[Solved]-Create a hidden field in the admin site

The Django admin does not support hidden fields yet. There is an open ticket for that: https://code.djangoproject.com/ticket/11277

However, there are workarounds that don’t require jQuery. The admin forms are rendered using admin/includes/fieldset.html. If you override this template, you can inject a CSS class to denote the row for hiding:

<div class="form-row
    {% if line.fields|length_is:'1' and line.errors %} errors{% endif %}
    {% for field in line %} {{ field.field.name }}
      {% if field.field.is_hidden %} has-hidden-field{% endif %}  # add this part
    {% endfor %}">

this is actually a single line in the file, I’ve expanded it to make it more readable.

( Neat detail: for an StackedInline/TabularInline objects, you can specify the template as variable in Python code. )

Next, you can hide that row in your CSS:

.form-row.has-hidden-field {
    display: none;
}

Which you can load via your admin page:

{% block extrastyle %}{{ block.super }}
<link rel="stylesheet" type="text/css" href="{{ STATIC_URL }}mysite/admin.css" />{% endblock %}

or by using the media definition in the modeladmin:

class Media:
    css = {'all': ('mysite/admin.css',)

In the template, while displaying

{% for field in form.visible_fields %}
    {{ field.label_tag }} : {{ field }}
{% endfor %}

It will hide the hidden field labels.

I found it quite handy to use the ‘classes’ attribute in fieldsets to hide fields but still leave them in a request. In your model admin you can write

fieldsets = [
        ('Visible Fields', 
         {'fields': [('name', 'comment'),]}),
        ('Collapsable Fields', 
         {'fields': [('rare_property',)],'classes': ['collapse']}),
        ('Hidden Fields', 
         {'fields': [('magic_property',)],'classes': ['hidden']}),
            ]

You’re giving ModelForm in your example, not ModelAdmin you should be using for admin site.

Anyway, method of excluding some field is the same: specify it in exclude property:

class OutForm(ModelForm):
  class Meta:
    exclude = ["reply_to"]

or

class OutAdmin(ModelAdmin):
  exclude = ["reply_to"]

See Django documentation for details: http://docs.djangoproject.com/en/1.2/ref/contrib/admin/

Try adding label=”” to your ModelChoiceField to make the label an empty string:

reply_to = forms.ModelChoiceField(queryset=InMessages.objects.all(), label="", widget=forms.HiddenInput)

It seems that in Django 3.2 the HiddenInput widget is enough to hide the entire row from the form. I have tried this both via custom admin form and via the formfield_override property. The div with class "form-row" containing the hidden field gets additional class "hidden" and is not shown.