300 lines
8.6 KiB
Markdown
300 lines
8.6 KiB
Markdown
Friendica Storage Backend Addon development
|
|
===========================================
|
|
|
|
* [Home](help)
|
|
|
|
Storage backends can be added via addons.
|
|
A storage backend is implemented as a class, and the plugin register the class to make it avaiable to the system.
|
|
|
|
## The Storage Backend Class
|
|
|
|
The class must live in `Friendica\Addon\youraddonname` namespace, where `youraddonname` the folder name of your addon.
|
|
|
|
The class must implement `Friendica\Model\Storage\IStorage` interface. All method in the interface must be implemented:
|
|
|
|
namespace Friendica\Model\Storage;
|
|
|
|
```php
|
|
interface IStorage
|
|
{
|
|
public function get(string $reference);
|
|
public function put(string $data, string $reference = '');
|
|
public function delete(string $reference);
|
|
public function getOptions();
|
|
public function saveOptions(array $data);
|
|
public function __toString();
|
|
public static function getName();
|
|
}
|
|
```
|
|
|
|
- `get(string $reference)` returns data pointed by `$reference`
|
|
- `put(string $data, string $reference)` saves data in `$data` to position `$reference`, or a new position if `$reference` is empty.
|
|
- `delete(string $reference)` delete data pointed by `$reference`
|
|
|
|
Each storage backend can have options the admin can set in admin page.
|
|
|
|
- `getOptions()` returns an array with details about each option to build the interface.
|
|
- `saveOptions(array $data)` get `$data` from admin page, validate it and save it.
|
|
|
|
The array returned by `getOptions()` is defined as:
|
|
|
|
[
|
|
'option1name' => [ ..info.. ],
|
|
'option2name' => [ ..info.. ],
|
|
...
|
|
]
|
|
|
|
An empty array can be returned if backend doesn't have any options.
|
|
|
|
The info array for each option is defined as:
|
|
|
|
[
|
|
'type',
|
|
|
|
define the field used in form, and the type of data.
|
|
one of 'checkbox', 'combobox', 'custom', 'datetime', 'input', 'intcheckbox', 'password', 'radio', 'richtext', 'select', 'select_raw', 'textarea', 'yesno'
|
|
|
|
'label',
|
|
|
|
Translatable label of the field. This label will be shown in admin page
|
|
|
|
value,
|
|
|
|
Current value of the option
|
|
|
|
'help text',
|
|
|
|
Translatable description for the field. Will be shown in admin page
|
|
|
|
extra data
|
|
|
|
Optional. Depends on which 'type' this option is:
|
|
|
|
- 'select': array `[ value => label ]` of choices
|
|
- 'intcheckbox': value of input element
|
|
- 'select_raw': prebuild html string of `<option >` tags
|
|
- 'yesno': array `[ 'label no', 'label yes']`
|
|
|
|
Each label should be translatable
|
|
|
|
];
|
|
|
|
|
|
See doxygen documentation of `IStorage` interface for details about each method.
|
|
|
|
## Register a storage backend class
|
|
|
|
Each backend must be registered in the system when the plugin is installed, to be aviable.
|
|
|
|
`DI::facStorage()->register(string $class)` is used to register the backend class.
|
|
|
|
When the plugin is uninstalled, registered backends must be unregistered using
|
|
`DI::facStorage()->unregister(string $class)`.
|
|
|
|
You have to register a new hook in your addon, listening on `storage_instance(App $a, array $data)`.
|
|
In case `$data['name']` is your storage class name, you have to instance a new instance of your `Friendica\Model\Storage\IStorage` class.
|
|
Set the instance of your class as `$data['storage']` to pass it back to the backend.
|
|
|
|
This is necessary because it isn't always clear, if you need further construction arguments.
|
|
|
|
## Adding tests
|
|
|
|
**Currently testing is limited to core Friendica only, this shows theoretically how tests should work in the future**
|
|
|
|
Each new Storage class should be added to the test-environment at [Storage Tests](https://github.com/friendica/friendica/tree/develop/tests/src/Model/Storage/).
|
|
|
|
Add a new test class which's naming convention is `StorageClassTest`, which extend the `StorageTest` in the same directory.
|
|
|
|
Override the two necessary instances:
|
|
```php
|
|
use Friendica\Model\Storage\IStorage;
|
|
|
|
abstract class StorageTest
|
|
{
|
|
// returns an instance of your newly created storage class
|
|
abstract protected function getInstance();
|
|
|
|
// Assertion for the option array you return for your new StorageClass
|
|
abstract protected function assertOption(IStorage $storage);
|
|
}
|
|
```
|
|
|
|
## Example
|
|
|
|
Here an hypotetical addon which register an unusefull storage backend.
|
|
Let's call it `samplestorage`.
|
|
|
|
This backend will discard all data we try to save and will return always the same image when we ask for some data.
|
|
The image returned can be set by the administrator in admin page.
|
|
|
|
First, the backend class.
|
|
The file will be `addon/samplestorage/SampleStorageBackend.php`:
|
|
|
|
```php
|
|
<?php
|
|
namespace Friendica\Addon\samplestorage;
|
|
|
|
use Friendica\Model\Storage\IStorage;
|
|
|
|
use Friendica\Core\Config\IConfig;
|
|
use Friendica\Core\L10n;
|
|
|
|
class SampleStorageBackend implements IStorage
|
|
{
|
|
const NAME = 'Sample Storage';
|
|
|
|
/** @var IConfig */
|
|
private $config;
|
|
/** @var L10n */
|
|
private $l10n;
|
|
|
|
/**
|
|
* SampleStorageBackend constructor.
|
|
* @param IConfig $config The configuration of Friendica
|
|
*
|
|
* You can add here every dynamic class as dependency you like and add them to a private field
|
|
* Friendica automatically creates these classes and passes them as argument to the constructor
|
|
*/
|
|
public function __construct(IConfig $config, L10n $l10n)
|
|
{
|
|
$this->config = $config;
|
|
$this->l10n = $l10n;
|
|
}
|
|
|
|
public function get(string $reference)
|
|
{
|
|
// we return always the same image data. Which file we load is defined by
|
|
// a config key
|
|
$filename = $this->config->get('storage', 'samplestorage', 'sample.jpg');
|
|
return file_get_contents($filename);
|
|
}
|
|
|
|
public function put(string $data, string $reference = '')
|
|
{
|
|
if ($reference === '') {
|
|
$reference = 'sample';
|
|
}
|
|
// we don't save $data !
|
|
return $reference;
|
|
}
|
|
|
|
public function delete(string $reference)
|
|
{
|
|
// we pretend to delete the data
|
|
return true;
|
|
}
|
|
|
|
public function getOptions()
|
|
{
|
|
$filename = $this->config->get('storage', 'samplestorage', 'sample.jpg');
|
|
return [
|
|
'filename' => [
|
|
'input', // will use a simple text input
|
|
$this->l10n->t('The file to return'), // the label
|
|
$filename, // the current value
|
|
$this->l10n->t('Enter the path to a file'), // the help text
|
|
// no extra data for 'input' type..
|
|
],
|
|
];
|
|
}
|
|
|
|
public function saveOptions(array $data)
|
|
{
|
|
// the keys in $data are the same keys we defined in getOptions()
|
|
$newfilename = trim($data['filename']);
|
|
|
|
// this function should always validate the data.
|
|
// in this example we check if file exists
|
|
if (!file_exists($newfilename)) {
|
|
// in case of error we return an array with
|
|
// ['optionname' => 'error message']
|
|
return ['filename' => 'The file doesn\'t exists'];
|
|
}
|
|
|
|
$this->config->set('storage', 'samplestorage', $newfilename);
|
|
|
|
// no errors, return empty array
|
|
return [];
|
|
}
|
|
|
|
public function __toString()
|
|
{
|
|
return self::NAME;
|
|
}
|
|
|
|
public static function getName()
|
|
{
|
|
return self::NAME;
|
|
}
|
|
}
|
|
```
|
|
|
|
Now the plugin main file. Here we register and unregister the backend class.
|
|
|
|
The file is `addon/samplestorage/samplestorage.php`
|
|
|
|
```php
|
|
<?php
|
|
/**
|
|
* Name: Sample Storage Addon
|
|
* Description: A sample addon which implements an unusefull storage backend
|
|
* Version: 1.0.0
|
|
* Author: Alice <https://alice.social/~alice>
|
|
*/
|
|
|
|
use Friendica\Addon\samplestorage\SampleStorageBackend;
|
|
use Friendica\DI;
|
|
|
|
function samplestorage_install()
|
|
{
|
|
// on addon install, we register our class with name "Sample Storage".
|
|
// note: we use `::class` property, which returns full class name as string
|
|
// this save us the problem of correctly escape backslashes in class name
|
|
DI::storageManager()->register(SampleStorageBackend::class);
|
|
}
|
|
|
|
function samplestorage_unistall()
|
|
{
|
|
// when the plugin is uninstalled, we unregister the backend.
|
|
DI::storageManager()->unregister(SampleStorageBackend::class);
|
|
}
|
|
|
|
function samplestorage_storage_instance(\Friendica\App $a, array $data)
|
|
{
|
|
if ($data['name'] === SampleStorageBackend::getName()) {
|
|
// instance a new sample storage instance and pass it back to the core for usage
|
|
$data['storage'] = new SampleStorageBackend(DI::config(), DI::l10n(), DI::cache());
|
|
}
|
|
}
|
|
```
|
|
|
|
**Theoretically - until tests for Addons are enabled too - create a test class with the name `addon/tests/SampleStorageTest.php`:
|
|
|
|
```php
|
|
use Friendica\Model\Storage\IStorage;
|
|
use Friendica\Test\src\Model\Storage\StorageTest;
|
|
|
|
class SampleStorageTest extends StorageTest
|
|
{
|
|
// returns an instance of your newly created storage class
|
|
protected function getInstance()
|
|
{
|
|
// create a new SampleStorageBackend instance with all it's dependencies
|
|
// Have a look at DatabaseStorageTest or FilesystemStorageTest for further insights
|
|
return new SampleStorageBackend();
|
|
}
|
|
|
|
// Assertion for the option array you return for your new StorageClass
|
|
protected function assertOption(IStorage $storage)
|
|
{
|
|
$this->assertEquals([
|
|
'filename' => [
|
|
'input',
|
|
'The file to return',
|
|
'sample.jpg',
|
|
'Enter the path to a file'
|
|
],
|
|
], $storage->getOptions());
|
|
}
|
|
}
|
|
```
|