cavepaintingsFork/core/extension.php
2020-01-29 20:22:50 +00:00

454 lines
15 KiB
PHP

<?php declare(strict_types=1);
/**
* \page eande Events and Extensions
*
* An event is a little blob of data saying "something happened", possibly
* "something happened, here's the specific data". Events are sent with the
* send_event() function. Since events can store data, they can be used to
* return data to the extension which sent them, for example:
*
* \code
* $tfe = send_event(new TextFormattingEvent($original_text));
* $formatted_text = $tfe->formatted;
* \endcode
*
* An extension is something which is capable of reacting to events.
*
*
* \page hello The Hello World Extension
*
* \code
* // ext/hello/main.php
* public class HelloEvent extends Event {
* public function __construct($username) {
* $this->username = $username;
* }
* }
*
* public class Hello extends Extension {
* public function onPageRequest(PageRequestEvent $event) { // Every time a page request is sent
* global $user; // Look at the global "currently logged in user" object
* send_event(new HelloEvent($user->name)); // Broadcast a signal saying hello to that user
* }
* public function onHello(HelloEvent $event) { // When the "Hello" signal is recieved
* $this->theme->display_hello($event->username); // Display a message on the web page
* }
* }
*
* // ext/hello/theme.php
* public class HelloTheme extends Themelet {
* public function display_hello($username) {
* global $page;
* $h_user = html_escape($username); // Escape the data before adding it to the page
* $block = new Block("Hello!", "Hello there $h_user"); // HTML-safe variables start with "h_"
* $page->add_block($block); // Add the block to the page
* }
* }
*
* // ext/hello/test.php
* public class HelloTest extends SCorePHPUnitTestCase {
* public function testHello() {
* $this->get_page("post/list"); // View a page, any page
* $this->assert_text("Hello there"); // Check that the specified text is in that page
* }
* }
*
* // themes/mytheme/hello.theme.php
* public class CustomHelloTheme extends HelloTheme { // CustomHelloTheme overrides HelloTheme
* public function display_hello($username) { // the display_hello() function is customised
* global $page;
* $h_user = html_escape($username);
* $page->add_block(new Block(
* "Hello!",
* "Hello there $h_user, look at my snazzy custom theme!"
* );
* }
* }
* \endcode
*
*/
/**
* Class Extension
*
* send_event(BlahEvent()) -> onBlah($event)
*
* Also loads the theme object into $this->theme if available
*
* The original concept came from Artanis's Extension extension
* --> http://github.com/Artanis/simple-extension/tree/master
* Then re-implemented by Shish after he broke the forum and couldn't
* find the thread where the original was posted >_<
*/
abstract class Extension
{
/** @var string */
public $key;
/** @var Themelet */
protected $theme;
/** @var ExtensionInfo */
public $info;
private static $enabled_extensions = [];
public function __construct($class = null)
{
$class = $class ?? get_called_class();
$this->theme = $this->get_theme_object($class);
$this->info = ExtensionInfo::get_for_extension_class($class);
if ($this->info===null) {
throw new ScoreException("Info class not found for extension $class");
}
$this->key = $this->info->key;
}
/**
* Find the theme object for a given extension.
*/
private function get_theme_object(string $base): ?Themelet
{
$custom = 'Custom'.$base.'Theme';
$normal = $base.'Theme';
if (class_exists($custom)) {
return new $custom();
} elseif (class_exists($normal)) {
return new $normal();
} else {
return null;
}
}
/**
* Override this to change the priority of the extension,
* lower numbered ones will receive events first.
*/
public function get_priority(): int
{
return 50;
}
public static function determine_enabled_extensions()
{
self::$enabled_extensions = [];
foreach (array_merge(
ExtensionInfo::get_core_extensions(),
explode(",", EXTRA_EXTS)
) as $key) {
$ext = ExtensionInfo::get_by_key($key);
if ($ext===null || !$ext->is_supported()) {
continue;
}
// FIXME: error if one of our dependencies isn't supported
self::$enabled_extensions[] = $ext->key;
if (!empty($ext->dependencies)) {
foreach ($ext->dependencies as $dep) {
self::$enabled_extensions[] = $dep;
}
}
}
}
public static function is_enabled(string $key): ?bool
{
return in_array($key, self::$enabled_extensions);
}
public static function get_enabled_extensions(): array
{
return self::$enabled_extensions;
}
public static function get_enabled_extensions_as_string(): string
{
return implode(",", self::$enabled_extensions);
}
protected function get_version(string $name): int
{
global $config;
return $config->get_int($name, 0);
}
protected function set_version(string $name, int $ver)
{
global $config;
$config->set_int($name, $ver);
log_info("upgrade", "Set version for $name to $ver");
}
}
abstract class ExtensionInfo
{
// Every credit you get costs us RAM. It stops now.
public const SHISH_NAME = "Shish";
public const SHISH_EMAIL = "webmaster@shishnet.org";
public const SHIMMIE_URL = "http://code.shishnet.org/shimmie2/";
public const SHISH_AUTHOR = [self::SHISH_NAME=>self::SHISH_EMAIL];
public const LICENSE_GPLV2 = "GPLv2";
public const LICENSE_MIT = "MIT";
public const LICENSE_WTFPL = "WTFPL";
public const VISIBLE_ADMIN = "admin";
public const VISIBLE_HIDDEN = "hidden";
private const VALID_VISIBILITY = [self::VISIBLE_ADMIN, self::VISIBLE_HIDDEN];
public $key;
public $core = false;
public $beta = false;
public $name;
public $authors = [];
public $link;
public $license;
public $version;
public $dependencies = [];
public $visibility;
public $description;
public $documentation;
/** @var array which DBs this ext supports (blank for 'all') */
public $db_support = [];
/** @var bool */
private $supported = null;
/** @var string */
private $support_info = null;
public function is_supported(): bool
{
if ($this->supported===null) {
$this->check_support();
}
return $this->supported;
}
public function get_support_info(): string
{
if ($this->supported===null) {
$this->check_support();
}
return $this->support_info;
}
private static $all_info_by_key = [];
private static $all_info_by_class = [];
private static $core_extensions = [];
protected function __construct()
{
assert(!empty($this->key), "key field is required");
assert(!empty($this->name), "name field is required for extension $this->key");
assert(empty($this->visibility) || in_array($this->visibility, self::VALID_VISIBILITY), "Invalid visibility for extension $this->key");
assert(is_array($this->db_support), "db_support has to be an array for extension $this->key");
assert(is_array($this->authors), "authors has to be an array for extension $this->key");
assert(is_array($this->dependencies), "dependencies has to be an array for extension $this->key");
}
public function is_enabled(): bool
{
return Extension::is_enabled($this->key);
}
private function check_support()
{
global $database;
$this->support_info = "";
if (!empty($this->db_support) && !in_array($database->get_driver_name(), $this->db_support)) {
$this->support_info .= "Database not supported. ";
}
// Additional checks here as needed
$this->supported = empty($this->support_info);
}
public static function get_all(): array
{
return array_values(self::$all_info_by_key);
}
public static function get_all_keys(): array
{
return array_keys(self::$all_info_by_key);
}
public static function get_core_extensions(): array
{
return self::$core_extensions;
}
public static function get_by_key(string $key): ?ExtensionInfo
{
if (array_key_exists($key, self::$all_info_by_key)) {
return self::$all_info_by_key[$key];
} else {
return null;
}
}
public static function get_for_extension_class(string $base): ?ExtensionInfo
{
$normal = $base.'Info';
if (array_key_exists($normal, self::$all_info_by_class)) {
return self::$all_info_by_class[$normal];
} else {
return null;
}
}
public static function load_all_extension_info()
{
foreach (get_declared_classes() as $class) {
$rclass = new ReflectionClass($class);
if (!$rclass->isAbstract() && is_subclass_of($class, "ExtensionInfo")) {
$extension_info = new $class();
if (array_key_exists($extension_info->key, self::$all_info_by_key)) {
throw new ScoreException("Extension Info $class with key $extension_info->key has already been loaded");
}
self::$all_info_by_key[$extension_info->key] = $extension_info;
self::$all_info_by_class[$class] = $extension_info;
if ($extension_info->core===true) {
self::$core_extensions[] = $extension_info->key;
}
}
}
}
}
/**
* Class FormatterExtension
*
* Several extensions have this in common, make a common API.
*/
abstract class FormatterExtension extends Extension
{
public function onTextFormatting(TextFormattingEvent $event)
{
$event->formatted = $this->format($event->formatted);
$event->stripped = $this->strip($event->stripped);
}
abstract public function format(string $text): string;
abstract public function strip(string $text): string;
}
/**
* Class DataHandlerExtension
*
* This too is a common class of extension with many methods in common,
* so we have a base class to extend from.
*/
abstract class DataHandlerExtension extends Extension
{
public function onDataUpload(DataUploadEvent $event)
{
$supported_ext = $this->supported_ext($event->type);
$check_contents = $this->check_contents($event->tmpname);
if ($supported_ext && $check_contents) {
move_upload_to_archive($event);
send_event(new ThumbnailGenerationEvent($event->hash, $event->type));
/* Check if we are replacing an image */
if (array_key_exists('replace', $event->metadata) && isset($event->metadata['replace'])) {
/* hax: This seems like such a dirty way to do this.. */
/* Validate things */
$image_id = int_escape($event->metadata['replace']);
/* Check to make sure the image exists. */
$existing = Image::by_id($image_id);
if (is_null($existing)) {
throw new UploadException("Image to replace does not exist!");
}
if ($existing->hash === $event->metadata['hash']) {
throw new UploadException("The uploaded image is the same as the one to replace.");
}
// even more hax..
$event->metadata['tags'] = $existing->get_tag_list();
$image = $this->create_image_from_data(warehouse_path(Image::IMAGE_DIR, $event->metadata['hash']), $event->metadata);
if (is_null($image)) {
throw new UploadException("Data handler failed to create image object from data");
}
try {
send_event(new MediaCheckPropertiesEvent($image));
} catch (MediaException $e) {
throw new UploadException("Unable to scan media properties: ".$e->getMessage());
}
$ire = send_event(new ImageReplaceEvent($image_id, $image));
$event->image_id = $image_id;
} else {
$image = $this->create_image_from_data(warehouse_path(Image::IMAGE_DIR, $event->hash), $event->metadata);
if (is_null($image)) {
throw new UploadException("Data handler failed to create image object from data");
}
try {
send_event(new MediaCheckPropertiesEvent($image));
} catch (MediaException $e) {
throw new UploadException("Unable to scan media properties: ".$e->getMessage());
}
$iae = send_event(new ImageAdditionEvent($image));
$event->image_id = $iae->image->id;
$event->merged = $iae->merged;
// Rating Stuff.
if (!empty($event->metadata['rating'])) {
$rating = $event->metadata['rating'];
send_event(new RatingSetEvent($image, $rating));
}
// Locked Stuff.
if (!empty($event->metadata['locked'])) {
$locked = $event->metadata['locked'];
send_event(new LockSetEvent($image, !empty($locked)));
}
}
} elseif ($supported_ext && !$check_contents) {
// We DO support this extension - but the file looks corrupt
throw new UploadException("Invalid or corrupted file");
}
}
public function onThumbnailGeneration(ThumbnailGenerationEvent $event)
{
$result = false;
if ($this->supported_ext($event->type)) {
if ($event->force) {
$result = $this->create_thumb($event->hash, $event->type);
} else {
$outname = warehouse_path(Image::THUMBNAIL_DIR, $event->hash);
if (file_exists($outname)) {
return;
}
$result = $this->create_thumb($event->hash, $event->type);
}
}
if ($result) {
$event->generated = true;
}
}
public function onDisplayingImage(DisplayingImageEvent $event)
{
global $page;
if ($this->supported_ext($event->image->ext)) {
$this->theme->display_image($page, $event->image);
}
}
abstract protected function supported_ext(string $ext): bool;
abstract protected function check_contents(string $tmpname): bool;
abstract protected function create_image_from_data(string $filename, array $metadata);
abstract protected function create_thumb(string $hash, string $type): bool;
}