To pull a random record using Python Django’s ORM, we can use the first method with order_by.
For instance, we write
MyModel.objects.order_by('?').first()
to call order_by with '?' to return the MyModel objects in random order.
And then we call first to pick the first one.
To build multiple submit buttons in a Python Django form, we can render the buttons conditionally.
For instance, we write
if 'newsletter_sub' in request.POST:
# do subscribe
elif 'newsletter_unsub' in request.POST:
# do unsubscribe
to render one submit button if the newletter_sub key is in request.POST.
And we render another submit button if the newsletter_unsub key is in request.POST.
To add Multiple ModelAdmins/views for same model in Python Django admin, we can call register with different ModelAdmin and model classes.
For instance, we write
class PostAdmin(admin.ModelAdmin):
list_display = ('title', 'pubdate','user')
class MyPost(Post):
class Meta:
proxy = True
class MyPostAdmin(PostAdmin):
def get_queryset(self, request):
return self.model.objects.filter(user = request.user)
admin.site.register(Post, PostAdmin)
admin.site.register(MyPost, MyPostAdmin)
to call admin.site.register with the Post model and PostAdmin model admin classes.
And we call admin.site.register with the MyPost model and MyPostAdmin model admin classes.
To add CSS styling in Python Django forms, we can call attrs.update.
For instance, we write
class MyForm(forms.ModelForm):
class Meta:
model = MyModel
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
self.fields['myfield'].widget.attrs.update({'class': 'myfieldclass'})
to call attrs.update with a dict with the class key set to the class with the styles we want to apply on the myfield field.
To show form with error message if not valid with Python Django Forms, we can use form.errors to check for errors.
For instance, we write
{% if form.errors %}
{% for field in form %}
{% for error in field.errors %}
<div class="alert alert-danger">
<strong>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endfor %}
{% for error in form.non_field_errors %}
<div class="alert alert-danger">
<strong>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endif %}
to use form.errors in the if block to check for errors.
If there’re any errors, then we loop through the form errors and render the field.errors with a for loop.
And we render non-field errors by looping through form.non_field_errors with another for loop.