validation - Django messages framework -

i'm looking add django messages in form in order display success message if form validated , error message if form not validated (missing field, data type error, ...)

my error message works well, don't overcome display success message in next template when form valid.

this view :

def birthcertificate_form_unique_number(request) :  validity = [] submission = [] #user fill fields query_social_number = request.get.get('social_number') query_social_number_father = request.get.get('social_number_father') query_social_number_mother = request.get.get('social_number_mother')  success = false  if request.method == 'post':      form = birthcertificateform2(request.post or none)      if form.is_valid() :   # vérification sur la validité des données         post = form.save()         messages.success(request, 'le formulaire été enregistré !')         return httpresponseredirect(reverse('bc_treated2', args=(messages,),kwargs={'id': post.id}))      else:         messages.error(request, "le formulaire est invalide !")  elif request.method == 'get':      form = birthcertificateform2()      parent1 = person.objects.filter(social_number=query_social_number_father)     parent2 = person.objects.filter(social_number=query_social_number_mother)      if query_social_number :         if person.objects.filter(social_number = query_social_number).exists() == true :              individu = get_object_or_404(person, social_number = query_social_number)             messages.success(request, 'le numéro unique existe !')              form.fields['fk_parent1'].queryset = parent1             form.fields['fk_parent2'].queryset = parent2             form.fields['lastname'].initial = individu.lastname             form.fields['firstname'].initial = individu.firstname             form.fields['birthday'].initial = individu.birthday             form.fields['birthcity'].initial = individu.birthcity             form.fields['birthcountry'].initial = individu.birthcountry             form.fields['sex'].initial = individu.sex             form.fields['social_number'].initial = individu.social_number          elif person.objects.filter(social_number = query_social_number).exists() == false :              validity = false             messages.error(request, "le numéro unique est invalide !")   context = {     "form" : form,     "validity" : validity,     "submission" : submission  }  return render(request, 'bc_form2.html', context) 

and in html template :

{% message in messages %}     <div class="alert {{ message.tags }} alert-dismissible" role="alert">         <button type="button" class="close" data-dismiss="alert" aria-label="close">             <span aria-hidden="true">&times;</span>         </button>         {{ message }}     </div> {% endfor %} 

how display success message when form valid ?

edit :

my urls.py file :

from django.conf.urls import url . import views  urlpatterns = [     url(r'^bc_accueil$', views.birthcertificate_home, name="bchome"),     url(r'^formulaire$', views.birthcertificate_form, name = "bcform"),     url(r'^formulaire2$', views.birthcertificate_form_unique_number, name = "bcform2"),     url(r'^formulaire_traite/(?p<id>\d+)/$', views.birthcertificate_resume, name="bc_treated"),     url(r'^formulaire2_traite/(?p<id>\d+)/$', views.birthcertificate_resume_unique_number, name="bc_treated2"),     url(r'^birthcertificate_pdf/(?p<id>\d+)/$', views.birthcertificate_pdf, name="pdf"),     url(r'^not_found$', views.birthcertificate_notfound, name="bcnotfound"), ] 

you need know 1 thing that, messages execute once. why did do

args=(messages, ) 

you can access messages in bc_treated2 without passing args