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