docs/geode-native-docs/serialization/cpp-serialization/using-pdxinstancefactory.html.md.erb

---
title:  Using PdxInstanceFactory to Create PdxInstances
---

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You can use the `PdxInstanceFactory` API to create a `PdxInstance` from raw data when the domain class is not available on the server.

Creating a `PdxInstance` can be particularly useful when you need an instance of a domain class for plug-in code such as a function or a loader. If you have raw data for the domain object (the class name and each field's type and data), then you can explicitly create a `PdxInstance`. The `PdxInstanceFactory` API is very similar to the `PdxWriter` API except that after writing each field, you need to call the create method which returns the created `PdxInstance`.

## PdxInstance Example

The following is a code example of creating a `PdxInstance`.

``` pre
class Person
{
private:
  char* m_name;    
  int m_id;
  int m_age;

public:
  Person() { }

  Person(char* name, int id, int age)
  {
    m_name = name;
    m_id = id;
    m_age = age;
  }

  char* getName() const
  {
    return m_name;
  }
  int getID()
  {
    return m_id;
  }
  int getAge()
  {
    return m_age;
  }
};

int main(int argc, char ** argv)
{
  try
  {
    // Create a Cache.
    CacheFactoryPtr cacheFactory = CacheFactory::createCacheFactory();

    CachePtr cachePtr = cacheFactory->set("cache-xml-file", 
                "XMLs/clientPdxInstance.xml")->create();          

    LOGINFO("Created the <%=vars.product_name%> Cache");

    // Get the example Region from the Cache which is declared in the 
    // Cache XML file.
    RegionPtr regionPtr = cachePtr->getRegion("Person");       

    LOGINFO("Obtained the Region from the Cache.");
 
    Person* p = new Person("Jack", 7, 21);

    //PdxInstanceFactory for Person class
    PdxInstanceFactoryPtr pif = cachePtr->createPdxInstanceFactory("Person");
    LOGINFO("Created PdxInstanceFactory for Person class");

    pif->writeString("m_name", p->getName());
    pif->writeInt("m_id", p->getID());
    pif->markIdentityField("m_id");
    pif->writeInt("m_age", p->getAge());

    PdxInstancePtr pdxInstance = pif->create();

    LOGINFO("Created PdxInstance for Person class");

    regionPtr->put("Key1", pdxInstance);    

    LOGINFO("Populated PdxInstance Object");

    PdxInstancePtr retPdxInstance = regionPtr->get("Key1");

    LOGINFO("Got PdxInstance Object");

    int id = 0;
    retPdxInstance->getField("m_id", id);

    int age = 0;
    retPdxInstance->getField("m_age", age);

    char* name = NULL;
    retPdxInstance->getField("m_name", &name);

    if (id == p->getID()&& age == p->getAge() && strcmp(name, p->getName()) == 0
      && retPdxInstance->isIdentityField("m_id") == true)
      LOGINFO("PdxInstance returns all fields value expected");
    else
      LOGINFO("PdxInstance doesn't returns all fields value expected");

    delete p;

    // Close the Cache.
    cachePtr->close();

    LOGINFO("Closed the Cache");

  }
  // An exception should not occur
  catch(const Exception & geodeExcp)
  {    
    LOGERROR("PdxInstance Exception: %s", geodeExcp.getMessage());
  }
}
```