Static Model variable that determines which model fields are displayed in ListView

Question

I am trying to make a generic ListView view that can be populated by the model connected to it. Therefore I have inserted several static variables in my model that are used to populate the view. These are to the bottom of the model definition.

class AssignmentAd(models.Model):
    class StatChoices(models.TextChoices):
        REGISTERED = "Registered"
        PENDING = "Pending"
        CANCELED = "Canceled"

    class FieldChoices(models.TextChoices):
        JFS = "JFS"
        JAVA = "Java"
        CLOUD = "Cloud"

    # id = models.CharField(max_length=20)
    # contact_person = models.ForeignKey(Question, on_delete=models.CASCADE)
    status = models.CharField(max_length=20, choices=StatChoices.choices, default=StatChoices.PENDING)
    # period = models.DateTimeField('period')
    # broker
    deadline = models.DateField('Deadline')
    field = models.CharField(max_length=20, choices=FieldChoices.choices, default=FieldChoices.JFS)
    location = models.CharField(max_length=40)
    remote = models.IntegerField(
        default=0,
        validators=[
            MaxValueValidator(100),
            MinValueValidator(0)
        ]
     )
    # status_reason
    # url
    title = models.CharField(max_length=200)

    REQUIRED_FIELDS = ['status', 'period', 'title']

    # These static values are used to populate the ListView template
    LIST_HEADLINE = 'assignment ads'

    SINGLE_ITEM = 'assignment ad'

    LIST_COLTITLES = ['title', 'field', 'status', 'deadline', 'remote', 'location']

    LIST_COLDATA = [title, field, status, deadline, remote, location]

I am having my list column headlines populated by reading the LIST_COLTITLES field but I am unable to read the column data for each object. Here is my template and how I tried to do it by reading the LIST_COLDATA.

In the view I am importing everything into the context like so:

class TrackAssignmentAds(generic.ListView):
    model = AssignmentAd
    template_name = 'track/assignment_ads.html'
    context_object_name = 'model_objs'
    paginate_by = 5

    def get_context_data(self, **kwargs):
        context = super(TrackAssignmentAds, self).get_context_data(**kwargs)
        context['currentpage'] = 'assignment_ads'
        context['listheadline'] = TrackAssignmentAds.model.LIST_HEADLINE
        context['listsingleitem'] = TrackAssignmentAds.model.SINGLE_ITEM
        context['listcoltitles'] = TrackAssignmentAds.model.LIST_COLTITLES
        context['listcoldata'] = TrackAssignmentAds.model.LIST_COLDATA
        context['model_form'] = AssignmentAdForm()
        return context

    def post(self, request, *args, **kwargs):
        form = AssignmentAdForm(request.POST)
        if form.is_valid():
            form.save()
        else:
            messages.success(request, "Invalid form")
        return redirect('assignment_ads')

Then I am using these values from context in the template.


        
            
                
                    
                        
                            
                                
                                    {{ listheadline|title }}
                                
                            
                            
                                
                            
                        
                    
                    
                        

                        
                                {% for coltitle in listcoltitles %}
                                    
                                {% endfor %}
                                
                            {% for ad in model_objs %}
                            {% for data in listcoldata %}
                                
                                {% endfor %}
                                
                            {% endfor %}

                            
                            
                            
                                        {{ coltitle|upper }}
                                    
                                
                            
                            
                            
                                    {{ ad.data }}
                                
                                    
                                        
                                    
                                    
                                        ActionAnother
                                        actionSomething
                                        else here
                                        
                                        
                                        Seprated
                                            link
                                    
                                
                            
                            
                        
                    
                    
                    
                        
                            
                                
                                {{ page_obj.number }} of {{ page_obj.paginator.num_pages }}
                                
                            
                        
                    
                
            
        
        {% include 'track/snippets/footer.html' %}

Sorry for the chaos of above HTML. The bit that wont work is:

{% for ad in model_objs %}
  {% for data in listcoldata %}
    
      {{ ad.data }}
    
  {% endfor %}
{% endfor %}

I need to extract the fields of the model objects that are defined in the LIST_COLDATA static variable and insert them above where {{ ad.data }} iteratively.

Windfish · Answer

I had to make a custom tag https://docs.djangoproject.com/en/4.1/howto/custom-template-tags/

Like so:

from django import template


def getattribute(value, arg):
    """Returns a model object's field value based on string name arg"""
    if hasattr(value, str(arg)):
        return getattr(value, arg)


register = template.Library()
register.filter('getattribute', getattribute)

And then use it in the HTML template like so:

{% for ad in model_objs %}
{% for data in ad.LIST_COLDATA %}
{{ ad|getattribute:data }}
{% endfor %}
{% endfor %}

Where data is a LIST_COLDATA is a list of strings that indicates which fields should populate the list columns. The custom tag helps extract the specific field by reading the strings from the list.

Static Model variable that determines which model fields are displayed in ListView

1 Answers