The Streaming JSON API provides a way of constructing (writing) JSON messages without RAM overhead. More...

#include <streaming_json.h>

Public Member Functions
	StreamingJson (Print &output)

void	check_comma ()

void	needs_comma ()

void	begin_dict ()

void	end_dict ()

void	begin_list ()

void	end_list ()

void	begin_str (char quote='"')

void	end_str (char quote='"')

void	key (const char *str, char quote='"')

void	key (const std::string &str)

void	val (const char *str, char quote='"')

void	val (const std::string &str)

void	val (bool b)

template<typename V >
void	val (V i)

void	null ()

void	json (const char *str)
	An embedded Raw json structure.

template<typename V >
void	kv (const char *_key, V _val)

void	endln ()

Public Attributes
Print &	output

Detailed Description

The Streaming JSON API provides a way of constructing (writing) JSON messages without RAM overhead.

In contrast to ArduinoJSON, there is no document which needs to be represented in memory and which is setup before serialization. Instead, serialization and printing happens here at method call time. Ideally, this uses the Arduino Print infrastructure and thus avoids any string representations where possible.

The class stores only a minimal state of parsing. JSON does not allow trailing commas so this is avoided with a simple state boolean. The lib is not aware of whether it constructs a map/dictionary or a list/array. It is up to the user to make sure the dict follows the key-value-key-value semantics.

Correct usage example:

StreamingJson s(some_client_or_so); s.begin_dict(); s.key("foo"); s.val("bar"); s.key("biz"); s.begin_list(); s.val(123); s.val(true); s.val(3.14); s.null(); s.end_list(); s.end_dict();

should create the following JSON document:

{"foo":"bar","biz":[123, true, 3.14, null]}

Definition at line 44 of file streaming_json.h.

Constructor & Destructor Documentation

◆ StreamingJson()

utils::StreamingJson::StreamingJson ( Print & output )

inline

Definition at line 49 of file streaming_json.h.

Member Function Documentation

◆ begin_dict()

void utils::StreamingJson::begin_dict ( )

inline

Definition at line 57 of file streaming_json.h.

References output.

Referenced by debug_print_json(), client::StreamingRunDataNotificationHandler::handle(), msg::StartupLog::stream_to_json(), and msg::StreamLogger::write().

◆ begin_list()

void utils::StreamingJson::begin_list ( )

inline

Definition at line 59 of file streaming_json.h.

References output.

Referenced by client::StreamingRunDataNotificationHandler::handle(), and msg::StartupLog::stream_to_json().

◆ begin_str()

void utils::StreamingJson::begin_str ( char quote = '"' )

inline

Definition at line 62 of file streaming_json.h.

References output.

Referenced by key(), val(), and msg::StreamLogger::write().

◆ check_comma()

void utils::StreamingJson::check_comma ( )

inline

Definition at line 51 of file streaming_json.h.

References output.

Referenced by client::StreamingRunDataNotificationHandler::handle(), json(), key(), null(), val(), val(), and val().

◆ end_dict()

void utils::StreamingJson::end_dict ( )

inline

Definition at line 58 of file streaming_json.h.

References needs_comma(), and output.

Referenced by debug_print_json(), client::StreamingRunDataNotificationHandler::handle(), msg::StartupLog::stream_to_json(), and msg::StreamLogger::write().

◆ end_list()

void utils::StreamingJson::end_list ( )

inline

Definition at line 60 of file streaming_json.h.

References needs_comma(), and output.

Referenced by client::StreamingRunDataNotificationHandler::handle(), and msg::StartupLog::stream_to_json().

◆ end_str()

void utils::StreamingJson::end_str ( char quote = '"' )

inline

Definition at line 63 of file streaming_json.h.

References output.

Referenced by key(), val(), and msg::StreamLogger::write().

◆ endln()

void utils::StreamingJson::endln ( )

inline

Definition at line 118 of file streaming_json.h.

References output.

Referenced by debug_print_json(), and client::StreamingRunDataNotificationHandler::handle().

◆ json()

void utils::StreamingJson::json ( const char * str )

inline

An embedded Raw json structure.

Definition at line 108 of file streaming_json.h.

References check_comma(), needs_comma(), and output.

Referenced by client::StreamingRunDataNotificationHandler::handle(), and msg::StartupLog::stream_to_json().

◆ key() [1/2]

void utils::StreamingJson::key	(	const char *	str,
		char	quote = '"' )

inline

Definition at line 65 of file streaming_json.h.

References begin_str(), check_comma(), end_str(), and output.

Referenced by debug_print_json(), client::StreamingRunDataNotificationHandler::handle(), kv(), msg::StartupLog::stream_to_json(), and msg::StreamLogger::write().

◆ key() [2/2]

void utils::StreamingJson::key ( const std::string & str )

inline

Definition at line 73 of file streaming_json.h.

References key().

Referenced by key().

◆ kv()

template<typename V >

void utils::StreamingJson::kv	(	const char *	_key,
		V	_val )

inline

Definition at line 116 of file streaming_json.h.

References key(), and val().

Referenced by debug_print_json(), client::StreamingRunDataNotificationHandler::handle(), msg::StartupLog::stream_to_json(), and msg::StreamLogger::write().

◆ needs_comma()

void utils::StreamingJson::needs_comma ( )

inline

Definition at line 55 of file streaming_json.h.

Referenced by end_dict(), end_list(), client::StreamingRunDataNotificationHandler::handle(), json(), null(), val(), val(), and val().

◆ null()

void utils::StreamingJson::null ( )

inline

Definition at line 101 of file streaming_json.h.

References check_comma(), needs_comma(), and output.

◆ val() [1/4]

void utils::StreamingJson::val ( bool b )

inline

Definition at line 87 of file streaming_json.h.

References check_comma(), needs_comma(), and output.

◆ val() [2/4]

void utils::StreamingJson::val	(	const char *	str,
		char	quote = '"' )

inline

Definition at line 77 of file streaming_json.h.

References begin_str(), check_comma(), end_str(), needs_comma(), and output.

Referenced by client::StreamingRunDataNotificationHandler::handle(), and kv().

◆ val() [3/4]

void utils::StreamingJson::val ( const std::string & str )

inline

Definition at line 85 of file streaming_json.h.

References val().

Referenced by val().

◆ val() [4/4]

template<typename V >

void utils::StreamingJson::val ( V i )

inline

Definition at line 95 of file streaming_json.h.

References check_comma(), needs_comma(), and output.

Member Data Documentation

◆ output

Print& utils::StreamingJson::output

Definition at line 48 of file streaming_json.h.

Referenced by begin_dict(), begin_list(), begin_str(), check_comma(), end_dict(), end_list(), end_str(), endln(), json(), key(), null(), val(), val(), val(), and msg::StreamLogger::write().

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

lib/controller/src/utils/streaming_json.h

Public Member Functions

Public Attributes

Detailed Description

Constructor & Destructor Documentation

◆ StreamingJson()

Member Function Documentation

◆ begin_dict()

◆ begin_list()

◆ begin_str()

◆ check_comma()

◆ end_dict()

◆ end_list()

◆ end_str()

◆ endln()

◆ json()

◆ key() [1/2]

◆ key() [2/2]

◆ kv()

◆ needs_comma()

◆ null()

◆ val() [1/4]

◆ val() [2/4]

◆ val() [3/4]

◆ val() [4/4]

Member Data Documentation

◆ output