How do I echo the value from the object? In the following example I expect 1105 service number to be printed after "case".
$vbk->set('service_no','1105');
echo "case".$vbk->service_no;
I need to use object for this purpose.
Implement a __get function which will handle that logic. When __get is called, it will look for our stored properties in $properties and return it if it's found. POC:
<?php
class service
{
private $properties = array();
public function set($key, $value)
{
$this->properties[$key] = $value;
}
public function __get($key)
{
if(isset($this->properties[$key]))
return $this->properties[$key];
return null;
}
}
$service = new service;
$service->set('service_no','1105');
// case1105
echo "case".$service->service_no;
Related
I'm trying to JSON encode some objects in PHP, but I'm facing a problem: I want to encode data which is kept by a class private members.
I found this piece of code to encode this object by calling an encode function like:
public function encodeJSON()
{
foreach ($this as $key => $value)
{
$json->$key = $value;
}
return json_encode($json);
}
However, this only works if the object I want to encode does not contain other objects inside, which is the case. How can I do to encode not only the "outer" object, but encode as well any members that are objects too?
The best method to serialize an object with private properties is to implement the \JsonSerializable interface and then implement your own JsonSerialize method to return the data you require to be serialized.
<?php
class Item implements \JsonSerializable
{
private $var;
private $var1;
private $var2;
public function __construct()
{
// ...
}
public function jsonSerialize()
{
$vars = get_object_vars($this);
return $vars;
}
}
json_encode will now serialize your object correctly.
If you're using php 5.4 you can use the JsonSerializable interface: http://www.php.net/manual/en/class.jsonserializable.php
You just implement a jsonSerialize method in your class which returns whatever you want to be encoded.
Then when you pass your object into json_encode, it'll encode the result of jsonSerialize.
Anyway. You need create public method in your class to return all their fields json encoded
public function getJSONEncode() {
return json_encode(get_object_vars($this));
}
I think #Petah's got the best approach, but that way you lose properties that are array or object. So I added a function wich do that recursively:
function json_encode_private($object) {
function extract_props($object) {
$public = [];
$reflection = new ReflectionClass(get_class($object));
foreach ($reflection->getProperties() as $property) {
$property->setAccessible(true);
$value = $property->getValue($object);
$name = $property->getName();
if(is_array($value)) {
$public[$name] = [];
foreach ($value as $item) {
if (is_object($item)) {
$itemArray = extract_props($item);
$public[$name][] = $itemArray;
} else {
$public[$name][] = $item;
}
}
} else if(is_object($value)) {
$public[$name] = extract_props($value);
} else $public[$name] = $value;
}
return $public;
}
return json_encode(extract_props($object));
}
EDIT: Added is_object() check inside the array loop to avoid a get_class() exception in the next extract_props() call when the array elements are not objects, like strings or numbers.
I think this may be a great case for the Usage of Traits
using the below guist I implemented jsonSerializable interface in multiple points of my app while keeping the code manageable
https://gist.github.com/zburgermeiszter/7dc5e65b06bb34a325a0363726fd8e14
trait JsonSerializeTrait
{
function jsonSerialize()
{
$reflect = new \ReflectionClass($this);
$props = $reflect->getProperties(\ReflectionProperty::IS_STATIC | \ReflectionProperty::IS_PUBLIC | \ReflectionProperty::IS_PROTECTED | \ReflectionProperty::IS_PRIVATE);
$propsIterator = function() use ($props) {
foreach ($props as $prop) {
yield $prop->getName() => $this->{$prop->getName()};
}
};
return iterator_to_array($propsIterator());
}
}
then you just have to do
class YourClass implements JsonSerializable
{
use JsonSerializeTrait;
... normal encapsulated code...
}
public function jsonSerialize()
{
$objectArray = [];
foreach($this as $key => $value) {
$objectArray[$key] = $value;
}
return json_encode($objectArray);
}
I personally think this is a way of doing it. It is similar to Petah's, except It keeps in line with encapsulation well, because the array is populated from the object.
Put this function in either your object or as a trait to be used by your object. To each their own though.
This would print a JSON with all of the properties (public, private and protected) of class foo:
$reflection = new ReflectionClass('Foo');
$properties = $reflection->getdefaultProperties();
echo json_encode($properties);
It would work from any context.
You can only encode an object's private members from within the class. As a side note though, does the json_enocde function not work for you? http://php.net/manual/en/function.json-encode.php
Using reflection you can json_encode private properties, although its not considered best practice:
function json_encode_private($object) {
$public = [];
$reflection = new ReflectionClass($object);
foreach ($reflection->getProperties() as $property) {
$property->setAccessible(true);
$public[$property->getName()] = $property->getValue($object);
}
return json_encode($public);
}
E.g.
class Foo {
public $a = 1;
public $b = 2;
}
class Bar {
private $c = 3;
private $d = 4;
}
var_dump(json_encode(new Foo()));
var_dump(json_encode_private(new Bar()));
Outputs:
string(13) "{"a":1,"b":2}"
string(13) "{"c":3,"d":4}"
http://codepad.viper-7.com/nCcKYW
I want to be able to do something like:
objects = getAllInstances(ClassName);
where ClassName has a unique field, so that two instances can not have the exact same value of that field.
class ClassName {
protected $unique_field;
public function __construct($value)
{
$objects = getAllInstances(self);
foreach($objects as $object)
{
if($object->getUniqueField() === $value)
{
return $object;
}
}
}
public function getUniqueField()
{
return $this->unique_field;
}
};
Is there a design pattern, a built-in function in PHP for this purpose, or must I use a static array that holds all the created instances and then just loop over it?
You could create a factory that keeps a reference to all instances created with it:
class ClassNameFactory
{
private $instances = [];
public function create($value)
{
return $this->instances[] = new ClassName($value);
}
public function getInstances()
{
return $this->instances;
}
}
$f = new ClassNameFactory();
$o1 = $f->create('foo');
$o2 = $f->create('bar');
print_r($f->getInstances());
You can hold a static array with all the existing instances. Something similar to this...
static $instances;
public function __construct($name) {
$this->unique_field = $name;
if (empty($instances)) {
self::$instances = array();
}
foreach (self::$instances as $instance) {
if ($instance->getUniqueField() === $name)
return $instance;
}
self::$instances[] = $this;
}
What you need is the registry pattern:
class ClassNameRegistry {
private $instances = array();
public function set($name, InterfaceName $instance) {
$this->instances[$name] = $instance;
}
public function get($name) {
if (!$this->has($name)) {
throw new \LogicException(sprintf(
'No instance "%s" found for class "ClassName".',
$name
);
}
return $this->instances[$name];
}
public function has($name) {
return isset($this->instances[$name]);
}
public function getAll() {
return $this->instances;
}
}
This is certainly the best OOP architecture option because you isolate the behaviour in a standalone class as a service. If you do not have a dependency injection mechanism with services, I would suggest you to define the registry class as a singleton!
In my example, I used a InterfaceName to have a low coupling between Registry and its handled instances.
I'm trying to JSON encode some objects in PHP, but I'm facing a problem: I want to encode data which is kept by a class private members.
I found this piece of code to encode this object by calling an encode function like:
public function encodeJSON()
{
foreach ($this as $key => $value)
{
$json->$key = $value;
}
return json_encode($json);
}
However, this only works if the object I want to encode does not contain other objects inside, which is the case. How can I do to encode not only the "outer" object, but encode as well any members that are objects too?
The best method to serialize an object with private properties is to implement the \JsonSerializable interface and then implement your own JsonSerialize method to return the data you require to be serialized.
<?php
class Item implements \JsonSerializable
{
private $var;
private $var1;
private $var2;
public function __construct()
{
// ...
}
public function jsonSerialize()
{
$vars = get_object_vars($this);
return $vars;
}
}
json_encode will now serialize your object correctly.
If you're using php 5.4 you can use the JsonSerializable interface: http://www.php.net/manual/en/class.jsonserializable.php
You just implement a jsonSerialize method in your class which returns whatever you want to be encoded.
Then when you pass your object into json_encode, it'll encode the result of jsonSerialize.
Anyway. You need create public method in your class to return all their fields json encoded
public function getJSONEncode() {
return json_encode(get_object_vars($this));
}
I think #Petah's got the best approach, but that way you lose properties that are array or object. So I added a function wich do that recursively:
function json_encode_private($object) {
function extract_props($object) {
$public = [];
$reflection = new ReflectionClass(get_class($object));
foreach ($reflection->getProperties() as $property) {
$property->setAccessible(true);
$value = $property->getValue($object);
$name = $property->getName();
if(is_array($value)) {
$public[$name] = [];
foreach ($value as $item) {
if (is_object($item)) {
$itemArray = extract_props($item);
$public[$name][] = $itemArray;
} else {
$public[$name][] = $item;
}
}
} else if(is_object($value)) {
$public[$name] = extract_props($value);
} else $public[$name] = $value;
}
return $public;
}
return json_encode(extract_props($object));
}
EDIT: Added is_object() check inside the array loop to avoid a get_class() exception in the next extract_props() call when the array elements are not objects, like strings or numbers.
I think this may be a great case for the Usage of Traits
using the below guist I implemented jsonSerializable interface in multiple points of my app while keeping the code manageable
https://gist.github.com/zburgermeiszter/7dc5e65b06bb34a325a0363726fd8e14
trait JsonSerializeTrait
{
function jsonSerialize()
{
$reflect = new \ReflectionClass($this);
$props = $reflect->getProperties(\ReflectionProperty::IS_STATIC | \ReflectionProperty::IS_PUBLIC | \ReflectionProperty::IS_PROTECTED | \ReflectionProperty::IS_PRIVATE);
$propsIterator = function() use ($props) {
foreach ($props as $prop) {
yield $prop->getName() => $this->{$prop->getName()};
}
};
return iterator_to_array($propsIterator());
}
}
then you just have to do
class YourClass implements JsonSerializable
{
use JsonSerializeTrait;
... normal encapsulated code...
}
public function jsonSerialize()
{
$objectArray = [];
foreach($this as $key => $value) {
$objectArray[$key] = $value;
}
return json_encode($objectArray);
}
I personally think this is a way of doing it. It is similar to Petah's, except It keeps in line with encapsulation well, because the array is populated from the object.
Put this function in either your object or as a trait to be used by your object. To each their own though.
This would print a JSON with all of the properties (public, private and protected) of class foo:
$reflection = new ReflectionClass('Foo');
$properties = $reflection->getdefaultProperties();
echo json_encode($properties);
It would work from any context.
You can only encode an object's private members from within the class. As a side note though, does the json_enocde function not work for you? http://php.net/manual/en/function.json-encode.php
Using reflection you can json_encode private properties, although its not considered best practice:
function json_encode_private($object) {
$public = [];
$reflection = new ReflectionClass($object);
foreach ($reflection->getProperties() as $property) {
$property->setAccessible(true);
$public[$property->getName()] = $property->getValue($object);
}
return json_encode($public);
}
E.g.
class Foo {
public $a = 1;
public $b = 2;
}
class Bar {
private $c = 3;
private $d = 4;
}
var_dump(json_encode(new Foo()));
var_dump(json_encode_private(new Bar()));
Outputs:
string(13) "{"a":1,"b":2}"
string(13) "{"c":3,"d":4}"
http://codepad.viper-7.com/nCcKYW
I have an array of reflectionClasses.
I need to get a reflectionObject from one of these and then call its constructor with some parameters.
The point is to instantiate an object without knowing the class name (i'll know it at runtime).
Example, just to render the idea:
foreach (Conf::get_array() as $reflection_class) {
//it's not right, just to render the idea
$reflectionObject = new ReflectionObject ($reflection_class);
$objects[] = $reflectionObject->construct($param_1, $param_2);
}
Another example:
foreach (Conf::get_array() as $reflection_class) {
$objects[] = new $reflection_class($param_1, $param_2); //not right. maybe from php 5.3?
}
You don't need an instance of ReflectionObject for that. ReflectionClass has the two methods
public stdclass newInstance(mixed args)
public stdclass newInstanceArgs(array args)
example:
<?php
class Foo {
public function __construct($a, $b) { echo "Foo($a,$b) "; }
}
class Bar {
public function __construct($a, $b) { echo "Bar($a,$b) "; }
}
class Conf {
public static function get_array() {
return array(new ReflectionClass('Foo'), new ReflectionClass('Bar'));
}
}
$args = array('A', 'B');
$object = array();
foreach (Conf::get_array() as $reflection_class) {
$objects[] = $reflection_class->newInstanceArgs($args);
}
var_dump($objects);
I need to serialize a proxy class. The class uses __set and __get to store values in an array. I want the serialization to look like it is just a flat object. In other words, my class looks like:
class Proxy
{
public $data = array();
public function __get($name)
{
return $data[$name]
}
}
and I want a foreach loop to return all the keys and values in $data, when I say:
foreach($myProxy as $key)
Is this possible?
class Proxy implements IteratorAggregate
{
public $data = array();
public function __get($name)
{
return $data[$name];
}
public function getIterator()
{
$o = new ArrayObject($this->data);
return $o->getIterator();
}
}
$p = new Proxy();
$p->data = array(2, 4, 6);
foreach ($p as $v)
{
echo $v;
}
Output is: 246.
See Object Iteration in the PHP docs for more details.
You want to implement the SPL iterator interface
Something like this:
class Proxy implements Iterator
{
public $data = array();
public function __get($name)
{
return $data[$name]
}
function rewind()
{
reset($this->data);
$this->valid = true;
}
function current()
{
return current($this->data)
}
function key()
{
return key($this->data)
}
function next() {
next($this->data);
}
function valid()
{
return key($this->data) !== null;
}
}