Improve documentation of api v3

The documentation is improved to reflect the new version.

Tune the options

Change-Id: I894c3db3bc0c10e89db66a9a51a9ad049bb8c0c4
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 937 insertions, 0 deletions

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+Functions of class **afb_api**
+============================
+
+## General functions
+
+### afb_api_name
+
+```C
+/**
+ * Get the name of the 'api'.
+ *
+ * @param api the api whose name is to be returned
+ *
+ * @return the name of the api.
+ *
+ * The returned value must not be changed nor freed.
+ */
+const char *afb_api_name(
+			afb_api_t api);
+```
+
+### afb_api_get_userdata
+
+```C
+/**
+ * Get the "userdata" pointer of the 'api'
+ *
+ * @param api the api whose user's data is to be returned
+ *
+ * @return the user's data  pointer of the api.
+ *
+ * @see afb_api_set_userdata
+ */
+void *afb_api_get_userdata(
+			afb_api_t api);
+```
+
+### afb_api_set_userdata
+
+```C
+/**
+ * Set the "userdata" pointer of the 'api' to 'value'
+ *
+ * @param api   the api whose user's data is to be set
+ * @param value the data to set
+ *
+ * @see afb_api_get_userdata
+ */
+void afb_api_set_userdata(
+			afb_api_t api,
+			void *value);
+```
+
+### afb_api_require_api
+
+```C
+/**
+ * Check that it requires the API of 'name'.
+ * If 'initialized' is not zero it request the API to be
+ * initialized, implying its initialization if needed.
+ * 
+ * Calling this function is only allowed within init.
+ *
+ * A single request allows to require multiple apis.
+ *
+ * @param api the api that requires the other api by its name
+ * @param name a space separated list of required api names
+ * @param initialized if zero, the api is just required to exist. If not zero,
+ * the api is required to exist and to be initialized at return of the call
+ * (initializing it if needed and possible as a side effect of the call).
+ *
+ * @return 0 in case of success or -1 in case of error with errno set appropriately.
+ */
+int afb_api_require_api(
+			afb_api_t api,
+			const char *name,
+			int initialized);
+```
+
+
+## Verbosity functions
+
+### afb_api_wants_log_level
+
+```C
+/**
+ * Is the log message of 'level (as defined for syslog) required for the api?
+ *
+ * @param api   the api to check
+ * @param level the level to check as defined for syslog:
+ *
+ *      EMERGENCY         0        System is unusable
+ *      ALERT             1        Action must be taken immediately
+ *      CRITICAL          2        Critical conditions
+ *      ERROR             3        Error conditions
+ *      WARNING           4        Warning conditions
+ *      NOTICE            5        Normal but significant condition
+ *      INFO              6        Informational
+ *      DEBUG             7        Debug-level messages
+ *
+ * @return 0 if not required or a value not null if required
+ *
+ * @see syslog
+ */
+int afb_api_wants_log_level(
+			afb_api_t api,
+			int level);
+```
+
+### afb_api_vverbose
+
+```C
+/**
+ * Send to the journal with the logging 'level' a message described
+ * by 'fmt' applied to the va-list 'args'.
+ *
+ * 'file', 'line' and 'func' are indicators of code position in source files
+ * (see macros __FILE__, __LINE__ and __func__).
+ *
+ * 'level' is defined by syslog standard:
+ *
+ *      EMERGENCY         0        System is unusable
+ *      ALERT             1        Action must be taken immediately
+ *      CRITICAL          2        Critical conditions
+ *      ERROR             3        Error conditions
+ *      WARNING           4        Warning conditions
+ *      NOTICE            5        Normal but significant condition
+ *      INFO              6        Informational
+ *      DEBUG             7        Debug-level messages
+ *
+ * @param api the api that collects the logging message
+ * @param level the level of the message
+ * @param file the source file that logs the messages or NULL
+ * @param line the line in the source file that logs the message
+ * @param func the name of the function in the source file that logs
+ * @param fmt the format of the message as in printf
+ * @param args the arguments to the format string of the message as a va_list
+ *
+ * @see syslog
+ * @see printf
+ */
+void afb_api_vverbose(
+			afb_api_t api,
+			int level,
+			const char *file,
+			int line,
+			const char *func,
+			const char *fmt,
+			va_list args);
+```
+
+### afb_api_verbose
+
+```C
+/**
+ * Send to the journal with the log 'level' a message described
+ * by 'fmt' and following parameters.
+ *
+ * 'file', 'line' and 'func' are indicators of position of the code in source files
+ * (see macros __FILE__, __LINE__ and __func__).
+ *
+ * 'level' is defined by syslog standard:
+ *      EMERGENCY         0        System is unusable
+ *      ALERT             1        Action must be taken immediately
+ *      CRITICAL          2        Critical conditions
+ *      ERROR             3        Error conditions
+ *      WARNING           4        Warning conditions
+ *      NOTICE            5        Normal but significant condition
+ *      INFO              6        Informational
+ *      DEBUG             7        Debug-level messages
+ *
+ * @param api the api that collects the logging message
+ * @param level the level of the message
+ * @param file the source file that logs the messages or NULL
+ * @param line the line in the source file that logs the message
+ * @param func the name of the function in the source file that logs
+ * @param fmt the format of the message as in printf
+ * @param ... the arguments to the format string of the message
+ *
+ * @see syslog
+ * @see printf
+ */
+void afb_api_verbose(
+			afb_api_t api,
+			int level,
+			const char *file,
+			int line,
+			const char *func,
+			const char *fmt,
+			...);
+```
+
+## Data retrieval functions
+
+### afb_api_rootdir_get_fd
+
+```C
+/**
+ * Get the root directory file descriptor. This file descriptor can
+ * be used with functions 'openat', 'fstatat', ...
+ *
+ * CAUTION, manipulate this this descriptor with care, in particular, don't close
+ * it.
+ *
+ * This can be used to get the path of the root directory using:
+ *
+ * char buffer[MAX_PATH], proc[100];
+ * int dirfd = afb_api_rootdir_get_fd(api);
+ * snprintf(proc, sizeof proc, "/proc/self/fd/%d", dirfd);
+ * readlink(proc, buffer, sizeof buffer);
+ *
+ * But note that within AGL this is the value given by the environment variable
+ * AFM_APP_INSTALL_DIR.
+ *
+ * @param api the api that uses the directory file descriptor
+ *
+ * @return the file descriptor of the root directory.
+ *
+ * @see afb_api_rootdir_open_locale
+ */
+int afb_api_rootdir_get_fd(
+			afb_api_t api);
+```
+
+### afb_api_rootdir_open_locale
+
+```C
+/**
+ * Opens 'filename' within the root directory with 'flags' (see function openat)
+ * using the 'locale' definition (example: "jp,en-US") that can be NULL.
+ *
+ * The filename must be relative to the root of the bindings.
+ *
+ * The opening mode must be for read or write but not for O_CREAT.
+ *
+ * The definition of locales and of how files are searched can be checked
+ * here: https://www.w3.org/TR/widgets/#folder-based-localization
+ * and https://tools.ietf.org/html/rfc7231#section-5.3.5
+ *
+ * @param api the api that queries the file
+ * @param filename the relative path to the file to open
+ * @param flags the flags for opening as for C function 'open'
+ * @param locale string indicating how to search content, can be NULL
+ *
+ * @return the file descriptor or -1 in case of error and errno is set with the
+ * error indication.
+ *
+ * @see open
+ * @see afb_api_rootdir_get_fd
+ */
+int afb_api_rootdir_open_locale(
+			afb_api_t api,
+			const char *filename,
+			int flags,
+			const char *locale);
+```
+
+## Calls and job functions
+
+### afb_api_call
+
+```C
+/**
+ * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
+ * The result of the call is delivered to the 'callback' function with the 'callback_closure'.
+ *
+ * For convenience, the function calls 'json_object_put' for 'args'.
+ * Thus, in the case where 'args' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * The 'callback' receives 5 arguments:
+ *  1. 'closure' the user defined closure pointer 'closure',
+ *  2. 'object'  a JSON object returned (can be NULL)
+ *  3. 'error'   a string not NULL in case of error but NULL on success
+ *  4. 'info'    a string handling some info (can be NULL)
+ *  5. 'api'     the api
+ *
+ * @param api      The api that makes the call
+ * @param apiname  The api name of the method to call
+ * @param verb     The verb name of the method to call
+ * @param args     The arguments to pass to the method
+ * @param callback The to call on completion
+ * @param closure  The closure to pass to the callback
+ *
+ *
+ * @see afb_req_subcall
+ * @see afb_req_subcall_sync
+ * @see afb_api_call_sync
+ */
+void afb_api_call(
+			afb_api_t api,
+			const char *apiname,
+			const char *verb,
+			struct json_object *args,
+			void (*callback)(
+					void *closure,
+					struct json_object *object,
+					const char *error,
+					const char * info,
+					afb_api_t api),
+			void *closure);
+```
+
+### afb_api_call_sync
+
+```C
+/**
+ * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
+ * 'result' will receive the response.
+ *
+ * For convenience, the function calls 'json_object_put' for 'args'.
+ * Thus, in the case where 'args' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * @param api      The api that makes the call
+ * @param apiname  The api name of the method to call
+ * @param verb     The verb name of the method to call
+ * @param args     The arguments to pass to the method
+ * @param object   Where to store the returned object - should call json_object_put on it - can be NULL
+ * @param error    Where to store the copied returned error - should call free on it - can be NULL
+ * @param info     Where to store the copied returned info - should call free on it - can be NULL
+ *
+ * @returns 0 in case of success or a negative value in case of error.
+ *
+ * @see afb_req_subcall
+ * @see afb_req_subcall_sync
+ * @see afb_api_call
+ */
+int afb_api_call_sync(
+			afb_api_t api,
+			const char *apiname,
+			const char *verb,
+			struct json_object *args,
+			struct json_object **object,
+			char **error,
+			char **info);
+```
+
+### afb_api_queue_job
+
+```C
+/**
+ * Queue the job defined by 'callback' and 'argument' for being executed asynchronously
+ * in this thread (later) or in an other thread.
+ *
+ * If 'group' is not NULL, the jobs queued with a same value (as the pointer value 'group')
+ * are executed in sequence in the order of there submission.
+ *
+ * If 'timeout' is not 0, it represent the maximum execution time for the job in seconds.
+ * At first, the job is called with 0 as signum and the given argument.
+ *
+ * The job is executed with the monitoring of its time and some signals like SIGSEGV and
+ * SIGFPE. When a such signal is catched, the job is terminated and reexecuted but with
+ * signum being the signal number (SIGALRM when timeout expired).
+ *
+ * When executed, the callback function receives 2 arguments:
+ *
+ *  - int signum: the signal catched if any or zero at the beginning
+ *  - void *arg: the parameter 'argument'
+ *
+ * A typical implementation of the job callback is:
+ *
+ * void my_job_cb(int signum, void *arg)
+ * {
+ *	struct myarg_t *myarg = arg;
+ *	if (signum)
+ *		AFB_API_ERROR(myarg->api, "job interrupted with signal %s", strsignal(signum));
+ *	else
+ *		really_do_my_job(myarg);
+ * }
+ *
+ * @param api the api that queue the job
+ * @param callback the job as a callback function
+ * @param argument the argument to pass to the queued job
+ * @param group the group of the job, NULL if no group
+ * @param timeout the timeout of execution of the job
+ *
+ * @return 0 in case of success or -1 in case of error with errno set appropriately.
+ */
+int afb_api_queue_job(
+			afb_api_t api,
+			void (*callback)(int signum, void *arg),
+			void *argument,
+			void *group,
+			int timeout);
+```
+
+## Event functions
+
+### afb_api_broadcast_event
+
+```C
+/**
+ * Broadcasts widely the event of 'name' with the data 'object'.
+ * 'object' can be NULL.
+ *
+ * For convenience, the function calls 'json_object_put' for 'object'.
+ * Thus, in the case where 'object' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * Calling this function is only forbidden during preinit.
+ *
+ * The event sent as the name API/name where API is the name of the
+ * api.
+ *
+ * @param api the api that broadcast the event
+ * @param name the event name suffix
+ * @param object the object that comes with the event
+ *
+ * @return the count of clients that received the event.
+ */
+int afb_api_broadcast_event(
+			afb_api_t api,
+			const char *name,
+			struct json_object *object);
+```
+
+### afb_api_make_event
+
+```C
+/**
+ * Creates an event of 'name' and returns it.
+ *
+ * Calling this function is only forbidden during preinit.
+ *
+ * See afb_event_is_valid to check if there is an error.
+ *
+ * The event created as the name API/name where API is the name of the
+ * api.
+ *
+ * @param api the api that creates the event
+ * @param name the event name suffix
+ *
+ * @return the created event. Use the function afb_event_is_valid to check
+ * whether the event is valid (created) or not (error as reported by errno).
+ *
+ * @see afb_event_is_valid
+ */
+afb_event_t afb_api_make_event(
+			afb_api_t api,
+			const char *name);
+```
+
+### afb_api_event_handler_add
+
+```C
+/**
+ * Add a specific event handler for the api
+ *
+ * The handler callback is called when an event matching the given pattern
+ * is received (it is received if broadcasted or after subscription through
+ * a call or a subcall).
+ *
+ * The handler callback receive 4 arguments:
+ *
+ *  - the closure given here
+ *  - the event full name
+ *  - the companion JSON object of the event
+ *  - the api that subscribed the event
+ *
+ * @param api the api that creates the handler
+ * @param pattern the global pattern of the event to handle
+ * @param callback the handler callback function
+ * @param closure the closure of the handler
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_api_on_event
+ * @see afb_api_event_handler_del
+ */
+int afb_api_event_handler_add(
+			afb_api_t api,
+			const char *pattern,
+			void (*callback)(
+					void *,
+					const char*,
+					struct json_object*,
+					afb_api_t),
+			void *closure);
+```
+
+### afb_api_event_handler_del
+
+```C
+/**
+ * Delete a specific event handler for the api
+ *
+ * @param api the api that the handler belongs to
+ * @param pattern the global pattern of the handler to remove
+ * @param closure if not NULL it will receive the closure set to the handler
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_api_on_event
+ * @see afb_api_event_handler_add
+ */
+int afb_api_event_handler_del(
+			afb_api_t api,
+			const char *pattern,
+			void **closure);
+
+```
+
+## Systemd functions
+
+### afb_api_get_event_loop
+
+```C
+/**
+ * Retrieves the common systemd's event loop of AFB
+ *
+ * @param api the api that uses the event loop
+ *
+ * @return the systemd event loop if active, NULL otherwise
+ *
+ * @see afb_api_get_user_bus
+ * @see afb_api_get_system_bus
+ */
+struct sd_event *afb_api_get_event_loop(
+			afb_api_t api);
+```
+
+### afb_api_get_user_bus
+
+```C
+/**
+ * Retrieves the common systemd's user/session d-bus of AFB
+ *
+ * @param api the api that uses the user dbus
+ *
+ * @return the systemd user connection to dbus if active, NULL otherwise
+ *
+ * @see afb_api_get_event_loop
+ * @see afb_api_get_system_bus
+ */
+struct sd_bus *afb_api_get_user_bus(
+			afb_api_t api);
+```
+
+### afb_api_get_system_bus
+
+```C
+/**
+ * Retrieves the common systemd's system d-bus of AFB
+ *
+ * @param api the api that uses the system dbus
+ *
+ * @return the systemd system connection to dbus if active, NULL otherwise
+ *
+ * @see afb_api_get_event_loop
+ * @see afb_api_get_user_bus
+ */
+struct sd_bus *afb_api_get_system_bus(
+			afb_api_t api);
+```
+
+
+## Dynamic api functions
+
+### afb_api_new_api
+
+```C
+/**
+ * Creates a new api of name 'apiname' briefly described by 'info' (that can
+ * be NULL).
+ *
+ * When the pre-initialization function is given, it is a function that
+ * receives 2 parameters:
+ *
+ *  - the closure as given in the call
+ *  - the created api that can be initialised
+ *
+ * This pre-initialization function must return a negative value to abort
+ * the creation of the api. Otherwise, it returns a non-negative value to
+ * continue.
+ *
+ * @param api the api that creates the other one
+ * @param apiname the name of the new api
+ * @param info the brief description of the new api (can be NULL)
+ * @param noconcurrency zero or not zero whether the new api is reentrant or not
+ * @param preinit the pre-initialization function if any (can be NULL)
+ * @param closure the closure for the pre-initialization \ref preinit
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_api_delete_api
+ */
+afb_api_t afb_api_new_api(
+			afb_api_t api,
+			const char *apiname,
+			const char *info,
+			int noconcurrency,
+			int (*preinit)(void*, afb_api_t ),
+			void *closure);
+```
+
+### afb_api_set_verbs_v2
+
+```C
+/**
+ * @deprecated use @ref afb_api_set_verbs_v3 instead
+ *
+ * Set the verbs of the 'api' using description of verbs of the api v2
+ *
+ * @param api the api that will get the verbs
+ * @param verbs the array of verbs to add terminated with an item with name=NULL
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_verb_v2
+ * @see afb_api_add_verb
+ * @see afb_api_set_verbs_v3
+ */
+int afb_api_set_verbs_v2(
+			afb_api_t api,
+			const struct afb_verb_v2 *verbs);
+```
+
+### afb_api_set_verbs_v3
+
+```C
+/**
+ * Set the verbs of the 'api' using description of verbs of the api v2
+ *
+ * @param api the api that will get the verbs
+ * @param verbs the array of verbs to add terminated with an item with name=NULL
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_verb_v3
+ * @see afb_api_add_verb
+ * @see afb_api_del_verb
+ */
+int afb_api_set_verbs_v3(
+			afb_api_t api,
+			const struct afb_verb_v3 *verbs);
+```
+
+### afb_api_add_verb
+
+```C
+/**
+ * Add one verb to the dynamic set of the api
+ *
+ * @param api the api to change
+ * @param verb name of the verb
+ * @param info brief description of the verb, can be NULL
+ * @param callback callback function implementing the verb
+ * @param vcbdata data for the verb callback, available through req
+ * @param auth required authorization, can be NULL
+ * @param session authorization and session requirements of the verb
+ * @param glob is the verb glob name
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_verb_v3
+ * @see afb_api_del_verb
+ * @see afb_api_set_verbs_v3
+ * @see fnmatch for matching names using glob
+ */
+int afb_api_add_verb(
+			afb_api_t api,
+			const char *verb,
+			const char *info,
+			void (*callback)(struct afb_req_x2 *req),
+			void *vcbdata,
+			const struct afb_auth *auth,
+			uint32_t session,
+			int glob);
+```
+
+### afb_api_del_verb
+
+```C
+/**
+ * Delete one verb from the dynamic set of the api
+ *
+ * @param api the api to change
+ * @param verb name of the verb to delete
+ * @param vcbdata if not NULL will receive the vcbdata of the deleted verb
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afb_api_add_verb
+ */
+int afb_api_del_verb(
+			afb_api_t api,
+			const char *verb,
+			void **vcbdata);
+```
+
+### afb_api_on_event
+
+```C
+/**
+ * Set the callback 'onevent' to process events in the name of the 'api'.
+ *
+ * This setting can be done statically using the global variable
+ * @ref afbBindingV3.
+ *
+ * This function replace any previously global event callback set.
+ *
+ * When an event is received, the callback 'onevent' is called with 3 parameters
+ *
+ *  - the api that recorded the event handler
+ *  - the full name of the event
+ *  - the companion JSON object of the event
+ *
+ * @param api the api that wants to process events
+ * @param onevent the callback function that will process events (can be NULL
+ *        to remove event callback)
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afbBindingV3
+ * @see afb_binding_v3
+ * @see afb_api_event_handler_add
+ * @see afb_api_event_handler_del
+ */
+int afb_api_on_event(
+			afb_api_t api,
+			void (*onevent)(
+					afb_api_t api,
+					const char *event,
+					struct json_object *object));
+```
+
+### afb_api_on_init
+
+```C
+/**
+ * Set the callback 'oninit' to process initialization of the 'api'.
+ *
+ * This setting can be done statically using the global variable
+ * @ref afbBindingV3
+ *
+ * This function replace any previously initialization callback set.
+ *
+ * This function is only valid during the pre-initialization stage.
+ *
+ * The callback initialization function will receive one argument: the api
+ * to initialize.
+ *
+ * @param api the api that wants to process events
+ * @param oninit the callback function that initialize the api
+ *
+ * @return 0 in case of success or -1 on failure with errno set
+ *
+ * @see afbBindingV3
+ * @see afb_binding_v3
+ */
+int afb_api_on_init(
+			afb_api_t api,
+			int (*oninit)(afb_api_t api));
+```
+
+### afb_api_provide_class
+
+```C
+/**
+ * Tells that the api provides a class of features. Classes are intended to
+ * allow ordering of initializations: apis that provides a given class are
+ * initialized before apis requiring it.
+ *
+ * This function is only valid during the pre-initialization stage.
+ *
+ * @param api  the api that provides the classes
+ * @param name a space separated list of the names of the provided classes
+ *
+ * @returns 0 in case of success or a negative value in case of error.
+ *
+ * @see afb_api_require_class
+ */
+int afb_api_provide_class(
+			afb_api_t api,
+			const char *name);
+```
+
+### afb_api_require_class
+
+```C
+/**
+ * Tells that the api requires a set of class features. Classes are intended to
+ * allow ordering of initializations: apis that provides a given class are
+ * initialized before apis requiring it.
+ *
+ * This function is only valid during the pre-initialization stage.
+ *
+ * @param api  the api that requires the classes
+ * @param name a space separated list of the names of the required classes
+ *
+ * @returns 0 in case of success or a negative value in case of error.
+ *
+ * @see afb_api_provide_class
+ */
+int afb_api_require_class(
+			afb_api_t api,
+			const char *name);
+```
+
+### afb_api_seal
+
+```C
+/**
+ * Seal the api. After a call to this function the api can not be modified
+ * anymore.
+ *
+ * @param api the api to be sealed
+ */
+void afb_api_seal(
+			afb_api_t api);
+```
+
+### afb_api_delete_api
+
+```C
+/**
+ * Delete the given api.
+ *
+ * It is of the responsibility of the caller to don't used the deleted api
+ * anymore after this function returned.
+ *
+ * @param api the api to delete
+ *
+ * @returns 0 in case of success or a negative value in case of error.
+ *
+ * @see afb_api_new_api
+ */
+int afb_api_delete_api(
+			afb_api_t api);
+```
+
+### afb_api_add_alias
+
+```C
+/**
+ * Create an aliased name 'as_name' for the api 'name'.
+ * Calling this function is only allowed within preinit.
+ *
+ * @param api the api that requires the aliasing
+ * @param name the api to alias
+ * @param as_name the aliased name of the aliased api
+ *
+ * @return 0 in case of success or -1 in case of error with errno set appropriately.
+ */
+int afb_api_add_alias(
+			afb_api_t api,
+			const char *name,
+			const char *as_name);
+```
+
+
+## Legacy functions
+
+The function for legacy calls are still provided for some time because
+adaptation of existing code to the new call functions require a small amount
+of work.
+
+### afb_api_call_legacy
+
+```C
+/**
+ * @deprecated try to use @ref afb_api_call instead
+ *
+ *  * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
+ * The result of the call is delivered to the 'callback' function with the 'callback_closure'.
+ *
+ * For convenience, the function calls 'json_object_put' for 'args'.
+ * Thus, in the case where 'args' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * The 'callback' receives 3 arguments:
+ *  1. 'closure' the user defined closure pointer 'closure',
+ *  2. 'status' a status being 0 on success or negative when an error occurred,
+ *  2. 'result' the resulting data as a JSON object.
+ *
+ * @param api      The api
+ * @param apiname  The api name of the method to call
+ * @param verb     The verb name of the method to call
+ * @param args     The arguments to pass to the method
+ * @param callback The to call on completion
+ * @param closure  The closure to pass to the callback
+ *
+ * @see also 'afb_api_call'
+ * @see also 'afb_api_call_sync'
+ * @see also 'afb_api_call_sync_legacy'
+ * @see also 'afb_req_subcall'
+ * @see also 'afb_req_subcall_sync'
+ */
+void afb_api_call_legacy(
+			afb_api_t api,
+			const char *apiname,
+			const char *verb,
+			struct json_object *args,
+			void (*callback)(
+					void *closure,
+					int status,
+					struct json_object *result,
+					afb_api_t api),
+			void *closure);
+```
+
+### afb_api_call_sync_legacy
+
+```C
+/**
+ * @deprecated try to use @ref afb_api_call_sync instead
+ *
+ * Calls the 'verb' of the 'api' with the arguments 'args' and 'verb' in the name of the binding.
+ * 'result' will receive the response.
+ *
+ * For convenience, the function calls 'json_object_put' for 'args'.
+ * Thus, in the case where 'args' should remain available after
+ * the function returns, the function 'json_object_get' shall be used.
+ *
+ * @param api      The api
+ * @param apiname  The api name of the method to call
+ * @param verb     The verb name of the method to call
+ * @param args     The arguments to pass to the method
+ * @param result   Where to store the result - should call json_object_put on it -
+ *
+ * @returns 0 in case of success or a negative value in case of error.
+ *
+ * @see also 'afb_api_call'
+ * @see also 'afb_api_call_sync'
+ * @see also 'afb_api_call_legacy'
+ * @see also 'afb_req_subcall'
+ * @see also 'afb_req_subcall_sync'
+ */
+int afb_api_call_sync_legacy(
+			afb_api_t api,
+			const char *apiname,
+			const char *verb,
+			struct json_object *args,
+			struct json_object **result);
+```
+