Changing JSON array to get smaller messages? - json

Question

When using JSON to send an array of objects from the same class the objects fields are repeated many times, often unnecessarily, and the message becomes very long for arrays with big length. To my knowledge, there is no way to remove the field's repetition using only JSON. So I'm looking for a solution that solves the encoding and decoding of arrays without repeating the fields names.
As an example, the array below:
A:
[
{id:1;name:Name 1;description:Description 1},
{id:2;name:Name 2;description:Description 2},
...,
{id:N;name:Name N;description:Description N}
]
can be represented by:
B:
{
fields:[id, name, description],
values:[
[1,Name 1,Description 1],
[2,Name 2,Description 2],
...,
[N,Name N,Description N]
]
}
spending lot less space in the case of arrays with big length.
But I need a solution that does this transformation (from A to B and B to A) automatically. It can use the B represantation, or a better, to reduce the message size by eliminating fields names.
Any solution?

Answer 1

You can do this by writing two simple javascript functions to encode and decode as you want. Some rules have to apply in order for this paterns to work:
There must be a valid JSON input data string, though you can use a
plain array with objects
All array elements must have the same object structure format
It does not wotk with child objects
Minify/Unminify object function:
function minifyObject(obj) {
var fields = Object.keys(obj[0]);
var values = [];
for(var record in obj) {
var value = [];
for(var field in fields) {
value.push(obj[record][fields[field]]);
}
values.push(value);
}
return {
fields: fields,
values: values
}
}
function unminifyObject(obj) {
var output = [];
for(var i = 0; i < obj.values.length; i++) {
var record = {};
for(var j = 0; j < obj.fields.length; j++) {
record[obj.fields[j]] = obj.values[i][j];
}
output.push(record);
}
return output;
}
var data = [
{"id":1, "name": "Name 1", "description": "Description 1"},
{"id":2, "name": "Name 2", "description": "Description 2"},
{"id":3, "name": "Name 3", "description": "Description 3"}
];
var minified = minifyObject(data);
console.log("Minified object\n", minified);
var unminified = unminifyObject(minified);
console.log("Unminified array\n", unminified);
This code can also be simplified using ES6.
You can also find my test JSON converter here: https://zikro.gr/dbg/so/20129724/