PHP: immutable public member fields - php

I need to create an immutable class which is simply a member field container. I want its fields to be instantiated once in its constructor (the values should be given as parameters to the constructor). I want the fields to be public but immutable. I could have done it with Java using the final keyword before each field. How is it done in PHP?

You should use __set and __get magic methods and declare that property as protected or private:
/**
* #property-read string $value
*/
class Example
{
private $value;
public function __construct()
{
$this->value = "test";
}
public function __get($key)
{
if (property_exists($this, $key)) {
return $this->{$key};
} else {
return null; // or throw an exception
}
}
public function __set($key, $value)
{
return; // or throw an exception
}
}
Example:
$example = new Example();
var_dump($example->value);
$example->value = "invalid";
var_dump($example->value);
Outputs:
string(4) "test"
string(4) "test"
#property-read should help your IDE acknowledge existence of this magic property.

You could use the __set() magic method and throw an exception when someone tries to set a property directly.
class ClassName {
public function __set($key, $value) {
throw new Exception('Can't modify property directly.');
}
}
However, this would prevent modification of properties regardless of whether they're public or not.

magic methods
so you can do better - if you have a dinamyc count of fields
class ClassName {
private $fields = array();
// use class : $cl = new ClassName(array('f'=>2,'field_4'=>5,''12));
// echo $cl->field_4; echo $cl->f;
public function __construct($data= array())
{
if (!is_array($data) || !count($data)) throw new Exception('Not enough args')
foreach ($data as $key=>$val)
{
if (is_numeric($key))
$this->fields['field_'.$key] = $val;
else
$this->fields[$key] = $val;
}
}
/* in this case you can use this class like $cl = new ClassName(12,14,13,15,12); echo $cl->field_1;
public function __construct()
{
$ata = funcs_get_args();
if (!count($data)) throw new Exception('Not enough args')
foreach ($data as $key=>$val)
{
if (is_numeric($key))
$this->fields['field_'.$key] = $val;
else
$this->fields[$key] = $val;
}
}
*/
public function __get($var) {
if (isset($this->fields[$var]))
return $this->fields[$var];
return false;
//or throw new Exception ('Undeclared property');
}
}

<?php
declare(strict_types=1);
final class Immutable
{
/** #var string */
private $value;
public static function withValue(string $value): self
{
return new self($value);
}
public function __construct(string $value)
{
$this->value = $value;
}
public function value(): string
{
return $this->value;
}
}
// Example of usage:
$immutable = Immutable::withValue("my value");
$immutable->value(); // You can get its value but there is no way to modify it.

Related

PHP - Assigning a string value to a variable that is type hinted as an enum

I have some PHP snippets for an application I am trying to restrict inputs coming from a request in the front end of my JavaScript application. The page sends a request using JSON object which contains a field value present that I assign as 'Open', 'Complete', or 'Closed'. I want to prevent unwanted input tampering or values to be sent through.
Question:
Below property $eventstatus is type hinted with the enum, but when I assign the string value inside $array['EventStatus'] PHP (7.4.9) reports an error that my types are not compatible. It needs to see a Status type when in fact I am assigning it a string.
How do I fix this?
$event->eventstatus = $array['EventStatus'];
Enum class (Status)
<?php
namespace app\enums;
abstract class Status
{
const Open = 'Open';
const Complete = 'Complete';
const Closed = 'Closed';
}
Mapper Class Member Function - snippet, code below takes an array value and maps it to a class property
<?php
function mapFromArray($event, $array) {
if (!is_null($array['EventStatus'])) $event->eventstatus = $array['EventStatus'];
}
Model Class
<?php
namespace data\model;
use app\enums\Status;
class Event
{
public $eventid;
public $riskid;
public $eventtitle;
public Status $eventstatus;
}
Your type hint actually tells PHP that you expect $eventstatus to be an instance of Status. But the values are actually just simple strings: 'Open', 'Complete' and 'Closed'.
So the correct type hint would be:
<?php
namespace data\model;
use app\enums\Status;
class Event
{
// ...
public string $eventstatus;
}
But with this PHP accepts any string and not only a "valid" one. Using proper Enums here would help but currently PHP 7 has no native support for Enums (which is implemented for PHP 8.1 though).
If you want to use the Status class for more readable code you can just change the type hint to string.
If you want to validate the input data you could extend the code like this:
<?php
namespace app\enums;
abstract class Status
{
const Open = 'Open';
const Complete = 'Complete';
const Closed = 'Closed';
const Valid_Statuses = [
self::Open,
self::Complete,
self::Closed,
];
}
function mapFromArray($event, $array) {
if (!is_null($array['EventStatus'])) {
if (in_array($array['EventStatus'], Status::Valid_Statuses)) {
$event->eventstatus = $array['EventStatus'];
} else {
// handle invalid status value here
}
}
}
If you want to use strict type hinting to ensure validity everywhere you'd need to wrap the value into a instance of the class, e.g.:
namespace app\enums;
abstract class Status
{
const Open = 'Open';
const Complete = 'Complete';
const Closed = 'Closed';
const Valid_Statuses = [
self::Open,
self::Complete,
self::Closed,
];
private string $value;
public function __construct(string $value) {
if (!in_array($value, self::Valid_Statuses)) {
throw \InvalidArgumentException(sprintf('Invalid status "%s"', $value));
}
$this->value = $value;
}
public function getValue(): string {
return $this->value;
}
public function __toString(): string {
return $this->value;
}
}
function mapFromArray($event, $array) {
if (!is_null($array['EventStatus'])) {
try {
$event->eventstatus = new Status($array['EventStatus']);
} catch (\Exception $exception) {
// handle invalid status value here
}
}
}
I tried a slightly different method from what was proposed using array values, but still relying on some sort of array to check for allowed values.
In my Events class I extended from abstract class Mapper (within which I added a new performMapping function to make mapping more dynamic)
<?php
namespace data\mapper;
use app\enums\Status;
use data\model\Event;
class Events extends Mapper
{
public function mapFromArray($array) : Event
{
$event = $this->_performMapping($array, new Event());
return $event;
}
}
Model - Added Magic Methods (__set, __get)
<?php
namespace data\model;
use app\enums\Status;
class Event
{
public $eventid;
public $riskid;
public $eventtitle;
private $eventstatus;
public $eventownerid;
public $actualdate;
public $scheduledate;
public $baselinedate;
public $actuallikelihood;
public $actualtechnical;
public $actualschedule;
public $actualcost;
public $scheduledlikelihood;
public $scheduledtechnical;
public $scheduledschedule;
public $scheduledcost;
public $baselinelikelihood;
public $baselinetechnical;
public $baselineschedule;
public $baselinecost;
public function __set($name, $value)
{
switch ($name)
{
case 'eventstatus':
{
$class = Status::class;
try
{
$reflection = new \ReflectionClass($class);
}
catch (\ReflectionException $ex)
{
return null;
}
$constants = $reflection->getConstants();
if (array_key_exists($value, $constants))
$this->$name = constant("\\".$class."::$constants[$value]");
else
throw (new \Exception("Property $name not found in " . $class));
}
default:
{
if (property_exists(get_class($this), $name))
$this->$name = $value;
else
throw (new \Exception("Property $name not found in " . get_class($this)));
}
}
}
public function __get($name)
{
switch ($name)
{
case 'eventstatus':
return $this->$name;
default:
if (property_exists($this, $name))
return $this->$name;
else
return null;
}
}
}
Mapper
<?php
namespace data\mapper;
abstract class mapper
{
protected $db = null;
public function __construct(\PDO $db)
{
$this->db = $db;
}
abstract public function mapFromArray($array);
protected function _populateFromCollection($results = null)
{
$return = [];
if ($results != null)
{
foreach($results as $result)
{
$return[] = $this->mapFromArray($result);
}
}
return $return;
}
protected function _performMapping($array, $object)
{
foreach (array_keys($array) as $property)
{
$lowerCaseProperty = strtolower($property);
if (property_exists(get_class($object), $property))
$object->$property = $array[$property];
else if (property_exists(get_class($object), $lowerCaseProperty))
$object->$lowerCaseProperty = $array[$property];
}
return $object;
}
Enum
<?php
namespace app\enums;
abstract class Status
{
const Open = 'Open';
const Complete = 'Complete';
const Closed = 'Closed';
}

php dynamically append method to class

Need dynamically append method to class.
My code:
<?php
class stdClass1 {
public function __call($method, $arguments) {
return call_user_func_array(Closure::bind($this->$method, $this, get_called_class()), $arguments);
}
}
class stdClass2 {
function stdRunMethod() {
$obj = new stdClass1();
$obj->test = function() {
echo 'a simple function';
};
$obj->test();
$obj2 = new stdClass1();
$obj2->test();
}
}
$obj = new stdClass2();
$obj->stdRunMethod();
Question: why test method run only for first instance of stdClass1 class? How to append this method for all new instances?
try this instead (demo):
<?php
class stdClass1 extends \stdClass
{
private static $addedClosures = array();
public function __set($name, $value)
{
if ($value instanceof \Closure) {
self::$addedClosures[$name] = $value;
}
else {
parent::__set($name, $value);
}
}
public function __call($method, $arguments)
{
if (isset(self::$addedClosures[$method]))
return call_user_func_array(self::$addedClosures[$method], $arguments);
return call_user_func_array($method, $arguments);
}
}
class stdClass2 extends \stdClass
{
function stdRunMethod()
{
$obj = new stdClass1();
$obj->test = function () {
print_r('a simple function');
};
$obj->test();
$obj2 = new stdClass1();
$obj2->test();
}
}
The reason it only runs once is that each copy of stdClass1 maintains their own set of variables. In the following
$obj1 = new stdClass1();
$obj1->a = '1';
$obj2 = new stdClass1();
$obj2->a = '2';
echo $obj1->a;
You'll get the value 1 as the output. Because in most cases they maintain different references. Unless you use the static keyword. Static properties are shared between all instances of the class, and should be used carefully, but that's what you're thinking of. What you're thinking of can be done like this
<?php
class stdClass1 {
private static $methods = [];
public function __call($method, $arguments) {
return call_user_func_array(Closure::bind($this->methods[$method], $this, get_called_class()), $arguments);
}
public function __set($name, $value) {
if (is_callable($value)) {
$this->methods[$name] = $value;
} else {
parent::__set($name, $value);
}
}
}
Here we're using a static, defined property to hold all of the dynamic methods, and we're using the magic __set property to set the methods in to the array.
That being said, dynamically loading methods in to an object is bad. Don't do that

Get all the instances of a particular class in PHP

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.

Can you create instance properties dynamically in PHP?

Is there any way to create all instance properties dynamically? For example, I would like to be able to generate all attributes in the constructor and still be able to access them after the class is instantiated like this: $object->property. Note that I want to access the properties separately, and not using an array; here's an example of what I don't want:
class Thing {
public $properties;
function __construct(array $props=array()) {
$this->properties = $props;
}
}
$foo = new Thing(array('bar' => 'baz');
# I don't want to have to do this:
$foo->properties['bar'];
# I want to do this:
//$foo->bar;
To be more specific, when I'm dealing with classes that have a large number of properties, I would like to be able to select all columns in a database (which represent the properties) and create instance properties from them. Each column value should be stored in a separate instance property.
Sort of. There are magic methods that allow you to hook your own code up to implement class behavior at runtime:
class foo {
public function __get($name) {
return('dynamic!');
}
public function __set($name, $value) {
$this->internalData[$name] = $value;
}
}
That's an example for dynamic getter and setter methods, it allows you to execute behavior whenever an object property is accessed. For example
print(new foo()->someProperty);
would print, in this case, "dynamic!" and you could also assign a value to an arbitrarily named property in which case the __set() method is silently invoked. The __call($name, $params) method does the same for object method calls. Very useful in special cases. But most of the time, you'll get by with:
class foo {
public function __construct() {
foreach(getSomeDataArray() as $k => $value)
$this->{$k} = $value;
}
}
...because mostly, all you need is to dump the content of an array into correspondingly named class fields once, or at least at very explicit points in the execution path. So, unless you really need dynamic behavior, use that last example to fill your objects with data.
This is called overloading
http://php.net/manual/en/language.oop5.overloading.php
It depends exactly what you want. Can you modify the class dynamically? Not really. But can you create object properties dynamically, as in one particular instance of that class? Yes.
class Test
{
public function __construct($x)
{
$this->{$x} = "dynamic";
}
}
$a = new Test("bar");
print $a->bar;
Outputs:
dynamic
So an object property named "bar" was created dynamically in the constructor.
Yes, you can.
class test
{
public function __construct()
{
$arr = array
(
'column1',
'column2',
'column3'
);
foreach ($arr as $key => $value)
{
$this->$value = '';
}
}
public function __set($key, $value)
{
$this->$key = $value;
}
public function __get($value)
{
return 'This is __get magic '.$value;
}
}
$test = new test;
// Results from our constructor test.
var_dump($test);
// Using __set
$test->new = 'variable';
var_dump($test);
// Using __get
print $test->hello;
Output
object(test)#1 (3) {
["column1"]=>
string(0) ""
["column2"]=>
string(0) ""
["column3"]=>
string(0) ""
}
object(test)#1 (4) {
["column1"]=>
string(0) ""
["column2"]=>
string(0) ""
["column3"]=>
string(0) ""
["new"]=>
string(8) "variable"
}
This is __get magic hello
This code will set dynamic properties in the constructor which can then be accessed with $this->column. It's also good practice to use the __get and __set magic methods to deal with properties that are not defined within the class. More information them can be found here.
http://www.tuxradar.com/practicalphp/6/14/2
http://www.tuxradar.com/practicalphp/6/14/3
You can use an instance variable to act as a holder for arbitrary values and then use the __get magic method to retrieve them as regular properties:
class My_Class
{
private $_properties = array();
public function __construct(Array $hash)
{
$this->_properties = $hash;
}
public function __get($name)
{
if (array_key_exists($name, $this->_properties)) {
return $this->_properties[$name];
}
return null;
}
}
Why is every example so complicated?
<?php namespace example;
error_reporting(E_ALL | E_STRICT);
class Foo
{
// class completely empty
}
$testcase = new Foo();
$testcase->example = 'Dynamic property';
echo $testcase->example;
Here is simple function to populate object members without making class members public.
It also leaves constructor for your own usage, creating new instance of object without invoking constructor! So, your domain object doesn't depend on database!
/**
* Create new instance of a specified class and populate it with given data.
*
* #param string $className
* #param array $data e.g. array(columnName => value, ..)
* #param array $mappings Map column name to class field name, e.g. array(columnName => fieldName)
* #return object Populated instance of $className
*/
function createEntity($className, array $data, $mappings = array())
{
$reflClass = new ReflectionClass($className);
// Creates a new instance of a given class, without invoking the constructor.
$entity = unserialize(sprintf('O:%d:"%s":0:{}', strlen($className), $className));
foreach ($data as $column => $value)
{
// translate column name to an entity field name
$field = isset($mappings[$column]) ? $mappings[$column] : $column;
if ($reflClass->hasProperty($field))
{
$reflProp = $reflClass->getProperty($field);
$reflProp->setAccessible(true);
$reflProp->setValue($entity, $value);
}
}
return $entity;
}
/******** And here is example ********/
/**
* Your domain class without any database specific code!
*/
class Employee
{
// Class members are not accessible for outside world
protected $id;
protected $name;
protected $email;
// Constructor will not be called by createEntity, it yours!
public function __construct($name, $email)
{
$this->name = $name;
$this->emai = $email;
}
public function getId()
{
return $this->id;
}
public function getName()
{
return $this->name;
}
public function getEmail()
{
return $this->email;
}
}
$row = array('employee_id' => '1', 'name' => 'John Galt', 'email' => 'john.galt#whoisjohngalt.com');
$mappings = array('employee_id' => 'id'); // Employee has id field, so we add translation for it
$john = createEntity('Employee', $row, $mappings);
print $john->getName(); // John Galt
print $john->getEmail(); // john.galt#whoisjohngalt.com
//...
P.S. Retrieving data from object is similar, e.g. use $reflProp->setValue($entity, $value);
P.P.S. This function is heavily inspired by Doctrine2 ORM which is awesome!
class DataStore // Automatically extends stdClass
{
public function __construct($Data) // $Data can be array or stdClass
{
foreach($Data AS $key => $value)
{
$this->$key = $value;
}
}
}
$arr = array('year_start' => 1995, 'year_end' => 2003);
$ds = new DataStore($arr);
$gap = $ds->year_end - $ds->year_start;
echo "Year gap = " . $gap; // Outputs 8
You can:
$variable = 'foo';
$this->$variable = 'bar';
Would set the attribute foo of the object it's called on to bar.
You can also use functions:
$this->{strtolower('FOO')} = 'bar';
This would also set foo (not FOO) to bar.
Extend stdClass.
class MyClass extends stdClass
{
public function __construct()
{
$this->prop=1;
}
}
I hope this is what you need.
This is really complicated way to handle this kind of rapid development. I like answers and magic methods but in my opinion it is better to use code generators like CodeSmith.
I have made template that connect to database, read all columns and their data types and generate whole class accordingly.
This way I have error free (no typos) readable code. And if your database model changes run generator again... it works for me.
If you really really must do it, the best way is to overload an ArrayObject, that allows to maintain iteration support (foreach) that will still loop through all your properties.
I note that you said "without using an array", and I just want to assure you that that while technically an array is being used in the background, you NEVER HAVE TO SEE IT. You access all properties via ->properyname or foreach ($class in $name => $value).
Here is a sample I was working on yesterday, note this is also STRONGLY TYPED. So properties that are marked "integer" will throw an error if you try and supply a "string".
You can remove that of course.
There is also an AddProperty() member function, although it is not demonstrated in the example. That will allow you to add properties later.
Sample usage:
$Action = new StronglyTypedDynamicObject("Action",
new StrongProperty("Player", "ActionPlayer"), // ActionPlayer
new StrongProperty("pos", "integer"),
new StrongProperty("type", "integer"),
new StrongProperty("amount", "double"),
new StrongProperty("toCall", "double"));
$ActionPlayer = new StronglyTypedDynamicObject("ActionPlayer",
new StrongProperty("Seat", "integer"),
new StrongProperty("BankRoll", "double"),
new StrongProperty("Name", "string"));
$ActionPlayer->Seat = 1;
$ActionPlayer->Name = "Doctor Phil";
$Action->pos = 2;
$Action->type = 1;
$Action->amount = 7.0;
$Action->Player = $ActionPlayer;
$newAction = $Action->factory();
$newAction->pos = 4;
print_r($Action);
print_r($newAction);
class StrongProperty {
var $value;
var $type;
function __construct($name, $type) {
$this->name = $name;
$this->type = $type;
}
}
class StronglyTypedDynamicObject extends ModifiedStrictArrayObject {
static $basic_types = array(
"boolean",
"integer",
"double",
"string",
"array",
"object",
"resource",
);
var $properties = array(
"__objectName" => "string"
);
function __construct($objectName /*, [ new StrongProperty("name", "string"), [ new StrongProperty("name", "string"), [ ... ]]] */) {
$this->__objectName = $objectName;
$args = func_get_args();
array_shift($args);
foreach ($args as $arg) {
if ($arg instanceof StrongProperty) {
$this->AddProperty($arg->name, $arg->type);
} else {
throw new Exception("Invalid Argument");
}
}
}
function factory() {
$new = clone $this;
foreach ($new as $key => $value) {
if ($key != "__objectName") {
unset($new[$key]);
}
}
// $new->__objectName = $this->__objectName;
return $new;
}
function AddProperty($name, $type) {
$this->properties[$name] = $type;
return;
if (in_array($short_type, self::$basic_types)) {
$this->properties[$name] = $type;
} else {
throw new Exception("Invalid Type: $type");
}
}
public function __set($name, $value) {
self::sdprintf("%s(%s)\n", __FUNCTION__, $name);
$this->check($name, $value);
$this->offsetSet($name, $value);
}
public function __get($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, $name);
$this->check($name);
return $this->offsetGet($name);
}
protected function check($name, $value = "r4nd0m") {
if (!array_key_exists($name, $this->properties)) {
throw new Exception("Attempt to access non-existent property '$name'");
}
$value__objectName = "";
if ($value != "r4nd0m") {
if ($value instanceof StronglyTypedDynamicObject) {
$value__objectName = $value->__objectName;
}
if (gettype($value) != $this->properties[$name] && $value__objectName != $this->properties[$name]) {
throw new Exception("Attempt to set {$name} ({$this->properties[$name]}) with type " . gettype($value) . ".$value__objectName");
}
}
}
}
class ModifiedStrictArrayObject extends ArrayObject {
static $debugLevel = 0;
/* Some example properties */
static public function StaticDebug($message) {
if (static::$debugLevel > 1) {
fprintf(STDERR, "%s\n", trim($message));
}
}
static public function sdprintf() {
$args = func_get_args();
$string = call_user_func_array("sprintf", $args);
self::StaticDebug("D " . trim($string));
}
protected function check($name) {
if (!array_key_exists($name, $this->properties)) {
throw new Exception("Attempt to access non-existent property '$name'");
}
}
//static public function sget($name, $default = NULL) {
/******/ public function get ($name, $default = NULL) {
self::sdprintf("%s(%s)\n", __FUNCTION__, $name);
$this->check($name);
if (array_key_exists($name, $this->storage)) {
return $this->storage[$name];
}
return $default;
}
public function offsetGet($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
$this->check($name);
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetSet($name, $value) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
$this->check($name);
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetExists($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
$this->check($name);
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function offsetUnset($name) {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
$this->check($name);
return call_user_func_array(array(parent, __FUNCTION__), func_get_args());
}
public function __toString() {
self::sdprintf("%s(%s)\n", __FUNCTION__, $name);
foreach ($this as $key => $value) {
$output .= "$key: $value\n";
}
return $output;
}
function __construct($array = false, $flags = 0, $iterator_class = "ArrayIterator") {
self::sdprintf("%s(%s)\n", __FUNCTION__, implode(",", func_get_args()));
parent::setFlags(parent::ARRAY_AS_PROPS);
}
}
After reading #Udo 's answer. I've come up with the following pattern, that doesn't bloat a class instance with what-ever items that is in your constructor array argument but still let you type less and easily add new properties to the class.
class DBModelConfig
{
public $host;
public $username;
public $password;
public $db;
public $port = '3306';
public $charset = 'utf8';
public $collation = 'utf8_unicode_ci';
public function __construct($config)
{
foreach ($config as $key => $value) {
if (property_exists($this, $key)) {
$this->{$key} = $value;
}
}
}
}
Then you can pass arrays like:
[
'host' => 'localhost',
'driver' => 'mysql',
'username' => 'myuser',
'password' => '1234',
'charset' => 'utf8',
'collation' => 'utf8_unicode_ci',
'db' => 'key not used in receiving class'
]

Refactoring To Remove Static Methods Code Smell

I have the current basic structure for each domain object that I need to create:
class Model_Company extends LP_Model
{
protected static $_gatewayName = 'Model_Table_Company';
protected static $_gateway;
protected static $_class;
public static function init()
{
if(self::$_gateway == null)
{
self::$_gateway = new self::$_gatewayName();
self::$_class = get_class();
}
}
public static function get()
{
self::init();
$param = func_get_arg(0);
if($param instanceof Zend_Db_Table_Row_Abstract)
{
$row = $param;
}
elseif(is_numeric($param))
{
$row = self::$_gateway->find($param)->current();
}
return new self::$_class($row);
}
public static function getCollection()
{
self::init();
$param = func_get_arg(0);
if($param instanceof Zend_Db_Table_Rowset_Abstract)
{
$rowset = $param;
}
elseif(!$param)
{
$rowset = self::$_gateway->fetchAll();
}
$array = array ();
foreach ($rowset as $row)
{
$array[] = new self::$_class($row);
}
return $array;
}
}
I initially tried to refactor the static methods into the parent LP_Model class only to learn finally what "late static binding" means in the php world.
I'm just wondering if anyone has suggestions on how to refactor this code so that I don't have to redeclare the same three functions in every domain object that I create?
How about this:
<?php
abstract class Model_Abstract
{
protected $_gatewayName = null;
protected $_gateway = null;
protected function _init()
{
$this->_gateway = new $this->_gatewayName();
}
protected function __construct($row = null)
{
$this->_init();
if ($row) {
$this->_data = $row;
}
}
public static function getAbstract($class, $param)
{
$model = new $class();
if($param instanceof Zend_Db_Table_Row_Abstract)
{
$row = $param;
}
elseif(is_numeric($param))
{
$row = $model->_gateway->find($param)->current();
}
return new $class($row);
}
public static function getAbstractCollection($class, $param = null)
{
$model = new $class();
if($param instanceof Zend_Db_Table_Rowset_Abstract)
{
$rowset = $param;
}
elseif($param === null)
{
$rowset = $model->_gateway->fetchAll();
}
$array = array ();
foreach ($rowset as $row)
{
$array[] = new $class($row);
}
return $array;
}
abstract public static function get($param);
abstract public static function getCollection($param = null);
}
class Model_Company extends Model_Abstract
{
protected $_gatewayName = 'Model_Table_Company';
public static function get($param) {
return self::getAbstract(__CLASS__, $param);
}
public static function getCollection($param = null) {
return self::getAbstractCollection(__CLASS__, $param);
}
}
class Model_Table_Company extends Zend_Db_Table_Abstract
{
protected $_name = 'company';
}
$model = Model_Company::get(1);
print "Got an object of type ".get_class($model)."\n";
$models = Model_Company::getCollection();
print "Got ".count($models)." objects of type ".get_class($models[0])."\n";
?>
Unfortunately, to make the functions easy to call, you have to duplicate get() and getCollection() in each subclass. The other option is to call the function in the parent class:
$model = Model_Abstract::getAbstract('Model_Company', 1);
print "Got an object of type ".get_class($model)."\n";
$models = Model_Abstract::getAbstractCollection('Model_Company');
print "Got ".count($models)." objects of type ".get_class($models[0])."\n";
You can rename the base class and its function names if you want to go that route. But the point is that you must name the child class in one place or the other: either make a boilerplate function in the child class as in my first example, or else name the class in a string as in my second example.

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