title: Angular: FormControl valueChanges Observable triggers for all changes
body: <p>FormControl <code>valueChanges</code> Observable works like how it should be. In my case, I need to stop triggering <code>valueChanges</code> for all previous changes in input field except the current value. I have been trying with following code to do that -</p>
  
  <pre><code>private getAutocompleteSuggestions(input){
      return this.SS.searchProducts(parseInt(this.filter), '', input);
  }
  
  
  private searchSuggestionsAPIRequest(input){
      this.queryField.valueChanges
          .debounceTime(1000)
          .distinctUntilChanged()
          .switchMap((input) =&gt;  this.getAutocompleteSuggestions(input))
          .subscribe( res =&gt; {
            // The res is triggered for all value changes in 
            // queryField formcontrol
  
            // Tried with following solution to stop emit previous 
            // changes but it does not work
  
            this.queryField.setValue(input, { emitEvent: false });
  
      });
  } 
  </code></pre>
  
  <p>I have been searching for all possible ways to stop emit previous values, but got this solution -</p>
  
  <pre><code>this.queryField.setValue(input, { emitEvent: false });
  </code></pre>
  
  <p>I think, I am missing something there. It would be great if there is any further solution or documentation.</p>
  
  <p>Thanks in advance.</p>