docs/geode-native-docs-dotnet/serialization/dotnet-serialization/dotnet-pdx-autoserializer.html.md.erb

<% set_title("Using the", product_name, "PDX Autoserializer") %>

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It's extremely easy for .NET Framework applications to store and retrieve data from Geode. All
that's required is a single line of code to set the `PdxSerializer` to the .NET Framework client's
`ReflectionBasedAutoSerializer`:

```csharp
cache.TypeRegistry.PdxSerializer = new ReflectionBasedAutoSerializer();
```

(The autoserializer can be registered only in the application code. It cannot be configured declaratively in `cache.xml`.)

After an autoserializer has been registered, all user classes can automatically be stored without needing to implement any
interfaces. For example, the following `Put` command stores `value`, which is an instance of a user defined class, in
the region.

```csharp
region.Put(key, value);
```
    
The .NET Framework client's `ReflectionBasedAutoSerializer` supports the full list of .NET
Framework primitives and other common built-in types.

Types without a no-arg constructor are not supported by the `ReflectionBasedAutoSerializer`. This
includes all user defined structs. `System.Data.Datatable` is an example of a system class that is not
supported due to lack of a no-arg constructor.

## <a id="auto-ser-java-interop"></a>Java Interoperability with .NET Framework Specific Types

Java does not have unsigned data types or exact equivalents of `Guid` and `Decimal`. Care should be
taken when passing these types between .NET Framework and Java applications using the .NET
Framework `ReflectionBasedAutoSerializer`. For example, if storing `UInt16` data (that is, 16-bit
unsigned values), be aware that values greater than `UInt16.MaxValue/2 - 1` will show up as
negative numbers in Java.
Using that data in a Java application may have unexpected behavior. If you expect to exceed
half the range for the given type (`Byte.MaxValue/2`, `UInt16.MaxValue/2`, `UInt32.MaxValue/2`, or
`UInt64.MaxValue/2`) you should use the next larger type. This obviously breaks down for
`UInt64`, which has no next larger type. However, if your range exceeds `UIn64.MaxValue/2`, you
likely have a much more complex set of issues to deal with, such as heavy paging due to such a
large data set.

## <a id="auto-ser-remote-queries"></a>Remote Queries of .NET Framework Only Types

At this time the .NET Framework Client does not support queries against user classes that have been
stored on the server using the `ReflectionBasedAutoSerializer`.

When you register the reflection-based serializer, <%=vars.product_name%> uses it to serialize all
objects that do not implement `IPdxSerializable`. You can customize the
auto-serialization behavior for your domain objects by adding serialization attributes to your
object’s fields.

## <a id='pdx-ser-extending-auto'></a>Extending the PDX Autoserializer

For each object you intend to have autoserialized, you can customize the serialization as needed.

**Note:** If you also use PDX serialization in Java for the object, customize your serialization in the same way for both languages.

The following extension methods apply to autoserialization:

-   **WriteTransform**. Controls what field value is written during auto serialization.
-   **ReadTransform**. Controls what field value is read during auto deserialization.
-   **GetFieldType**. Defines the specific field names that will be generated during autoserialization.
-   **IsIdentityField**. Controls which field is marked as the identity field. Identity fields are used when a `PdxInstance` computes its hash code to determine whether it is equal to another object.
-   **GetFieldType**. Determines the field type that will be used when autoserializing the given field.
-   **IsFieldIncluded**. Specifies which fields of a class to autoserialize.

To specify an identifier field in your domain object, add the attribute `PdxIdentityField` to the field.

For example:

```csharp
[PdxIdentityField] private int id;
```

To exclude a field from serialization, add the .NET Framework attribute `NonSerialized` to the field.

For example:

```csharp
[NonSerialized] private int myLocalData;
```

For each domain class <%=vars.product_name%> serializes using the autoserializer, all fields are
considered for serialization except those defined as `static`, `literal` or `readonly` and those you
explicitly exclude using the .NET Framework `NonSerialized` attribute.

This example code demonstrates how to extend the autoserializer to customize serialization.

```csharp
public class AutoSerializerEx : ReflectionBasedAutoSerializer
{
   public override object WriteTransform(FieldInfo fi, Type type, object originalValue) {
      if (fi.FieldType.Equals(Type.GetType("System.Guid"))) {
        return originalValue.ToString();
      } else if (fi.FieldType.Equals(Type.GetType("System.Decimal"))) {
        return originalValue.ToString();
      } else
        return base.WriteTransform(fi, type, originalValue);
    }

    public override object ReadTransform(FieldInfo fi, Type type, object serializeValue) {
      if (fi.FieldType.Equals(Type.GetType("System.Guid"))) {
        Guid g = new Guid((string)serializeValue);
        return g;
      } else if (fi.FieldType.Equals(Type.GetType("System.Decimal"))) {
        return Convert.ToDecimal((string)serializeValue);
      } else
        return base.ReadTransform(fi, type, serializeValue);
    }

   public override FieldType GetFieldType(FieldInfo fi, Type type) {
      if (fi.FieldType.Equals(Type.GetType("System.Guid")) ||
              fi.FieldType.Equals(Type.GetType("System.Decimal")))
        return FieldType.STRING;
      return base.GetFieldType(fi, type);
   }

   public override bool IsIdentityField(FieldInfo fi, Type type) {
      if (fi.Name == "_identityField")
        return true;
      return base.IsIdentityField(fi, type);
   }

   public override string GetFieldName(FieldInfo fi, Type type) {
      if (fi.Name == "_nameChange")
        return fi.Name + "NewName";
      return fi.Name;
    }
 
   public override bool IsFieldIncluded(FieldInfo fi, Type type)
   {
      if (fi.Name == "_notInclude")
        return false;
      return base.IsFieldIncluded(fi, type);
    }
}
```