Django - Using context_processor - django

Question

I want to put a login form everywhere in my webpage so I added a context_processor and I included it in base.html file. The problem now is I cannot see the form.
Here is my context_processors.py:
def global_login_form(request):
if request.method == 'POST':
formLogin = LoginForm(data=request.POST)
if formLogin.is_valid():
from django.contrib.auth import login
login(request, formLogin.get_user())
...
else:
formLogin = LoginForm()
return {'formLogin': formLogin}
And here are the diferents htmls I tried in base.html trying to invoke the form:
<form action="/myapp/login/" method="post">
{% csrf_token %}
{{global_login_form}}
</form>
<form action="/myapp/login/" method="post">
{% csrf_token %}
{{global_login_form.as_p}}
</form>
<form action="/myapp/login/" method="post">
{% csrf_token %}
{{request.formLogin}}
</form>
first time I load the page, the context_process returns {'formLogin': formLogin} (cause formLogin is LoginForm()) but I cannot see the form while inspecting the html. It is not there... but I can see the csrf_token so I think I'm not invoking the context properly.
Just it case (maybe the order is incorrect), here is settings.py:
TEMPLATE_CONTEXT_PROCESSORS = (
"myapp.context_processors.global_login_form",
"django.core.context_processors.request",
"django.contrib.auth.context_processors.auth",
)
Any ideas?

Answer 1

I believe OP has incorrectly assumed that the template context variable is going to match the function name of the context processor.
OP's context processor global_login_form() injects formLogin to the template context. Therefore, in the templates the form should be referenced as, for example, {{ formLogin.as_p }}.

Answer 2

you must have the form variable in every views, or you should implement a templatetag instead. example:
https://docs.djangoproject.com/en/dev/howto/custom-template-tags/#writing-custom-template-tags
from django import template
from django.contrib.auth.forms import AuthenticationForm
register = template.Library()
#register.inclusion_tag('registration/login.html', takes_context=True)
def login(context):
"""
the login form
{% load login %}{% login %}
"""
request = context.get('request', None)
if not request:
return
if request.user.is_authenticated():
return dict(formLogin=AuthenticationForm())
return dict(user=request.user)

Answer 3

I want to use everywhere on my site gives a signal that you might need a template context processor.
def global_login_form(request):
next = request.GET.get('next', '/')
login_form = AuthenticationForm(initial={'next': next})
return {'login_form': login_form}
Having this and adding this context processor to TEMPLATE_CONTEXT_PROCESSORS section in settings you can use {{global_login_form}} in your templates.
Probably you'll have more or less something like this
....
<form action="{% url login_view_name %}" method="POST">
{{global_login_form.as_p}}
</form>
....
I used this pattern in one of my projects and it worked pretty fine. Only note here that in case if form is not validated it is better to display form in errors on separated page. Here's an example of the view:
def login(request):
if request.method == "POST":
login_form =LoginForm(data=request.POST)
if login_form.is_valid():
next = login_form.cleaned_data.get('next', '/')
login(request, login_form.get_user())
return HttpResponseRedirect(next)
return render_to_response(
'users/login/login_page.html',
{'form': login_form},
context_instance=RequestContext(request),
)

Answer 4

class MyForm(forms.Form):
username = forms.CharField(widget=forms.TextInput(attrs={'class':'login_text'}))
password = forms.CharField(widget=forms.TextInput(attrs={'class':'password_text'}))
This may be your solution. Css is passed as an attribute of the form field, so you don't need to explicitly declare it into your html.

Answer 5

Don't try to put in POST something that wasn't really POSTed. If you need to get some information to the templatetag, just use the context.

Answer 6

Finally I used a middleware to process the request, instead of using a context_processor. Also, I deleted my login view and I changed the form action to "." so the login functionality is in the middleware.
I followed this question to find the solution.