How to implement hierarchical multilevel datatable in javaScript?

Question

I am implementing multi level datatable without using any plugin or library. I want to implement based on javaScript, JQuery or angular js. I checked one below links,

Answer 1

The simplest way I can think of accomplishing this with vanilla Javascript would be a modified depth first traversal of an object:

function renderJSON(json) {
  const wrapper = document.createElement('div');

  const stack = [{
    node: json,
    name: 'root',
    parentEl: wrapper
  }];

  while (stack.length > 0) {
    let current = stack.pop();
    let currentObj = current.node;
    let currentParentEl = current.parentEl;

    let level = document.createElement('div');

    level.classList.add('level');
    level.textContent = current.name + ': ';

    if (currentObj.renderContent) {
      // render custom html content
      currentObj.renderContent(level);
    } else if (!(currentObj instanceof Object)) {
      level.textContent += currentObj;
    }

    currentParentEl.append(level);

    if (currentObj instanceof Object) {
      let keys = Object.keys(currentObj);

      if (!currentObj.skipChildren) {
        // push in reverse to preserve key order
        for (let i = keys.length - 1; i >= 0; i--) {
          let key = keys[i];
          let node = currentObj[key];

          stack.push({
            node: node,
            name: key,
            parentEl: level
          });
        }
      }
    }
  }

  return wrapper;
}

// Example Use Case:
const Permissions = function Permissions() {
  this.skipChildren = true;
  this.view = false;
  this.edit = false;
  this.delete = false;
};
Permissions.prototype = {
  renderContent(el) {
    const fields = ['view', 'edit', 'delete'];

    for (let field of fields) {
      const label = document.createElement('label');
      label.textContent = field;

      const checkbox = document.createElement('input');
      checkbox.type = 'checkbox';
      checkbox.checked = this[field];

      label.appendChild(checkbox);
      el.appendChild(label);
    }
  }
};

const rendered = renderJSON({
  element1: {
    a: 4,
    b: 6,
    c: 24,
    element1a: {
      a: 'hello'
    }
  },
  element2: {
    a: 'abc',
    permissions: new Permissions()
  },
  element3: ["first", "second", "third"]
});

document.body.append(rendered);

.level {
  margin-left: 1em;
}

There's a lot of different ways you could branch off of this code depending on your needs. Since you're given a JSON string to begin with, you'll need to find some way to convert that into a Javascript object that will produce the result you want.