# Zend_Serializer_Adapter

`Zend_Serializer` adapters create a bridge for different methods of serializing with very little effort.

Every adapter has different pros and cons. In some cases, not every PHP datatype (e.g., objects) can be converted to a string representation. In most such cases, the type will be converted to a similar type that is serializable -- as an example, PHP objects will often be cast to arrays. If this fails, a `Zend_Serializer_Exception` will be thrown.

Below is a list of available adapters.

## Zend_Serializer_Adapter_PhpSerialize

This adapter uses the built-in `un/serialize` PHP functions, and is a good default adapter choice.

There are no configurable options for this adapter.

## Zend_Serializer_Adapter_Igbinary

Igbinary is Open Source Software released by Sulake Dynamoid Oy. It's a drop-in replacement for the standard PHP serializer. Instead of time and space consuming textual representation, igbinary stores PHP data structures in a compact binary form. Savings are significant when using memcached or similar memory based storages for serialized data.

You need the igbinary PHP extension installed on your system in order to use this adapter.

There adapter takes no configuration options.

## Zend_Serializer_Adapter_Wddx

WDDX (Web Distributed Data eXchange) is a programming-language-, platform-, and transport-neutral data interchange mechanism for passing data between different environments and different computers.

The adapter simply uses the wddx_*() PHP functions. Please read the PHP manual to determine how you may enable them in your PHP installation.

Additionally, the SimpleXML PHP extension is used to check if a returned `NULL` value from `wddx_unserialize()` is based on a serialized `NULL` or on invalid data.

Available options include:

### Zend_Serializer_Adapter_Wddx Options

Option | Data Type | Default Value | Description
--- | --- | --- | ---
comment | string |  | An optional comment that appears in the packet header.

## Zend_Serializer_Adapter_Json

The JSON adapter provides a bridge to the `Zend_Json` component and/or ext/json. Please read the Zend_Json documentation for further information.

Available options include:

### Zend_Serializer_Adapter_Json Options

Option | Data Type | Default Value | Description
--- | --- | --- | ---
cycleCheck | boolean | false | See this section
objectDecodeType | Zend_Json::TYPE_* | Zend_Json::TYPE_ARRAY | See this section
enableJsonExprFinder | boolean | false | See this section

## Zend_Serializer_Adapter_Amf 0 and 3

The AMF adapters, `Zend_Serializer_Adapter_Amf0` and `Zend_Serializer_Adapter_Amf3`, provide a bridge to the serializer of the `Zend_Amf` component. Please read the Zend_Amf documentation for further information.

There are no options for these adapters.

## Zend_Serializer_Adapter_PythonPickle

This adapter converts PHP types to a Python Pickle string representation. With it, you can read the serialized data with Python and read Pickled data of Python with PHP.

Available options include:

### Zend_Serializer_Adapter_PythonPickle Options

Option | Data Type | Default Value | Description
--- | --- | --- | ---
protocol | integer (0 | 1 | 2 | 3) | 0 | The Pickle protocol version used on `serialize`

Datatype merging (PHP to Python) occurs as follows:

### Datatype merging (PHP to Python)

PHP Type | Python Type
--- | ---
NULL | None
boolean | boolean
integer | integer
float | float
string | string
array | list
associative array | dictionary
object | dictionary

Datatype merging (Python to PHP) occurs per the following:

### Datatype merging (Python to PHP)

Python-Type | PHP-Type
--- | ---
None | NULL
boolean | boolean
integer | integer
long | integer | float | string | `Zend_Serializer_Exception`
float | float
string | string
bytes | string
Unicode string | UTF-8 string
list | array
tuple | array
dictionary | associative array
All other types | `Zend_Serializer_Exception`

## Zend_Serializer_Adapter_PhpCode

This adapter generates a parsable PHP code representation using var_export(). On restoring, the data will be executed using eval.

There are no configuration options for this adapter.

### Unserializing objects

Objects will be serialized using the __set_state magic method. If the class doesn't implement this method, a fatal error will occur during execution.

### Uses eval()

The `PhpCode` adapter utilizes `eval()` to unserialize. This introduces both a performance and potential security issue as a new process will be executed. Typically, you should use the `PhpSerialize` adapter unless you require human-readability of the serialized data.