* Added two optional arguments to addError method to make it easier for custom error messages

* Added more information to the error message of StringConstraint
* Added more information to the Constraint addError
* Unknown format does not generate error
* Updated the test so that unknown format does not throw an error
* Make messages to start with a capital letter consistently

src/JsonSchema/Constraints/CollectionConstraint.php

@@ -24,12 +24,12 @@ class CollectionConstraint extends Constraint
     {
         // Verify minItems
         if (isset($schema->minItems) && count($value) < $schema->minItems) {
-            $this->addError($path, "There must be a minimum of " . $schema->minItems . " items in the array");
+            $this->addError($path, "There must be a minimum of " . $schema->minItems . " items in the array", 'minItems', array('minItems' => $schema->minItems,));
         }
 
         // Verify maxItems
         if (isset($schema->maxItems) && count($value) > $schema->maxItems) {
-            $this->addError($path, "There must be a maximum of " . $schema->maxItems . " items in the array");
+            $this->addError($path, "There must be a maximum of " . $schema->maxItems . " items in the array", 'maxItems', array('maxItems' => $schema->maxItems,));
         }
 
         // Verify uniqueItems
@@ -39,7 +39,7 @@ class CollectionConstraint extends Constraint
                 $unique = array_map(function($e) { return var_export($e, true); }, $value);
             }
             if (count(array_unique($unique)) != count($value)) {
-                $this->addError($path, "There are no duplicates allowed in the array");
+                $this->addError($path, "There are no duplicates allowed in the array", 'uniqueItems');
             }
         }
 
@@ -92,7 +92,7 @@ class CollectionConstraint extends Constraint
                             $this->checkUndefined($v, $schema->additionalItems, $path, $k);
                         } else {
                             $this->addError(
-                                $path, 'The item ' . $i . '[' . $k . '] is not defined and the definition does not allow additional items');
+                                $path, 'The item ' . $i . '[' . $k . '] is not defined and the definition does not allow additional items', 'additionalItems', array('additionalItems' => $schema->additionalItems,));
                         }
                     } else {
                         // Should be valid against an empty schema

src/JsonSchema/Constraints/Constraint.php

@@ -61,12 +61,20 @@ abstract class Constraint implements ConstraintInterface
     /**
      * {@inheritDoc}
      */
-    public function addError($path, $message)
+    public function addError($path, $message, $constraint='', array $more=null)
     {
-        $this->errors[] = array(
+        $error = array(
             'property' => $path,
-            'message' => $message
+            'message' => $message,
+            'constraint' => $constraint,
         );
+
+        if (is_array($more) && count($more) > 0)
+        {
+            $error += $more;
+        }
+
+        $this->errors[] = $error;
     }
 
     /**

src/JsonSchema/Constraints/ConstraintInterface.php

@@ -33,10 +33,12 @@ interface ConstraintInterface
     /**
      * adds an error
      *
-     * @param $path
+     * @param string $path
-     * @param $message
+     * @param string $message
+     * @param string $constraint the constraint/rule that is broken, e.g.: 'minLength'
+     * @param array $more more array elements to add to the error
      */
-    public function addError($path, $message);
+    public function addError($path, $message, $constraint='', array $more=null);
 
     /**
      * checks if the validator has not raised errors

src/JsonSchema/Constraints/EnumConstraint.php

@@ -41,6 +41,6 @@ class EnumConstraint extends Constraint
             }
         }
 
-        $this->addError($path, "Does not have a value in the enumeration " . print_r($schema->enum, true));
+        $this->addError($path, "Does not have a value in the enumeration " . print_r($schema->enum, true), 'enum', array('enum' => $schema->enum,));
     }
 }

src/JsonSchema/Constraints/FormatConstraint.php

@@ -29,13 +29,13 @@ class FormatConstraint extends Constraint
         switch ($schema->format) {
             case 'date':
                 if (!$date = $this->validateDateTime($element, 'Y-m-d')) {
-                    $this->addError($path, sprintf('Invalid date %s, expected format YYYY-MM-DD', json_encode($element)));
+                    $this->addError($path, sprintf('Invalid date %s, expected format YYYY-MM-DD', json_encode($element)), 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'time':
                 if (!$this->validateDateTime($element, 'H:i:s')) {
-                    $this->addError($path, sprintf('Invalid time %s, expected format hh:mm:ss', json_encode($element)));
+                    $this->addError($path, sprintf('Invalid time %s, expected format hh:mm:ss', json_encode($element)), 'format', array('format' => $schema->format,));
                 }
                 break;
 
@@ -45,74 +45,79 @@ class FormatConstraint extends Constraint
                     !$this->validateDateTime($element, 'Y-m-d\TH:i:sP') &&
                     !$this->validateDateTime($element, 'Y-m-d\TH:i:sO')
                 ) {
-                    $this->addError($path, sprintf('Invalid date-time %s, expected format YYYY-MM-DDThh:mm:ssZ or YYYY-MM-DDThh:mm:ss+hh:mm', json_encode($element)));
+                    $this->addError($path, sprintf('Invalid date-time %s, expected format YYYY-MM-DDThh:mm:ssZ or YYYY-MM-DDThh:mm:ss+hh:mm', json_encode($element)), 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'utc-millisec':
                 if (!$this->validateDateTime($element, 'U')) {
-                    $this->addError($path, sprintf('Invalid time %s, expected integer of milliseconds since Epoch', json_encode($element)));
+                    $this->addError($path, sprintf('Invalid time %s, expected integer of milliseconds since Epoch', json_encode($element)), 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'regex':
                 if (!$this->validateRegex($element)) {
-                    $this->addError($path, 'Invalid regex format ' . $element);
+                    $this->addError($path, 'Invalid regex format ' . $element, 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'color':
                 if (!$this->validateColor($element)) {
-                    $this->addError($path, "Invalid color");
+                    $this->addError($path, "Invalid color", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'style':
                 if (!$this->validateStyle($element)) {
-                    $this->addError($path, "Invalid style");
+                    $this->addError($path, "Invalid style", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'phone':
                 if (!$this->validatePhone($element)) {
-                    $this->addError($path, "Invalid phone number");
+                    $this->addError($path, "Invalid phone number", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'uri':
                 if (null === filter_var($element, FILTER_VALIDATE_URL, FILTER_NULL_ON_FAILURE)) {
-                    $this->addError($path, "Invalid URL format");
+                    $this->addError($path, "Invalid URL format", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'email':
                 if (null === filter_var($element, FILTER_VALIDATE_EMAIL, FILTER_NULL_ON_FAILURE)) {
-                    $this->addError($path, "Invalid email");
+                    $this->addError($path, "Invalid email", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'ip-address':
             case 'ipv4':
                 if (null === filter_var($element, FILTER_VALIDATE_IP, FILTER_NULL_ON_FAILURE | FILTER_FLAG_IPV4)) {
-                    $this->addError($path, "Invalid IP address");
+                    $this->addError($path, "Invalid IP address", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'ipv6':
                 if (null === filter_var($element, FILTER_VALIDATE_IP, FILTER_NULL_ON_FAILURE | FILTER_FLAG_IPV6)) {
-                    $this->addError($path, "Invalid IP address");
+                    $this->addError($path, "Invalid IP address", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             case 'host-name':
             case 'hostname':
                 if (!$this->validateHostname($element)) {
-                    $this->addError($path, "Invalid hostname");
+                    $this->addError($path, "Invalid hostname", 'format', array('format' => $schema->format,));
                 }
                 break;
 
             default:
-                // Do nothing so that custom formats can be used.
+                // Empty as it should be:
+                // The value of this keyword is called a format attribute. It MUST be a string.
+                // A format attribute can generally only validate a given set of instance types.
+                // If the type of the instance to validate is not in this set, validation for
+                // this format attribute and instance SHOULD succeed.
+                // http://json-schema.org/latest/json-schema-validation.html#anchor105
                 break;
         }
     }

src/JsonSchema/Constraints/NumberConstraint.php

@@ -26,40 +26,40 @@ class NumberConstraint extends Constraint
         if (isset($schema->exclusiveMinimum)) {
             if (isset($schema->minimum)) {
                 if ($schema->exclusiveMinimum && $element === $schema->minimum) {
-                    $this->addError($path, "Must have a minimum value greater than boundary value of " . $schema->minimum);
+                    $this->addError($path, "Must have a minimum value greater than boundary value of " . $schema->minimum, 'exclusiveMinimum', array('minimum' => $schema->minimum,));
                 } else if ($element < $schema->minimum) {
-                    $this->addError($path, "Must have a minimum value of " . $schema->minimum);
+                    $this->addError($path, "Must have a minimum value of " . $schema->minimum, 'minimum', array('minimum' => $schema->minimum,));
                 }
             } else {
-                $this->addError($path, "Use of exclusiveMinimum requires presence of minimum");
+                $this->addError($path, "Use of exclusiveMinimum requires presence of minimum", 'missingMinimum');
             }
         } else if (isset($schema->minimum) && $element < $schema->minimum) {
-            $this->addError($path, "Must have a minimum value of " . $schema->minimum);
+            $this->addError($path, "Must have a minimum value of " . $schema->minimum, 'minimum', array('minimum' => $schema->minimum,));
         }
 
         // Verify maximum
         if (isset($schema->exclusiveMaximum)) {
             if (isset($schema->maximum)) {
                 if ($schema->exclusiveMaximum && $element === $schema->maximum) {
-                    $this->addError($path, "Must have a maximum value less than boundary value of " . $schema->maximum);
+                    $this->addError($path, "Must have a maximum value less than boundary value of " . $schema->maximum, 'exclusiveMaximum', array('maximum' => $schema->maximum,));
                 } else if ($element > $schema->maximum) {
-                    $this->addError($path, "Must have a maximum value of " . $schema->maximum);
+                    $this->addError($path, "Must have a maximum value of " . $schema->maximum, 'maximum', array('maximum' => $schema->maximum,));
                 }
             } else {
-                $this->addError($path, "Use of exclusiveMaximum requires presence of maximum");
+                $this->addError($path, "Use of exclusiveMaximum requires presence of maximum", 'missingMinimum');
             }
         } else if (isset($schema->maximum) && $element > $schema->maximum) {
-            $this->addError($path, "Must have a maximum value of " . $schema->maximum);
+            $this->addError($path, "Must have a maximum value of " . $schema->maximum, 'maximum', array('maximum' => $schema->maximum,));
         }
 
         // Verify divisibleBy - Draft v3
         if (isset($schema->divisibleBy) && $this->fmod($element, $schema->divisibleBy) != 0) {
-            $this->addError($path, "Is not divisible by " . $schema->divisibleBy);
+            $this->addError($path, "Is not divisible by " . $schema->divisibleBy, 'divisibleBy', array('divisibleBy' => $schema->divisibleBy,));
         }
 
         // Verify multipleOf - Draft v4
         if (isset($schema->multipleOf) && $this->fmod($element, $schema->multipleOf) != 0) {
-            $this->addError($path, "Must be a multiple of " . $schema->multipleOf);
+            $this->addError($path, "Must be a multiple of " . $schema->multipleOf, 'multipleOf', array('multipleOf' => $schema->multipleOf,));
         }
 
         $this->checkFormat($element, $schema, $path, $i);

src/JsonSchema/Constraints/ObjectConstraint.php

@@ -46,7 +46,7 @@ class ObjectConstraint extends Constraint
         foreach ($patternProperties as $pregex => $schema) {
             // Validate the pattern before using it to test for matches
             if (@preg_match('/'. $pregex . '/', '') === false) {
-                $this->addError($path, 'The pattern "' . $pregex . '" is invalid');
+                $this->addError($path, 'The pattern "' . $pregex . '" is invalid', 'pregex', array('pregex' => $pregex,));
                 continue;
             }
             foreach ($element as $i => $value) {
@@ -77,7 +77,7 @@ class ObjectConstraint extends Constraint
 
             // no additional properties allowed
             if (!in_array($i, $matches) && $additionalProp === false && $this->inlineSchemaProperty !== $i && !$definition) {
-                $this->addError($path, "The property - " . $i . " - is not defined and the definition does not allow additional properties");
+                $this->addError($path, "The property " . $i . " is not defined and the definition does not allow additional properties", 'additionalProp');
             }
 
             // additional properties defined
@@ -92,7 +92,7 @@ class ObjectConstraint extends Constraint
             // property requires presence of another
             $require = $this->getProperty($definition, 'requires');
             if ($require && !$this->getProperty($element, $require)) {
-                $this->addError($path, "The presence of the property " . $i . " requires that " . $require . " also be present");
+                $this->addError($path, "The presence of the property " . $i . " requires that " . $require . " also be present", 'requires');
             }
 
             if (!$definition) {

src/JsonSchema/Constraints/StringConstraint.php

@@ -24,17 +24,23 @@ class StringConstraint extends Constraint
     {
         // Verify maxLength
         if (isset($schema->maxLength) && $this->strlen($element) > $schema->maxLength) {
-            $this->addError($path, "Must be at most " . $schema->maxLength . " characters long");
+            $this->addError($path, "Must be at most " . $schema->maxLength . " characters long", 'maxLength', array(
+                'maxLength' => $schema->maxLength,
+            ));
         }
 
         //verify minLength
         if (isset($schema->minLength) && $this->strlen($element) < $schema->minLength) {
-            $this->addError($path, "Must be at least " . $schema->minLength . " characters long");
+            $this->addError($path, "Must be at least " . $schema->minLength . " characters long", 'minLength', array(
+                'minLength' => $schema->minLength,
+            ));
         }
 
         // Verify a regex pattern
         if (isset($schema->pattern) && !preg_match('#' . str_replace('#', '\\#', $schema->pattern) . '#', $element)) {
-            $this->addError($path, "Does not match the regex pattern " . $schema->pattern);
+            $this->addError($path, "Does not match the regex pattern " . $schema->pattern, 'pattern', array(
+                'pattern' => $schema->pattern,
+            ));
         }
 
         $this->checkFormat($element, $schema, $path, $i);

src/JsonSchema/Constraints/TypeConstraint.php

@@ -82,7 +82,7 @@ class TypeConstraint extends Constraint
                         implode(', ', array_filter(self::$wording)))
                 );
             }
-            $this->addError($path, gettype($value) . " value found, but " . self::$wording[$type] . " is required");
+            $this->addError($path, ucwords(gettype($value)) . " value found, but " . self::$wording[$type] . " is required", 'type');
         }
     }
 

src/JsonSchema/Constraints/UndefinedConstraint.php

@@ -117,18 +117,17 @@ class UndefinedConstraint extends Constraint
 
         // Verify required values
         if (is_object($value)) {
-
             if (!($value instanceof UndefinedConstraint) && isset($schema->required) && is_array($schema->required) ) {
                 // Draft 4 - Required is an array of strings - e.g. "required": ["foo", ...]
                 foreach ($schema->required as $required) {
                     if (!property_exists($value, $required)) {
-                        $this->addError($required, "The property " . $required . " is required");
+                        $this->addError($required, "The property " . $required . " is required", 'required');
                     }
                 }
             } else if (isset($schema->required) && !is_array($schema->required)) {
                 // Draft 3 - Required attribute - e.g. "foo": {"type": "string", "required": true}
                 if ( $schema->required && $value instanceof UndefinedConstraint) {
-                    $this->addError($path, "Is missing and it is required");
+                    $this->addError($path, "Is missing and it is required", 'required');
                 }
             }
         }
@@ -148,7 +147,7 @@ class UndefinedConstraint extends Constraint
 
             // if no new errors were raised it must be a disallowed value
             if (count($this->getErrors()) == count($initErrors)) {
-                $this->addError($path, "Disallowed value was matched");
+                $this->addError($path, "Disallowed value was matched", 'disallow');
             } else {
                 $this->errors = $initErrors;
             }
@@ -160,7 +159,7 @@ class UndefinedConstraint extends Constraint
 
             // if no new errors were raised then the instance validated against the "not" schema
             if (count($this->getErrors()) == count($initErrors)) {
-                $this->addError($path, "Matched a schema which it should not");
+                $this->addError($path, "Matched a schema which it should not", 'not');
             } else {
                 $this->errors = $initErrors;
             }
@@ -170,12 +169,12 @@ class UndefinedConstraint extends Constraint
         if (is_object($value)) {
             if (isset($schema->minProperties)) {
                 if (count(get_object_vars($value)) < $schema->minProperties) {
-                    $this->addError($path, "Must contain a minimum of " . $schema->minProperties . " properties");
+                    $this->addError($path, "Must contain a minimum of " . $schema->minProperties . " properties", 'minProperties', array('minProperties' => $schema->minProperties,));
                 }
             }
             if (isset($schema->maxProperties)) {
                 if (count(get_object_vars($value)) > $schema->maxProperties) {
-                    $this->addError($path, "Must contain no more than " . $schema->maxProperties . " properties");
+                    $this->addError($path, "Must contain no more than " . $schema->maxProperties . " properties", 'maxProperties', array('maxProperties' => $schema->maxProperties,));
                 }
             }
         }
@@ -209,7 +208,7 @@ class UndefinedConstraint extends Constraint
                 $isValid = $isValid && (count($this->getErrors()) == count($initErrors));
             }
             if (!$isValid) {
-                $this->addError($path, "Failed to match all schemas");
+                $this->addError($path, "Failed to match all schemas", 'allOf');
             }
         }
 
@@ -224,7 +223,7 @@ class UndefinedConstraint extends Constraint
                 }
             }
             if (!$isValid) {
-                $this->addError($path, "Failed to match at least one schema");
+                $this->addError($path, "Failed to match at least one schema", 'anyOf');
             } else {
                 $this->errors = $startErrors;
             }
@@ -248,7 +247,8 @@ class UndefinedConstraint extends Constraint
                         $allErrors,
                         array(array(
                             'property' => $path,
-                            'message' => "failed to match exactly one schema"
+                            'message' => "Failed to match exactly one schema",
+                            'constraint' => 'oneOf',
                         ),),
                         $startErrors
                     )
@@ -274,13 +274,13 @@ class UndefinedConstraint extends Constraint
                 if (is_string($dependency)) {
                     // Draft 3 string is allowed - e.g. "dependencies": {"bar": "foo"}
                     if (!property_exists($value, $dependency)) {
-                        $this->addError($path, "$key depends on $dependency and $dependency is missing");
+                        $this->addError($path, "$key depends on $dependency and $dependency is missing", 'dependencies');
                     }
                 } else if (is_array($dependency)) {
                     // Draft 4 must be an array - e.g. "dependencies": {"bar": ["foo"]}
                     foreach ($dependency as $d) {
                         if (!property_exists($value, $d)) {
-                            $this->addError($path, "$key depends on $d and $d is missing");
+                            $this->addError($path, "$key depends on $d and $d is missing", 'dependencies');
                         }
                     }
                 } else if (is_object($dependency)) {

tests/JsonSchema/Tests/Constraints/AdditionalPropertiesTest.php

@@ -35,8 +35,9 @@ class AdditionalPropertiesTest extends BaseTestCase
                 null,
                 array(
                     array(
-                        'property' => '',
+                        'property'   => '',
-                        'message'  => 'The property - additionalProp - is not defined and the definition does not allow additional properties'
+                        'message'    => 'The property additionalProp is not defined and the definition does not allow additional properties',
+                        'constraint' => 'additionalProp',
                     )
                 )
             ),

tests/JsonSchema/Tests/Constraints/FormatTest.php

@@ -120,6 +120,7 @@ class FormatTest extends BaseTestCase
             array('www.example.com', 'host-name'),
 
             array('anything', '*'),
+            array('unknown', '*'),
         );
     }
 
@@ -160,6 +161,7 @@ class FormatTest extends BaseTestCase
             array(':::ff', 'ipv6'),
 
             array('localhost', 'host-name'),
+
         );
     }
 

tests/JsonSchema/Tests/Constraints/OfPropertiesTest.php

@@ -74,17 +74,19 @@ class OfPropertiesTest extends BaseTestCase
                 Validator::CHECK_MODE_NORMAL,
                 array(
                     array(
-                        "property" => "prop2",
+                        "property"   => "prop2",
-                        "message"  => "array value found, but a string is required",
+                        "message"    => "Array value found, but a string is required",
-
+                        "constraint" => "type",
                     ),
                     array(
-                        "property" => "prop2",
+                        "property"   => "prop2",
-                        "message"  => "array value found, but a number is required",
+                        "message"    => "Array value found, but a number is required",
+                        "constraint" => "type",
                     ),
                     array(
-                        "property" => "prop2",
+                        "property"   => "prop2",
-                        "message"  => "failed to match exactly one schema",
+                        "message"    => "Failed to match exactly one schema",
+                        "constraint" => "oneOf",
                     ),
                 ),
             ),

tests/JsonSchema/Tests/Constraints/TypeTest.php

@@ -43,7 +43,7 @@ class TypeTest extends \PHPUnit_Framework_TestCase
     {
         $constraint = new TypeConstraint();
         $constraint->check($value, (object)array('type' => $type));
-        $this->assertTypeConstraintError("$label value found, but $wording $type is required", $constraint);
+        $this->assertTypeConstraintError(ucwords($label)." value found, but $wording $type is required", $constraint);
     }
 
     /**