Django form - Calling is_valid() in a template -

i'm using django 1.5. have template multiple forms: 1 driver has many cars (inline forms). want display hint indicating section contains errors.

the template:

{% if driver_form.is_bound , not driver_form.is_valid %}     please correct errors in driver data. {% endif %} {% if car_form.is_bound , not car_form.is_valid %}     please correct errors in car data. {% endif %} 

the problem if first form invalid, second message pops well, though second form valid. noticed if put {{ car_form.is_valid }} 3 times in row, first time empty, next time (and following) true.

the original view:

if request.method == 'post':     driver_form = drivermodelform(request.post)     car_form_set = carinlineformset(request.post)  # wrong: no instance passed     if driver_form.is_valid():         driver = driver_form.save(commit=false)         car_form_set = carinlineformset(request.post, instance=driver)         if car_form_set.is_valid():             driver.save()             car_form_set.save() else:     driver_form = drivermodelform()     car_form_set = carinlineformset() return render(request, 'template.html', {     'driver_form': driver_form,     'car_form_set': car_form_set }) 

update:

it seems simplicity's sake left out details caused problem. lesson learned.

1. there javascript setting values on page load, while needed done on dropdown change. hiding erroneous values , causing form valid next time around.

2. there dependency: driver_form model form, , car_form_set inline form set based on instance driver_form adding.

the problem indeed in view, seddonym suggested: car_form_set not being initialized instance if driver_form invalid. is_valid() neither true nor false. conclusion: using is_valid() in template works fine.

the fixed view:

driver = driver() if request.method == 'post':     driver_form = drivermodelform(request.post, instance=driver)     if driver_form.is_valid():         driver = driver_form.save(commit=false)     car_form_set = carinlineformset(request.post, instance=driver)     if car_form_set.is_valid():         driver.save()         car_form_set.save() else:     driver_form = drivermodelform(instance=driver)     car_form_set = carinlineformset(instance=driver) return render(request, 'template.html', {     'driver_form': driver_form,     'car_form_set': car_form_set }) 

you don't need call form.is_valid, have been called view. instead, check errors:

{% if first_form.errors %}     please correct errors in first form. {% endif %} {% if second_form.errors %}     please correct errors in second form. {% endif %}