jsonv::polymorphic_adapter< TPointer > Class Template Reference

An adapter which can create polymorphic types. More...

#include <jsonv/serialization/polymorphic_adapter.hpp>

Inheritance diagram for jsonv::polymorphic_adapter< TPointer >:

Collaboration diagram for jsonv::polymorphic_adapter< TPointer >:

Public Types
using	match_predicate = std::function< bool(extraction_context &, const value &)>

Public Member Functions
template<typename T >
void	add_subtype (match_predicate pred)
	Add a subtype which can be transformed into TPointer which will be called if the discriminator pred is matched.
template<typename T >
void	add_subtype_keyed (std::string key, value expected_value, keyed_subtype_action action=keyed_subtype_action::none)
	Add a subtype which can be transformed into TPointer which will be called if given a JSON value with kind::object which has a member with key and the provided expected_value.
void	check_null_input (bool on)
bool	check_null_input () const
void	check_null_output (bool on)
	}
bool	check_null_output () const
Public Member Functions inherited from jsonv::adapter_for< T >
virtual const std::type_info &	get_type () const noexcept override
virtual std::expected< void, ast_node_type >	extract (extraction_context &context, reader &from, void *into) const override
virtual value	to_json (const serialization_context &context, const void *from) const override

Protected Member Functions
virtual TPointer	create (extraction_context &context, const value &from) const override
	Create an instance of T from the materialised from.
virtual value	to_json (const serialization_context &context, const TPointer &from) const override
Protected Member Functions inherited from jsonv::value_adapter_for< TPointer >
virtual std::expected< TPointer, ast_node_type >	create (extraction_context &context, reader &from) const final override
	Create an instance of T by reading from.
Protected Member Functions inherited from jsonv::adapter_for< T >
virtual value	to_json (const serialization_context &context, const T &from) const =0

Detailed Description

template<typename TPointer>
class jsonv::polymorphic_adapter< TPointer >

An adapter which can create polymorphic types.

This allows you to parse JSON directly into a type heirarchy without some middle layer.

[
  {
    "type": "worker",
    "name": "Adam"
  },
  {
    "type": "manager",
    "name": "Bob",
    "head": "Development"
  }
]

Template Parameters

TPointer

Some pointer-like type (likely unique_ptr or shared_ptr) you wish to extract values into. It must support operator*, an explicit conversion to bool, construction with a pointer to a subtype of what it contains and default construction.

Definition at line 59 of file polymorphic_adapter.hpp.

Member Typedef Documentation

match_predicate

template<typename TPointer >

using jsonv::polymorphic_adapter< TPointer >::match_predicate = std::function<bool (extraction_context&, const value&)>

Definition at line 63 of file polymorphic_adapter.hpp.

Member Function Documentation

add_subtype()

template<typename TPointer >

template<typename T >

void jsonv::polymorphic_adapter< TPointer >::add_subtype ( match_predicate  pred )

inline

Add a subtype which can be transformed into TPointer which will be called if the discriminator pred is matched.

See also

add_subtype_keyed

Definition at line 73 of file polymorphic_adapter.hpp.

add_subtype_keyed()

template<typename TPointer >

template<typename T >

void jsonv::polymorphic_adapter< TPointer >::add_subtype_keyed ( std::string  key, value  expected_value, keyed_subtype_action  action = keyed_subtype_action::none  )

inline

Add a subtype which can be transformed into TPointer which will be called if given a JSON value with kind::object which has a member with key and the provided expected_value.

See also

add_subtype

Definition at line 88 of file polymorphic_adapter.hpp.

Here is the call graph for this function:

check_null_input() [1/2]

template<typename TPointer >

bool jsonv::polymorphic_adapter< TPointer >::check_null_input ( ) const

inline

Definition at line 116 of file polymorphic_adapter.hpp.

check_null_input() [2/2]

template<typename TPointer >

void jsonv::polymorphic_adapter< TPointer >::check_null_input ( bool  on )

inline

When extracting a C++ value, should kind::null in JSON automatically become a default-constructed TPointer (which is usually the null representation)?

Definition at line 110 of file polymorphic_adapter.hpp.

check_null_output() [1/2]

template<typename TPointer >

bool jsonv::polymorphic_adapter< TPointer >::check_null_output ( ) const

inline

Definition at line 130 of file polymorphic_adapter.hpp.

check_null_output() [2/2]

template<typename TPointer >

void jsonv::polymorphic_adapter< TPointer >::check_null_output ( bool  on )

inline

}

When converting with to_json, should a null input translate into a kind::null?

Definition at line 124 of file polymorphic_adapter.hpp.

create()

template<typename TPointer >

virtual TPointer jsonv::polymorphic_adapter< TPointer >::create ( extraction_context &  context, const value &  from  ) const

inlineoverrideprotectedvirtual

Create an instance of T from the materialised from.

Exceptions

extraction_error

if from cannot be converted to a T.

Implements jsonv::value_adapter_for< TPointer >.

Definition at line 138 of file polymorphic_adapter.hpp.

to_json()

template<typename TPointer >

virtual value jsonv::polymorphic_adapter< TPointer >::to_json ( const serialization_context &  context, const TPointer &  from  ) const

inlineoverrideprotectedvirtual

Definition at line 161 of file polymorphic_adapter.hpp.

---

The documentation for this class was generated from the following file:

• jsonv/serialization/polymorphic_adapter.hpp