list-to-tree

conver list to tree

by Avinashullal

JavaScript

function listToTree(data, options) {
  options = options || {};
  var ID_KEY = options.idKey || 'id';
  var PARENT_KEY = options.parentKey || 'parent';
  var CHILDREN_KEY = options.childrenKey || 'children';

  var tree = [],
    childrenOf = {};
  var item, id, parentId;

  for (var i = 0, length = data.length; i < length; i++) {
    item = data[i];
    id = item[ID_KEY];
    parentId = item[PARENT_KEY] || 0;
    // every item may have children
    childrenOf[id] = childrenOf[id] || [];
    // init its children
    item[CHILDREN_KEY] = childrenOf[id];
    if (parentId != 0) {
      // init its parent's children object
      childrenOf[parentId] = childrenOf[parentId] || [];
      // push it into its parent's children object
      childrenOf[parentId].push(item);
    } else {
      tree.push(item);
    }
  };

  return tree;
}

var list = [{
  "id": "12",
  "parentId": "0",
  "text": "Man",
  "level": "1",
  "children": null
}, {
  "id": "6",
  "parentId": "12",
  "text": "Boy",
  "level": "2",
  "children": null
}, {
  "id": "7",
  "parentId": "12",
  "text": "Other",
  "level": "2",
  "children": null
}, {
  "id": "9",
  "parentId": "0",
  "text": "Woman",
  "level": "1",
  "children": null
}, {
  "id": "11",
  "parentId": "9",
  "text": "Girl",
  "level": "2",
  "children": null
}];

var tree = listToTree(list, {
  idKey: 'id',
  parentKey: 'parentId',
  childrenKey: 'children'
});
document.body.innerHTML = "<pre>" + (JSON.stringify(tree, null, " "))