For now you unfortunately need to declare all getters and setters by hand.
private $ID;
public function setID($ID) {
$this->ID = $ID;
}
public function getID() {
return $this->ID;
}
for some magic (PHP likes magic), you can look up __set and __get magic methods.
Example
class MyClass {
private $ID;
private function setID($ID) {
$this->ID = $ID;
}
private function getID() {
return $this->ID;
}
public function __set($name,$value) {
switch($name) { //this is kind of silly example, bt shows the idea
case 'ID':
return $this->setID($value);
}
}
public function __get($name) {
switch($name) {
case 'ID':
return $this->getID();
}
}
}
$object = new MyClass();
$object->ID = 'foo'; //setID('foo') will be called
Thanks for your answers everyone. It helped me to create something like this:
In my parent class:
public function __get($name){
if (ObjectHelper::existsMethod($this,$name)){
return $this->$name();
}
return null;
}
public function __set($name, $value){
if (ObjectHelper::existsMethod($this,$name))
$this->$name($value);
}
ObjectHelper::existsMethod is a method which just check if given protected method exists.
private $_propertyName = null;
protected function PropertyName($value = ""){
if (empty($value)) // getter
{
if ($this-> _propertyName != null)
return $this->_propertyName;
}
else // setter
{
$this-> _propertyName = $value;
}
return null;
}
So I can use something like this in any class:
$class = new Class();
$class->PropertyName = "test";
echo $class->PropertyName;
I was inspired by C# :)
What do you think about this, guys?
Here is my ObjectHelper if someone would like to use it:
namespace Helpers;
use ReflectionMethod;
class ObjectHelper {
public static function existsMethod($obj, $methodName){
$methods = self::getMethods($obj);
$neededObject = array_filter(
$methods,
function ($e) use($methodName) {
return $e->Name == $methodName;
}
);
if (is_array($neededObject))
return true;
return false;
}
public static function getMethods($obj){
$var = new \ReflectionClass($obj);
return $var->getMethods(ReflectionMethod::IS_PROTECTED);
}
}
Mchi is right, but there is another way of doing it by using single function
private $ID;
public function ID( $value = "" )
{
if( empty( $value ) )
return $this->ID;
else
$this->ID = $value;
}
But yeah this approach is pretty much inline with what you do in c#. but this is only an alternative
Or try using php's __set and __get in your class more info here
http://php.net/manual/en/language.oop5.overloading.php
Another exampled using Variable function name
class MyClass {
private $ID;
protected $ID2;
private function setID($ID) {
$this->ID = $ID;
}
private function getID() {
return $this->ID;
}
private function setID2($ID2) {
$this->ID2 = $ID2;
}
private function getID2() {
return $this->ID2;
}
public function __set($name,$value) {
$functionname='set'.$name;
return $this->$functionname($value);
}
public function __get($name) {
$functionname='get'.$name;
return $this->$functionname();
}
}
$object = new MyClass();
$object->ID = 'foo'; //setID('foo') will be called
$object->ID2 = 'bar'; //setID2('bar') will be called
private $ID;
public function getsetID($value = NULL)
{
if ($value === NULL) {
return $this->ID;
} else {
$this->ID = $value;
}
}
I know I am a bit late to the party on this question, but I had the same question/thought myself. As a C# developer who does PHP, when the job requires, I want to have a simple way to create properties just I would be able to in C#.
I whipped up a first draft this afternoon which allows you to create the backing fields and specify their accessors or have pure accessors with no backing field. I will update my answer as the code evolves and provide a link when I get it to the state where it can be imported as a composer package.
For simplicity, I created the functionality as a PHP trait so you can drop it in to any class you want instead of having to extend a base class. Eventually I hope to extend this functionality to discern between external public calls to the properties and protected/private calls.
Here is the code for the trait itself:
trait PropertyAccessorTrait
{
private static $__propertyAccessors = [];
/* #property string $__propertyPrefix */
public function __get($name)
{
$this->__populatePropertyAcessors($name);
return $this->__performGet($name);
}
public function __set($name, $value)
{
$this->__populatePropertyAcessors($name);
$this->__performSet($name, $value);
}
public function __isset($name)
{
// TODO: Implement __isset() method.
}
public function __unset($name)
{
// TODO: Implement __unset() method.
}
protected function __getBackingFieldName($name)
{
if (property_exists(self::class, '__propertyPrefix')) {
$prefix = $this->__propertyPrefix;
} else {
$prefix = '';
}
return $prefix . $name;
}
protected function __canget($name)
{
$accessors = $this->__getPropertyAccessors($name);
return $accessors !== null && isset($accessors['get']);
}
protected function __canset($name)
{
$accessors = $this->__getPropertyAccessors($name);
return $accessors !== null && isset($accessors['set']);
}
protected function __performGet($name)
{
if (!$this->__canget($name)) {
throw new \Exception('Getter not allowed for property: ' . $name);
}
$accessors = $this->__getPropertyAccessors($name)['get'];
/* #var \ReflectionMethod $method */
$method = $accessors['method'];
if (!empty($method)) {
return $method->invoke($this);
}
return $this->{$this->__getBackingFieldName($name)};
}
protected function __performSet($name, $value)
{
if (!$this->__canset($name)) {
throw new \Exception('Setter not allowed for property: ' . $name);
}
$accessors = $this->__getPropertyAccessors($name)['set'];
/* #var \ReflectionMethod $method */
$method = $accessors['method'];
if (!empty($method)) {
return $method->invoke($this, $value);
}
$this->{$this->__getBackingFieldName($name)} = $value;
}
protected function __getPropertyAccessors($name)
{
return isset(self::$__propertyAccessors[$name])
? self::$__propertyAccessors[$name]
: null
;
}
protected function __getAccessorsFromDocBlock($docblock)
{
$accessors = [];
if (!empty(trim($docblock))) {
$doclines = null;
if (!empty($docblock)) {
$doclines = explode("\n", $docblock);
}
if (!empty($doclines)) {
foreach ($doclines as $line) {
if (preg_match('/#(get|set)\\s+(public|private|protected)/', $line, $matches)) {
$accessors[$matches[1]]['visibility'] = $matches[2];
}
}
}
}
return $accessors;
}
protected function __populatePropertyAcessors($name)
{
if ($this->__getPropertyAccessors($name) !== null) return;
try {
$property = new \ReflectionProperty(self::class, $this->__getBackingFieldName($name));
} catch (\ReflectionException $ex) {
$property = null;
}
$accessors = [];
if ($property != null) {
$accessors = $this->__getAccessorsFromDocBlock($property->getDocComment());
}
try {
$methodName = 'get' . ucfirst($name);
$method = new \ReflectionMethod(self::class, $methodName);
$method->setAccessible(true);
$accessors = array_merge($accessors, $this->__getAccessorsFromDocBlock($method->getDocComment()));
} catch (\ReflectionException $ex) {
$method = null;
}
if ($method !== null || isset($accessors['get'])) {
$accessors['get']['method'] = $method;
}
try {
$methodName = 'set' . ucfirst($name);
$method = new \ReflectionMethod(self::class, $methodName);
$method->setAccessible(true);
$accessors = array_merge($accessors, $this->__getAccessorsFromDocBlock($method->getDocComment()));
} catch (\ReflectionException $ex) {
$method = null;
}
if ($method !== null || isset($accessors['set'])) {
$accessors['set']['method'] = $method;
}
self::$__propertyAccessors[$name] = $accessors;
}
}
Here is a quick unit test I created using the Codeception format:
<?php
class PropertyAssesorTraitTestClass
{
use PropertyAccessorTrait;
private $__propertyPrefix = '_';
/**
* #get public
* #set public
*/
private $_integer = 1;
/**
* #get public
*/
private $_getonly = 100;
/**
* #set public
*/
private $_setonly;
private $_customDoubler;
private function getCustomDoubler()
{
return $this->_customDoubler * 2;
}
private function setCustomDoubler($value)
{
$this->_customDoubler = $value * 2;
}
public $publicField = 1234;
/**
* #return int
* #get public
*/
private function getPureAccessor()
{
return $this->publicField;
}
/**
* #param $value
* #set public
*/
private function setPureAccessor($value)
{
$this->publicField = $value;
}
private $_purePrivate = 256;
}
$I = new UnitTester($scenario);
$I->wantTo('Ensure properties are accessed correctly');
$instance = new PropertyAssesorTraitTestClass();
$I->assertSame(1, $instance->integer);
$instance->integer = 2;
$I->assertSame(2, $instance->integer);
$instance->integer = $instance->integer + 1;
$I->assertSame(3, $instance->integer);
$instance->integer++;
$I->assertSame(4, $instance->integer);
$I->assertSame(100, $instance->getonly);
$I->expectException('Exception', function () use ($instance) { $instance->getonly = 50; });
$instance->setonly = 50;
$I->expectException('Exception', function () use ($instance) { $a = $instance->setonly; });
$instance->customDoubler = 100;
$I->assertSame(400, $instance->customDoubler);
$I->assertSame(1234, $instance->publicField);
$instance->pureAccessor = 1000;
$I->assertSame(1000, $instance->publicField);
$instance->publicField = 1234;
$I->assertSame(1234, $instance->publicField);
$I->assertSame(1234, $instance->pureAccessor);
$I->expectException('Exception', function () use ($instance) { return $instance->purePrivate; });
I like to use this pattern:
class foo
{
//just add p as prefix to be different than method name.
protected $pData;
public funtion __construct() {}
public funtion __destruct() {}
public funtion __clone() {}
public function Data($value == "")
{
if ($value != "") {
$this->pData = $value;
}
return $this->pData;
}
}
$myVar = new foo();
//for SET
$myVar->Data("A Value");
//for GET
$item = $myVar->Data();
class MyClass
{
private $name = null;
public function __construct($name = null)
{
$this->name = $name;
}
public function __set($name, $value)
{
if (property_exists($this, $name)) {
$this->name = $value;
}
return $this;
}
public function __get($name)
{
if (property_exists($this, $name)) {
return $this->$name;
}
return null;
}
}
this is PHP ; you don't need get set
class MyClass {
public $ID;
}
$object = new MyClass();
$object->ID = 'foo';
echo $object->ID;
will work

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