How can I raise Validation Error for a FileField - django

Question

I have a form field like this
class FeedForm(ModelForm):
files=form.FileField(validators=[validate_file_extension])
class Meta:
model=Feed
fields=('text','auth','files',)
with the validator used to allow specific file types:
validator.py
def validate_file_extension(value):
ext = os.path.splitext(value.name)[1] # [0] returns path+filename
valid_extensions = ['.pdf', '.doc', '.docx', '.jpg', '.png', '.xlsx', '.xls']
if not ext.lower() in valid_extensions:
raise ValidationError(u'Unsupported file extension.')
I want to raise the above Validation Error in my template,how can I go about it?
views.py that generate form:
def post_feed(request):
form_class = FeedForm
if request.method == 'POST':
form = form_class(request.POST,request.FILES)
if form.is_valid():
feed = form.save(commit=False)
feed.user = User.objects.get(pk=7)
feed.pub_date=timezone.now()
#instance = Feed(files=request.FILES['files'])
# feed.files=request.FILES['files']
feed.save()
return redirect('home')
else:
form = form_class()
concern='Concern'
feeds=Feed.objects.filter(pub_date__lte=timezone.now()).order_by('-pub_date')
paginator = Paginator(feeds,5) # Show 25 contacts per page
page = request.GET.get('page')
try:
feedz = paginator.page(page)
except PageNotAnInteger:
feedz = paginator.page(1)
except EmptyPage:
feedz = paginator.page(paginator.num_pages)
#return redirect('home')
return render_to_response('index.html', {"feeds":feeds,"feedz": feedz,'form':FeedForm(),'feed_detail':feed_detail,})
views that the form is on using an include tag:
def home(request):
concern='Concern'
feeds=Feed.objects.filter(pub_date__lte=timezone.now()).order_by('-pub_date')
paginator = Paginator(feeds,5) # Show 25 contacts per page
page = request.GET.get('page')
try:
feedz = paginator.page(page)
except PageNotAnInteger:
# If page is not an integer, deliver first page.
feedz = paginator.page(1)
except EmptyPage:
# If page is out of range (e.g. 9999), deliver last page of results.
feedz = paginator.page(paginator.num_pages)
return render_to_response('index.html', {"feeds":feeds,"feedz": feedz,'form':FeedForm(),'feed_detail':feed_detail,},context_instance=RequestContext(request))
html that generates the form:post_feed.html
<form role="form" action="{% url 'post_feed' %}" enctype="multipart/form-data" method="post">
{% csrf_token %}
<div class="mdl-textfield mdl-js-textfield ">
{{form.text}}
<label class="mdl-textfield__label" for="{{form.text.id_for_label}}">Cheated on?Blow the whistle here</label>
</div>
<div class="mdl-select mdl-js-select mdl-select--floating-label">
<label class="mdl-select__label" for="{{form.auth.id_for_label}}">Authority addressed to:<br/></label>
{{form.auth}}
</div><br/>
{{form.files}}
<br/> {{form.files2}}
<br/> {{form.files3}}
<br/><br/> <button class="mdl-button mdl-js-button mdl-js-ripple-effect mdl-button--raised mdl-button--colored">Post</button>
{% if form.errors %}
{% for field in form %}
{% for error in field.errors %}
<div class="alert alert-error">
<strong>{{error|escape}}</strong>
</div>
{% endfor %}
{% endfor %}
{% endif %}
</form>
The html that has the above form on using an include tag
{% include "post_feed.html" %}
<h2>Feed Stream</h2>
{% for feed in feedz %}
<strong> {{feed.full_name_of_poster|title}} </strong> |
{% if feed.resolved == True %}
RESOLVED
{% else %}
UNRESOLVED
{% endif %}
<p> To:{{feed.auth}} </p>
<p>{{feed.text}} </p>
Full details
<p id='count'> {{feed.total_concerns}} concern{{feed.total_concerns|pluralize:'s'}} &nbsp {{feed.no_of_comments}} comment{{feed.no_of_comments|pluralize:'s'}} </p>
<p> {{feed.pub_date|naturaltime|capfirst}} </p>
<hr/>
{% endfor %}
<div class="pagination">
<span class="step-links">
{% if feedz.has_previous %}
previous
{% endif %}
<span class="current">
Page {{ feedz.number }} of {{ feedz.paginator.num_pages }}.
</span>
{% if feedz.has_next %}
next
{% endif %}
</span>
</div>
{% endblock %}
I have gone through the docs but no breakthrough,Kindly help me out.Thanks in advance

Answer 1

The usual format for a function based view that handles a form is:
def post_feed(request):
form_class = FeedForm
if request.method == 'POST':
form = form_class(request.POST,request.FILES)
if form.is_valid():
# process the form then redirect
...
return redirect('home')
else:
# You don't actually need this else statement here
print form.errors
else:
# create blank form for GET requests
form = form_class()
# Now return a response for GET requests and invalid POST requests
concern='Concern'
feeds=Feed.objects.filter(pub_date__lte=timezone.now()).order_by('-pub_date')
return render(request , 'index.html' ,{'feeds':feeds,'form':FeedForm(),'feed_detail':feed_detail,})
So you just need to change the indentation at the end of the view, so that you return a response for invalid POST requests as well.
Django will automatically display any validation errors if you use {{ form }} in your template. If you render the fields individually, then see the docs for rendering fields manually for how to include errors manually.