title: How to create a reactive formgroup based on any object
body: <p>I need to construct a formgroup based on any object(from api). Is it possible to assign that object directly to the formgroup?</p>
  
  <p><strong>For example this is the object,</strong></p>
  
  <pre><code>parent: 'All', value: 1, children: [
              {
                  parent: 'Programming', value: 91, children: [
                      {
                          parent: 'Frontend', value: 911, children: [
                              { parent: 'Angular 1', value: 9111 },
                              { parent: 'Angular 2', value: 9112 },
                              { parent: 'ReactJS', value: 9113, disabled: true }
                          ]
                      }, 
                      {
                          parent: 'Backend', value: 912, children: [
                              { parent: 'C#', value: 9121 },
                              { parent: 'Java', value: 9122 },
                              { parent: 'Python', value: 9123, checked: false, disabled: true }
                          ]
                      }
                  ]
              },
              {
                  parent: 'Networking', value: 92, children: [
                      { parent: 'Internet', value: 921 },
                      { parent: 'Security', value: 922 }
                  ]
              }
          ]
      }
  </code></pre>
  
  <p><strong>Finally the desired formgroup should be like this,</strong></p>
  
  <pre><code>form: {
    "username": "",
    "password": "",
    "treeView": {
      "All": null,
      "children": [
        "programming": "",
        "children": ["Angular 1": "","Angular 2": "", "ReactJS": "" ]   
       ]
    }
  }
  </code></pre>