Add object to json in Template

[Ipf]

Hi Guys,

I´ve been trying to get more into templating and I am currently testing arround whats possible and it went OK so far but now I got stuck.

I try to build a template for an gtfs sensor containing the next departures from the trainstation as an attribute. I want to make some kind of schedule as json file/string/object containing all these next departures in order to access them.

I managed to create some kind of json but that is only for the first of a few departures “departure_1” and I cant find a way to add a second object “departure_2” to that json. Is there any easy way I am missing to achieve that?

## read sensor attribute and save it as a list
{% set next_departures_list = state_attr('sensor.mex18_es_bh','next_departures_lines') | list %}

## Load first Departure from list
{% set next_departure = next_departures_list[0] %}

## departure time of next departure
{% set next_line_deptime = next_departure[:25] %}

## calc timediff to now and testing conversion of timezone but thats not working. 
## with that code I just replace the timezone but the departure time stays the same 
{% set next_line_timediff = as_datetime(next_departure[:25]) - now() %}
How to get a string out of datetime object in order to save it in json format?

## to JSON
{% set schedule_json = {
        "next_departures": [{
            "departure_1": {
              "line": next_departure[26:].replace('(','').replace(')',''),
              "from_station_id": state_attr('sensor.mex18_es_bh','origin_station_stop_id'),
              "from_station_name": state_attr('sensor.mex18_es_bh','destination_station_stop_name'),
              'to_statio_id': state_attr('sensor.mex18_es_bh','destination_station_stop_id'),
              'to_station_name': state_attr('sensor.mex18_es_bh','origin_station_stop_name'),
              'departure_time': next_departure[:25],
              'departure_day': state_attr('sensor.mex18_es_bh','day'),
              'time_to_departure': "next_line_timediff"
              }
          }]
        }
%}

which gives me this result…

Additionally I wasn`t able to find a solution for saving datetime object within json. When I try to save the next_line_timediff as datetime I get an error message

How to convert the datetime object in oirder to save it to json?

And why cant I access the line within the first departure directly? It doesn`t even print an error message…

{{ schedule_json['next_departures'][0].line

Hope you can give me an hint into the right direction :). Thanks!

[mobile.andrew.jones (Andrew Jones)]

@Ipf

{{ schedule_json['next_departures'][0].line

Right well the first thing I can answer is because - that doesn’t exist.
You have created an object inside index 0 called “departure_1” so it would be

schedule_json['next_departures'][0]['departure_1']['line']

So the very first thing I would suggest would be not label them as departure_1, departure_2 etc, because you are going to be adding them to an array / list inside the next_departures object anyway, just called it departure.

We need to see the output of {{ next_departure[:25] }} because we have no idea what that is outputting right now from the code you have posted.

[123 (Taras)]

@Ipf

find a way to add a second object “departure_2” to that json

I suggest you change the data structure you have chosen for the value of next_departures.

Currently, each departure has a unique key in a dictionary (departure_1, departure_2, etc). I suggest you simply create a list of departures. A list structure will not make it harder to reference each departure but it will make it easier to generate multiple departures (using a for-loop to iterate through next_departures_lines).

[Ipf]

HI,

thank you for your answers. I tried a bit with lists before I decided to try json but your suggestion made me think of it again and I found a solution.

The key was to adding all the Information for one departure (Line, Time, Station, ID`s etc) as one List item to a list. Just tried it quick and dirty as a proof without all Information and without a loop but thats working code for me. Will post the whole solution after I am done. Thank you for pointing me to the right direction.

[Ipf]

{{ next_departure[:25] }}

gives back the day and time of the departure with UTC timezone 2024-01-23T03:57:00+00:00.
From this point I try to calculate the time difference between now and the departure
. Therefore I need this Information as a date_time object and the result is also a date_time object. But the object can`t get serialized to an JSON.

{% set next_line_timediff = as_datetime(next_departure[:25]) - now() %}
{{ next_line_timediff }}

Saving to a list
{% set data.departures = data.departures + [{"line": "Line1", 'departure_time': next_departure[:25], 'time_to_departure': next_line_timediff}] %}

I Tried to save the timediff within a List and not in an JSON and now I can save it directly within the list but the output isn`t really what I wanted. Is will be saved within the list as datetime.timedelta. A simple string would bo ok for me.

[mobile.andrew.jones (Andrew Jones)]

If you look around the forum you will find datetime jinja macros - hold on -

Easy Time Macros for Templates!

Hello community! As you may know, 2023.4 offers a new global template macro option in Home Assistant. How does this benefit you? The introduction of this feature allows me to easily share all the templates I’ve helped you create over the years in a single easy-to-use template library! All in your native language! Introducing… Easy Time Jinja A 1-stop-shop for easy time calculations. Get it from HACS! These templates are now available in HACS, with a caveat. In order to see templat…

This is what you will be wanting to convert your next_line_timediff to I assume you are wanting 13mins etc

[Ipf]

Thats exactly what I want. Great thank you!

[Ipf]

Hi,

with your help I found a solution, thank you!

{% from 'easy_time.jinja' import easy_time_between %}
## Set variables
{% set data = namespace(departures=[]) %}
{% set origin_station_name = state_attr('sensor.mex12_bh_es','origin_station_stop_name')%}
{% set destination_station_name = state_attr('sensor.mex12_bh_es','destination_station_stop_name')%}
## Loop through departure_list
{% for departure in state_attr('sensor.mex12_bh_es','next_departures_lines') | list %}
  {% set departure_line = departure[27:].replace('(','').replace(')','') %}
  {% set departure_time = departure[:25] %}
  {% set departure_timediff = easy_time_between(now(), departure_time) %}
  {% set data.departures = data.departures + [{"line": departure_line, "origin_station_name": origin_station_name, "destination_station_name": destination_station_name, "time": departure_time, "timediff": departure_timediff }]%}
{% endfor %}
## Output
{{ data.departures | to_json(pretty_print=true)}}

## output departure 1
{{ data.departures[0].line }} {{ data.departures[0].time }}

## output departure 2
Line: {{ data.departures[1].line }}
Departure Time: {{ data.departures[1].time[11:19] }}
Time to Departure: {{ data.departures[1].timediff }}

This Template gives me the output I wanted.

Next steps is to add a second gtfs sensor with departures from the same Station, combine the departures from these Sensors and sort them in the order of the departure time. But thats an other topic :). Thank You again!