Returning an array of objects from other object

Question

Hello am trying to extract some information from an object to create a graph but it returns undefined my object looks like

{
"concepts": [
        {
            "id_cpt": "1",
            "fr_cpt": "Proche",  
        },
        {
            "id_cpt": "2",
            "fr_cpt": "Loin",  
        }{
            "id_cpt": "3",
            "fr_cpt": "Here",  
        },...
],
"arcs":  [
     {
       "idfrom":"1",
       "idto":"2"
     },
     {
       "idfrom":"3",
       "idto":"2"
     },....
]
}

I want to make an object looks like

const data = {
    nodes: [{ id: 'Proche' }, { id: 'Loin' },{ id: 'Here' } ...],
    links: [{ source: 'Proche', target: 'Loin' }, { source: 'Here', target: 'Loin' },...]
};

I want extract names not ids in links but the object arcs only have ids the code in es6 and thank you for helping me

Answer 1

You could loop through the concepts using for...of. Populate the nodes array and a map object. The map object has id_cpt as key and fr_cpt as value.

{
  "1": "Proche",
  "2": "Loin",
  "3": "Here"
}

This object can be used to get the source and target value for links. Then loop through arcs and create links using map object

Here's a snippet:

const input = {"concepts":[{"id_cpt":"1","fr_cpt":"Proche",},{"id_cpt":"2","fr_cpt":"Loin",},{"id_cpt":"3","fr_cpt":"Here",},],"arcs":[{"idfrom":"1","idto":"2"},{"idfrom":"3","idto":"2"},]}

let nodes = [], 
    links = [], 
    map = {};

for (const { id_cpt, fr_cpt } of input.concepts) {
  nodes.push({ id: fr_cpt });
  map[id_cpt] = fr_cpt
}

for (const { idfrom, idto } of input.arcs) {
  links.push({ source: map[idfrom], target: map[idto] }) // get the value using map
}

const output = { nodes, links }

console.log(output)