libgcal-dev 0.9.6-3.1 / usr / include / libgcal / gcalendar.h

/*
  Copyright (c) 2008 Instituto Nokia de Tecnologia
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  are permitted provided that the following conditions are met:

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  may be used to endorse or promote products derived from this software
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/**
 * @file   gcalendar.h
 * @author Adenilson Cavalcanti da Silva <adenilson.silva@indt.org.br>
 * @date   Tue Jun 24 16:17:25 2008
 *
 * @brief  libgcal calendar user public API.
 *
 * Use this functions to handle common tasks when dealing with google calendar.
 */

#ifndef __GCALENDAR_LIB__
#define __GCALENDAR_LIB__

#include "gcal.h"

/** Since user cannot create an static instance of it, it entitles itself
 * to be a completely abstract data type. See \ref gcal_event.
 */
typedef struct gcal_event* gcal_event_t;


/** Structure to hold events array, use it as a parameter for
 * \ref gcal_get_events.
 *
 * This structure will contain the number of retrieved entries, as also
 * the pointer to an array of \ref gcal_event structures.
 */
struct gcal_event_array {
	/** See \ref gcal_event. */
	gcal_event_t entries;
	/** The number of entries */
	size_t length;
};

/** Creates a new gcal object (you need then to talk with google
 * servers).
 *
 * @param mode Which google service to handle (GCONTACT and GCALENDAR)
 *
 * @return The new object on success or NULL otherwise.
 */
gcal_t gcal_new(gservice mode);

/** Deletes a gcal object.
 *
 * @param gcal_obj A gcal object created with \ref gcal_new.
 */
void gcal_delete(gcal_t gcal_obj);

/** Creates a new google calendar event object.
 *
 * If you are going to add new event, see also \ref gcal_add_event.
 *
 * @param raw_xml A string with google data XML of this entry.
 *
 * @return A gcal_event_t object on success or NULL otherwise.
 */
gcal_event_t gcal_event_new(char *raw_xml);

/** Free an gcal event object.
 *
 *
 * @param event An gcal event object, see also \ref gcal_event_new.
 */
void gcal_event_delete(gcal_event_t event);


/** Helper function, does all calendar events dump and parsing, returning
 * the data as an array of \ref gcal_event. See too \ref gcal_event_array.
 *
 * @param gcalobj A libgcal object, must be previously authenticated with
 * \ref gcal_get_authentication.
 *
 * @param events_array Pointer to an events array structure. See
 * \ref gcal_event_array.
 *
 * @return 0 on success, -1 otherwise.
 */
int gcal_get_events(gcal_t gcalobj, struct gcal_event_array *events_array);


/** Use this function to cleanup an array of calendar events.
 *
 * See also \ref gcal_get_events.
 *
 * @param events A pointer to an events array structure. See
 * \ref gcal_event_array.
 */
void gcal_cleanup_events(struct gcal_event_array *events);

/** Create a new event in user's calendar.
 *
 * You should have authenticate before using \ref gcal_get_authentication.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param event An event object, see \ref gcal_event_new.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_add_event(gcal_t gcal_obj, gcal_event_t event);

/** Updates an already existant event.
 *
 * Use it to update an event, but pay attention that you neeed to have
 * a valid event object (i.e. that has at least the edit_url to this entry).
 * See also \ref gcal_get_edit_url and \ref gcal_event_get_xml).
 *
 * A common use case is when you added a new event using \ref gcal_add_event
 * and later whant to edit it.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param event An event object.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_update_event(gcal_t gcal_obj, gcal_event_t event);

/** Deletes an event (pay attention that google server will mark this
 * event as 'cancelled').
 *
 * Being cancelled still makes possible to retrieve all the data of this
 * event (for a timeframe of a few weeks).
 *
 * The event object must be valid (i.e. has at least the edit_url to this
 * entry). See also \ref gcal_get_edit_url and \ref gcal_event_get_xml).
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param event An event object.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_erase_event(gcal_t gcal_obj, gcal_event_t event);

/** Query for updated events (added/edited/deleted).
 *
 * Its going to retrieve only updated events from user's calendar, its
 * useful if you implementing sync software and have downloaded all events
 * at least one time.
 *
 * Use this function to get only the changed data.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param events A pointer to a struct of type \ref gcal_event_array.
 *
 * @param timestamp A timestamp in format RFC 3339 format
 * (e.g. 2008-09-10T21:00:00Z) (see \ref TIMESTAMP_MAX_SIZE and
 * \ref get_mili_timestamp). It can include timezones too.
 * If you just want to get the updated events starting from today at 06:00Z,
 * use NULL as parameter.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_get_updated_events(gcal_t gcal_obj, struct gcal_event_array *events,
			    char *timestamp);


/** Helper function, extracts the edit URL in a XML entry
 *
 * The use of this function is a corner case: say that you just added an event
 * (so you dont have the gevent object for some reason) and want to load a
 * completely different event (say from a XML file) and want to update the
 * event with the new data.
 * You need to being able to access the older edit_url from the raw XML (that
 * I hope its still available somewhere) and that is when this function can
 * save your ass.
 *
 * A better approach would just create a new event object out from the older
 * XML data and use \ref gcal_event_get_url.
 * \todo: revise the real need of this function (at least as a public function).
 *
 * @param entry A pointer to a string that represents an event as raw XML.
 *
 * @param extracted_url This will be loaded with the edit_url, remember to free
 * it up.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_get_edit_url(char *entry, char **extracted_url);

/** Helper function, extracts the ETag code in a XML entry, required by
 * (Google Data API 2.0).
 *
 * The use of this function is a corner case: say that you just added an event
 * (so you dont have the gevent object for some reason) and want to load a
 * completely different event (say from a XML file) and want to update the
 * event with the new data.
 * You need to being able to access the older ETag from the raw XML (that
 * I hope its still available somewhere) and that is when this function can
 * save your ass.
 *
 * A better approach would just create a new event object out from the older
 * XML data and use \ref gcal_event_get_url. See also \ref gcal_get_edit_url.
 * \todo: revise the real need of this function (at least as a public function).
 *
 * @param entry A pointer to a string that represents an event as raw XML.
 *
 * @param extracted_etag This will be loaded with the edit_url, remember to free
 * it up.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_get_extract_etag(char *entry, char **extracted_etag);

/* Raw XML base functions: common for both calendar/contacts */

/** Adds a new entry (event or contact) in to user's feed, using raw xml.
 *
 * Use this if you already have the input data as a valid atom entry
 * XML data.  You don't need to create an entry object (gcal_event or
 * gcal_contact).
 *
 * A context where this function is handy is if you are going to load the
 * entries from XML files. Another context is if you use XSLT to convert
 * from another XML format (e.g. opensync) to create the gdata format.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param xml_entry A pointer to a string with XML representing the entry.
 *
 * @param xml_updated A pointer to pointer to string, it will have the updated
 * entry with new fields (updated, edit_url, ID). Remember to clean up this
 * memory. If you don't care about getting this information, just pass NULL.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_add_xmlentry(gcal_t gcal_obj, char *xml_entry, char **xml_updated);


/** Updates an entry (event or contact) using raw xml.
 *
 * For rationale of xml functions, see \ref gcal_add_xmlentry. Use it to update
 * (i.e. change) an entry.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param xml_entry A pointer to a string with XML representing the entry.
 *
 * @param xml_updated A pointer to pointer to string, it will have the updated
 * entry with new fields (updated, edit_url, ID). Remember to clean up this
 * memory. If you don't care about getting this information, just pass NULL.
 *
 * @param edit_url Common case, pass NULL (it assumes that 'xml_entry' has
 * a valid edit_url field). Case negative, you can supply the edit_url using
 * this parameter.
 *
 * @param etag Common case, pass NULL (it assumes that 'xml_entry' has
 * a valid etag field). Case negative, you can supply the etag using
 * this parameter. Required by Google Data protocols 2.0.
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_update_xmlentry(gcal_t gcal_obj, char *xml_entry, char **xml_updated,
			 char *edit_url, char *etag);


/** Deletes an entry (event or contact) using raw xml.
 *
 * For rationale of xml functions, see \ref gcal_add_xmlentry. Use it to update
 * (i.e. change) an entry.
 *
 * @param gcal_obj A gcal object, see \ref gcal_new.
 *
 * @param xml_entry A pointer to a string with XML representing the entry. It
 * has to have a valid edit_url field or operation will fail (i.e. you must
 * have created this xml out of an pre-existant entry).
 *
 * @return 0 on sucess, -1 otherwise.
 */
int gcal_erase_xmlentry(gcal_t gcal_obj, char *xml_entry);


/** Returns an event element from an event array.
 *
 * Since to final user events are abstract types, even if is possible to access
 * internal \ref gcal_event_array vector of events, its not possible to do
 * pointer arithmetic with it. Use this function as an
 * accessor to them.
 * A context where this function is useful is when downloading all events
 * from user calendar using \ref gcal_get_events.
 *
 * @param events An array of events, see \ref gcal_event_array.
 *
 * @param _index Index of element (is zero based).
 *
 * @return Either a pointer to the event object or NULL.
 */
gcal_event_t gcal_event_element(struct gcal_event_array *events, size_t _index);


/* Here starts gcal_event accessors */

/** Access event ID.
 *
 * Each entry has a unique ID assigned by google server.
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_id(gcal_event_t event);

/** Access last updated timestamp.
 *
 * Each operation (add/edit/delete) will set a timestamp to the entry.
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_updated(gcal_event_t event);

/** Access event title.
 *
 * All entries have a title, with semantic depending on the entry type:
 * events (event title) or contact (contact name).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_title(gcal_event_t event);

/** Access the edit_url field.
 *
 * All entries have an edit_url field (which is the combo of ID+cookie) that
 * must be used to do operations (edit/delete).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_url(gcal_event_t event);

/** Access the etag field.
 *
 * All entries have an etag field (required by Google Data API 2.0) that
 * must be used to do operations (edit/delete).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_etag(gcal_event_t event);

/** Access the raw XML representation of the entry.
 *
 * Besides having the more important information already parsed, its still
 * possible to access the raw xml of the entry if and *only* if you set
 * this mode in \ref gcal_t object using \ref gcal_set_store_xml function
 * *before* getting the data (using \ref gcal_get_events).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set).
 */
char *gcal_event_get_xml(gcal_event_t event);


/** Checks if the current event was deleted or not.
 *
 * When parsing the entry, the respective element used to represent deleted or
 * cancelled status (for calendar events) is stored internally of event object.
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return 1 for deleted, 0 for not deleted, -1 for error case (f the event
 * object is invalid).
 */
char gcal_event_is_deleted(gcal_event_t event);


/* This are the fields unique to calendar events */

/** Access event description.
 *
 * Events have an extra field for description (like: "Meeting with someone and
 * remember to discuss whatever targeting do something").
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_content(gcal_event_t event);

/** Checks if this is a recurrent event.
 *
 * Case positive, it will return the string with the representation of recurrence
 * rule. Google calendar uses a subset of iCalendar to represent this (yeah, brain
 * f*ked in my opinion put another text format inside of XML...). See more
 * information here: http://code.google.com/apis/calendar/developers_guide_protocol.html#CreatingRecurring
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_recurrent(gcal_event_t event);

/** Access event start timestamp.
 *
 * Google calendar uses RFC 3339 format (e.g. "2008-09-11T21:00:00Z") to represent
 * when an event will start. It can have the timezone information too
 * (e.g. "2008-09-11T12:39:00-04:00" for a -4hours from UTC timezone, a.k.a. Manaus).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_start(gcal_event_t event);

/** Access event end timestamp.
 *
 * See too \ref gcal_event_get_start for further discussion.
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_end(gcal_event_t event);

/** Access event location/place.
 *
 * Google calendar allows to store any string as the place where the event
 * will happen (even GPS coordinates).
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_where(gcal_event_t event);


/** Access event status.
 *
 * An event can have some status (confirmed/cancelled) and its possible to
 * access then. For while, libgcal store the whole URL with the description
 * of event status (e.g. "http://schemas.google.com/g/2005#event.confirmed").
 * \todo Use enumeration to represent status.
 *
 * @param event An event object, see \ref gcal_event.
 *
 * @return Pointer to internal object field (dont free it!) or NULL (in error
 * case or if the field is not set). If the entry hasn't this field in the
 * atom stream, it will be set to an empty string (i.e. "").
 */
char *gcal_event_get_status(gcal_event_t event);


/* Here starts the setters */

/** Sets event title.
 *
 * Use this to assign an event title (or to change it if you wish to update an
 * already existant calendar event).
 *
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field String with event title (e.g. "Dinner with Mary").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_title(gcal_event_t event, const char *field);

/** Set event detailed description.
 *
 * See also \ref gcal_event_get_content for an example of valid description.
 *
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field A string with event description.
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_content(gcal_event_t event, const char *field);

/** Set event start time.
 *
 * See also \ref gcal_event_get_start.
 *
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field A string with the timestamp for start time using RFC 3339 format
 * (e.g. "2008-09-11T21:00:00Z").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_start(gcal_event_t event, const char *field);


/** Set event end time.
 *
 * See also \ref gcal_event_set_start.
 *
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field A string with the timestamp for start time using RFC 3339 format
 * (e.g. "2008-09-11T22:00:00Z").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_end(gcal_event_t event, const char *field);

/** Set event location/place.
 *
 * See also \ref gcal_event_get_where.
 *
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field The place where event is supposed to happen (e.g. "Nearby an
 * nice pub, close the church")
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_where(gcal_event_t event, const char *field);

/* TODO: Not implemented */

/** Sets recurrence rule.
 *
 * \todo implement this method, its just stub now.
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field A string with google invalid iCalendar format
 * to represent recurrence rules.
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_recurrent(gcal_event_t event, const char *field);

/** Set event status (for while, all then were created as 'confirmed').
 *
 * \todo implement this method, its just stub now.
 * @param event An event object, see \ref gcal_event and \ref gcal_event_new.
 *
 * @param field Status description (should I use enums or string?).
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_status(gcal_event_t event, const char *field);

/** Sets event edit url.
 *
 * This field is a hard requirement to edit/delete a event. Starting with
 * google data API 2.0, the ETag is also required.
 *
 * @param event A event object, see \ref gcal_event.
 *
 * @param field String with the edit url email
 * (e.g. "http://www.google.com/m8/feeds/events/user%40gmail.com/base/2").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_url(gcal_event_t event, const char *field);


/** Sets event ID.
 *
 * Each event has an ID (but this can extracted from the edit_url).
 *
 * @param event A event object, see \ref gcal_event.
 *
 * @param field String with event ID (e.g. "joe.doe@nobody.com").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_id(gcal_event_t event, const char *field);


/** Sets event ETag.
 *
 * Starting with google data API 2.0, the ETag is used for versioning the
 * entries. Is required for edit/delete.
 *
 * @param event A event object, see \ref gcal_event.
 *
 * @param field String with event ETag (e.g. "Q3c5eDVSLyp7ImA9WxRbFE0KRAY.").
 *
 * @return 0 for sucess, -1 otherwise.
 */
int gcal_event_set_etag(gcal_event_t event, const char *field);




#endif