old_contents: from django.forms import ModelForm, CharField, Textarea
  
  from .models import Song
  from .utils import strip_whitespace_lines
  
  
  class AddSongForm(ModelForm):
      artist_txt = CharField(
              max_length=100,
              label='Artist',
              help_text='Surname Name format, required'
      )
  
      class Meta:
          model = Song
          fields = ['title', 'artist_txt', 'genre', 'video', 'tabs', 'content']
  
          widgets = {
              'content' : Textarea(attrs={'cols': 70, 'rows': 35}),
          }
  
          labels = {
              'title' : 'Title',
              'genre' : 'Genre',
              'video' : 'Video',
              'tabs' : 'Tabs',
              'content' : '',
          }
  
          help_texts = {
              'title' : 'required',
              'video' : 'Youtube etc.',
              'tabs' : 'does this version contain tabs?',
          }
  
          error_messages = {
              'content' : {
                  'required' : "Remember to include the song!"
              },
          }
  
      def clean(self):
          self.cleaned_data['content'] = strip_whitespace_lines(
                  self.cleaned_data['content'])
          return self.cleaned_data
  
new_contents: from django.forms import ModelForm, CharField, Textarea
  
  from .models import Song
  from .utils import strip_whitespace_lines
  
  
  class AddSongForm(ModelForm):
      artist_txt = CharField(
              max_length=100,
              label='Artist',
              help_text='Surname Name format, required'
      )
  
      class Meta:
          model = Song
          fields = ['title', 'artist_txt', 'genre', 'video', 'tabs', 'content']
  
          widgets = {
              'content' : Textarea(attrs={'cols': 70, 'rows': 35}),
          }
  
          labels = {
              'title' : 'Title',
              'genre' : 'Genre',
              'video' : 'Video',
              'tabs' : 'Tabs',
              'content' : '',
          }
  
          help_texts = {
              'title' : 'required',
              'video' : 'Youtube etc.',
              'tabs' : 'does this version contain tabs?',
          }
  
          error_messages = {
              'content' : {
                  'required' : "Remember to include the song!"
              },
          }
  
      def clean(self):
          if 'content' in self.cleaned_data:
              self.cleaned_data['content'] = strip_whitespace_lines(
                      self.cleaned_data['content'])
          return self.cleaned_data
  
subject: check if content exist before clean it