To store an entry in the registry, use the static method set().

<?php

Zend_Registry::set('index', $value);

?>

The value can be an object, an array, or a scalar. You can change the value stored in a specific entry of the registry by using set() to set it to a new value.

The index can be a scalar, either string or integer, like an ordinary array.

To retrieve an entry from the registry, use the static method get().

<?php

$value = Zend_Registry::get('index');

?>

The getInstance() method returns the static registry object.

A registry object is iterable.

<?php

$registry = Zend_Registry::getInstance();

foreach ($registry as $index => $value) {
    echo "Registry index $index contains:\n";
    var_dump($value);
}

?>

In addition to accessing the static registry through static methods, you can create an instance directly and use it as an object.

The registry instance you access through the static methods is simply one such instance, and it is for convenience that it is stored statically, so you can access it from anywhere in your appliation.

Use a traditional new constructor to create an instance of the registry. This gives you the opportunity to initialize the entries in the registry as an associatve array.

<?php

$registry = new Zend_Registry(array('index' => $value));

?>

After constructing this instance, you can use it using array-object methods, or you can set this instance to become the static instance using the static method setInstance().

<?php

$registry = new Zend_Registry(array('index' => $value));

Zend_Registry::setInstance($registry);

?>

The setInstance() method throws a Zend_Exception if the static registry has already been initialized by its first access.

If you have several values to get or set, you may find it convenient to access the registry with array notation.

<?php

$registry = Zend_Registry::getInstance();

$registry['index'] = $value;

var_dump( $registry['index'] );

?>

You may also find it convenient to access the registry in an object-oriented fashion, using index names as object properties. To do this, you need to specifically construct the registry object using the ArrayObject::ARRAY_AS_PROPS option, and initialize the static instance. You must do this before the static registry has been accessed for the first time. Beware of using this option, since some versions of PHP have bugs when using the registry with this option.

<?php

// in your application bootstrap:
$registry = new Zend_Registry(array(), ArrayObject::ARRAY_AS_PROPS)
Zend_Registry::setInstance($registry);
$registry->tree = 'apple';

.
.
.

// in a different function, elsewhere in your application:
$registry = Zend_Registry::getInstance();

echo $registry->tree; // echo's "apple"

$registry->index = $value;

var_dump($registry->index);

?>

To find out if a particular index in the registry has a value, use the static method isRegistered().

<?php

if (Zend_Registry::isRegistered($index)) {
    $value = Zend_Registry::get($index);
}

?>

To find out if a particular index in a registry array-object has a value, use isset() like you would with an ordinary array.

<?php

$registry = Zend_Registry::getInstance();

// using array-access syntax
if (isset($registry['index'])) {
    var_dump( $registry['index'] );
}

// using object-access syntax, if enabled
if (isset($registry->index)) {
    var_dump( $registry->index );
}

?>

The static registry is an instance of the class Zend_Registry. If you want to add functionality to the registry, you can create a class that extends Zend_Registry, and then you can specify this class as the class to use for the static registry. Use the static method setClassName() to specify the class. The class must extend Zend_Registry.

<?php

Zend_Registry::setClassName('My_Registry');

Zend_Registry::set('index', $value);

?>

The registry throws a Zend_Exception if you try to set the classname after the registry has been accessed for the first time. It is recommended that you specify the classname for your static registry in your application bootstrap.

Although it is not normally necessary, you can unset the static instance of the registry. Use the static method _unsetInstance().

	Data loss risk
	When you use _unsetInstance(), all data in the static registry are discarded and cannot be recovered.

You might use this method, for example, if you want to use setInstance() or setClassName() after the static registry object has been initialized. Unsetting the static instance allows you to use these methods.

<?php

Zend_Registry::set('index', $value);

Zend_Registry::_unsetInstance();

// change the class
Zend_Registry::setClassName('My_Registry');

Zend_Registry::set('index', $value);

?>