cannam@147: // Copyright (c) 2015 Sandstorm Development Group, Inc. and contributors
cannam@147: // Licensed under the MIT License:
cannam@147: //
cannam@147: // Permission is hereby granted, free of charge, to any person obtaining a copy
cannam@147: // of this software and associated documentation files (the "Software"), to deal
cannam@147: // in the Software without restriction, including without limitation the rights
cannam@147: // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
cannam@147: // copies of the Software, and to permit persons to whom the Software is
cannam@147: // furnished to do so, subject to the following conditions:
cannam@147: //
cannam@147: // The above copyright notice and this permission notice shall be included in
cannam@147: // all copies or substantial portions of the Software.
cannam@147: //
cannam@147: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
cannam@147: // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
cannam@147: // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
cannam@147: // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
cannam@147: // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
cannam@147: // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
cannam@147: // THE SOFTWARE.
cannam@147: 
cannam@147: #ifndef CAPNP_COMPAT_JSON_H_
cannam@147: #define CAPNP_COMPAT_JSON_H_
cannam@147: 
cannam@147: #include <capnp/schema.h>
cannam@147: #include <capnp/dynamic.h>
cannam@147: #include <capnp/compat/json.capnp.h>
cannam@147: 
cannam@147: namespace capnp {
cannam@147: 
cannam@147: class JsonCodec {
cannam@147:   // Flexible class for encoding Cap'n Proto types as JSON, and decoding JSON back to Cap'n Proto.
cannam@147:   //
cannam@147:   // Typical usage:
cannam@147:   //
cannam@147:   //     JsonCodec json;
cannam@147:   //
cannam@147:   //     // encode
cannam@147:   //     kj::String encoded = json.encode(someStructReader);
cannam@147:   //
cannam@147:   //     // decode
cannam@147:   //     json.decode(encoded, someStructBuilder);
cannam@147:   //
cannam@147:   // Advanced users can do fancy things like override the way certain types or fields are
cannam@147:   // represented in JSON by registering handlers. See the unit test for an example.
cannam@147:   //
cannam@147:   // Notes:
cannam@147:   // - When encoding, all primitive fields are always encoded, even if default-valued. Pointer
cannam@147:   //   fields are only encoded if they are non-null.
cannam@147:   // - 64-bit integers are encoded as strings, since JSON "numbers" are double-precision floating
cannam@147:   //   points which cannot store a 64-bit integer without losing data.
cannam@147:   // - NaNs and infinite floating point numbers are not allowed by the JSON spec, and so are encoded
cannam@147:   //   as null. This matches the behavior of `JSON.stringify` in at least Firefox and Chrome.
cannam@147:   // - Data is encoded as an array of numbers in the range [0,255]. You probably want to register
cannam@147:   //   a handler that does something better, like maybe base64 encoding, but there are a zillion
cannam@147:   //   different ways people do this.
cannam@147:   // - Encoding/decoding capabilities and AnyPointers requires registering a Handler, since there's
cannam@147:   //   no obvious default behavior.
cannam@147:   // - When decoding, unrecognized field names are ignored. Note: This means that JSON is NOT a
cannam@147:   //   good format for receiving input from a human. Consider `capnp eval` or the SchemaParser
cannam@147:   //   library for human input.
cannam@147: 
cannam@147: public:
cannam@147:   JsonCodec();
cannam@147:   ~JsonCodec() noexcept(false);
cannam@147: 
cannam@147:   // ---------------------------------------------------------------------------
cannam@147:   // standard API
cannam@147: 
cannam@147:   void setPrettyPrint(bool enabled);
cannam@147:   // Enable to insert newlines, indentation, and other extra spacing into the output. The default
cannam@147:   // is to use minimal whitespace.
cannam@147: 
cannam@147:   void setMaxNestingDepth(size_t maxNestingDepth);
cannam@147:   // Set maximum nesting depth when decoding JSON to prevent highly nested input from overflowing
cannam@147:   // the call stack. The default is 64.
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   kj::String encode(T&& value);
cannam@147:   // Encode any Cap'n Proto value to JSON, including primitives and
cannam@147:   // Dynamic{Enum,Struct,List,Capability}, but not DynamicValue (see below).
cannam@147: 
cannam@147:   kj::String encode(DynamicValue::Reader value, Type type) const;
cannam@147:   // Encode a DynamicValue to JSON. `type` is needed because `DynamicValue` itself does
cannam@147:   // not distinguish between e.g. int32 and int64, which in JSON are handled differently. Most
cannam@147:   // of the time, though, you can use the single-argument templated version of `encode()` instead.
cannam@147: 
cannam@147:   void decode(kj::ArrayPtr<const char> input, DynamicStruct::Builder output) const;
cannam@147:   // Decode JSON text directly into a struct builder. This only works for structs since lists
cannam@147:   // need to be allocated with the correct size in advance.
cannam@147:   //
cannam@147:   // (Remember that any Cap'n Proto struct reader type can be implicitly cast to
cannam@147:   // DynamicStruct::Reader.)
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   Orphan<T> decode(kj::ArrayPtr<const char> input, Orphanage orphanage) const;
cannam@147:   // Decode JSON text to any Cap'n Proto object (pointer value), allocated using the given
cannam@147:   // orphanage. T must be specified explicitly and cannot be dynamic, e.g.:
cannam@147:   //
cannam@147:   //     Orphan<MyType> orphan = json.decode<MyType>(text, orphanage);
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   ReaderFor<T> decode(kj::ArrayPtr<const char> input) const;
cannam@147:   // Decode JSON text into a primitive or capability value. T must be specified explicitly and
cannam@147:   // cannot be dynamic, e.g.:
cannam@147:   //
cannam@147:   //     uint32_t n = json.decode<uint32_t>(text);
cannam@147: 
cannam@147:   Orphan<DynamicValue> decode(kj::ArrayPtr<const char> input, Type type, Orphanage orphanage) const;
cannam@147:   Orphan<DynamicList> decode(
cannam@147:       kj::ArrayPtr<const char> input, ListSchema type, Orphanage orphanage) const;
cannam@147:   Orphan<DynamicStruct> decode(
cannam@147:       kj::ArrayPtr<const char> input, StructSchema type, Orphanage orphanage) const;
cannam@147:   DynamicCapability::Client decode(kj::ArrayPtr<const char> input, InterfaceSchema type) const;
cannam@147:   DynamicEnum decode(kj::ArrayPtr<const char> input, EnumSchema type) const;
cannam@147:   // Decode to a dynamic value, specifying the type schema.
cannam@147: 
cannam@147:   // ---------------------------------------------------------------------------
cannam@147:   // layered API
cannam@147:   //
cannam@147:   // You can separate text <-> JsonValue from JsonValue <-> T. These are particularly useful
cannam@147:   // for calling from Handler implementations.
cannam@147: 
cannam@147:   kj::String encodeRaw(JsonValue::Reader value) const;
cannam@147:   void decodeRaw(kj::ArrayPtr<const char> input, JsonValue::Builder output) const;
cannam@147:   // Translate JsonValue <-> text.
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   void encode(T&& value, JsonValue::Builder output);
cannam@147:   void encode(DynamicValue::Reader input, Type type, JsonValue::Builder output) const;
cannam@147:   void decode(JsonValue::Reader input, DynamicStruct::Builder output) const;
cannam@147:   template <typename T>
cannam@147:   Orphan<T> decode(JsonValue::Reader input, Orphanage orphanage) const;
cannam@147:   template <typename T>
cannam@147:   ReaderFor<T> decode(JsonValue::Reader input) const;
cannam@147: 
cannam@147:   Orphan<DynamicValue> decode(JsonValue::Reader input, Type type, Orphanage orphanage) const;
cannam@147:   Orphan<DynamicList> decode(JsonValue::Reader input, ListSchema type, Orphanage orphanage) const;
cannam@147:   Orphan<DynamicStruct> decode(
cannam@147:       JsonValue::Reader input, StructSchema type, Orphanage orphanage) const;
cannam@147:   DynamicCapability::Client decode(JsonValue::Reader input, InterfaceSchema type) const;
cannam@147:   DynamicEnum decode(JsonValue::Reader input, EnumSchema type) const;
cannam@147: 
cannam@147:   // ---------------------------------------------------------------------------
cannam@147:   // specializing particular types
cannam@147: 
cannam@147:   template <typename T, Style s = style<T>()>
cannam@147:   class Handler;
cannam@147:   // Implement this interface to specify a special encoding for a particular type or field.
cannam@147:   //
cannam@147:   // The templates are a bit ugly, but subclasses of this type essentially implement two methods,
cannam@147:   // one to encode values of this type and one to decode values of this type. `encode()` is simple:
cannam@147:   //
cannam@147:   //   void encode(const JsonCodec& codec, ReaderFor<T> input, JsonValue::Builder output) const;
cannam@147:   //
cannam@147:   // `decode()` is a bit trickier. When T is a struct (including DynamicStruct), it is:
cannam@147:   //
cannam@147:   //   void decode(const JsonCodec& codec, JsonValue::Reader input, BuilderFor<T> output) const;
cannam@147:   //
cannam@147:   // However, when T is a primitive, decode() is:
cannam@147:   //
cannam@147:   //   T decode(const JsonCodec& codec, JsonValue::Reader input) const;
cannam@147:   //
cannam@147:   // Or when T is any non-struct object (list, blob), decode() is:
cannam@147:   //
cannam@147:   //   Orphan<T> decode(const JsonCodec& codec, JsonValue::Reader input, Orphanage orphanage) const;
cannam@147:   //
cannam@147:   // Or when T is an interface:
cannam@147:   //
cannam@147:   //   T::Client decode(const JsonCodec& codec, JsonValue::Reader input) const;
cannam@147:   //
cannam@147:   // Additionally, when T is a struct you can *optionally* also implement the orphan-returning form
cannam@147:   // of decode(), but it will only be called when the struct would be allocated as an individual
cannam@147:   // object, not as part of a list. This allows you to return "nullptr" in these cases to say that
cannam@147:   // the pointer value should be null. This does not apply to list elements because struct list
cannam@147:   // elements cannot ever be null (since Cap'n Proto encodes struct lists as a flat list rather
cannam@147:   // than list-of-pointers).
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   void addTypeHandler(Handler<T>& handler);
cannam@147:   void addTypeHandler(Type type, Handler<DynamicValue>& handler);
cannam@147:   void addTypeHandler(EnumSchema type, Handler<DynamicEnum>& handler);
cannam@147:   void addTypeHandler(StructSchema type, Handler<DynamicStruct>& handler);
cannam@147:   void addTypeHandler(ListSchema type, Handler<DynamicList>& handler);
cannam@147:   void addTypeHandler(InterfaceSchema type, Handler<DynamicCapability>& handler);
cannam@147:   // Arrange that whenever the type T appears in the message, your handler will be used to
cannam@147:   // encode/decode it.
cannam@147:   //
cannam@147:   // Note that if you register a handler for a capability type, it will also apply to subtypes.
cannam@147:   // Thus Handler<Capability> handles all capabilities.
cannam@147: 
cannam@147:   template <typename T>
cannam@147:   void addFieldHandler(StructSchema::Field field, Handler<T>& handler);
cannam@147:   // Matches only the specific field. T can be a dynamic type. T must match the field's type.
cannam@147: 
cannam@147: private:
cannam@147:   class HandlerBase;
cannam@147:   struct Impl;
cannam@147: 
cannam@147:   kj::Own<Impl> impl;
cannam@147: 
cannam@147:   void encodeField(StructSchema::Field field, DynamicValue::Reader input,
cannam@147:                    JsonValue::Builder output) const;
cannam@147:   void decodeArray(List<JsonValue>::Reader input, DynamicList::Builder output) const;
cannam@147:   void decodeObject(List<JsonValue::Field>::Reader input, DynamicStruct::Builder output) const;
cannam@147:   void addTypeHandlerImpl(Type type, HandlerBase& handler);
cannam@147:   void addFieldHandlerImpl(StructSchema::Field field, Type type, HandlerBase& handler);
cannam@147: };
cannam@147: 
cannam@147: // =======================================================================================
cannam@147: // inline implementation details
cannam@147: 
cannam@147: template <typename T>
cannam@147: kj::String JsonCodec::encode(T&& value) {
cannam@147:   typedef FromAny<kj::Decay<T>> Base;
cannam@147:   return encode(DynamicValue::Reader(ReaderFor<Base>(kj::fwd<T>(value))), Type::from<Base>());
cannam@147: }
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline Orphan<T> JsonCodec::decode(kj::ArrayPtr<const char> input, Orphanage orphanage) const {
cannam@147:   return decode(input, Type::from<T>(), orphanage).template releaseAs<T>();
cannam@147: }
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline ReaderFor<T> JsonCodec::decode(kj::ArrayPtr<const char> input) const {
cannam@147:   static_assert(style<T>() == Style::PRIMITIVE || style<T>() == Style::CAPABILITY,
cannam@147:                 "must specify an orphanage to decode an object type");
cannam@147:   return decode(input, Type::from<T>(), Orphanage()).getReader().template as<T>();
cannam@147: }
cannam@147: 
cannam@147: inline Orphan<DynamicList> JsonCodec::decode(
cannam@147:     kj::ArrayPtr<const char> input, ListSchema type, Orphanage orphanage) const {
cannam@147:   return decode(input, Type(type), orphanage).releaseAs<DynamicList>();
cannam@147: }
cannam@147: inline Orphan<DynamicStruct> JsonCodec::decode(
cannam@147:     kj::ArrayPtr<const char> input, StructSchema type, Orphanage orphanage) const {
cannam@147:   return decode(input, Type(type), orphanage).releaseAs<DynamicStruct>();
cannam@147: }
cannam@147: inline DynamicCapability::Client JsonCodec::decode(
cannam@147:     kj::ArrayPtr<const char> input, InterfaceSchema type) const {
cannam@147:   return decode(input, Type(type), Orphanage()).getReader().as<DynamicCapability>();
cannam@147: }
cannam@147: inline DynamicEnum JsonCodec::decode(kj::ArrayPtr<const char> input, EnumSchema type) const {
cannam@147:   return decode(input, Type(type), Orphanage()).getReader().as<DynamicEnum>();
cannam@147: }
cannam@147: 
cannam@147: // -----------------------------------------------------------------------------
cannam@147: 
cannam@147: template <typename T>
cannam@147: void JsonCodec::encode(T&& value, JsonValue::Builder output) {
cannam@147:   typedef FromAny<kj::Decay<T>> Base;
cannam@147:   encode(DynamicValue::Reader(ReaderFor<Base>(kj::fwd<T>(value))), Type::from<Base>(), output);
cannam@147: }
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline Orphan<T> JsonCodec::decode(JsonValue::Reader input, Orphanage orphanage) const {
cannam@147:   return decode(input, Type::from<T>(), orphanage).template releaseAs<T>();
cannam@147: }
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline ReaderFor<T> JsonCodec::decode(JsonValue::Reader input) const {
cannam@147:   static_assert(style<T>() == Style::PRIMITIVE || style<T>() == Style::CAPABILITY,
cannam@147:                 "must specify an orphanage to decode an object type");
cannam@147:   return decode(input, Type::from<T>(), Orphanage()).getReader().template as<T>();
cannam@147: }
cannam@147: 
cannam@147: inline Orphan<DynamicList> JsonCodec::decode(
cannam@147:     JsonValue::Reader input, ListSchema type, Orphanage orphanage) const {
cannam@147:   return decode(input, Type(type), orphanage).releaseAs<DynamicList>();
cannam@147: }
cannam@147: inline Orphan<DynamicStruct> JsonCodec::decode(
cannam@147:     JsonValue::Reader input, StructSchema type, Orphanage orphanage) const {
cannam@147:   return decode(input, Type(type), orphanage).releaseAs<DynamicStruct>();
cannam@147: }
cannam@147: inline DynamicCapability::Client JsonCodec::decode(
cannam@147:     JsonValue::Reader input, InterfaceSchema type) const {
cannam@147:   return decode(input, Type(type), Orphanage()).getReader().as<DynamicCapability>();
cannam@147: }
cannam@147: inline DynamicEnum JsonCodec::decode(JsonValue::Reader input, EnumSchema type) const {
cannam@147:   return decode(input, Type(type), Orphanage()).getReader().as<DynamicEnum>();
cannam@147: }
cannam@147: 
cannam@147: // -----------------------------------------------------------------------------
cannam@147: 
cannam@147: class JsonCodec::HandlerBase {
cannam@147:   // Internal helper; ignore.
cannam@147: public:
cannam@147:   virtual void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                           JsonValue::Builder output) const = 0;
cannam@147:   virtual Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                           Type type, Orphanage orphanage) const;
cannam@147:   virtual void decodeStructBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                 DynamicStruct::Builder output) const;
cannam@147: };
cannam@147: 
cannam@147: template <typename T>
cannam@147: class JsonCodec::Handler<T, Style::POINTER>: private JsonCodec::HandlerBase {
cannam@147: public:
cannam@147:   virtual void encode(const JsonCodec& codec, ReaderFor<T> input,
cannam@147:                       JsonValue::Builder output) const = 0;
cannam@147:   virtual Orphan<T> decode(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                            Orphanage orphanage) const = 0;
cannam@147: 
cannam@147: private:
cannam@147:   void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                   JsonValue::Builder output) const override final {
cannam@147:     encode(codec, input.as<T>(), output);
cannam@147:   }
cannam@147:   Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                   Type type, Orphanage orphanage) const override final {
cannam@147:     return decode(codec, input, orphanage);
cannam@147:   }
cannam@147:   friend class JsonCodec;
cannam@147: };
cannam@147: 
cannam@147: template <typename T>
cannam@147: class JsonCodec::Handler<T, Style::STRUCT>: private JsonCodec::HandlerBase {
cannam@147: public:
cannam@147:   virtual void encode(const JsonCodec& codec, ReaderFor<T> input,
cannam@147:                       JsonValue::Builder output) const = 0;
cannam@147:   virtual void decode(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                       BuilderFor<T> output) const = 0;
cannam@147:   virtual Orphan<T> decode(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                            Orphanage orphanage) const {
cannam@147:     // If subclass does not override, fall back to regular version.
cannam@147:     auto result = orphanage.newOrphan<T>();
cannam@147:     decode(codec, input, result.get());
cannam@147:     return result;
cannam@147:   }
cannam@147: 
cannam@147: private:
cannam@147:   void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                   JsonValue::Builder output) const override final {
cannam@147:     encode(codec, input.as<T>(), output);
cannam@147:   }
cannam@147:   Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                   Type type, Orphanage orphanage) const override final {
cannam@147:     return decode(codec, input, orphanage);
cannam@147:   }
cannam@147:   void decodeStructBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                         DynamicStruct::Builder output) const override final {
cannam@147:     decode(codec, input, output.as<T>());
cannam@147:   }
cannam@147:   friend class JsonCodec;
cannam@147: };
cannam@147: 
cannam@147: template <>
cannam@147: class JsonCodec::Handler<DynamicStruct>: private JsonCodec::HandlerBase {
cannam@147:   // Almost identical to Style::STRUCT except that we pass the struct type to decode().
cannam@147: 
cannam@147: public:
cannam@147:   virtual void encode(const JsonCodec& codec, DynamicStruct::Reader input,
cannam@147:                       JsonValue::Builder output) const = 0;
cannam@147:   virtual void decode(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                       DynamicStruct::Builder output) const = 0;
cannam@147:   virtual Orphan<DynamicStruct> decode(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                        StructSchema type, Orphanage orphanage) const {
cannam@147:     // If subclass does not override, fall back to regular version.
cannam@147:     auto result = orphanage.newOrphan(type);
cannam@147:     decode(codec, input, result.get());
cannam@147:     return result;
cannam@147:   }
cannam@147: 
cannam@147: private:
cannam@147:   void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                   JsonValue::Builder output) const override final {
cannam@147:     encode(codec, input.as<DynamicStruct>(), output);
cannam@147:   }
cannam@147:   Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                   Type type, Orphanage orphanage) const override final {
cannam@147:     return decode(codec, input, type.asStruct(), orphanage);
cannam@147:   }
cannam@147:   void decodeStructBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                         DynamicStruct::Builder output) const override final {
cannam@147:     decode(codec, input, output.as<DynamicStruct>());
cannam@147:   }
cannam@147:   friend class JsonCodec;
cannam@147: };
cannam@147: 
cannam@147: template <typename T>
cannam@147: class JsonCodec::Handler<T, Style::PRIMITIVE>: private JsonCodec::HandlerBase {
cannam@147: public:
cannam@147:   virtual void encode(const JsonCodec& codec, T input, JsonValue::Builder output) const = 0;
cannam@147:   virtual T decode(const JsonCodec& codec, JsonValue::Reader input) const = 0;
cannam@147: 
cannam@147: private:
cannam@147:   void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                   JsonValue::Builder output) const override final {
cannam@147:     encode(codec, input.as<T>(), output);
cannam@147:   }
cannam@147:   Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                   Type type, Orphanage orphanage) const override final {
cannam@147:     return decode(codec, input);
cannam@147:   }
cannam@147:   friend class JsonCodec;
cannam@147: };
cannam@147: 
cannam@147: template <typename T>
cannam@147: class JsonCodec::Handler<T, Style::CAPABILITY>: private JsonCodec::HandlerBase {
cannam@147: public:
cannam@147:   virtual void encode(const JsonCodec& codec, typename T::Client input,
cannam@147:                       JsonValue::Builder output) const = 0;
cannam@147:   virtual typename T::Client decode(const JsonCodec& codec, JsonValue::Reader input) const = 0;
cannam@147: 
cannam@147: private:
cannam@147:   void encodeBase(const JsonCodec& codec, DynamicValue::Reader input,
cannam@147:                   JsonValue::Builder output) const override final {
cannam@147:     encode(codec, input.as<T>(), output);
cannam@147:   }
cannam@147:   Orphan<DynamicValue> decodeBase(const JsonCodec& codec, JsonValue::Reader input,
cannam@147:                                   Type type, Orphanage orphanage) const override final {
cannam@147:     return orphanage.newOrphanCopy(decode(codec, input));
cannam@147:   }
cannam@147:   friend class JsonCodec;
cannam@147: };
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline void JsonCodec::addTypeHandler(Handler<T>& handler) {
cannam@147:   addTypeHandlerImpl(Type::from<T>(), handler);
cannam@147: }
cannam@147: inline void JsonCodec::addTypeHandler(Type type, Handler<DynamicValue>& handler) {
cannam@147:   addTypeHandlerImpl(type, handler);
cannam@147: }
cannam@147: inline void JsonCodec::addTypeHandler(EnumSchema type, Handler<DynamicEnum>& handler) {
cannam@147:   addTypeHandlerImpl(type, handler);
cannam@147: }
cannam@147: inline void JsonCodec::addTypeHandler(StructSchema type, Handler<DynamicStruct>& handler) {
cannam@147:   addTypeHandlerImpl(type, handler);
cannam@147: }
cannam@147: inline void JsonCodec::addTypeHandler(ListSchema type, Handler<DynamicList>& handler) {
cannam@147:   addTypeHandlerImpl(type, handler);
cannam@147: }
cannam@147: inline void JsonCodec::addTypeHandler(InterfaceSchema type, Handler<DynamicCapability>& handler) {
cannam@147:   addTypeHandlerImpl(type, handler);
cannam@147: }
cannam@147: 
cannam@147: template <typename T>
cannam@147: inline void JsonCodec::addFieldHandler(StructSchema::Field field, Handler<T>& handler) {
cannam@147:   addFieldHandlerImpl(field, Type::from<T>(), handler);
cannam@147: }
cannam@147: 
cannam@147: template <> void JsonCodec::addTypeHandler(Handler<DynamicValue>& handler)
cannam@147:     KJ_UNAVAILABLE("JSON handlers for type sets (e.g. all structs, all lists) not implemented; "
cannam@147:                    "try specifying a specific type schema as the first parameter");
cannam@147: template <> void JsonCodec::addTypeHandler(Handler<DynamicEnum>& handler)
cannam@147:     KJ_UNAVAILABLE("JSON handlers for type sets (e.g. all structs, all lists) not implemented; "
cannam@147:                    "try specifying a specific type schema as the first parameter");
cannam@147: template <> void JsonCodec::addTypeHandler(Handler<DynamicStruct>& handler)
cannam@147:     KJ_UNAVAILABLE("JSON handlers for type sets (e.g. all structs, all lists) not implemented; "
cannam@147:                    "try specifying a specific type schema as the first parameter");
cannam@147: template <> void JsonCodec::addTypeHandler(Handler<DynamicList>& handler)
cannam@147:     KJ_UNAVAILABLE("JSON handlers for type sets (e.g. all structs, all lists) not implemented; "
cannam@147:                    "try specifying a specific type schema as the first parameter");
cannam@147: template <> void JsonCodec::addTypeHandler(Handler<DynamicCapability>& handler)
cannam@147:     KJ_UNAVAILABLE("JSON handlers for type sets (e.g. all structs, all lists) not implemented; "
cannam@147:                    "try specifying a specific type schema as the first parameter");
cannam@147: // TODO(someday): Implement support for registering handlers that cover thinsg like "all structs"
cannam@147: //   or "all lists". Currently you can only target a specific struct or list type.
cannam@147: 
cannam@147: } // namespace capnp
cannam@147: 
cannam@147: #endif // CAPNP_COMPAT_JSON_H_