diff --git a/modules/swagger-codegen/src/main/resources/php/model.mustache b/modules/swagger-codegen/src/main/resources/php/model.mustache
index f230286a1207..f4f415cd4a43 100644
--- a/modules/swagger-codegen/src/main/resources/php/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/php/model.mustache
@@ -135,6 +135,51 @@ class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}implements ArrayA
         }
     }
 
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        {{#vars}}{{#required}}
+        if ($this->{{name}} === null) {
+            $invalid_properties[] = "'${{name}}' can't be null";
+        }{{/required}}
+        {{#isEnum}}$allowed_values = array({{#allowableValues}}{{#values}}"{{{this}}}"{{^-last}}, {{/-last}}{{/values}}{{/allowableValues}});
+        if (!in_array($this->{{name}}, $allowed_values))) {
+            $invalid_properties[] = "invalid value for '${{name}}', must be one of #{allowed_values}.";
+        }{{/isEnum}}
+        {{#hasValidation}}
+        {{#maxLength}}
+        if (strlen($this->{{name}}) > {{maxLength}}) {
+            $invalid_properties[] = "invalid value for '${{name}}', the character length must be smaller than or equal to {{{maxLength}}}.";
+        }
+        {{/maxLength}}
+        {{#minLength}}
+        if (strlen($this->{{name}}) < {{minLength}}) {
+            $invalid_properties[] = "invalid value for '${{name}}', the character length must be bigger than or equal to {{{minLength}}}.";
+        }
+        {{/minLength}}
+        {{#maximum}}
+        if ($this->{{name}} > {{maximum}}) {
+            $invalid_properties[] = "invalid value for '${{name}}', must be smaller than or equal to {{maximum}}.";
+        }
+        {{/maximum}}
+        {{#minimum}}
+        if ($this->{{name}} < {{minimum}}) {
+            $invalid_properties[] = "invalid value for '${{name}}', must be bigger than or equal to {{minimum}}.";
+        }
+        {{/minimum}}
+        {{#pattern}}
+        if (!preg_match("{{pattern}}", $this->{{name}})) {
+            $invalid_properties[] = "invalid value for '${{name}}', must be conform to the pattern {{pattern}}.";
+        }
+        {{/pattern}}{{/hasValidation}}{{/vars}}
+        return $invalid_properties;
+    }
+
     /**
      * validate all the parameters in the model
      * return true if all passed
@@ -143,12 +188,14 @@ class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}implements ArrayA
      */
     public function valid()
     {
-        {{#vars}}
-        {{#required}}
+        {{#vars}}{{#required}}
         if ($this->{{name}} === null) {
             return false;
-        }
-        {{/required}}
+        }{{/required}}
+        {{#isEnum}}$allowed_values = array({{#allowableValues}}{{#values}}"{{{this}}}"{{^-last}}, {{/-last}}{{/values}}{{/allowableValues}});
+        if (!in_array($this->{{name}}, $allowed_values))) {
+            return false;
+        }{{/isEnum}}
         {{#hasValidation}}
         {{#maxLength}}
         if (strlen($this->{{name}}) > {{maxLength}}) {
@@ -174,9 +221,7 @@ class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}implements ArrayA
         if (!preg_match("{{pattern}}", $this->{{name}})) {
             return false;
         }
-        {{/pattern}}
-        {{/hasValidation}}
-        {{/vars}}
+        {{/pattern}}{{/hasValidation}}{{/vars}}
         return true;
     }
 
@@ -224,10 +269,9 @@ class {{classname}} {{#parent}}extends {{{parent}}} {{/parent}}implements ArrayA
         {{/minimum}}
         {{#pattern}}
         if (!preg_match("{{pattern}}", ${{name}})) {
-            throw new \InvalidArgumentException('invalid value for ${{name}} when calling {{classname}}.{{operationId}}, must conform to the pattern {{pattern}}.');
+            throw new \InvalidArgumentException('invalid value for ${{name}} when calling {{classname}}.{{operationId}}, must be conform to the pattern {{pattern}}.');
         }
-        {{/pattern}}
-        {{/hasValidation}}
+        {{/pattern}}{{/hasValidation}}
         $this->{{name}} = ${{name}};
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/README.md b/samples/client/petstore/php/SwaggerClient-php/README.md
index e7d9b552b043..c202495f7ac4 100644
--- a/samples/client/petstore/php/SwaggerClient-php/README.md
+++ b/samples/client/petstore/php/SwaggerClient-php/README.md
@@ -5,7 +5,7 @@ This PHP package is automatically generated by the [Swagger Codegen](https://git
 
 - API version: 1.0.0
 - Package version: 1.0.0
-- Build date: 2016-04-29T03:01:58.276Z
+- Build date: 2016-05-05T03:40:26.342Z
 - Build package: class io.swagger.codegen.languages.PhpClientCodegen
 
 ## Requirements
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php b/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
index ee15a10d025a..8fefa9340588 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Api/FakeApi.php
@@ -198,7 +198,7 @@ class FakeApi
         if (strlen($password) > 64) {
             throw new \InvalidArgumentException('invalid length for "$password" when calling FakeApi.testEndpointParameters, must be smaller than or equal to 64.');
         }
-        if (strlen($password) > 10) {
+        if (strlen($password) < 10) {
             throw new \InvalidArgumentException('invalid length for "$password" when calling FakeApi.testEndpointParameters, must be bigger than or equal to 10.');
         }
 
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Animal.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Animal.php
index 3f01e789547e..82d29699f8a4 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Animal.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Animal.php
@@ -118,9 +118,47 @@ class Animal implements ArrayAccess
         $this->{$discrimintor} = static::$swaggerModelName;
 
         if ($data != null) {
-            $this->class_name = $data["class_name"];
+            if (isset($data["class_name"])) {
+                $this->class_name = $data["class_name"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        if ($this->class_name === null) {
+            $invalid_properties[] = "'$class_name' can't be null";
+        }
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        if ($this->class_name === null) {
+            return false;
+        }
+        
+
+        return true;
+    }
+
+
     /**
      * Gets class_name
      * @return string
@@ -138,6 +176,7 @@ class Animal implements ArrayAccess
     public function setClassName($class_name)
     {
         
+
         $this->class_name = $class_name;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/ApiResponse.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ApiResponse.php
index 4f467a5aab55..e6e7b7bcd841 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/ApiResponse.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ApiResponse.php
@@ -133,11 +133,55 @@ class ApiResponse implements ArrayAccess
         
         
         if ($data != null) {
-            $this->code = $data["code"];
-            $this->type = $data["type"];
-            $this->message = $data["message"];
+            if (isset($data["code"])) {
+                $this->code = $data["code"];
+            }
+            if (isset($data["type"])) {
+                $this->type = $data["type"];
+            }
+            if (isset($data["message"])) {
+                $this->message = $data["message"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets code
      * @return int
@@ -155,6 +199,7 @@ class ApiResponse implements ArrayAccess
     public function setCode($code)
     {
         
+
         $this->code = $code;
         return $this;
     }
@@ -175,6 +220,7 @@ class ApiResponse implements ArrayAccess
     public function setType($type)
     {
         
+
         $this->type = $type;
         return $this;
     }
@@ -195,6 +241,7 @@ class ApiResponse implements ArrayAccess
     public function setMessage($message)
     {
         
+
         $this->message = $message;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Cat.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Cat.php
index e0eaf7a106d6..4bc0f89d9e28 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Cat.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Cat.php
@@ -115,9 +115,41 @@ class Cat extends Animal implements ArrayAccess
         parent::__construct($data);
         
         if ($data != null) {
-            $this->declawed = $data["declawed"];
+            if (isset($data["declawed"])) {
+                $this->declawed = $data["declawed"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        return true;
+    }
+
+
     /**
      * Gets declawed
      * @return bool
@@ -135,6 +167,7 @@ class Cat extends Animal implements ArrayAccess
     public function setDeclawed($declawed)
     {
         
+
         $this->declawed = $declawed;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Category.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Category.php
index fb6eed3af292..55b391feabd7 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Category.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Category.php
@@ -124,10 +124,48 @@ class Category implements ArrayAccess
         
         
         if ($data != null) {
-            $this->id = $data["id"];
-            $this->name = $data["name"];
+            if (isset($data["id"])) {
+                $this->id = $data["id"];
+            }
+            if (isset($data["name"])) {
+                $this->name = $data["name"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets id
      * @return int
@@ -145,6 +183,7 @@ class Category implements ArrayAccess
     public function setId($id)
     {
         
+
         $this->id = $id;
         return $this;
     }
@@ -165,6 +204,7 @@ class Category implements ArrayAccess
     public function setName($name)
     {
         
+
         $this->name = $name;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Dog.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Dog.php
index 6fd43d3a9447..d092850ab799 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Dog.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Dog.php
@@ -115,9 +115,41 @@ class Dog extends Animal implements ArrayAccess
         parent::__construct($data);
         
         if ($data != null) {
-            $this->breed = $data["breed"];
+            if (isset($data["breed"])) {
+                $this->breed = $data["breed"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        return true;
+    }
+
+
     /**
      * Gets breed
      * @return string
@@ -135,6 +167,7 @@ class Dog extends Animal implements ArrayAccess
     public function setBreed($breed)
     {
         
+
         $this->breed = $breed;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/FormatTest.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/FormatTest.php
index 7bfe30c0ef76..6f5c75d28ebc 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/FormatTest.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/FormatTest.php
@@ -214,20 +214,220 @@ class FormatTest implements ArrayAccess
         
         
         if ($data != null) {
-            $this->integer = $data["integer"];
-            $this->int32 = $data["int32"];
-            $this->int64 = $data["int64"];
-            $this->number = $data["number"];
-            $this->float = $data["float"];
-            $this->double = $data["double"];
-            $this->string = $data["string"];
-            $this->byte = $data["byte"];
-            $this->binary = $data["binary"];
-            $this->date = $data["date"];
-            $this->date_time = $data["date_time"];
-            $this->password = $data["password"];
+            if (isset($data["integer"])) {
+                $this->integer = $data["integer"];
+            }
+            if (isset($data["int32"])) {
+                $this->int32 = $data["int32"];
+            }
+            if (isset($data["int64"])) {
+                $this->int64 = $data["int64"];
+            }
+            if (isset($data["number"])) {
+                $this->number = $data["number"];
+            }
+            if (isset($data["float"])) {
+                $this->float = $data["float"];
+            }
+            if (isset($data["double"])) {
+                $this->double = $data["double"];
+            }
+            if (isset($data["string"])) {
+                $this->string = $data["string"];
+            }
+            if (isset($data["byte"])) {
+                $this->byte = $data["byte"];
+            }
+            if (isset($data["binary"])) {
+                $this->binary = $data["binary"];
+            }
+            if (isset($data["date"])) {
+                $this->date = $data["date"];
+            }
+            if (isset($data["date_time"])) {
+                $this->date_time = $data["date_time"];
+            }
+            if (isset($data["password"])) {
+                $this->password = $data["password"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+        if ($this->integer > 100.0) {
+            $invalid_properties[] = "invalid value for '$integer', must be smaller than or equal to 100.0.";
+        }
+        if ($this->integer < 10.0) {
+            $invalid_properties[] = "invalid value for '$integer', must be bigger than or equal to 10.0.";
+        }
+
+        
+        if ($this->int32 > 200.0) {
+            $invalid_properties[] = "invalid value for '$int32', must be smaller than or equal to 200.0.";
+        }
+        if ($this->int32 < 20.0) {
+            $invalid_properties[] = "invalid value for '$int32', must be bigger than or equal to 20.0.";
+        }
+
+        
+
+        if ($this->number === null) {
+            $invalid_properties[] = "'$number' can't be null";
+        }
+        
+        if ($this->number > 543.2) {
+            $invalid_properties[] = "invalid value for '$number', must be smaller than or equal to 543.2.";
+        }
+        if ($this->number < 32.1) {
+            $invalid_properties[] = "invalid value for '$number', must be bigger than or equal to 32.1.";
+        }
+
+        
+        if ($this->float > 987.6) {
+            $invalid_properties[] = "invalid value for '$float', must be smaller than or equal to 987.6.";
+        }
+        if ($this->float < 54.3) {
+            $invalid_properties[] = "invalid value for '$float', must be bigger than or equal to 54.3.";
+        }
+
+        
+        if ($this->double > 123.4) {
+            $invalid_properties[] = "invalid value for '$double', must be smaller than or equal to 123.4.";
+        }
+        if ($this->double < 67.8) {
+            $invalid_properties[] = "invalid value for '$double', must be bigger than or equal to 67.8.";
+        }
+
+        
+        if (!preg_match("/[a-z]/i", $this->string)) {
+            $invalid_properties[] = "invalid value for '$string', must be conform to the pattern /[a-z]/i.";
+        }
+        
+        if ($this->byte === null) {
+            $invalid_properties[] = "'$byte' can't be null";
+        }
+        
+
+        
+
+        if ($this->date === null) {
+            $invalid_properties[] = "'$date' can't be null";
+        }
+        
+
+        
+
+        if ($this->password === null) {
+            $invalid_properties[] = "'$password' can't be null";
+        }
+        
+        if (strlen($this->password) > 64) {
+            $invalid_properties[] = "invalid value for '$password', the character length must be smaller than or equal to 64.";
+        }
+        if (strlen($this->password) < 10) {
+            $invalid_properties[] = "invalid value for '$password', the character length must be bigger than or equal to 10.";
+        }
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+        if ($this->integer > 100.0) {
+            return false;
+        }
+        if ($this->integer < 10.0) {
+            return false;
+        }
+
+        
+        if ($this->int32 > 200.0) {
+            return false;
+        }
+        if ($this->int32 < 20.0) {
+            return false;
+        }
+
+        
+
+        if ($this->number === null) {
+            return false;
+        }
+        
+        if ($this->number > 543.2) {
+            return false;
+        }
+        if ($this->number < 32.1) {
+            return false;
+        }
+
+        
+        if ($this->float > 987.6) {
+            return false;
+        }
+        if ($this->float < 54.3) {
+            return false;
+        }
+
+        
+        if ($this->double > 123.4) {
+            return false;
+        }
+        if ($this->double < 67.8) {
+            return false;
+        }
+
+        
+        if (!preg_match("/[a-z]/i", $this->string)) {
+            return false;
+        }
+        
+        if ($this->byte === null) {
+            return false;
+        }
+        
+
+        
+
+        if ($this->date === null) {
+            return false;
+        }
+        
+
+        
+
+        if ($this->password === null) {
+            return false;
+        }
+        
+        if (strlen($this->password) > 64) {
+            return false;
+        }
+        if (strlen($this->password) < 10) {
+            return false;
+        }
+
+        return true;
+    }
+
+
     /**
      * Gets integer
      * @return int
@@ -245,6 +445,14 @@ class FormatTest implements ArrayAccess
     public function setInteger($integer)
     {
         
+
+        if ($integer > 100.0) {
+            throw new \InvalidArgumentException('invalid value for $integer when calling FormatTest., must be smaller than or equal to 100.0.');
+        }
+        if ($integer < 10.0) {
+            throw new \InvalidArgumentException('invalid value for $integer when calling FormatTest., must be bigger than or equal to 10.0.');
+        }
+
         $this->integer = $integer;
         return $this;
     }
@@ -265,6 +473,14 @@ class FormatTest implements ArrayAccess
     public function setInt32($int32)
     {
         
+
+        if ($int32 > 200.0) {
+            throw new \InvalidArgumentException('invalid value for $int32 when calling FormatTest., must be smaller than or equal to 200.0.');
+        }
+        if ($int32 < 20.0) {
+            throw new \InvalidArgumentException('invalid value for $int32 when calling FormatTest., must be bigger than or equal to 20.0.');
+        }
+
         $this->int32 = $int32;
         return $this;
     }
@@ -285,6 +501,7 @@ class FormatTest implements ArrayAccess
     public function setInt64($int64)
     {
         
+
         $this->int64 = $int64;
         return $this;
     }
@@ -305,6 +522,14 @@ class FormatTest implements ArrayAccess
     public function setNumber($number)
     {
         
+
+        if ($number > 543.2) {
+            throw new \InvalidArgumentException('invalid value for $number when calling FormatTest., must be smaller than or equal to 543.2.');
+        }
+        if ($number < 32.1) {
+            throw new \InvalidArgumentException('invalid value for $number when calling FormatTest., must be bigger than or equal to 32.1.');
+        }
+
         $this->number = $number;
         return $this;
     }
@@ -325,6 +550,14 @@ class FormatTest implements ArrayAccess
     public function setFloat($float)
     {
         
+
+        if ($float > 987.6) {
+            throw new \InvalidArgumentException('invalid value for $float when calling FormatTest., must be smaller than or equal to 987.6.');
+        }
+        if ($float < 54.3) {
+            throw new \InvalidArgumentException('invalid value for $float when calling FormatTest., must be bigger than or equal to 54.3.');
+        }
+
         $this->float = $float;
         return $this;
     }
@@ -345,6 +578,14 @@ class FormatTest implements ArrayAccess
     public function setDouble($double)
     {
         
+
+        if ($double > 123.4) {
+            throw new \InvalidArgumentException('invalid value for $double when calling FormatTest., must be smaller than or equal to 123.4.');
+        }
+        if ($double < 67.8) {
+            throw new \InvalidArgumentException('invalid value for $double when calling FormatTest., must be bigger than or equal to 67.8.');
+        }
+
         $this->double = $double;
         return $this;
     }
@@ -365,6 +606,11 @@ class FormatTest implements ArrayAccess
     public function setString($string)
     {
         
+
+        if (!preg_match("/[a-z]/i", $string)) {
+            throw new \InvalidArgumentException('invalid value for $string when calling FormatTest., must be conform to the pattern /[a-z]/i.');
+        }
+        
         $this->string = $string;
         return $this;
     }
@@ -385,6 +631,7 @@ class FormatTest implements ArrayAccess
     public function setByte($byte)
     {
         
+
         $this->byte = $byte;
         return $this;
     }
@@ -405,6 +652,7 @@ class FormatTest implements ArrayAccess
     public function setBinary($binary)
     {
         
+
         $this->binary = $binary;
         return $this;
     }
@@ -425,6 +673,7 @@ class FormatTest implements ArrayAccess
     public function setDate($date)
     {
         
+
         $this->date = $date;
         return $this;
     }
@@ -445,6 +694,7 @@ class FormatTest implements ArrayAccess
     public function setDateTime($date_time)
     {
         
+
         $this->date_time = $date_time;
         return $this;
     }
@@ -465,6 +715,13 @@ class FormatTest implements ArrayAccess
     public function setPassword($password)
     {
         
+        if (strlen($password) > 64) {
+            throw new \InvalidArgumentException('invalid length for $password when calling FormatTest., must be smaller than or equal to 64.');
+        }
+        if (strlen($password) < 10) {
+            throw new \InvalidArgumentException('invalid length for $password when calling FormatTest., must be bigger than or equal to 10.');
+        }
+
         $this->password = $password;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Model200Response.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Model200Response.php
index 8d62f9531ec6..1ee9011b8f74 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Model200Response.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Model200Response.php
@@ -115,9 +115,41 @@ class Model200Response implements ArrayAccess
         
         
         if ($data != null) {
-            $this->name = $data["name"];
+            if (isset($data["name"])) {
+                $this->name = $data["name"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        return true;
+    }
+
+
     /**
      * Gets name
      * @return int
@@ -135,6 +167,7 @@ class Model200Response implements ArrayAccess
     public function setName($name)
     {
         
+
         $this->name = $name;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/ModelReturn.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ModelReturn.php
index d4660e118fde..d15f82a5057f 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/ModelReturn.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/ModelReturn.php
@@ -115,9 +115,41 @@ class ModelReturn implements ArrayAccess
         
         
         if ($data != null) {
-            $this->return = $data["return"];
+            if (isset($data["return"])) {
+                $this->return = $data["return"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        return true;
+    }
+
+
     /**
      * Gets return
      * @return int
@@ -135,6 +167,7 @@ class ModelReturn implements ArrayAccess
     public function setReturn($return)
     {
         
+
         $this->return = $return;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Name.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Name.php
index 9e1c4b927620..991ab945b4e4 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Name.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Name.php
@@ -133,11 +133,61 @@ class Name implements ArrayAccess
         
         
         if ($data != null) {
-            $this->name = $data["name"];
-            $this->snake_case = $data["snake_case"];
-            $this->property = $data["property"];
+            if (isset($data["name"])) {
+                $this->name = $data["name"];
+            }
+            if (isset($data["snake_case"])) {
+                $this->snake_case = $data["snake_case"];
+            }
+            if (isset($data["property"])) {
+                $this->property = $data["property"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        if ($this->name === null) {
+            $invalid_properties[] = "'$name' can't be null";
+        }
+        
+
+        
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        if ($this->name === null) {
+            return false;
+        }
+        
+
+        
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets name
      * @return int
@@ -155,6 +205,7 @@ class Name implements ArrayAccess
     public function setName($name)
     {
         
+
         $this->name = $name;
         return $this;
     }
@@ -175,6 +226,7 @@ class Name implements ArrayAccess
     public function setSnakeCase($snake_case)
     {
         
+
         $this->snake_case = $snake_case;
         return $this;
     }
@@ -195,6 +247,7 @@ class Name implements ArrayAccess
     public function setProperty($property)
     {
         
+
         $this->property = $property;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Order.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Order.php
index 7ee5c124d2cd..a7b6b22f4c74 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Order.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Order.php
@@ -160,14 +160,82 @@ class Order implements ArrayAccess
         
         
         if ($data != null) {
-            $this->id = $data["id"];
-            $this->pet_id = $data["pet_id"];
-            $this->quantity = $data["quantity"];
-            $this->ship_date = $data["ship_date"];
-            $this->status = $data["status"];
-            $this->complete = $data["complete"];
+            if (isset($data["id"])) {
+                $this->id = $data["id"];
+            }
+            if (isset($data["pet_id"])) {
+                $this->pet_id = $data["pet_id"];
+            }
+            if (isset($data["quantity"])) {
+                $this->quantity = $data["quantity"];
+            }
+            if (isset($data["ship_date"])) {
+                $this->ship_date = $data["ship_date"];
+            }
+            if (isset($data["status"])) {
+                $this->status = $data["status"];
+            }
+            if (isset($data["complete"])) {
+                $this->complete = $data["complete"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        
+
+        
+
+        $allowed_values = array("placed", "approved", "delivered");
+        if (!in_array($this->status, $allowed_values))) {
+            $invalid_properties[] = "invalid value for '$status', must be one of #{allowed_values}.";
+        }
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        
+
+        
+
+        $allowed_values = array("placed", "approved", "delivered");
+        if (!in_array($this->status, $allowed_values))) {
+            return false;
+        }
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets id
      * @return int
@@ -185,6 +253,7 @@ class Order implements ArrayAccess
     public function setId($id)
     {
         
+
         $this->id = $id;
         return $this;
     }
@@ -205,6 +274,7 @@ class Order implements ArrayAccess
     public function setPetId($pet_id)
     {
         
+
         $this->pet_id = $pet_id;
         return $this;
     }
@@ -225,6 +295,7 @@ class Order implements ArrayAccess
     public function setQuantity($quantity)
     {
         
+
         $this->quantity = $quantity;
         return $this;
     }
@@ -245,6 +316,7 @@ class Order implements ArrayAccess
     public function setShipDate($ship_date)
     {
         
+
         $this->ship_date = $ship_date;
         return $this;
     }
@@ -268,6 +340,7 @@ class Order implements ArrayAccess
         if (!in_array($status, $allowed_values)) {
             throw new \InvalidArgumentException("Invalid value for 'status', must be one of 'placed', 'approved', 'delivered'");
         }
+
         $this->status = $status;
         return $this;
     }
@@ -288,6 +361,7 @@ class Order implements ArrayAccess
     public function setComplete($complete)
     {
         
+
         $this->complete = $complete;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Pet.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Pet.php
index 3a9e46cd3fb4..319d23a839e5 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Pet.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Pet.php
@@ -160,14 +160,94 @@ class Pet implements ArrayAccess
         
         
         if ($data != null) {
-            $this->id = $data["id"];
-            $this->category = $data["category"];
-            $this->name = $data["name"];
-            $this->photo_urls = $data["photo_urls"];
-            $this->tags = $data["tags"];
-            $this->status = $data["status"];
+            if (isset($data["id"])) {
+                $this->id = $data["id"];
+            }
+            if (isset($data["category"])) {
+                $this->category = $data["category"];
+            }
+            if (isset($data["name"])) {
+                $this->name = $data["name"];
+            }
+            if (isset($data["photo_urls"])) {
+                $this->photo_urls = $data["photo_urls"];
+            }
+            if (isset($data["tags"])) {
+                $this->tags = $data["tags"];
+            }
+            if (isset($data["status"])) {
+                $this->status = $data["status"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        if ($this->name === null) {
+            $invalid_properties[] = "'$name' can't be null";
+        }
+        
+
+        if ($this->photo_urls === null) {
+            $invalid_properties[] = "'$photo_urls' can't be null";
+        }
+        
+
+        
+
+        $allowed_values = array("available", "pending", "sold");
+        if (!in_array($this->status, $allowed_values))) {
+            $invalid_properties[] = "invalid value for '$status', must be one of #{allowed_values}.";
+        }
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        if ($this->name === null) {
+            return false;
+        }
+        
+
+        if ($this->photo_urls === null) {
+            return false;
+        }
+        
+
+        
+
+        $allowed_values = array("available", "pending", "sold");
+        if (!in_array($this->status, $allowed_values))) {
+            return false;
+        }
+
+        return true;
+    }
+
+
     /**
      * Gets id
      * @return int
@@ -185,6 +265,7 @@ class Pet implements ArrayAccess
     public function setId($id)
     {
         
+
         $this->id = $id;
         return $this;
     }
@@ -205,6 +286,7 @@ class Pet implements ArrayAccess
     public function setCategory($category)
     {
         
+
         $this->category = $category;
         return $this;
     }
@@ -225,6 +307,7 @@ class Pet implements ArrayAccess
     public function setName($name)
     {
         
+
         $this->name = $name;
         return $this;
     }
@@ -245,6 +328,7 @@ class Pet implements ArrayAccess
     public function setPhotoUrls($photo_urls)
     {
         
+
         $this->photo_urls = $photo_urls;
         return $this;
     }
@@ -265,6 +349,7 @@ class Pet implements ArrayAccess
     public function setTags($tags)
     {
         
+
         $this->tags = $tags;
         return $this;
     }
@@ -288,6 +373,7 @@ class Pet implements ArrayAccess
         if (!in_array($status, $allowed_values)) {
             throw new \InvalidArgumentException("Invalid value for 'status', must be one of 'available', 'pending', 'sold'");
         }
+
         $this->status = $status;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/SpecialModelName.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/SpecialModelName.php
index fb748811cf27..200470d99d27 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/SpecialModelName.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/SpecialModelName.php
@@ -115,9 +115,41 @@ class SpecialModelName implements ArrayAccess
         
         
         if ($data != null) {
-            $this->special_property_name = $data["special_property_name"];
+            if (isset($data["special_property_name"])) {
+                $this->special_property_name = $data["special_property_name"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        return true;
+    }
+
+
     /**
      * Gets special_property_name
      * @return int
@@ -135,6 +167,7 @@ class SpecialModelName implements ArrayAccess
     public function setSpecialPropertyName($special_property_name)
     {
         
+
         $this->special_property_name = $special_property_name;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Tag.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Tag.php
index 4bb56401c48b..e493bdfd3e39 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/Tag.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/Tag.php
@@ -124,10 +124,48 @@ class Tag implements ArrayAccess
         
         
         if ($data != null) {
-            $this->id = $data["id"];
-            $this->name = $data["name"];
+            if (isset($data["id"])) {
+                $this->id = $data["id"];
+            }
+            if (isset($data["name"])) {
+                $this->name = $data["name"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets id
      * @return int
@@ -145,6 +183,7 @@ class Tag implements ArrayAccess
     public function setId($id)
     {
         
+
         $this->id = $id;
         return $this;
     }
@@ -165,6 +204,7 @@ class Tag implements ArrayAccess
     public function setName($name)
     {
         
+
         $this->name = $name;
         return $this;
     }
diff --git a/samples/client/petstore/php/SwaggerClient-php/lib/Model/User.php b/samples/client/petstore/php/SwaggerClient-php/lib/Model/User.php
index da9cc20ff4cc..3b09cea0fd23 100644
--- a/samples/client/petstore/php/SwaggerClient-php/lib/Model/User.php
+++ b/samples/client/petstore/php/SwaggerClient-php/lib/Model/User.php
@@ -178,16 +178,90 @@ class User implements ArrayAccess
         
         
         if ($data != null) {
-            $this->id = $data["id"];
-            $this->username = $data["username"];
-            $this->first_name = $data["first_name"];
-            $this->last_name = $data["last_name"];
-            $this->email = $data["email"];
-            $this->password = $data["password"];
-            $this->phone = $data["phone"];
-            $this->user_status = $data["user_status"];
+            if (isset($data["id"])) {
+                $this->id = $data["id"];
+            }
+            if (isset($data["username"])) {
+                $this->username = $data["username"];
+            }
+            if (isset($data["first_name"])) {
+                $this->first_name = $data["first_name"];
+            }
+            if (isset($data["last_name"])) {
+                $this->last_name = $data["last_name"];
+            }
+            if (isset($data["email"])) {
+                $this->email = $data["email"];
+            }
+            if (isset($data["password"])) {
+                $this->password = $data["password"];
+            }
+            if (isset($data["phone"])) {
+                $this->phone = $data["phone"];
+            }
+            if (isset($data["user_status"])) {
+                $this->user_status = $data["user_status"];
+            }
         }
     }
+
+    /**
+     * show all the invalid properties with reasons.
+     * 
+     * @return array invalid properties with reasons
+     */
+    public function list_invalid_properties()
+    {
+        $invalid_properties = array();
+        
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        return $invalid_properties;
+    }
+
+    /**
+     * validate all the parameters in the model
+     * return true if all passed
+     * 
+     * @return bool [description]
+     */
+    public function valid()
+    {
+        
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        
+
+        return true;
+    }
+
+
     /**
      * Gets id
      * @return int
@@ -205,6 +279,7 @@ class User implements ArrayAccess
     public function setId($id)
     {
         
+
         $this->id = $id;
         return $this;
     }
@@ -225,6 +300,7 @@ class User implements ArrayAccess
     public function setUsername($username)
     {
         
+
         $this->username = $username;
         return $this;
     }
@@ -245,6 +321,7 @@ class User implements ArrayAccess
     public function setFirstName($first_name)
     {
         
+
         $this->first_name = $first_name;
         return $this;
     }
@@ -265,6 +342,7 @@ class User implements ArrayAccess
     public function setLastName($last_name)
     {
         
+
         $this->last_name = $last_name;
         return $this;
     }
@@ -285,6 +363,7 @@ class User implements ArrayAccess
     public function setEmail($email)
     {
         
+
         $this->email = $email;
         return $this;
     }
@@ -305,6 +384,7 @@ class User implements ArrayAccess
     public function setPassword($password)
     {
         
+
         $this->password = $password;
         return $this;
     }
@@ -325,6 +405,7 @@ class User implements ArrayAccess
     public function setPhone($phone)
     {
         
+
         $this->phone = $phone;
         return $this;
     }
@@ -345,6 +426,7 @@ class User implements ArrayAccess
     public function setUserStatus($user_status)
     {
         
+
         $this->user_status = $user_status;
         return $this;
     }