Django login form not keeping input after bad submit - html

Question

I have a login form and if a user enters an invalid username or password, the page refreshes and removes the Username value they entered. I would like it so that the username field doesn't empty on failed submit.
views.py
def login_page(request):
if request.user.is_authenticated:
return redirect('dashboard:dashboard')
elif request.method == 'POST':
username = request.POST.get('username')
password = request.POST.get('password')
user = authenticate(request, username=username, password=password)
if user is not None:
login(request, user)
return redirect('dashboard:dashboard')
else:
messages.info(request, 'Username or Password is invalid.')
return render(request, 'main/login.html', {})
login.html:
<form id="login-form" action="" method="post" role="form">
{% csrf_token %}
<div class="form-group">
<input type="text" name="username" id="username" tabindex="1" class="form-control" placeholder="Username" value="">
</div>
<div class="form-group">
<input type="password" name="password" id="password" tabindex="2" class="form-control" placeholder="Password">
</div>
<div class="form-group">
<div class="row">
<div class="col-sm-6 center" style="border-radius: 16px;">
<input type="submit" name="login-submit" id="login-submit" tabindex="5" class="form-control btn btn-login" value="Login">
</div>
</div>
</div>
<div class="form-group">
<div class="row">
<div class="col-lg-12">
<div class="center">
Forgot Password?
</div>
</div>
</div>
</div>
</form>

Answer 1

It's all about passing the username in the context.
try this:
views.py
def login_page(request):
context = {}
if request.user.is_authenticated:
return redirect('dashboard:dashboard')
elif request.method == 'POST':
username = request.POST.get('username')
password = request.POST.get('password')
user = authenticate(request, username=username, password=password)
if user is not None:
login(request, user)
return redirect('dashboard:dashboard')
else:
context["username"] = username
messages.info(request, 'Username or Password is invalid.')
return render(request, 'main/login.html', context)
login.html:
...
<input type="text" name="username" id="username" tabindex="1" class="form-control" placeholder="Username" value="{{ username }}">
...