JsonSchema.php

<?php
/*

Copyright (c) 2008, Gradua Networks
Author: Bruno Prieto Reis
All rights reserved.


Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
    * Neither the name of the Gradua Networks nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Usage:

//this optional check mode may be set so that strings containing doubles or integers are
//validated ok against a schema defining an integer or a double.
//JsonSchema::$checkMode = JsonSchema::CHECK_MODE_TYPE_CAST;
 
$result = JsonSchema::validate(
  $json,
  $schema
);
* */

class JsonSchema {
  
  static $errors = array();
  static $formatValidator;
  
  const CHECK_MODE_NORMAL = 1;
  const CHECK_MODE_TYPE_CAST = 2;
  public static $checkMode = self::CHECK_MODE_NORMAL;
  
  /**
   * Validates a php object against a schema. Both the php object and the schema
   * are supposed to be a result of a json_decode call. 
   * The validation works as defined by the schema proposal in
   * http://www.json.com/json-schema-proposal/
   *
   * @param StdClass $instance
   * @param StdClass $schema
   * @param JsonFormatValidator $formatValidator an optional class that have methods to validate the format definitions. 
   * If this is null, so format validation will not be applied, but if its true, then the validation will throw
   * an error if any format defined on the schema is not supported by the validator.
   * @return unknown
   */
  static public function validate($instance, $schema = null, $formatValidator = null) {
    self::$errors = array();
    self::$formatValidator = null;
    
    if($formatValidator) self::$formatValidator = $formatValidator;
    $res = self::_validate($instance,$schema,false);
    self::$formatValidator = null;
    return $res;
  }
  
  static function _validate($instance,$schema = null,$_changing) {
  	// verify passed schema
    if ($schema) {
	  self::checkProp($instance,$schema,'','',$_changing);
    }
    // verify "inline" schema
    $propName = '$schema';
	if (!$_changing && isset($instance->$propName)) {
	  self::checkProp($instance,$instance->$propName,'','',$_changing);
	}
	// show results
	$obj = new stdClass();
	$obj->valid = ! ((boolean)count(self::$errors));
	$obj->errors = self::$errors;
	return $obj;
  }
  
  static function incrementPath($path,$i) {
    if($path !== '') {
	  if(is_int($i)) {
	    $path .= '['.$i.']';
	  }
	  elseif($i == '') {
	    $path .= '';
	  }
	  else {
	    $path .= '.'.$i;
	  }
    }
    else {
      $path = $i;
    }
    return $path;
  }
  
  static function checkArray($value,$schema,$path,$i,$_changing) {
    //verify items
    if(isset($schema->items)) {
      //tuple typing
      if(is_array($schema->items)) {
        foreach($value as $k=>$v) {
          if(array_key_exists($k,$schema->items)) {
            self::checkProp($v,$schema->items[$k],$path,$k,$_changing);
          }
          else {
            // aditional array properties
            if(array_key_exists('additionalProperties',$schema)) { 
              if($schema->additionalProperties === false) { 	
                self::adderror(
                  $path,
                  'The item '.$i.'['.$k.'] is not defined in the objTypeDef and the objTypeDef does not allow additional properties'
                );
              }
              else {
                self::checkProp($v,$schema->additionalProperties,$path,$k,$_changing);	
              }
            }
          }
        }//foreach($value as $k=>$v) {
        // treat when we have more schema definitions than values
        for($k = count($value); $k < count($schema->items); $k++) {
          self::checkProp( 
            new JsonSchemaUndefined(),
            $schema->items[$k], $path, $k, $_changing
          );
        }
      }
      // just one type definition for the whole array
      else {
        foreach($value as $k=>$v) {
          self::checkProp($v,$schema->items,$path,$k,$_changing);
        }
      }
    }
    // verify number of array items
    if(isset($schema->minItems) && count($value) < $schema->minItems) {
      self::adderror($path,"There must be a minimum of " . $schema->minItems . " in the array");
    }
    if(isset($schema->maxItems) && count($value) > $schema->maxItems) {
      self::adderror($path,"There must be a maximum of " . $schema->maxItems . " in the array");
    }
  }
  
  static function checkProp($value, $schema, $path, $i = '', $_changing = false) {
    if (!is_object($schema)) {
    	return;
    }
    $path = self::incrementPath($path,$i);
    // verify readonly
    if($_changing && $schema->readonly) {
      self::adderror($path,'is a readonly field, it can not be changed');
    }
    // I think a schema cant be an array, only the items property
    /*if(is_array($schema)) {
      if(!is_array($value)) {
      	return array(array('property'=>$path,'message'=>'An array tuple is required'));
      }
      for($a = 0; $a < count($schema); $a++) {
      	self::$errors = array_merge(
      	  self::$errors,
      	  self::checkProp($value->$a,$schema->$a,$path,$i,$_changing)
      	);
      	return self::$errors;
      }
    }*/
    // if it extends another schema, it must pass that schema as well
    if(isset($schema->extends)) {
      self::checkProp($value,$schema->extends,$path,$i,$_changing);
    }
    // verify optional values
    if (is_object($value) && $value instanceOf JsonSchemaUndefined) {
  	  if ( isset($schema->optional) ? !$schema->optional : true) {
	    self::adderror($path,"is missing and it is not optional");
	  }
    } 
    // normal verifications
    else {
      self::$errors = array_merge(
        self::$errors,
        self::checkType( isset($schema->type) ? $schema->type : null , $value, $path)
      );
    }
    if(array_key_exists('disallow',$schema)) {
      $errorsBeforeDisallowCheck = self::$errors;
      $response = self::checkType($schema->disallow, $value, $path);
      if(
        ( count($errorsBeforeDisallowCheck) == count(self::$errors) )  &&
        !count($response)
      ) {
        self::adderror($path," disallowed value was matched");
      }
      else {
        self::$errors = $errorsBeforeDisallowCheck;
      }
    }
    //verify the itens on an array and min and max number of items.
    if(is_array($value)) {
      if(
        self::$checkMode == self::CHECK_MODE_TYPE_CAST &&
        $schema->type == 'object'
      ) {
        self::checkObj(
          $value,
          $schema->properties,
          $path,
          isset($schema->additionalProperties) ? $schema->additionalProperties : null,
          $_changing 
        );
      }
      self::checkArray($value,$schema,$path,$i,$_changing);
    }
    ############ verificar!
    elseif(isset($schema->properties) && is_object($value)) {
      self::checkObj(
        $value,
        $schema->properties,
        $path,
        isset($schema->additionalProperties) ? $schema->additionalProperties : null,
        $_changing 
      );
    }
    // verify a regex pattern
    if( isset($schema->pattern) && is_string($value) && !preg_match('/'.$schema->pattern.'/',$value)) {
      self::adderror($path,"does not match the regex pattern " . $schema->pattern);
    }  
    // verify maxLength, minLength, maximum and minimum values
    if( isset($schema->maxLength) && is_string($value) && (strlen($value) > $schema->maxLength)) {
      self::adderror($path,"must be at most " . $schema->maxLength . " characters long");
    }
    if( isset($schema->minLength) && is_string($value) && strlen($value) < $schema->minLength) {
      self::adderror($path,"must be at least " . $schema->minLength . " characters long");
    }
    
    if( 
      isset($schema->minimum) && 
      gettype($value) == gettype($schema->minimum) && 
      $value < $schema->minimum
    ) {
      self::adderror($path,"must have a minimum value of " . $schema->minimum);
    }
    if( isset($schema->maximum) && gettype($value) == gettype($schema->maximum) && $value > $schema->maximum) {
      self::adderror($path,"must have a maximum value of " . $schema->maximum);
    }
    // verify enum values
    if(isset($schema->enum)) {
      $found = false;
      foreach($schema->enum as $possibleValue) {
        if($possibleValue == $value) {
          $found = true;
          break;
        }
      }
      if(!$found) {
        self::adderror($path,"does not have a value in the enumeration " . implode(', ',$schema->enum));
      }
    }
    if( 
      isset($schema->maxDecimal) && 
      (  ($value * pow(10,$schema->maxDecimal)) != (int)($value * pow(10,$schema->maxDecimal))  )
    ) {
      self::adderror($path,"may only have " . $schema->maxDecimal . " digits of decimal places");
    }
    if( isset($schema->format) && isset(self::$formatValidator) ) {
      $error = self::$formatValidator->validate($value,$schema->format);
      if($error) {
        self::adderror($path,$error);
      }
    }
  }
  
  static function adderror($path,$message) {
  	self::$errors[] = array(
      'property'=>$path,
      'message'=>$message
    );
  }
  
  /**
   * Take Care: Value is being passed by ref to continue validation with proper format.
   * @return array
   */
  static function checkType($type, &$value, $path) {
    if($type) {
      $wrongType = false;
      if(is_string($type) && $type !== 'any') {
        if($type == 'null') {
          if (!is_null($value)) {
            $wrongType = true;	
          }
        } 
        else {
          if($type == 'number') {
            if(self::$checkMode == self::CHECK_MODE_TYPE_CAST) {
              $wrongType = !self::checkTypeCast($type,$value);
            }
          	elseif(!in_array(gettype($value),array('integer','double'))) {
          	  $wrongType = true;	
          	}
          } else{
            if(
              self::$checkMode == self::CHECK_MODE_TYPE_CAST
              && $type == 'integer'
            ) {
              $wrongType = !self::checkTypeCast($type,$value);
            } elseif (
              self::$checkMode == self::CHECK_MODE_TYPE_CAST
              && $type == 'object' && is_array($value)
            ) {
              $wrongType = false;
            } elseif ($type !== gettype($value)) {
          	  $wrongType = true;
            }
          }  
        } 
      }
      if($wrongType) {
      	return array(
      	  array(
      	    'property'=>$path,
      	    'message'=>gettype($value)." value found, but a ".$type." is required "
      	  )
      	);
      }
      // Union Types  :: for now, just return the message for the last expected type!!
      if(is_array($type)) {
        $validatedOneType = false;
        $errors = array();
        foreach($type as $tp) {
          $error = self::checkType($tp,$value,$path);
          if(!count($error)) {
          	$validatedOneType = true;
          	break;
          }
          else {
          	$errors[] = $error;
          	$errors = $error;
          }
        }
        if(!$validatedOneType) {
          return $errors; 
        }
      }
      elseif(is_object($type)) {
      	self::checkProp($value,$type,$path);
      }
    }
    return array();
  }
  
  /**
   * Take Care: Value is being passed by ref to continue validation with proper format.
   */
  static function checkTypeCast($type,&$value) {
    switch($type) {
  	  case 'integer':
  	    $castValue = (integer)$value;
  	    break;
  	  case 'number':
  		$castValue = (double)$value;
  		break;
  	  default:
  	    trigger_error('this method should only be called for the above supported types.');
  	    break;
  	}
  	if( (string)$value == (string)$castValue ) {
  	  $res = true;
  	  $value = $castValue;
  	}
  	else {
  	  $res = false;
  	}
  	return $res;
  }
  
  static function checkObj($instance, $objTypeDef, $path, $additionalProp,$_changing) {
    if($objTypeDef instanceOf StdClass) {
      if( ! (($instance instanceOf StdClass) || is_array($instance)) ) {
      	self::$errors[] = array(
      	  'property'=>$path,
      	  'message'=>"an object is required"
      	);
      }
      foreach($objTypeDef as $i=>$value) {
        $value = 
          array_key_exists($i,$instance) ? 
            (is_array($instance) ? $instance[$i] : $instance->$i) : 
            new JsonSchemaUndefined();
        $propDef = $objTypeDef->$i;
        self::checkProp($value,$propDef,$path,$i,$_changing);
      }
    }
    // additional properties and requires
    foreach($instance as $i=>$value) {
      // verify additional properties, when its not allowed
      if( !isset($objTypeDef->$i) && ($additionalProp === false) && $i !== '$schema' ) {
      	self::$errors[] = array(
      	  'property'=>$path,
      	  'message'=>"The property " . $i . " is not defined in the objTypeDef and the objTypeDef does not allow additional properties"
      	);
      }
      // verify requires
      if($objTypeDef && isset($objTypeDef->$i) && isset($objTypeDef->$i->requires)) {
        $requires = $objTypeDef->$i->requires;
        if(!array_key_exists($requires,$instance)) {
          self::$errors[] = array(
      	    'property'=>$path,
      	    'message'=>"the presence of the property " . $i . " requires that " . $requires . " also be present"
      	  );
        }	
      }
	  $value = is_array($instance) ? $instance[$i] : $instance->$i;
	  
	  // To verify additional properties types. 
	  if ($objTypeDef && is_object($objTypeDef) && !isset($objTypeDef->$i)) {
	    self::checkProp($value,$additionalProp,$path,$i); 
      }
      // Verify inner schema definitions 			
	  $schemaPropName = '$schema';
	  if (!$_changing && $value && isset($value->$schemaPropName)) {
        self::$errors = array_merge(
          self::$errors,
          checkProp($value,$value->$schemaPropname,$path,$i)
        );
	  }
    }
	return self::$errors;
  }
}

class Dbg {
	
  static public $quietMode = false;
  
  static function includeJqueryJs() {
    echo "<script type='text/javascript' src='/js/jquery.js'></script>";
  }
  
  static function func($print = true, $numStackSteps = 1) {
  	$ar = debug_backtrace();
  	$ret = '';
  	
  	for($a = $numStackSteps; $a >= 1; $a--) {
  	  $line = $ar[$a-1]['line'];
  	  $step = $ar[$a];
  	  $ret .= str_repeat('&nbsp;&nbsp;&nbsp;',$a).self::showStep($step,$print,$line);	
  	}
  	if($print && !self::$quietMode) echo $ret;
  	return $ret;
  }
  
  static function mark($title,$print = true) {
  	$ar = debug_backtrace();
  	$ret = '';
  	$line = $ar[0]['line'];
  	$ret = "[MARK]".$title.'(line '.$line.')<br/>';
  	if($print && !self::$quietMode) echo $ret;
  	return $ret;
  }
  
  static function object($object,$linkTitle = 'object',$varDump = false,$print = true) {
  	static $divCount = 0;
  	$divCount++;
  	$ar = debug_backtrace();
  	$ret = '';
  	$line = $ar[0]['line'];
  	$ret = '[OBJECT]<a href="javascript:void(0);" onclick="$(\'#div-obj-'.$divCount.'\').toggle()">'.$linkTitle.'</a>';
  	$ret .= '(line '.$line.')<br/>';
  	$ret .= '<div id=\'div-obj-'.$divCount.'\' style="display:none;">';
  	if($varDump) {
  	  ob_start();
  	  var_dump($object);
  	  $ret .= ob_get_clean();
  	}
  	else {
  	  $ret .= print_r($object,true); 
  	}
  	$ret .= '</div>';
  	if($print && !self::$quietMode) echo $ret;
  	return $ret;
  }
  
  static function showStep($step,$print,$line) {
  	static $divCount = 0;
    $ret = '[STEP]'.$step['class'] . $step['type'] . $step['function'];
  	if(count($step['args'])) {
  	  $ret .= '(';
  	  $comma = '';
  	  $exp = array();
  	  foreach($step['args'] as $num=>$arg) {
  	  	$divCount++;
  	  	if(in_array(gettype($arg),array('object','array'))) {
  	  	  if(is_object($arg)) {
  	  	    $type = get_class($arg);
  	  	  }
  	  	  else {
  	  	  	$type = gettype($arg);
  	  	  }
  	  	  $argVal = '<a href="javascript:void(0);" onclick="$(\'#div-step-'.$divCount.'\').toggle()">click to see</a>';
  	  	  $exp[] = 
  	  	    '<div id=\'div-step-'.$divCount.'\' style="display:none;">'
  	  	    .print_r($arg,true)
  	  	    .'</div>';
  	  	}
  	  	else {
  	  	  $type = gettype($arg);
  	  	  if($type == 'string') {
  	  	    $argVal = "'".$arg."'";
  	  	  }
  	  	  else {
  	  	  	$argVal = $arg;
  	  	  }
  	  	  $argVal = '<font style="color:#060">'.$argVal.'</font>';
  	  	}
  	  	$ret .= $comma.' <i>' . $type . "</i> " . $argVal;
  	  	$comma = ',';
  	  }
  	  $ret .= ')  (line '.$line.')<br/>';
  	  foreach($exp as $text) {
  	  	$ret .= '<pre>' . $text . '</pre>';
  	  }
  	}
  	return $ret;
  }
}
?>