lib/externallib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 /**
  19  * Support for external API
  20  *
  21  * @package    core_webservice
  22  * @copyright  2009 Petr Skodak
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 /**
  29  * Returns detailed function information
  30  *
  31  * @param string|object $function name of external function or record from external_function
  32  * @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
  33  *                        MUST_EXIST means throw exception if no record or multiple records found
  34  * @return stdClass description or false if not found or exception thrown
  35  * @since Moodle 2.0
  36  */
  37 function external_function_info($function, $strictness=MUST_EXIST) {
  38     global $DB, $CFG;
  39
  40     if (!is_object($function)) {
  41         if (!$function = $DB->get_record('external_functions', array('name'=>$function), '*', $strictness)) {
  42             return false;
  43         }
  44     }
  45
  46     // First try class autoloading.
  47     if (!class_exists($function->classname)) {
  48         // Fallback to explicit include of externallib.php.
  49         $function->classpath = empty($function->classpath) ? core_component::get_component_directory($function->component).'/externallib.php' : $CFG->dirroot.'/'.$function->classpath;
  50         if (!file_exists($function->classpath)) {
  51             throw new coding_exception('Cannot find file with external function implementation');
  52         }
  53         require_once($function->classpath);
  54         if (!class_exists($function->classname)) {
  55             throw new coding_exception('Cannot find external class');
  56         }
  57     }
  58
  59     $function->ajax_method = $function->methodname.'_is_allowed_from_ajax';
  60     $function->parameters_method = $function->methodname.'_parameters';
  61     $function->returns_method    = $function->methodname.'_returns';
  62     $function->deprecated_method = $function->methodname.'_is_deprecated';
  63
  64     // make sure the implementaion class is ok
  65     if (!method_exists($function->classname, $function->methodname)) {
  66         throw new coding_exception('Missing implementation method of '.$function->classname.'::'.$function->methodname);
  67     }
  68     if (!method_exists($function->classname, $function->parameters_method)) {
  69         throw new coding_exception('Missing parameters description');
  70     }
  71     if (!method_exists($function->classname, $function->returns_method)) {
  72         throw new coding_exception('Missing returned values description');
  73     }
  74     if (method_exists($function->classname, $function->deprecated_method)) {
  75         if (call_user_func(array($function->classname, $function->deprecated_method)) === true) {
  76             $function->deprecated = true;
  77         }
  78     }
  79     $function->allowed_from_ajax = false;
  80     if (method_exists($function->classname, $function->ajax_method)) {
  81         if (call_user_func(array($function->classname, $function->ajax_method)) === true) {
  82             $function->allowed_from_ajax = true;
  83         }
  84     }
  85
  86     // fetch the parameters description
  87     $function->parameters_desc = call_user_func(array($function->classname, $function->parameters_method));
  88     if (!($function->parameters_desc instanceof external_function_parameters)) {
  89         throw new coding_exception('Invalid parameters description');
  90     }
  91
  92     // fetch the return values description
  93     $function->returns_desc = call_user_func(array($function->classname, $function->returns_method));
  94     // null means void result or result is ignored
  95     if (!is_null($function->returns_desc) and !($function->returns_desc instanceof external_description)) {
  96         throw new coding_exception('Invalid return description');
  97     }
  98
  99     //now get the function description
 100     //TODO MDL-31115 use localised lang pack descriptions, it would be nice to have
 101     //      easy to understand descriptions in admin UI,
 102     //      on the other hand this is still a bit in a flux and we need to find some new naming
 103     //      conventions for these descriptions in lang packs
 104     $function->description = null;
 105     $servicesfile = core_component::get_component_directory($function->component).'/db/services.php';
 106     if (file_exists($servicesfile)) {
 107         $functions = null;
 108         include($servicesfile);
 109         if (isset($functions[$function->name]['description'])) {
 110             $function->description = $functions[$function->name]['description'];
 111         }
 112         if (isset($functions[$function->name]['testclientpath'])) {
 113             $function->testclientpath = $functions[$function->name]['testclientpath'];
 114         }
 115     }
 116
 117     return $function;
 118 }
 119
 120 /**
 121  * Exception indicating user is not allowed to use external function in the current context.
 122  *
 123  * @package    core_webservice
 124  * @copyright  2009 Petr Skodak
 125  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 126  * @since Moodle 2.0
 127  */
 128 class restricted_context_exception extends moodle_exception {
 129     /**
 130      * Constructor
 131      *
 132      * @since Moodle 2.0
 133      */
 134     function __construct() {
 135         parent::__construct('restrictedcontextexception', 'error');
 136     }
 137 }
 138
 139 /**
 140  * Base class for external api methods.
 141  *
 142  * @package    core_webservice
 143  * @copyright  2009 Petr Skodak
 144  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 145  * @since Moodle 2.0
 146  */
 147 class external_api {
 148
 149     /** @var stdClass context where the function calls will be restricted */
 150     private static $contextrestriction;
 151
 152     /**
 153      * Set context restriction for all following subsequent function calls.
 154      *
 155      * @param stdClass $context the context restriction
 156      * @since Moodle 2.0
 157      */
 158     public static function set_context_restriction($context) {
 159         self::$contextrestriction = $context;
 160     }
 161
 162     /**
 163      * This method has to be called before every operation
 164      * that takes a longer time to finish!
 165      *
 166      * @param int $seconds max expected time the next operation needs
 167      * @since Moodle 2.0
 168      */
 169     public static function set_timeout($seconds=360) {
 170         $seconds = ($seconds < 300) ? 300 : $seconds;
 171         core_php_time_limit::raise($seconds);
 172     }
 173
 174     /**
 175      * Validates submitted function parameters, if anything is incorrect
 176      * invalid_parameter_exception is thrown.
 177      * This is a simple recursive method which is intended to be called from
 178      * each implementation method of external API.
 179      *
 180      * @param external_description $description description of parameters
 181      * @param mixed $params the actual parameters
 182      * @return mixed params with added defaults for optional items, invalid_parameters_exception thrown if any problem found
 183      * @since Moodle 2.0
 184      */
 185     public static function validate_parameters(external_description $description, $params) {
 186         if ($description instanceof external_value) {
 187             if (is_array($params) or is_object($params)) {
 188                 throw new invalid_parameter_exception('Scalar type expected, array or object received.');
 189             }
 190
 191             if ($description->type == PARAM_BOOL) {
 192                 // special case for PARAM_BOOL - we want true/false instead of the usual 1/0 - we can not be too strict here ;-)
 193                 if (is_bool($params) or $params === 0 or $params === 1 or $params === '0' or $params === '1') {
 194                     return (bool)$params;
 195                 }
 196             }
 197             $debuginfo = 'Invalid external api parameter: the value is "' . $params .
 198                     '", the server was expecting "' . $description->type . '" type';
 199             return validate_param($params, $description->type, $description->allownull, $debuginfo);
 200
 201         } else if ($description instanceof external_single_structure) {
 202             if (!is_array($params)) {
 203                 throw new invalid_parameter_exception('Only arrays accepted. The bad value is: \''
 204                         . print_r($params, true) . '\'');
 205             }
 206             $result = array();
 207             foreach ($description->keys as $key=>$subdesc) {
 208                 if (!array_key_exists($key, $params)) {
 209                     if ($subdesc->required == VALUE_REQUIRED) {
 210                         throw new invalid_parameter_exception('Missing required key in single structure: '. $key);
 211                     }
 212                     if ($subdesc->required == VALUE_DEFAULT) {
 213                         try {
 214                             $result[$key] = self::validate_parameters($subdesc, $subdesc->default);
 215                         } catch (invalid_parameter_exception $e) {
 216                             //we are only interested by exceptions returned by validate_param() and validate_parameters()
 217                             //(in order to build the path to the faulty attribut)
 218                             throw new invalid_parameter_exception($key." => ".$e->getMessage() . ': ' .$e->debuginfo);
 219                         }
 220                     }
 221                 } else {
 222                     try {
 223                         $result[$key] = self::validate_parameters($subdesc, $params[$key]);
 224                     } catch (invalid_parameter_exception $e) {
 225                         //we are only interested by exceptions returned by validate_param() and validate_parameters()
 226                         //(in order to build the path to the faulty attribut)
 227                         throw new invalid_parameter_exception($key." => ".$e->getMessage() . ': ' .$e->debuginfo);
 228                     }
 229                 }
 230                 unset($params[$key]);
 231             }
 232             if (!empty($params)) {
 233                 throw new invalid_parameter_exception('Unexpected keys (' . implode(', ', array_keys($params)) . ') detected in parameter array.');
 234             }
 235             return $result;
 236
 237         } else if ($description instanceof external_multiple_structure) {
 238             if (!is_array($params)) {
 239                 throw new invalid_parameter_exception('Only arrays accepted. The bad value is: \''
 240                         . print_r($params, true) . '\'');
 241             }
 242             $result = array();
 243             foreach ($params as $param) {
 244                 $result[] = self::validate_parameters($description->content, $param);
 245             }
 246             return $result;
 247
 248         } else {
 249             throw new invalid_parameter_exception('Invalid external api description');
 250         }
 251     }
 252
 253     /**
 254      * Clean response
 255      * If a response attribute is unknown from the description, we just ignore the attribute.
 256      * If a response attribute is incorrect, invalid_response_exception is thrown.
 257      * Note: this function is similar to validate parameters, however it is distinct because
 258      * parameters validation must be distinct from cleaning return values.
 259      *
 260      * @param external_description $description description of the return values
 261      * @param mixed $response the actual response
 262      * @return mixed response with added defaults for optional items, invalid_response_exception thrown if any problem found
 263      * @author 2010 Jerome Mouneyrac
 264      * @since Moodle 2.0
 265      */
 266     public static function clean_returnvalue(external_description $description, $response) {
 267         if ($description instanceof external_value) {
 268             if (is_array($response) or is_object($response)) {
 269                 throw new invalid_response_exception('Scalar type expected, array or object received.');
 270             }
 271
 272             if ($description->type == PARAM_BOOL) {
 273                 // special case for PARAM_BOOL - we want true/false instead of the usual 1/0 - we can not be too strict here ;-)
 274                 if (is_bool($response) or $response === 0 or $response === 1 or $response === '0' or $response === '1') {
 275                     return (bool)$response;
 276                 }
 277             }
 278             $debuginfo = 'Invalid external api response: the value is "' . $response .
 279                     '", the server was expecting "' . $description->type . '" type';
 280             try {
 281                 return validate_param($response, $description->type, $description->allownull, $debuginfo);
 282             } catch (invalid_parameter_exception $e) {
 283                 //proper exception name, to be recursively catched to build the path to the faulty attribut
 284                 throw new invalid_response_exception($e->debuginfo);
 285             }
 286
 287         } else if ($description instanceof external_single_structure) {
 288             if (!is_array($response) && !is_object($response)) {
 289                 throw new invalid_response_exception('Only arrays/objects accepted. The bad value is: \'' .
 290                         print_r($response, true) . '\'');
 291             }
 292
 293             // Cast objects into arrays.
 294             if (is_object($response)) {
 295                 $response = (array) $response;
 296             }
 297
 298             $result = array();
 299             foreach ($description->keys as $key=>$subdesc) {
 300                 if (!array_key_exists($key, $response)) {
 301                     if ($subdesc->required == VALUE_REQUIRED) {
 302                         throw new invalid_response_exception('Error in response - Missing following required key in a single structure: ' . $key);
 303                     }
 304                     if ($subdesc instanceof external_value) {
 305                         if ($subdesc->required == VALUE_DEFAULT) {
 306                             try {
 307                                     $result[$key] = self::clean_returnvalue($subdesc, $subdesc->default);
 308                             } catch (invalid_response_exception $e) {
 309                                 //build the path to the faulty attribut
 310                                 throw new invalid_response_exception($key." => ".$e->getMessage() . ': ' . $e->debuginfo);
 311                             }
 312                         }
 313                     }
 314                 } else {
 315                     try {
 316                         $result[$key] = self::clean_returnvalue($subdesc, $response[$key]);
 317                     } catch (invalid_response_exception $e) {
 318                         //build the path to the faulty attribut
 319                         throw new invalid_response_exception($key." => ".$e->getMessage() . ': ' . $e->debuginfo);
 320                     }
 321                 }
 322                 unset($response[$key]);
 323             }
 324
 325             return $result;
 326
 327         } else if ($description instanceof external_multiple_structure) {
 328             if (!is_array($response)) {
 329                 throw new invalid_response_exception('Only arrays accepted. The bad value is: \'' .
 330                         print_r($response, true) . '\'');
 331             }
 332             $result = array();
 333             foreach ($response as $param) {
 334                 $result[] = self::clean_returnvalue($description->content, $param);
 335             }
 336             return $result;
 337
 338         } else {
 339             throw new invalid_response_exception('Invalid external api response description');
 340         }
 341     }
 342
 343     /**
 344      * Makes sure user may execute functions in this context.
 345      *
 346      * @param stdClass $context
 347      * @since Moodle 2.0
 348      */
 349     protected static function validate_context($context) {
 350         global $CFG;
 351
 352         if (empty($context)) {
 353             throw new invalid_parameter_exception('Context does not exist');
 354         }
 355         if (empty(self::$contextrestriction)) {
 356             self::$contextrestriction = context_system::instance();
 357         }
 358         $rcontext = self::$contextrestriction;
 359
 360         if ($rcontext->contextlevel == $context->contextlevel) {
 361             if ($rcontext->id != $context->id) {
 362                 throw new restricted_context_exception();
 363             }
 364         } else if ($rcontext->contextlevel > $context->contextlevel) {
 365             throw new restricted_context_exception();
 366         } else {
 367             $parents = $context->get_parent_context_ids();
 368             if (!in_array($rcontext->id, $parents)) {
 369                 throw new restricted_context_exception();
 370             }
 371         }
 372
 373         if ($context->contextlevel >= CONTEXT_COURSE) {
 374             list($context, $course, $cm) = get_context_info_array($context->id);
 375             require_login($course, false, $cm, false, true);
 376         }
 377     }
 378
 379     /**
 380      * Get context from passed parameters.
 381      * The passed array must either contain a contextid or a combination of context level and instance id to fetch the context.
 382      * For example, the context level can be "course" and instanceid can be courseid.
 383      *
 384      * See context_helper::get_all_levels() for a list of valid context levels.
 385      *
 386      * @param array $param
 387      * @since Moodle 2.6
 388      * @throws invalid_parameter_exception
 389      * @return context
 390      */
 391     protected static function get_context_from_params($param) {
 392         $levels = context_helper::get_all_levels();
 393         if (!empty($param['contextid'])) {
 394             return context::instance_by_id($param['contextid'], IGNORE_MISSING);
 395         } else if (!empty($param['contextlevel']) && isset($param['instanceid'])) {
 396             $contextlevel = "context_".$param['contextlevel'];
 397             if (!array_search($contextlevel, $levels)) {
 398                 throw new invalid_parameter_exception('Invalid context level = '.$param['contextlevel']);
 399             }
 400            return $contextlevel::instance($param['instanceid'], IGNORE_MISSING);
 401         } else {
 402             // No valid context info was found.
 403             throw new invalid_parameter_exception('Missing parameters, please provide either context level with instance id or contextid');
 404         }
 405     }
 406 }
 407
 408 /**
 409  * Common ancestor of all parameter description classes
 410  *
 411  * @package    core_webservice
 412  * @copyright  2009 Petr Skodak
 413  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 414  * @since Moodle 2.0
 415  */
 416 abstract class external_description {
 417     /** @var string Description of element */
 418     public $desc;
 419
 420     /** @var bool Element value required, null not allowed */
 421     public $required;
 422
 423     /** @var mixed Default value */
 424     public $default;
 425
 426     /**
 427      * Contructor
 428      *
 429      * @param string $desc
 430      * @param bool $required
 431      * @param mixed $default
 432      * @since Moodle 2.0
 433      */
 434     public function __construct($desc, $required, $default) {
 435         $this->desc = $desc;
 436         $this->required = $required;
 437         $this->default = $default;
 438     }
 439 }
 440
 441 /**
 442  * Scalar value description class
 443  *
 444  * @package    core_webservice
 445  * @copyright  2009 Petr Skodak
 446  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 447  * @since Moodle 2.0
 448  */
 449 class external_value extends external_description {
 450
 451     /** @var mixed Value type PARAM_XX */
 452     public $type;
 453
 454     /** @var bool Allow null values */
 455     public $allownull;
 456
 457     /**
 458      * Constructor
 459      *
 460      * @param mixed $type
 461      * @param string $desc
 462      * @param bool $required
 463      * @param mixed $default
 464      * @param bool $allownull
 465      * @since Moodle 2.0
 466      */
 467     public function __construct($type, $desc='', $required=VALUE_REQUIRED,
 468             $default=null, $allownull=NULL_ALLOWED) {
 469         parent::__construct($desc, $required, $default);
 470         $this->type      = $type;
 471         $this->allownull = $allownull;
 472     }
 473 }
 474
 475 /**
 476  * Associative array description class
 477  *
 478  * @package    core_webservice
 479  * @copyright  2009 Petr Skodak
 480  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 481  * @since Moodle 2.0
 482  */
 483 class external_single_structure extends external_description {
 484
 485      /** @var array Description of array keys key=>external_description */
 486     public $keys;
 487
 488     /**
 489      * Constructor
 490      *
 491      * @param array $keys
 492      * @param string $desc
 493      * @param bool $required
 494      * @param array $default
 495      * @since Moodle 2.0
 496      */
 497     public function __construct(array $keys, $desc='',
 498             $required=VALUE_REQUIRED, $default=null) {
 499         parent::__construct($desc, $required, $default);
 500         $this->keys = $keys;
 501     }
 502 }
 503
 504 /**
 505  * Bulk array description class.
 506  *
 507  * @package    core_webservice
 508  * @copyright  2009 Petr Skodak
 509  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 510  * @since Moodle 2.0
 511  */
 512 class external_multiple_structure extends external_description {
 513
 514      /** @var external_description content */
 515     public $content;
 516
 517     /**
 518      * Constructor
 519      *
 520      * @param external_description $content
 521      * @param string $desc
 522      * @param bool $required
 523      * @param array $default
 524      * @since Moodle 2.0
 525      */
 526     public function __construct(external_description $content, $desc='',
 527             $required=VALUE_REQUIRED, $default=null) {
 528         parent::__construct($desc, $required, $default);
 529         $this->content = $content;
 530     }
 531 }
 532
 533 /**
 534  * Description of top level - PHP function parameters.
 535  *
 536  * @package    core_webservice
 537  * @copyright  2009 Petr Skodak
 538  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 539  * @since Moodle 2.0
 540  */
 541 class external_function_parameters extends external_single_structure {
 542 }
 543
 544 /**
 545  * Generate a token
 546  *
 547  * @param string $tokentype EXTERNAL_TOKEN_EMBEDDED|EXTERNAL_TOKEN_PERMANENT
 548  * @param stdClass|int $serviceorid service linked to the token
 549  * @param int $userid user linked to the token
 550  * @param stdClass|int $contextorid
 551  * @param int $validuntil date when the token expired
 552  * @param string $iprestriction allowed ip - if 0 or empty then all ips are allowed
 553  * @return string generated token
 554  * @author  2010 Jamie Pratt
 555  * @since Moodle 2.0
 556  */
 557 function external_generate_token($tokentype, $serviceorid, $userid, $contextorid, $validuntil=0, $iprestriction=''){
 558     global $DB, $USER;
 559     // make sure the token doesn't exist (even if it should be almost impossible with the random generation)
 560     $numtries = 0;
 561     do {
 562         $numtries ++;
 563         $generatedtoken = md5(uniqid(rand(),1));
 564         if ($numtries > 5){
 565             throw new moodle_exception('tokengenerationfailed');
 566         }
 567     } while ($DB->record_exists('external_tokens', array('token'=>$generatedtoken)));
 568     $newtoken = new stdClass();
 569     $newtoken->token = $generatedtoken;
 570     if (!is_object($serviceorid)){
 571         $service = $DB->get_record('external_services', array('id' => $serviceorid));
 572     } else {
 573         $service = $serviceorid;
 574     }
 575     if (!is_object($contextorid)){
 576         $context = context::instance_by_id($contextorid, MUST_EXIST);
 577     } else {
 578         $context = $contextorid;
 579     }
 580     if (empty($service->requiredcapability) || has_capability($service->requiredcapability, $context, $userid)) {
 581         $newtoken->externalserviceid = $service->id;
 582     } else {
 583         throw new moodle_exception('nocapabilitytousethisservice');
 584     }
 585     $newtoken->tokentype = $tokentype;
 586     $newtoken->userid = $userid;
 587     if ($tokentype == EXTERNAL_TOKEN_EMBEDDED){
 588         $newtoken->sid = session_id();
 589     }
 590
 591     $newtoken->contextid = $context->id;
 592     $newtoken->creatorid = $USER->id;
 593     $newtoken->timecreated = time();
 594     $newtoken->validuntil = $validuntil;
 595     if (!empty($iprestriction)) {
 596         $newtoken->iprestriction = $iprestriction;
 597     }
 598     $DB->insert_record('external_tokens', $newtoken);
 599     return $newtoken->token;
 600 }
 601
 602 /**
 603  * Create and return a session linked token. Token to be used for html embedded client apps that want to communicate
 604  * with the Moodle server through web services. The token is linked to the current session for the current page request.
 605  * It is expected this will be called in the script generating the html page that is embedding the client app and that the
 606  * returned token will be somehow passed into the client app being embedded in the page.
 607  *
 608  * @param string $servicename name of the web service. Service name as defined in db/services.php
 609  * @param int $context context within which the web service can operate.
 610  * @return int returns token id.
 611  * @since Moodle 2.0
 612  */
 613 function external_create_service_token($servicename, $context){
 614     global $USER, $DB;
 615     $service = $DB->get_record('external_services', array('name'=>$servicename), '*', MUST_EXIST);
 616     return external_generate_token(EXTERNAL_TOKEN_EMBEDDED, $service, $USER->id, $context, 0);
 617 }
 618
 619 /**
 620  * Delete all pre-built services (+ related tokens) and external functions information defined in the specified component.
 621  *
 622  * @param string $component name of component (moodle, mod_assignment, etc.)
 623  */
 624 function external_delete_descriptions($component) {
 625     global $DB;
 626
 627     $params = array($component);
 628
 629     $DB->delete_records_select('external_tokens',
 630             "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
 631     $DB->delete_records_select('external_services_users',
 632             "externalserviceid IN (SELECT id FROM {external_services} WHERE component = ?)", $params);
 633     $DB->delete_records_select('external_services_functions',
 634             "functionname IN (SELECT name FROM {external_functions} WHERE component = ?)", $params);
 635     $DB->delete_records('external_services', array('component'=>$component));
 636     $DB->delete_records('external_functions', array('component'=>$component));
 637 }
 638
 639 /**
 640  * Standard Moodle web service warnings
 641  *
 642  * @package    core_webservice
 643  * @copyright  2012 Jerome Mouneyrac
 644  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 645  * @since Moodle 2.3
 646  */
 647 class external_warnings extends external_multiple_structure {
 648
 649     /**
 650      * Constructor
 651      *
 652      * @since Moodle 2.3
 653      */
 654     public function __construct($itemdesc = 'item', $itemiddesc = 'item id',
 655         $warningcodedesc = 'the warning code can be used by the client app to implement specific behaviour') {
 656
 657         parent::__construct(
 658             new external_single_structure(
 659                 array(
 660                     'item' => new external_value(PARAM_TEXT, $itemdesc, VALUE_OPTIONAL),
 661                     'itemid' => new external_value(PARAM_INT, $itemiddesc, VALUE_OPTIONAL),
 662                     'warningcode' => new external_value(PARAM_ALPHANUM, $warningcodedesc),
 663                     'message' => new external_value(PARAM_TEXT,
 664                             'untranslated english message to explain the warning')
 665                 ), 'warning'),
 666             'list of warnings', VALUE_OPTIONAL);
 667     }
 668 }
 669
 670 /**
 671  * A pre-filled external_value class for text format.
 672  *
 673  * Default is FORMAT_HTML
 674  * This should be used all the time in external xxx_params()/xxx_returns functions
 675  * as it is the standard way to implement text format param/return values.
 676  *
 677  * @package    core_webservice
 678  * @copyright  2012 Jerome Mouneyrac
 679  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 680  * @since Moodle 2.3
 681  */
 682 class external_format_value extends external_value {
 683
 684     /**
 685      * Constructor
 686      *
 687      * @param string $textfieldname Name of the text field
 688      * @param int $required if VALUE_REQUIRED then set standard default FORMAT_HTML
 689      * @since Moodle 2.3
 690      */
 691     public function __construct($textfieldname, $required = VALUE_REQUIRED) {
 692
 693         $default = ($required == VALUE_DEFAULT) ? FORMAT_HTML : null;
 694
 695         $desc = $textfieldname . ' format (' . FORMAT_HTML . ' = HTML, '
 696                 . FORMAT_MOODLE . ' = MOODLE, '
 697                 . FORMAT_PLAIN . ' = PLAIN or '
 698                 . FORMAT_MARKDOWN . ' = MARKDOWN)';
 699
 700         parent::__construct(PARAM_INT, $desc, $required, $default);
 701     }
 702 }
 703
 704 /**
 705  * Validate text field format against known FORMAT_XXX
 706  *
 707  * @param array $format the format to validate
 708  * @return the validated format
 709  * @throws coding_exception
 710  * @since Moodle 2.3
 711  */
 712 function external_validate_format($format) {
 713     $allowedformats = array(FORMAT_HTML, FORMAT_MOODLE, FORMAT_PLAIN, FORMAT_MARKDOWN);
 714     if (!in_array($format, $allowedformats)) {
 715         throw new moodle_exception('formatnotsupported', 'webservice', '' , null,
 716                 'The format with value=' . $format . ' is not supported by this Moodle site');
 717     }
 718     return $format;
 719 }
 720
 721 /**
 722  * Format the text to be returned properly as requested by the either the web service server,
 723  * either by an internally call.
 724  * The caller can change the format (raw, filter, file, fileurl) with the external_settings singleton
 725  * All web service servers must set this singleton when parsing the $_GET and $_POST.
 726  *
 727  * @param string $text The content that may contain ULRs in need of rewriting.
 728  * @param int $textformat The text format, by default FORMAT_HTML.
 729  * @param int $contextid This parameter and the next two identify the file area to use.
 730  * @param string $component
 731  * @param string $filearea helps identify the file area.
 732  * @param int $itemid helps identify the file area.
 733  * @return array text + textformat
 734  * @since Moodle 2.3
 735  */
 736 function external_format_text($text, $textformat, $contextid, $component, $filearea, $itemid) {
 737     global $CFG;
 738
 739     // Get settings (singleton).
 740     $settings = external_settings::get_instance();
 741
 742     if ($settings->get_fileurl()) {
 743         require_once($CFG->libdir . "/filelib.php");
 744         $text = file_rewrite_pluginfile_urls($text, $settings->get_file(), $contextid, $component, $filearea, $itemid);
 745     }
 746
 747     if (!$settings->get_raw()) {
 748         $textformat = FORMAT_HTML; // Force format to HTML when not raw.
 749         $text = format_text($text, $textformat,
 750                 array('noclean' => true, 'para' => false, 'filter' => $settings->get_filter()));
 751     }
 752
 753     return array($text, $textformat);
 754 }
 755
 756 /**
 757  * Singleton to handle the external settings.
 758  *
 759  * We use singleton to encapsulate the "logic"
 760  *
 761  * @package    core_webservice
 762  * @copyright  2012 Jerome Mouneyrac
 763  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 764  * @since Moodle 2.3
 765  */
 766 class external_settings {
 767
 768     /** @var object the singleton instance */
 769     public static $instance = null;
 770
 771     /** @var boolean Should the external function return raw text or formatted */
 772     private $raw = false;
 773
 774     /** @var boolean Should the external function filter the text */
 775     private $filter = false;
 776
 777     /** @var boolean Should the external function rewrite plugin file url */
 778     private $fileurl = true;
 779
 780     /** @var string In which file should the urls be rewritten */
 781     private $file = 'webservice/pluginfile.php';
 782
 783     /**
 784      * Constructor - protected - can not be instanciated
 785      */
 786     protected function __construct() {
 787     }
 788
 789     /**
 790      * Clone - private - can not be cloned
 791      */
 792     private final function __clone() {
 793     }
 794
 795     /**
 796      * Return only one instance
 797      *
 798      * @return object
 799      */
 800     public static function get_instance() {
 801         if (self::$instance === null) {
 802             self::$instance = new external_settings;
 803         }
 804
 805         return self::$instance;
 806     }
 807
 808     /**
 809      * Set raw
 810      *
 811      * @param boolean $raw
 812      */
 813     public function set_raw($raw) {
 814         $this->raw = $raw;
 815     }
 816
 817     /**
 818      * Get raw
 819      *
 820      * @return boolean
 821      */
 822     public function get_raw() {
 823         return $this->raw;
 824     }
 825
 826     /**
 827      * Set filter
 828      *
 829      * @param boolean $filter
 830      */
 831     public function set_filter($filter) {
 832         $this->filter = $filter;
 833     }
 834
 835     /**
 836      * Get filter
 837      *
 838      * @return boolean
 839      */
 840     public function get_filter() {
 841         return $this->filter;
 842     }
 843
 844     /**
 845      * Set fileurl
 846      *
 847      * @param boolean $fileurl
 848      */
 849     public function set_fileurl($fileurl) {
 850         $this->fileurl = $fileurl;
 851     }
 852
 853     /**
 854      * Get fileurl
 855      *
 856      * @return boolean
 857      */
 858     public function get_fileurl() {
 859         return $this->fileurl;
 860     }
 861
 862     /**
 863      * Set file
 864      *
 865      * @param string $file
 866      */
 867     public function set_file($file) {
 868         $this->file = $file;
 869     }
 870
 871     /**
 872      * Get file
 873      *
 874      * @return string
 875      */
 876     public function get_file() {
 877         return $this->file;
 878     }
 879 }