mlib::http::jbridge Class Reference

JSON objects support. More...

#include <jbridge.h>

Classes
class	entry
	JSON data dictionary entry. More...

Public Types
enum	jb_type {   JT_UNKNOWN , JT_SHORT , JT_USHORT , JT_INT ,   JT_UINT , JT_LONG , JT_ULONG , JT_FLT ,   JT_DBL , JT_PSTR , JT_CSTR , JT_STR ,   JT_BOOL , JT_OBJECT , JT_POSTFUN }
	Dictionary entry types. More...
typedef std::list< entry >	dictionary
	Data dictionary structure.
typedef dictionary::iterator	dict_ptr
	Dictionary iterator.
typedef dictionary::const_iterator	dict_cptr
	Dictionary iterator.

Public Member Functions
	jbridge (const char *path)
	Creates a jbridge object for the given path.
void	attach_to (server &server)
	Attach jbridge object to a HTTP server.
void	lock ()
	Enter the critical section associated with this bridge.
void	unlock ()
	Leave the critical section associated with this bridge.
const std::string &	path () const
	Return the root path where bridge is attached.
void	redirect_to (const std::string &uri)
	Set default redirection target for POST requests.
void	set_post_action (uri_handler pfn)
	Set the function invoked after successful processing of a POST request.
connection &	client ()
	Return currently connected client (if any)
bool	parse_urlencoded () const
	Parse the URL-encoded body of a POST request assigning new values to all variables.
bool	parse_jsonencoded () const
	Parse a JSON-encoded body of a POST message.
template<typename T, size_t C>
void	add_var (T(&var)[C], const std::string &name)
	add array
template<typename T>
std::enable_if_t< std::is_same_v< T, std::string >||std::is_same_v< T, short >||std::is_same_v< T, unsigned short >||std::is_same_v< T, int >||std::is_same_v< T, unsigned int >||std::is_same_v< T, long >||std::is_same_v< T, unsigned long >||std::is_same_v< T, float >||std::is_same_v< T, double >||std::is_same_v< T, bool > >	add_var (T &var, const std::string &name)
	add variable of one of basic types
entry &	add_object (const std::string &name)
	Add an object to data dictionary.
void	add_postfun (const std::string &name, uri_handler pfn)
	Add a handler function invoked in response to a POST request with an additional parameter.

Protected Member Functions
erc	jsonify (json::node &n, dict_cptr entry)
	Serializes a variable to JSON format.
void	not_found (const char *varname)
	Generate 410 response if a variable was not found in JSON dictionary.
bool	find (const std::string &name, dict_cptr &found, size_t *idx=0) const
	Search a variable in JSON dictionary.
bool	deep_find (const std::string &name, dict_cptr &found, size_t *idx=0) const
	Search for a variable name in JSON dictionary.

Detailed Description

JSON objects support.

This class provides JSON serialization/deserialization of variables.

It gives an easy access mechanism to program variables for the HTTP server.

A jbridge object is attached to a HTTP server using the attach_to() function. Behind the scene, this function registers a handler for the path associated with the jbridge.

Sample Usage

Assume the HTTP server hs answers requests sent to http://localhost:8080 and the jbridge object was created as:

jbridge jb("/var");

Then:

jb.attach_to(hs);

will register a handler for requests to http://localhost:8080/var

When this handler is invoked with a GET request for http://localhost:8080/var?data, it will search in the JSON dictionary a variable called 'data' and return its content as a JSON object.

Member Enumeration Documentation

jb_type

enum mlib::http::jbridge::jb_type

Dictionary entry types.

Enumerator
JT_SHORT	short int
JT_USHORT	unsigned short int
JT_INT	int
JT_UINT	unsigned int
JT_LONG	long
JT_ULONG	unsigned long
JT_FLT	float
JT_DBL	double
JT_PSTR	char*
JT_CSTR	char[]
JT_STR	std::string
JT_BOOL	bool
JT_OBJECT	composite object
JT_POSTFUN	POST function call.

Member Function Documentation

add_object()

jbridge::entry & mlib::http::jbridge::add_object ( const std::string & name )

inline

Add an object to data dictionary.

Parameters

name	object's name

Returns

reference to newly created dictionary entry

add_postfun()

void mlib::http::jbridge::add_postfun ( const std::string & qparam, uri_handler pfn )

inline

Add a handler function invoked in response to a POST request with an additional parameter.

Parameters

qparam	additional query parameter
pfn	handler function

If the handler function does not return HTTP_OK, the post_action function is not invoked and client is not redirected to ‘redirect_uri’

find()

bool mlib::http::jbridge::find ( const std::string & name, dict_cptr & found, size_t * pidx = 0 ) const

protected

Search a variable in JSON dictionary.

The variable name can be a construct <name>_<index> for an indexed variable.

set_post_action()

void mlib::http::jbridge::set_post_action ( uri_handler pfn )

inline

Set the function invoked after successful processing of a POST request.

This function is invoked before redirecting the client to the redirect_uri. If the function does not return HTTP_OK, the client is not redirected.

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

• include/mlib/jbridge.h
• src/jbridge.cpp