data-serialisation.md

Question Definitions

definition:

• backend/include/survey.h struct question

serialization:

• backend/src/serialisers.c: serialise_question()

corresponding frontend module:

• front/src/Question.js

Format of an question row:

<uid>:<question_text>:<question_html>:<type>:<flags>:<default_value>:<min_value>:<max_value>:<decimal_places>:<num_choices>:<choices>:<unit>

Location: surveys/<surveyID>/current (can be symlinked)

field	data type	json	notes
uid	char[]	string	question id
question_text	char[]	string	question label
question_html	char[]	string	question description (html tags allowed)
type	char[]	string	question type
flags	int	number
default_value	char[]	string
min_value	long long	number
max_value	long long	number
decimal_places	int	number
num_choices	int	number
choices	char[]	string	comma separated list
unit	char[]	string

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Answer Definitions

definition:

• backend/include/survey.h struct answer

serialization:

• backend/src/serialisers.c: serialise_answer()

corresponding frontend module:

• front/src/Answer.js

Format of an answer row:

request

request payload format (serialisation mode: public):

<uid>:<text>:<value>:<lat>:<lon>:<time_begin>:<time_end>:<time_zone_delta>:<dst_delta>

session

session storageformat (serialisation mode: private):

<uid>:<text>:<value>:<lat>:<lon>:<time_begin>:<time_end>:<time_zone_delta>:<dst_delta>:<unit>:<flag>:<stored>

Location: sessions/<session-prefix>/sessionID

field	API access		data type	json	notes
uid	read/write	answer value	char[]	string	question id
type	-	control field	int	-	question type
text	read/write	answer value	char[]	string
value	read/write	answer value	long long	number
lat	read/write	answer value	long long	number
lon	read/write	answer value	long long	number
time_begin	read/write	answer value	long long	number
time_end	read/write	answer value	long long	number
time_zone_delta	read/write	answer value	int	number
dst_delta	read/write	answer value	int	number
unit	read/write	answer value	char[]	string	unit for numeric types, see below
flag	-	control field	int	-	bit control flag, see below
stored	-	control field	long long	-	UNIX timestamp, time of answer storage, see below

unit

• Time based question times: Use seconds only. The returned answer unit will always be a duration in seconds since midnight (where midnight == 0)
• All other numeric qquestion types are free to define a human friendly unit (displayed on the frontend form) the unit will be included into the returned answer

flag

• Currently only supported flags are answered (0) or deleted (1)

stored

• timestamp is set on adding, deleting or updating an answer