ILIAS\WOPI\Discovery\Crawler Class Reference

Collaboration diagram for ILIAS\WOPI\Discovery\Crawler:

Public Member Functions
	__construct ()
	validate (URI $discovery_url)
	crawl (URI $discovery_url)
	crawlContent (string $content)
	Parses discovery XML that has already been fetched. More...
	getProofKeys ()
	The proof keys of the discovery read last, null if it publishes none. More...

Static Public Member Functions
static	isWebUrl (URI $url)

Data Fields
const	ALLOWED_SCHEMES = ['https', 'http']
	the discovery and the URLs it publishes must be web URLs, anything else (file, php, ...) would let the discovery read local resources or launch script in the ILIAS origin More...

Private Member Functions
	fetch (URI $discovery_url)
	load (?string $content)
	parse ()
	favIconUrl (\SimpleXMLElement $app)

Private Attributes
const	XPATH = '/wopi-discovery/net-zone/app'
const	TIMEOUT_SECONDS = 10
const	MAX_REDIRECTS = 3
const	MAX_SIZE_BYTES = 2 * 1024 * 1024
array	$crawl_actions = []
string	$content = null
SimpleXMLElement	$discovery = null
array	$xml_app_elements = null

Detailed Description

Author

Fabian Schmid fabia.nosp@m.n@sr.nosp@m..solu.nosp@m.tion.nosp@m.s

Definition at line 28 of file Crawler.php.

Constructor & Destructor Documentation

__construct()

ILIAS\WOPI\Discovery\Crawler::__construct

(

)

Definition at line 50 of file Crawler.php.

    {
        $this->crawl_actions = [
            ActionTarget::VIEW->value,
            ActionTarget::EMBED_VIEW->value,
            ActionTarget::EDIT->value,
            ActionTarget::EMBED_EDIT->value,
            ActionTarget::EDIT_NEW->value,
            ActionTarget::CONVERT->value,
        ];
    }

Member Function Documentation

crawl()

ILIAS\WOPI\Discovery\Crawler::crawl

(

URI

$discovery_url

)

Definition at line 120 of file Crawler.php.

                                             : ?Apps
    {
        if (!$this->validate($discovery_url)) {
            return null;
        }
 
        return $this->parse();
    }

References ILIAS\WOPI\Discovery\Crawler\parse(), and ILIAS\WOPI\Discovery\Crawler\validate().

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crawlContent()

ILIAS\WOPI\Discovery\Crawler::crawlContent

(

string

$content

)

Parses discovery XML that has already been fetched.

Definition at line 132 of file Crawler.php.

                                                 : ?Apps
    {
        if (!$this->load($content)) {
            return null;
        }
 
        return $this->parse();
    }

References ILIAS\WOPI\Discovery\Crawler\load(), and ILIAS\WOPI\Discovery\Crawler\parse().

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favIconUrl()

ILIAS\WOPI\Discovery\Crawler::favIconUrl ( \SimpleXMLElement  $app )

private

Definition at line 231 of file Crawler.php.

                                                       : ?URI
    {
        $value = $app['favIconUrl'] ?? null;
        if ($value === null) {
            return null;
        }
        try {
            $url = new URI((string) $value);
        } catch (\Throwable) {
            return null;
        }
 
        return self::isWebUrl($url) ? $url : null;
    }

References ILIAS\WOPI\Discovery\Crawler\isWebUrl().

Referenced by ILIAS\WOPI\Discovery\Crawler\parse().

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fetch()

ILIAS\WOPI\Discovery\Crawler::fetch ( URI  $discovery_url )

private

Definition at line 79 of file Crawler.php.

                                              : ?string
    {
        $context = stream_context_create([
            'http' => [
                'timeout' => self::TIMEOUT_SECONDS,
                'max_redirects' => self::MAX_REDIRECTS,
            ],
        ]);
        // one byte more than allowed tells a discovery which is too large
        $content = @file_get_contents((string) $discovery_url, false, $context, 0, self::MAX_SIZE_BYTES + 1);
        if ($content === false || $content === '' || strlen($content) > self::MAX_SIZE_BYTES) {
            return null;
        }
 
        return $content;
    }

References ILIAS\WOPI\Discovery\Crawler\$content.

Referenced by ILIAS\WOPI\Discovery\Crawler\validate().

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getProofKeys()

ILIAS\WOPI\Discovery\Crawler::getProofKeys

(

)

The proof keys of the discovery read last, null if it publishes none.

Definition at line 144 of file Crawler.php.

                                  : ?ProofKeys
    {
        $element = $this->discovery?->xpath('/wopi-discovery/proof-key')[0] ?? null;
        if (!$element instanceof \SimpleXMLElement) {
            return null;
        }
        $modulus = (string) ($element['modulus'] ?? '');
        $exponent = (string) ($element['exponent'] ?? '');
        if ($modulus === '' || $exponent === '') {
            return null;
        }
        $old_modulus = (string) ($element['oldmodulus'] ?? '');
        $old_exponent = (string) ($element['oldexponent'] ?? '');
 
        return new ProofKeys(
            new ProofKey($modulus, $exponent),
            $old_modulus === '' || $old_exponent === '' ? null : new ProofKey($old_modulus, $old_exponent)
        );
    }

isWebUrl()

static ILIAS\WOPI\Discovery\Crawler::isWebUrl ( URI  $url )

static

Definition at line 62 of file Crawler.php.

                                             : bool
    {
        return in_array(strtolower($url->getSchema()), self::ALLOWED_SCHEMES, true);
    }

References ILIAS\Data\URI\getSchema().

Referenced by ILIAS\WOPI\Discovery\Crawler\favIconUrl(), and ILIAS\WOPI\Embed\EmbeddedApplication\getActionLauncherURL().

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load()

ILIAS\WOPI\Discovery\Crawler::load ( ?string  $content )

private

Definition at line 96 of file Crawler.php.

                                           : bool
    {
        try {
            $this->content = $content;
            if ($this->content === null) {
                return false;
            }
 
            // invalid XML is reported by returning false, not by warnings
            $use_internal_errors = libxml_use_internal_errors(true);
            $this->discovery = simplexml_load_string($this->content) ?: null;
            libxml_clear_errors();
            libxml_use_internal_errors($use_internal_errors);
            if ($this->discovery === null) {
                return false;
            }
            $this->xml_app_elements = $this->discovery->xpath(self::XPATH);
 
            return is_array($this->xml_app_elements);
        } catch (\Throwable) {
            return false;
        }
    }

References ILIAS\WOPI\Discovery\Crawler\$content.

Referenced by ILIAS\WOPI\Discovery\Crawler\crawlContent(), and ILIAS\WOPI\Discovery\Crawler\validate().

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parse()

ILIAS\WOPI\Discovery\Crawler::parse ( )

private

Definition at line 164 of file Crawler.php.

                            : Apps
    {
        // read wopi-discovery XML from $discovery_url and parse Apps with it's Actions
        $apps = [];
        foreach ($this->xml_app_elements as $app) {
            $actions = [];
            foreach ($app->action as $action) {
                $action_name = $action['name'] ?? null;
                $action_ext = $action['ext'] ?? null;
                $action_urlsrc = $action['urlsrc'] ?? null;
                // the extension of the resulting file: targetext for convert, newext for editnew
                $target_text = isset($action['targetext'])
                    ? (string) $action['targetext']
                    : (isset($action['newext']) ? (string) $action['newext'] : null);
                if (!$action_name instanceof \SimpleXMLElement) {
                    continue;
                }
                if (!$action_ext instanceof \SimpleXMLElement) {
                    continue;
                }
                if (!$action_urlsrc instanceof \SimpleXMLElement) {
                    continue;
                }
 
                if (!in_array((string) $action_name, $this->crawl_actions, true)) {
                    continue;
                }
 
                $uri_string = rtrim((string) $action_urlsrc, '?');
                // remove all after ?
                $uri = explode('?', $uri_string);
                $uri_string = $uri[0];
                try {
                    $launcher_url = new URI($uri_string);
                } catch (\Throwable) {
                    continue;
                }
                if (!self::isWebUrl($launcher_url)) {
                    continue;
                }
                $actions[] = new Action(
                    0,
                    (string) $action_name,
                    (string) $action_ext,
                    $launcher_url,
                    $uri[1] ?? null,
                    $target_text
                );
            }
            if ($actions === []) {
                continue;
            }
 
            $app_name = $app['name'] ?? null;
            if ($app_name === null) {
                continue;
            }
            $apps[] = new App(
                0,
                (string) $app_name,
                $actions,
                $this->favIconUrl($app)
            );
        }
        return new Apps($apps);
    }

References ILIAS\WOPI\Discovery\Crawler\$crawl_actions, and ILIAS\WOPI\Discovery\Crawler\favIconUrl().

Referenced by ILIAS\WOPI\Discovery\Crawler\crawl(), and ILIAS\WOPI\Discovery\Crawler\crawlContent().

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validate()

ILIAS\WOPI\Discovery\Crawler::validate

(

URI

$discovery_url

)

Definition at line 67 of file Crawler.php.

                                                : bool
    {
        if (!self::isWebUrl($discovery_url)) {
            return false;
        }
        try {
            return $this->load($this->fetch($discovery_url));
        } catch (\Throwable) {
            return false;
        }
    }

References ILIAS\WOPI\Discovery\Crawler\fetch(), and ILIAS\WOPI\Discovery\Crawler\load().

Referenced by ILIAS\WOPI\Discovery\Crawler\crawl().

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Field Documentation

$content

string ILIAS\WOPI\Discovery\Crawler::$content = null

private

Definition at line 43 of file Crawler.php.

Referenced by ILIAS\WOPI\Discovery\Crawler\fetch(), and ILIAS\WOPI\Discovery\Crawler\load().

$crawl_actions

array ILIAS\WOPI\Discovery\Crawler::$crawl_actions = []

private

Definition at line 42 of file Crawler.php.

Referenced by ILIAS\WOPI\Discovery\Crawler\parse().

$discovery

SimpleXMLElement ILIAS\WOPI\Discovery\Crawler::$discovery = null

private

Definition at line 44 of file Crawler.php.

$xml_app_elements

array ILIAS\WOPI\Discovery\Crawler::$xml_app_elements = null

private

Definition at line 48 of file Crawler.php.

ALLOWED_SCHEMES

const ILIAS\WOPI\Discovery\Crawler::ALLOWED_SCHEMES = ['https', 'http']

the discovery and the URLs it publishes must be web URLs, anything else (file, php, ...) would let the discovery read local resources or launch script in the ILIAS origin

Definition at line 38 of file Crawler.php.

MAX_REDIRECTS

const ILIAS\WOPI\Discovery\Crawler::MAX_REDIRECTS = 3

private

Definition at line 40 of file Crawler.php.

MAX_SIZE_BYTES

const ILIAS\WOPI\Discovery\Crawler::MAX_SIZE_BYTES = 2 * 1024 * 1024

private

Definition at line 41 of file Crawler.php.

TIMEOUT_SECONDS

const ILIAS\WOPI\Discovery\Crawler::TIMEOUT_SECONDS = 10

private

Definition at line 39 of file Crawler.php.

XPATH

const ILIAS\WOPI\Discovery\Crawler::XPATH = '/wopi-discovery/net-zone/app'

private

Definition at line 33 of file Crawler.php.

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The documentation for this class was generated from the following file:

• components/ILIAS/WOPI/classes/Discovery/Crawler.php