Creating Appointments from Time and Hours of Availability in Dataweave

Author: Sanket Kangle

This article will learn how to create slots if you have starting time, duration of one slot, and total availability in hours using Dataweave script.

Use case: Let us say we are running a hospital, we have a visiting doctor coming in tomorrow, who will be available from morning 10:30 am for 3 hours and evening 5 pm for 2 hours. We want to create all possible appointments on that particular day.

Sample input:

{ “Doc_name”: “Dr. Max Mule”, “duration_in_minutes”: 30, “timeslots”: { “start_time”: [ “10:30”, “17:00” ], “hours”: [ 3, 2 ] }}

Required sample output:

[ { “Dr. Max Mule”: { “timeslot_start”: “10:30:00”, “timeslot_end”: “11:00:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “11:00:00”, “timeslot_end”: “11:30:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “11:30:00”, “timeslot_end”: “12:00:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “12:00:00”, “timeslot_end”: “12:30:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “12:30:00”, “timeslot_end”: “13:00:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “13:00:00”, “timeslot_end”: “13:30:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “17:00:00”, “timeslot_end”: “17:30:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “17:30:00”, “timeslot_end”: “18:00:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “18:00:00”, “timeslot_end”: “18:30:00” } }, { “Dr. Max Mule”: { “timeslot_start”: “18:30:00”, “timeslot_end”: “19:00:00” } }]

We can achieve this in following steps:

1. Create an array of the number of time slots per window of availability
2. Create an array of slots by adding duration in starting time appropriate number of times.
3. Get the required output format.

Step 1: Create an array of number of time slots slots per window of availability

We need to find how many slots can be created. In our example, the duration for a single appointment is 30 minutes. The doctor is available for 3 hours from 10:30, i.e. we can have 6 slots in the morning. Similarly, in the evening we can have 4 appointments. We can get this using following script

%dw 2.0output application/jsonfun getNoOfSlots(hour, duration) = ((((hour as Number)*60)/duration)) as String {format: “#”} as Number var dur = payload.duration_in_minutesvar noOfSlots = payload.timeslots.hours map (hour, index) -> { a: getNoOfSlots(hour, dur)}.a — noOfSlots

The output will be as following

[ 6, 4]

Step 2: Create an array of slots by adding duration in starting time appropriate number of times.

This can be achieved by adding a few additional functions and variables in the above dataweave script which will look something like the following.

%dw 2.0output application/jsonfun getNoOfSlots(hour, duration) = ((((hour as Number)*60)/duration)) as String {format: “#”} as Number fun prepareList(list:Array, maxSize: Number) = if(sizeOf(list) >= maxSize )listelseprepareList(list ++ [(sizeOf(list)) as Number],maxSize) var dur = payload.duration_in_minutesvar duration_in_period = “PT” ++ (dur as String) ++ “M” var noOfSlots = payload.timeslots.hours map (hour, index) -> { a: getNoOfSlots(hour, dur)}.a var slot_num_list = noOfSlots map(slot, index) ->{ a: prepareList([], slot)}.a var start_time = payload.timeslots.start_timevar size = prepareList([], sizeOf(start_time))var slotsPerDay = flatten(size map(object, index) -> { a: slot_num_list[index] map(slot) ->{ b: start_time[index] as LocalTime+ (“PT” ++ (slot*dur) as String ++ “M”) }.b}.a) — slotsPerDay

The output is as following:

[ “10:30:00”, “11:00:00”, “11:30:00”, “12:00:00”, “12:30:00”, “13:00:00”, “17:00:00”, “17:30:00”, “18:00:00”, “18:30:00”]

Step 3: Get the required output format

With a few tweeks in the body section, we can get required output. Now body of our script will be as below

— flatten (slotsPerDay map(slot_start) ->{ (payload.Doc_name):{ timeslot_start: slot_start, timeslot_end: slot_start + duration_in_period }})

We will get the required output format as stated above.

Hope this was useful