Presenting Tree Hierarchy with Javascript

Question

I have terms as below:

var terms = [
        { id: 1, name: "Name 1", parent: null },
        { id: 2, name: "Name 2", parent: 6 },
        { id: 3, name: "Name 3", parent: null },
        { id: 4, name: "Name 4", parent: 2},
        { id: 5, name: "Name 5", parent: 3 },
        { id: 6, name: "Name 6", parent: null },
        { id: 7, name: "Name 7", parent: 3 },
        { id: 8, name: "Name 8", parent: 9 },
        { id: 9, name: "Name 9", parent: 4 }
];

Now, I want to process term to have the output:

var orderedTerms = [
        { id: 1, name: "Name 1", parent: null , deep: 0},
        { id: 3, name: "Name 3", parent: null , deep: 0},
        { id: 5, name: "Name 5", parent: 3 , deep: 1},
        { id: 7, name: "Name 7", parent: 3 , deep: 1},
        { id: 6, name: "Name 6", parent: null , deep: 0},
        { id: 2, name: "Name 2", parent: 6, deep: 1},
        { id: 4, name: "Name 4", parent: 2, deep: 2},
        { id: 9, name: "Name 9", parent: 4, deep: 3},
        { id: 8, name: "Name 8", parent: 9, deep: 4 }
];

I think that someone can help me do it with Javascript (NodeJS). Thank you in advance.

Answer 1

The code below should help you:

 var terms = [ { id: 1, name: "Name 1", parent: null }, { id: 2, name: "Name 2", parent: 6 }, { id: 3, name: "Name 3", parent: null }, { id: 4, name: "Name 4", parent: 2}, { id: 5, name: "Name 5", parent: 3 }, { id: 6, name: "Name 6", parent: null }, { id: 7, name: "Name 7", parent: 3 }, { id: 8, name: "Name 8", parent: 9 }, { id: 9, name: "Name 9", parent: 4 } ]; var deep0 = terms.filter(function(term) { if (term.parent === null) { term.deep = 0; return true; } return false; }); function makeTree(source, arr, final) { if (!final) final = arr.slice(); if (arr.length > 0) { var deep = arr[0].deep + 1; source.forEach(function (item, i) { if (arr.map(function(term) { return term.id; }).indexOf(item.parent) >= 0) { item.deep = deep; var idx = final.map(function(term) { return (term.id === item.parent || term.parent === item.parent); }).lastIndexOf(true); final.splice(idx + 1, 0, item); } }); makeTree(source, final.filter(function(term) { return term.deep === deep; }), final); } return final; } var final = makeTree(terms, deep0); document.body.innerHTML = '<pre><code>' + JSON.stringify(final, null, 2) + '</code></pre>'; 

The hole idea behind the code was to firstly find all the items which didn't have a parent, and then recursively iterate through their children (deeply), inserting them in the correct order into the final array.

If you have any doubts, leave a comment.

Answer 2

Just a little recursion will do.

 function getTree(parent, level) { level = level || 0; terms.forEach(function (a) { if (a.parent === parent) { orderedTerms.push({ id: a.id, name: a.name, parent: a.parent, deep: level }); getTree(a.id, level + 1); } }); } var terms = [ { id: 1, name: "Name 1", parent: null }, { id: 2, name: "Name 2", parent: 6 }, { id: 3, name: "Name 3", parent: null }, { id: 4, name: "Name 4", parent: 2 }, { id: 5, name: "Name 5", parent: 3 }, { id: 6, name: "Name 6", parent: null }, { id: 7, name: "Name 7", parent: 3 }, { id: 8, name: "Name 8", parent: 9 }, { id: 9, name: "Name 9", parent: 4 } ], orderedTerms = []; getTree(null); document.write('<pre>' + JSON.stringify(orderedTerms, 0, 4) + '</pre>'); 

Bonus: Version with temporary storage.

 function sortTree(array) { function getTree(parent, level) { temp[parent] && temp[parent].forEach(function (a) { result.push({ id: array[a].id, name: array[a].name, parent: array[a].parent, deep: level }); getTree(array[a].id, level + 1); }); } var temp = {}, result = []; array.forEach(function (a, i) { temp[a.parent] = temp[a.parent] || []; temp[a.parent].push(i); }); getTree(null, 0); return result; } var terms = [ { id: 1, name: "Name 1", parent: null }, { id: 2, name: "Name 2", parent: 6 }, { id: 3, name: "Name 3", parent: null }, { id: 4, name: "Name 4", parent: 2 }, { id: 5, name: "Name 5", parent: 3 }, { id: 6, name: "Name 6", parent: null }, { id: 7, name: "Name 7", parent: 3 }, { id: 8, name: "Name 8", parent: 9 }, { id: 9, name: "Name 9", parent: 4 } ]; document.write('<pre>' + JSON.stringify(sortTree(terms), 0, 4) + '</pre>');