title: Django rest framework: how to change default widget of a ModelSerializer renderer with HTMLFormRenderer?
body: <p>I want to change the default widget of a ModelSerializer field renderered with the HTMLFormRenderer. The field default representation is a ChoiceField as it is a ForeignKey field in the model. I Would like to render it as a CharField.</p>
  
  <p>I have tried to redefine the field in the serializer: </p>
  
  <pre><code>myField = serializers.CharField()
  </code></pre>
  
  <p>It is shown correctly as a textbox in the form but when saving the form I receive an error saying that it cannot assign the value because it must be an instance of the related model.</p>
  
  <p>How can I do that?</p>