title: How to hide a field in django modelform?
body: <p>For example:</p>
  
  <pre><code>class TestModel(models.Model):
      ref1 = models.ForeignKey(RefModel)
      text1 = models.TextField()
  
  class TestModelForm(ModelForm):
      class Meta:
          model = TestModel
          fields = ('text1')
  </code></pre>
  
  <p>I only allow the user to input <strong>text1</strong> field, but when I redefine the <em>post method</em> of my view, I also want to set the <strong>ref1</strong> value, how should I do that?</p>
  
  <p>I wish I can let TestModelForm has the ref1 field but don't let user modify it, then I can modify the value of request.POSt in post method, and pass it to TestModelForm, is that possible?</p>