Wagtail base page with common fields

models.py

  from django.db import models
  from wagtail.wagtailcore.models import Page
  from wagtail.wagtailcore.fields import RichTextField
  from wagtail.wagtailadmin.edit_handlers import FieldPanel, MultiFieldPanel
  from wagtail.wagtailimages.edit_handlers import ImageChooserPanel
  

  class BaseFieldsMixin(models.Model):                                                                                                                                                                                                        
      header_title = models.CharField(max_length=512, blank=True)                                                                                                                                                                             
      header_slogan = models.CharField(max_length=512, blank=True)                                                                                                                                                                            
      header_img = models.ForeignKey(                                                                                                                                                                                                         
          'wagtailimages.Image',                                                                                                                                                                                                              
          null=True,                                                                                                                                                                                                                          
          blank=True,                                                                                                                                                                                                                         
          on_delete=models.SET_NULL,                                                                                                                                                                                                          
          related_name='+'                                                                                                                                                                                                                    
      )                                                                                                                                                                                                                                       
      hide_navigation = models.BooleanField(default=False)                                                                                                                                                                                    
      footer_text = RichTextField(blank=True)                                                                                                                                                                                                 
                                                                                                                                                                                                                                              
      settings_panels = [                                                                                                                                                                                                                     
          MultiFieldPanel([                                                                                                                                                                                                                   
              FieldPanel('hide_navigation'),                                                                                                                                                                                                  
          ] + Page.settings_panels, "Page settings"),                                                                                                                                                                                         
      ]                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                              
      content_panels = [                                                                                                                                                                                                                      
          MultiFieldPanel(                                                                                                                                                                                                                    
              [                                                                                                                                                                                                                               
                  FieldPanel('header_title', classname="full"),                                                                                                                                                                               
                  FieldPanel('header_slogan', classname="full"),                                                                                                                                                                              
                  ImageChooserPanel('header_img'),                                                                                                                                                                                            
              ],                                                                                                                                                                                                                              
              heading='Header elements', classname="collapsible collapsed"                                                                                                                                                                    
          ),                                                                                                                                                                                                                                  
          MultiFieldPanel(                                                                                                                                                                                                                    
              [                                                                                                                                                                                                                               
                  FieldPanel('footer_text', classname="full"),                                                                                                                                                                                
              ],                                                                                                                                                                                                                              
              heading='Footer elements', classname="collapsible collapsed"                                                                                                                                                                    
          ),                                                                                                                                                                                                                                  
          FieldPanel('title', classname="full title"),                                                                                                                                                                                        
                                                                                                                                                                                                                                              
      ]                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                              
      class Meta:                                                                                                                                                                                                                             
          abstract = True                                                                                                                                                                                                                     
                                                                                                                                                                                                                                              
                                                                                                                                                                                                                                              
  class UniversalStreamPage(Page, BaseFieldsMixin):                                                                                                                                                                                           
      # page specific fields
      settings_panels = BaseFieldsMixin.settings_panels                                                                                                                                                                                       
      content_panels = BaseFieldsMixin.content_panels + [
        # page specific fields
      ]