Class to implement utility methods. More...

Static Public Member Functions
static bool	isLtiMessage ()
	Check whether the request received could be an LTI message.

static array	getRequestParameters ()
	Return GET and POST request parameters (POST parameters take precedence).

static void	logError (string $message, bool $showSource=true)
	Log an error message.

static void	logInfo (string $message, bool $showSource=false)
	Log an information message.

static void	logDebug (string $message, bool $showSource=false)
	Log a debug message.

static void	logRequest (bool $debugLevel=false)
	Log a request received.

static void	logForm (string $url, array $params, string $method='POST', bool $debugLevel=false)
	Log a form submission.

static void	log (string $message, bool $showSource=false)
	Log an error message irrespective of the logging level.

static void	setMessage (bool $isError, string $message)
	Set an error or warning message.

static array	getMessages (bool $isError)
	Get the system error or warning messages.

static string	sendForm (string $url, array $params, string $target='', string $javascript='')
	Generate a web page containing an auto-submitted form of parameters.

static never	redirect (string $url, array $params)
	Redirect to a URL with query parameters.

static void	setTestCookie (bool $delete=false)
	Set or delete a test cookie.

static string	getRandomString (int $length=8)
	Generate a random string.

static string	stripHtml (string $html)
	Strip HTML tags from a string.

static string	urlEncode (?string $val)
	URL encode a value.

static string	valToString (mixed $val, ?string $default='')
	Convert a value to a string.

static int float null	valToNumber (mixed $val)
	Convert a value to a numeric.

static bool	valToBoolean (mixed $val)
	Convert a value to a boolean.

static object null	checkObject (object $obj, string $fullname, bool $required=false, bool $stringValues=false)
	Get the named object element from object.

static array	checkArray (object $obj, string $fullname, bool $required=false, bool $notEmpty=false)
	Get the named array element from object.

static string	checkString (object $obj, string $fullname, bool $required=false, ?bool $notEmpty=false, string\|array $fixedValue='', bool $overrideStrictMode=false, ?string $default='')
	Get the named string element from object.

static string	checkUrl (object $obj, string $fullname, bool $required=false)
	Get the named filly-qualified URL element from object.

static int float null	checkNumber (object $obj, string $fullname, bool $required=false, int\|false $minimum=false, bool $minimumExclusive=false, bool $overrideStrictMode=false)
	Get the named number element from object.

static int null	checkInteger (object $obj, string $fullname, bool $required=false, int\|false $minimum=false, bool $minimumExclusive=false, bool $overrideStrictMode=false)
	Get the named integer element from object.

static bool null	checkBoolean (object $obj, string $fullname, bool $required=false, ?bool $default=null)
	Get the named boolean element from object.

static int	checkDateTime (object $obj, string $fullname, bool $required=false)
	Get the named number element from object.

static mixed	jsonDecode (?string $str, bool $associative=false)
	Decode a JSON string.

static object	cloneObject (object $obj)
	Clone an object and any objects it contains.

Public Attributes
const	JWT_CLAIM_PREFIX = 'https://purl.imsglobal.org/spec/lti'
	Prefix for standard JWT message claims.

const	MESSAGE_TYPE_MAPPING
	Mapping for standard message types.

const	JWT_CLAIM_MAPPING
	Mapping for standard message parameters to JWT claim.

const	TEST_COOKIE_NAME = 'celtic_lti_test_cookie'
	Name of test cookie.

Static Public Attributes
static array	$METHOD_NAMES
	List of supported message types and associated class methods.

static array	$requestParameters = null
	GET and POST request parameters.

static LogLevel	$logLevel = LogLevel::None
	Current logging level.

static bool	$strictMode = false
	Whether full compliance with the LTI specification is required.

static bool	$disableFetchedPublicKeysSave = false
	Whether the automatic saving of fetched valid public keys should be disabled.

static int	$formSubmissionTimeout = 2
	Delay (in seconds) before a manual button is displayed in case a browser is blocking a form submission.

Detailed Description

Class to implement utility methods.

Author: Stephen P Vickers steph.nosp@m.en@s.nosp@m.pvsof.nosp@m.twar.nosp@m.eprod.nosp@m.ucts.nosp@m..com

Copyright: SPV Software Products

Licence: http://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License, version 3

Member Function Documentation

◆ checkArray()

static array ceLTIc\LTI\Util::checkArray	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		bool	$notEmpty = false )

static

Get the named array element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element
bool	$required	True if the element must be present
bool	$notEmpty	True if the element must not have an empty value

Returns: array Value of element (or empty string if not found)

References checkString().

Referenced by checkObject(), and ceLTIc\LTI\Service\Groups\get().

◆ checkBoolean()

static bool null ceLTIc\LTI\Util::checkBoolean	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		?bool	$default = null )

static

Get the named boolean element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present
string \| null	$default	Value to return when a conversion is not possible (optional, default is an empty string)

Returns: bool|null Value of element (or null if not found or valid)

Referenced by ceLTIc\LTI\Service\Groups\get(), ceLTIc\LTI\Service\LineItem\get(), and ceLTIc\LTI\Content\FileItem\toJsonldObject().

◆ checkDateTime()

static int ceLTIc\LTI\Util::checkDateTime	(	object	$obj,
		string	$fullname,
		bool	$required = false )

static

Get the named number element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present

Returns: int Value of element (or 0 if not found or valid)

Referenced by ceLTIc\LTI\Service\LineItem\get().

◆ checkInteger()

static int null ceLTIc\LTI\Util::checkInteger	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		int\|false	$minimum = false,
		bool	$minimumExclusive = false,
		bool	$overrideStrictMode = false )

static

Get the named integer element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present
int \| false	$minimum	Minimum value (or false is none)
bool	$minimumExclusive	True if value must exceed the minimum
bool	$overrideStrictMode	Ignore strict mode setting

Returns: int|null Value of element (or null if not found or valid)

Referenced by checkNumber(), and ceLTIc\LTI\Content\Image\toJsonldObject().

◆ checkNumber()

static int float null ceLTIc\LTI\Util::checkNumber	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		int\|false	$minimum = false,
		bool	$minimumExclusive = false,
		bool	$overrideStrictMode = false )

static

Get the named number element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present
int \| false	$minimum	Minimum value (or false is none)
bool	$minimumExclusive	True if value must exceed the minimum
bool	$overrideStrictMode	Ignore strict mode setting

Returns: int|float|null Value of element (or null if not found or valid)

References checkInteger().

Referenced by ceLTIc\LTI\Service\LineItem\get(), and ceLTIc\LTI\Content\LineItem\toJsonObject().

◆ checkObject()

static object null ceLTIc\LTI\Util::checkObject	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		bool	$stringValues = false )

static

Get the named object element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element
bool	$required	True if the element must be present
bool	$stringValues	True if the values must be strings

Returns: object|null Value of element (or null if not found)

References checkArray().

◆ checkString()

static string ceLTIc\LTI\Util::checkString	(	object	$obj,
		string	$fullname,
		bool	$required = false,
		?bool	$notEmpty = false,
		string\|array	$fixedValue = '',
		bool	$overrideStrictMode = false,
		?string	$default = '' )

static

Get the named string element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present
bool \| null	$notEmpty	True if the element must not have an empty value (use null to issue a warning message when it does)
string	$fixedValue	Required value of element (empty string if none)
bool	$overrideStrictMode	Ignore strict mode setting
string \| null	$default	Value to return when a conversion is not possible (optional, default is an empty string)

Returns: string Value of element (or default value if not found or valid)

Referenced by checkArray(), ceLTIc\LTI\Service\Groups\get(), ceLTIc\LTI\Service\LineItem\get(), and ceLTIc\LTI\Content\LineItem\toJsonObject().

◆ checkUrl()

static string ceLTIc\LTI\Util::checkUrl	(	object	$obj,
		string	$fullname,
		bool	$required = false )

static

Get the named filly-qualified URL element from object.

Parameters

object	$obj	Object containing the element
string	$fullname	Name of element (may include a path)
bool	$required	True if the element must be present

Returns: string Value of element (or default value if not found or valid)

Referenced by ceLTIc\LTI\Content\Image\toJsonldObject().

◆ cloneObject()

static object ceLTIc\LTI\Util::cloneObject ( object $obj )

static

Clone an object and any objects it contains.

Parameters

object $obj Object to be cloned

Returns: object

◆ getMessages()

static array ceLTIc\LTI\Util::getMessages ( bool $isError )

static

Get the system error or warning messages.

Parameters

bool $isError True if error messages are to be returned

Returns: array Array of messages

◆ getRandomString()

static string ceLTIc\LTI\Util::getRandomString ( int $length = 8 )

static

Generate a random string.

The generated string will only comprise letters (upper- and lower-case) and digits.

Parameters

int $length Length of string to be generated (optional, default is 8 characters)

Returns: string Random string

Referenced by ceLTIc\LTI\ResourceLinkShareKey\__construct(), and ceLTIc\LTI\Tool\findService().

◆ getRequestParameters()

static array ceLTIc\LTI\Util::getRequestParameters ( )

static

Return GET and POST request parameters (POST parameters take precedence).

Returns: array

References log(), and logDebug().

Referenced by ceLTIc\LTI\Tool\getMessageParameters(), and ceLTIc\LTI\Platform\getTools().

◆ isLtiMessage()

static bool ceLTIc\LTI\Util::isLtiMessage ( )

static

Check whether the request received could be an LTI message.

Returns: bool

References log(), and logInfo().

◆ jsonDecode()

static mixed ceLTIc\LTI\Util::jsonDecode	(	?string	$str,
		bool	$associative = false )

static

Decode a JSON string.

Parameters

string \| null	$str	The JSON string to be decoded
bool	$associative	True to return JSON objects as associative arrays

Returns: mixed

◆ log()

static void ceLTIc\LTI\Util::log	(	string	$message,
		bool	$showSource = false )

static

Log an error message irrespective of the logging level.

Parameters

string	$message	Message to be logged
bool	$showSource	True if the name and line number of the current file are to be included

Referenced by getRequestParameters(), and isLtiMessage().

◆ logDebug()

static void ceLTIc\LTI\Util::logDebug	(	string	$message,
		bool	$showSource = false )

static

Log a debug message.

Parameters

string	$message	Message to be logged
bool	$showSource	True if the name and line number of the current file are to be included

References logInfo().

Referenced by ceLTIc\LTI\Http\HttpMessage\__construct(), ceLTIc\LTI\Service\LineItem\deleteLineItem(), ceLTIc\LTI\Jwt\FirebaseClient\getClaim(), ceLTIc\LTI\Jwt\WebTokenClient\getClaim(), getRequestParameters(), logError(), and logRequest().

◆ logError()

static void ceLTIc\LTI\Util::logError	(	string	$message,
		bool	$showSource = true )

static

Log an error message.

Parameters

string	$message	Message to be logged
bool	$showSource	True if the name and line number of the current file are to be included

References ceLTIc\LTI\OAuth\OAuthRequest\$POST_INPUT, logDebug(), logInfo(), and ceLTIc\LTI\OAuth\OAuthUtil\parse_parameters().

Referenced by ceLTIc\LTI\Jwt\FirebaseClient\verify().

◆ logForm()

static void ceLTIc\LTI\Util::logForm	(	string	$url,
		array	$params,
		string	$method = 'POST',
		bool	$debugLevel = false )

static

Log a form submission.

Parameters

string	$url	URL to which the form should be submitted
array	$params	Array of form parameters
string	$method	HTTP Method used to submit form (optional, default is POST)
bool	$debugLevel	True if the form details should always be logged (optional, default is false to use current log level)

◆ logInfo()

static void ceLTIc\LTI\Util::logInfo	(	string	$message,
		bool	$showSource = false )

static

Log an information message.

Parameters

string	$message	Message to be logged
bool	$showSource	True if the name and line number of the current file are to be included

Referenced by isLtiMessage(), logDebug(), and logError().

◆ logRequest()

static void ceLTIc\LTI\Util::logRequest ( bool $debugLevel = false )

static

Log a request received.

Parameters

bool $debugLevel True if the request details should be logged at the debug level (optional, default is false for information level)

References logDebug().

Referenced by ceLTIc\LTI\Tool\getMessageParameters().

◆ redirect()

static never ceLTIc\LTI\Util::redirect	(	string	$url,
		array	$params )

static

Redirect to a URL with query parameters.

Parameters

string	$url	URL to which the form should be submitted
array	$params	Array of form parameters

Returns: never

◆ sendForm()

static string ceLTIc\LTI\Util::sendForm	(	string	$url,
		array	$params,
		string	$target = '',
		string	$javascript = '' )

static

Generate a web page containing an auto-submitted form of parameters.

Parameters

string	$url	URL to which the form should be submitted
array	$params	Array of form parameters
string	$target	Name of target (optional)
string	$javascript	Javascript to be inserted (optional, default is to just auto-submit form)

Returns: string

Referenced by ceLTIc\LTI\Tool\onLtiEndAssessment().

◆ setMessage()

static void ceLTIc\LTI\Util::setMessage	(	bool	$isError,
		string	$message )

static

Set an error or warning message.

Parameters

bool	$isError	True if the message represents an error
string	$message	Message

Referenced by ceLTIc\LTI\Service\Groups\get(), ceLTIc\LTI\Service\ToolSettings\set(), and valToNumber().

◆ setTestCookie()

static void ceLTIc\LTI\Util::setTestCookie ( bool $delete = false )

static

Set or delete a test cookie.

Parameters

bool $delete True if the cookie is to be deleted (optional, default is false)

◆ stripHtml()

static string ceLTIc\LTI\Util::stripHtml ( string $html )

static

Strip HTML tags from a string.

Parameters

string $html HTML string to be stripped

Returns: string

◆ urlEncode()

static string ceLTIc\LTI\Util::urlEncode ( ?string $val )

static

URL encode a value.

Parameters

string | null $val The value to be encoded

Returns: string

◆ valToBoolean()

static bool ceLTIc\LTI\Util::valToBoolean ( mixed $val )

static

Convert a value to a boolean.

Parameters

mixed $val The value to be converted

Returns: bool

◆ valToNumber()

static int float null ceLTIc\LTI\Util::valToNumber ( mixed $val )

static

Convert a value to a numeric.

Parameters

mixed $val The value to be converted

Returns: int|float|null

References setMessage().

◆ valToString()

static string ceLTIc\LTI\Util::valToString	(	mixed	$val,
		?string	$default = '' )

static

Convert a value to a string.

Parameters

mixed	$val	The value to be converted
string \| null	$default	Value to return when a conversion is not possible (optional, default is an empty string)

Returns: string

Referenced by ceLTIc\LTI\Service\ToolSettings\set(), and ceLTIc\LTI\Content\TimePeriod\toJsonldObject().

Member Data Documentation

◆ $disableFetchedPublicKeysSave

bool ceLTIc\LTI\Util::$disableFetchedPublicKeysSave = false

static

Whether the automatic saving of fetched valid public keys should be disabled.

◆ $formSubmissionTimeout

int ceLTIc\LTI\Util::$formSubmissionTimeout = 2

static

Delay (in seconds) before a manual button is displayed in case a browser is blocking a form submission.

◆ $logLevel

LogLevel ceLTIc\LTI\Util::$logLevel = LogLevel::None

static

Current logging level.

Referenced by ceLTIc\LTI\DataConnector\DataConnector\fixPlatformSettings(), ceLTIc\LTI\DataConnector\DataConnector\getDataConnector(), ceLTIc\LTI\Tool\getMessageParameters(), ceLTIc\LTI\Platform\getTools(), and ceLTIc\LTI\Tool\save().

◆ $METHOD_NAMES

array ceLTIc\LTI\Util::$METHOD_NAMES

static

Initial value:

= [
        'basic-lti-launch-request' => 'onLaunch',
        'ConfigureLaunchRequest' => 'onConfigure',
        'DashboardRequest' => 'onDashboard',
        'ContentItemSelectionRequest' => 'onContentItem',
        'ContentItemSelection' => 'onContentItem',
        'ContentItemUpdateRequest' => 'onContentItemUpdate',
        'LtiSubmissionReviewRequest' => 'onSubmissionReview',
        'ToolProxyRegistrationRequest' => 'onRegister',
        'LtiStartProctoring' => 'onLtiStartProctoring',
        'LtiStartAssessment' => 'onLtiStartAssessment',
        'LtiEndAssessment' => 'onLtiEndAssessment'
    ]

List of supported message types and associated class methods.

◆ $requestParameters

array ceLTIc\LTI\Util::$requestParameters = null

static

GET and POST request parameters.

◆ $strictMode

bool ceLTIc\LTI\Util::$strictMode = false

static

Whether full compliance with the LTI specification is required.

Referenced by ceLTIc\LTI\Tool\getMessageParameters(), ceLTIc\LTI\Service\ToolSettings\set(), ceLTIc\LTI\Content\TimePeriod\toJsonldObject(), and ceLTIc\LTI\Content\Image\toJsonObject().

◆ JWT_CLAIM_MAPPING

const ceLTIc\LTI\Util::JWT_CLAIM_MAPPING

Mapping for standard message parameters to JWT claim.

◆ JWT_CLAIM_PREFIX

const ceLTIc\LTI\Util::JWT_CLAIM_PREFIX = 'https://purl.imsglobal.org/spec/lti'

Prefix for standard JWT message claims.

◆ MESSAGE_TYPE_MAPPING

const ceLTIc\LTI\Util::MESSAGE_TYPE_MAPPING

Initial value:

= [
        'basic-lti-launch-request' => 'LtiResourceLinkRequest',
        'ContentItemSelectionRequest' => 'LtiDeepLinkingRequest',
        'ContentItemSelection' => 'LtiDeepLinkingResponse',
        'ContentItemUpdateRequest' => 'LtiDeepLinkingUpdateRequest'
    ]

Mapping for standard message types.

Referenced by ceLTIc\LTI\System\hasJwt().

◆ TEST_COOKIE_NAME

const ceLTIc\LTI\Util::TEST_COOKIE_NAME = 'celtic_lti_test_cookie'

Name of test cookie.

Static Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Member Function Documentation

◆ checkArray()

◆ checkBoolean()

◆ checkDateTime()

◆ checkInteger()

◆ checkNumber()

◆ checkObject()

◆ checkString()

◆ checkUrl()

◆ cloneObject()

◆ getMessages()

◆ getRandomString()

◆ getRequestParameters()

◆ isLtiMessage()

◆ jsonDecode()

◆ log()

◆ logDebug()

◆ logError()

◆ logForm()

◆ logInfo()

◆ logRequest()

◆ redirect()

◆ sendForm()

◆ setMessage()

◆ setTestCookie()

◆ stripHtml()

◆ urlEncode()

◆ valToBoolean()

◆ valToNumber()

◆ valToString()

Member Data Documentation

◆ $disableFetchedPublicKeysSave

◆ $formSubmissionTimeout

◆ $logLevel

◆ $METHOD_NAMES

◆ $requestParameters

◆ $strictMode

◆ JWT_CLAIM_MAPPING

◆ JWT_CLAIM_PREFIX

◆ MESSAGE_TYPE_MAPPING

◆ TEST_COOKIE_NAME