Json – 1.0: Serializing GBoxed Types
Description: Reference for Json-1.0: Serializing GBoxed Types

# Serializing GBoxed Types

GLib’s `GBoxed` type is a generic wrapper for arbitrary C structures.

JSON-GLib allows serialization and deserialization of a boxed type by registering functions mapping a `JsonNodeType` to a specific `GType`.

When registering a boxed type you should also register the corresponding transformation functions, e.g.:

    GType
    my_struct_get_type (void)
    {
      static GType boxed_type = 0;

      if (boxed_type == 0)
        {
          boxed_type =
            g_boxed_type_register_static (g_intern_static_string ("MyStruct"),
                                          (GBoxedCopyFunc) my_struct_copy,
                                          (GBoxedFreeFunc) my_struct_free);

          json_boxed_register_serialize_func (boxed_type, JSON_NODE_OBJECT,
                                              my_struct_serialize);
          json_boxed_register_deserialize_func (boxed_type, JSON_NODE_OBJECT,
                                                my_struct_deserialize);
        }

      return boxed_type;
    }

The serialization function will be invoked by `json_boxed_serialize()`: it will be passed a pointer to the C structure and it must return a `JsonNode`. The deserialization function will be invoked by `json_boxed_deserialize()`: it will be passed a `JsonNode` for the declared type and it must return a newly allocated C structure.

It is possible to check whether a boxed type can be deserialized from a specific `JsonNodeType`, and whether a boxed can be serialized and to which specific `JsonNodeType`.