title: No value of FormArray inside a Formgroup
body: <p>I have a form defined like this:</p>
  
  <pre><code>this.entityForm = this.fb.group({
          // Searching ID
          search: this.fb.group({
              procedures: '',
              areas: '',
              entities: '',
              versions: '',
          }),
          // Entity
          entity: this.fb.group({
              // Id
              name: '',
              version: '',
              // Data Source
              cobolFileName: '',
              cobolUri: '',
              hostDbUri: '',
              hostDbTable: '',    // Format (schema.table)
              wsUri: '',
              // Historice
              historicizeStrategy: '',
              pwx: '',
              // Rows
              rows: this.fb.array([this.newRow()])
          })
      });
  </code></pre>
  
  <p>When i do:</p>
  
  <pre><code>let a = this.entityForm.get('entity');
      let b = this.entityForm.get('entity.rows');
      console.log(a.value);
      console.log(b.value);
  </code></pre>
  
  <p>the answer is :</p>
  
  <pre><code>{
  cobolFileName: "NAME OF FILE"
  cobolUri: "mainframe"
  historicizeStrategy: "START_END_VALIDITY"
  hostDbTable: null
  hostDbUri: null
  name: "GRZ_PERS"
  pwx: false
  rows: Array(0)
  length: 0
  __proto__: Array(0)
  version: 1
  wsUri: null
  __proto__: Object
  }
  
  {
      0: {name: "Column_2", datatype: "INTEGER", defaultValue: "", key: false, masked: true, …}
      1: {name: "Column_1", datatype: "INTEGER", defaultValue: "", key: false, masked: true, …}
      length: 2
      __proto__: Array(0)
  }
  </code></pre>
  
  <p>I want to send a.value to the backend but for something the rows array is 0 length but the array is full how we can see in the second console.log?</p>
  
  <p>Thanks</p>