Are JSON nested objects necessary? - json

Question

I have a question about the way JSON is written. Which is better in terms of usability? I am trying to use a single JSON file for decoding in PHP and Swift, and was wondering which would be the better way for the JSON to be written. Nested objects or no nested objects, essentially.
Option 1
{
"title": "Test",
"image": "image",
"imageCard": "imae2",
"count": 20,
"section": "personal",
"description": "Description",
"color": "#F17B08",
"content": {
"video": true,
"text": true,
"updated": false
},
"homepage": {
"featured": false,
"popular": false,
"new": false
},
"levels": "7-12"
}
]
Option 2
[
{
"title": "Test",
"image": "image",
"imageCard": "imae2",
"count": 20,
"section": "personal",
"description": "Description",
"color": "#F17B08",
"video": true,
"text": true,
"updated": false,
"featured": false,
"popular": false,
"new": false,
"levels": "7-12"
}
]
Thanks!

Answer 1

A JSON structure is often bound to be mapped to an object-oriented class. The closer the JSON structure is from the Model of your program (all the classes, and how each has one or many relationships to others), the easier it will be to deserialize the response from the API.
Now, JSON nesting is necessary just as much as you make associations, compositions and aggregations with your classes.
Let's say you have a Student that has a name, an unique ID and a Teacher which gives many Courses
Having a nested JSON such as:
[
{
"Name":"John Doe",
"ID":"948AFF",
"Teacher":{
"John Nash",
"Classes":[
{...},
{...},
{...}
]
}
},
{
"Name":"William Smooth",
"ID":"123LMLG",
"Teacher":{
"Ulrich Stokes",
"Classes":[
{...},
{...},
{...}
]
}
}
]
Is an intuitive, clean, flexible way to structure the JSON. Because it maps easily to your model. Each element of the array is an instance of a Student which has an instance of Teacher, which has a list of Courses.
Whereas if you had a flat structure like you suggest :
[
{
"Name":"John Doe",
"ID":"948AFF",
"TeacherName":"John Nash",
"ClassesOfTheTeacher":[
{...},
{...},
{...}
]
},
{
"Name":"William Smooth",
"ID":"123LMLG",
"TeacherName":"Ulrich Stokes",
"ClassesOfTheTeacher":[
{...},
{...},
{...}
]
}
]
Forces you to systematically map each field to the attribute of one of your classes. It doesn't stick easily to your model, you have to make some manipulations to map this to your model.
Furthermore, what if suddenly you wanted to have .. 3 Teachers for each student ? Would you end up with TeacherName1, TeacherName2, TeacherName3, and ClassesOfTheTeacher1, ClassesOfTheTeacher2, etc. ? Probably not.
Nested JSON is necessary if you have association/composition/aggregation in your classes.