Easy problem: Unable to output the yml data with liquid - yaml

Question

I have a problem very similar to this one, but unfortunately, the solution doesn't work for me. So I'm posting another question.
I'm making a website with Jekyll and would like to print the information of a yml file on a page or post. Here is a dummy yml file:
- Master student:
- Dummy name1:
- email: blabal#bla.com
- room: 1
- tel: [phone]
- Bachelor student:
- Dummy name:
- email: blabal#bla.com
- room: 12
- tel: [phone]
- Guest:
- Bird:
- email: blabal#bla.com
- room: 10856
- tel: [phone]
This file is placed in a newly made _data directory, under the name people.yml. Then, I made a new post on a freshly made site with the minimal theme, which goes as follows:
---
layout: post
title: "Test"
date: 2023-01-12 23:42:09 +0100
---
{% assign people = site.data.people | read_yaml %}
<!-- {{ people }} --> // this tests if the files is loaded or not
{% for role in people %}
{% assign role_data = role[1] %}
{{ role_data[0] }} has the following role: {{ role[0] }}.
{% endfor %}
Once I generate the site, I expect the following text on the post (except maybe for some linebreaks):
Dummy name1 has the following role: Master student
Dummy name has the following role: Bachelor student
Bird has the following role: Guest
Instead, I get this:
has the following role: .
has the following role: .
has the following role: .
that puzzles me. I suspect the reason is the way I access the item values. But can't figure it out. Removing the read_yml also seems to have no effect.

Answer 1

You were on the right track, but didn't do enough un-nesting of your hashes. The data structure is a bit unfortunate; maybe when you look at the equivalent JSON, it's more obvious:
[
{
"Master student": [
{
"Dummy name1": [
{
"email": "blabal#bla.com"
},
{
"room": 1
},
{
"tel": 12345678
}
]
}
]
},
{
"Bachelor student": [
{
"Dummy name": [
{
"email": "blabal#bla.com"
},
{
"room": 12
},
{
"tel": 987654
}
]
}
]
},
{
"Guest": [
{
"Bird": [
{
"email": "blabal#bla.com"
},
{
"room": 10856
},
{
"tel": 71864270
}
]
}
]
}
]
So, each array element is a hash (object), and to get key and value, you have to iterate over the hashes; the values themselves are again arrays of hashes. This snippet produces your desired output:
{% assign people = site.data.people %}
{% for person in people %}
{%- for person_hash in person %}
{%- assign role = person_hash[0] %}
{%- for role_hash in person_hash[1][0] %}
{{- role_hash[0] }} has the following role: {{ role }}.
{% endfor %}
{% endfor %}
{% endfor %}
I would recommend you re-structure your data, to something like this:
- role: Master student
name: Dummy name1
email: blabal#bla.com
room: 1
tel: [phone]
- role: Bachelor student
name: Dummy name
email: blabal#bla.com
room: 12
tel: [phone]
- role: Guest
name: Bird
email: blabal#bla.com
room: 10856
tel: [phone]
which corresponds to this JSON:
[
{
"role": "Master student",
"name": "Dummy name1",
"email": "blabal#bla.com",
"room": 1,
"tel": 12345678
},
{
"role": "Bachelor student",
"name": "Dummy name",
"email": "blabal#bla.com",
"room": 12,
"tel": 987654
},
{
"role": "Guest",
"name": "Bird",
"email": "blabal#bla.com",
"room": 10856,
"tel": 71864270
}
]
Then, iterating over it becomes as simple as this:
{% for person in site.data.people %}
{{ person.name }} has the following role: {{ person.role }}
{% endfor %}