Get parent object from key or its value in a nested object

Question

I have an object which contains all information about folders and files of a directory in hierarchical manner.
for example

{
  "path": "./parent",
  "name": "parent",
  "type": "folder",
  "children": [
    {
      "path": "./parent/child1",
      "name": "child1",
      "type": "folder",
      "children": [
        {
          "path": "./parent/child1/file1",
          "name": "file1",
          "size": 651956838,
          "extension": ".pdf",
          "type": "file"
        },
        {
          "path": "./parent/child1/file2",
          "name": "file2",
          "size": 468327031,
          "extension": ".pdf",
          "type": "file"
        }
      ]
    },
    {
      "path": "./parent/child2",
      "name": "child2",
      "type": "folder",
      "children": [
        {
          "path": "./parent/child2/file3",
          "name": "file1",
          "size": 651956838,
          "extension": ".pdf",
          "type": "file"
        },
        {
          "path": "./parent/child2/file4",
          "name": "file2",
          "size": 468327031,
          "extension": ".pdf",
          "type": "file"
        }
      ]
    }
  ]
}

Now, I will have the path value and from this information I want to access the children property, which is sibling to the key of which that path was value of. Say, I have path "./parent/child1", then I want to have the value of children property relative to this path which will be

  [
    {
      "path": "./parent/child1/file1",
      "name": "file1",
      "size": 651956838,
      "extension": ".pdf",
      "type": "file"
    },
    {
      "path": "./parent/child1/file2",
      "name": "file2",
      "size": 468327031,
      "extension": ".pdf",
      "type": "file"
    }
  ]

So I want to know if it is possible or not. If yes then how and if not then is there any other way to achieve similar result?

You might want to look at https://stackoverflow.com/questions/2980763/javascript-objects-get-parent since the second answer (first that is not accepted) is most likely the closest you can get with parent objects — Andrej Dobeš, Aug 02 '20 at 16:07

score 1 · Accepted Answer · answered Aug 02 '20 at 16:26

This can be done using a recursive function.


const paths = {
  "path": "./parent",
  "name": "parent",
  "type": "folder",
  "children": [
    {
      "path": "./parent/child1",
      "name": "child1",
      "type": "folder",
      "children": [
        {
          "path": "./parent/child1/file1",
          "name": "file1",
          "size": 651956838,
          "extension": ".pdf",
          "type": "file"
        },
        {
          "path": "./parent/child1/file2",
          "name": "file2",
          "size": 468327031,
          "extension": ".pdf",
          "type": "file"
        }
      ]
    },
    {
      "path": "./parent/child2",
      "name": "child2",
      "type": "folder",
      "children": [
        {
          "path": "./parent/child2/file3",
          "name": "file1",
          "size": 651956838,
          "extension": ".pdf",
          "type": "file"
        },
        {
          "path": "./parent/child2/file4",
          "name": "file2",
          "size": 468327031,
          "extension": ".pdf",
          "type": "file"
        }
      ]
    }
  ]
}

const pathtofind = "./parent/child1";

function findChildrenInPath(object, path) {
    if (path.startsWith(object.path)) {
        if (object.path == path) {
            return object.children;
        }
        else {
            for (let child of object.children) {
                const result = findChildrenInPath(child, path);
                if (result) {
                    return result;
                }
            }
        }
    }
}

const res = findChildrenInPath(paths, pathtofind);
console.log(res);

Carsten Massmann · Answer 2 · 2020-08-02T17:09:48.853

And here is another approach, without recursion:

const data={
  "path": "./parent",
  "name": "parent",
  "type": "folder",
  "children": [
{
  "path": "./parent/child1",
  "name": "child1",
  "type": "folder",
  "children": [
    {
      "path": "./parent/child1/file1",
      "name": "file1",
      "size": 651956838,
      "extension": ".pdf",
      "type": "file"
    },
    {
      "path": "./parent/child1/file2",
      "name": "file2",
      "size": 468327031,
      "extension": ".pdf",
      "type": "file"
    }
  ]
},
{
  "path": "./parent/child2",
  "name": "child2",
  "type": "folder",
  "children": [
    {
      "path": "./parent/child2/file3",
      "name": "file1",
      "size": 651956838,
      "extension": ".pdf",
      "type": "file"
    },
    {
      "path": "./parent/child2/file4",
      "name": "file2",
      "size": 468327031,
      "extension": ".pdf",
      "type": "file"
    }
  ]
}
  ]
};

function getChildrenOf(fs,pth){
  let ptha=pth.split('/');
  ptha.forEach((d,i,a)=>a[i]=(i?a[i-1]+'/':'')+d);
  // console.log(ptha);
  return ptha.filter(d=>d!==".").reduce((a,c)=>
a=a.find(d=>d.path===c && d.type==="folder").children
  ,[fs]);
}

console.log(getChildrenOf(data,"./parent/child1"));

As the data array does not contain any information about the current directory (./) I remove that element from the ptha array. Otherwise the search will allow searches in arbitrary depths of file structures.

Get parent object from key or its value in a nested object

2 Answers2