In Django forms, it can check whether the form is valid:
if form.is_valid():
return HttpResponseRedirect('/thanks/')
But I'm missing what to do if it isn't valid? How do I return the form with the error messages? I'm not seeing the "else" in any of the examples.
If you render the same view when the form is not valid then in template you can access the form errors using form.errors.
{% if form.errors %}
{% for field in form %}
{% for error in field.errors %}
<div class="alert alert-danger">
<strong>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endfor %}
{% for error in form.non_field_errors %}
<div class="alert alert-danger">
<strong>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endif %}
An example:
def myView(request):
form = myForm(request.POST or None, request.FILES or None)
if request.method == 'POST':
if form.is_valid():
return HttpResponseRedirect('/thanks/')
return render(request, 'my_template.html', {'form': form})
views.py
from django.contrib import messages
def view_name(request):
if request.method == 'POST':
form = form_class(request.POST)
if form.is_valid():
return HttpResponseRedirect('/thanks'/)
else:
messages.error(request, "Error")
return render(request, 'page.html', {'form':form_class()})
If you want to show the errors of the form other than that not valid just put {{form.as_p}} like what I did below
page.html
<html>
<head>
<script>
{% if messages %}
{% for message in messages %}
alert('{{message}}')
{% endfor %}
{% endif %}
</script>
</head>
<body>
{{form.as_p}}
</body>
</html>
UPDATE:
Added a more detailed description of the formset errors.
Form.errors combines all field and non_field_errors. Therefore you can simplify the html to this:
template
{% load form_tags %}
{% if form.errors %}
<div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
<div id="form_errors">
{% for key, value in form.errors.items %}
<span class="fieldWrapper">
{{ key }}:{{ value }}
</span>
{% endfor %}
</div>
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
{% endif %}
If you want to generalise it you can create a list_errors.html which you include in every form template. It handles form and formset errors:
{% if form.errors %}
<div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
<div id="form_errors">
{% for key, value in form.errors.items %}
<span class="fieldWrapper">
{{ key }}:{{ value }}
</span>
{% endfor %}
</div>
<button type="button" class="close" data-dismiss="alert" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
{% elif formset.total_error_count %}
<div class="alert alert-danger alert-dismissible col-12 mx-1" role="alert">
<div id="form_errors">
{% if formset.non_form_errors %}
{{ formset.non_form_errors }}
{% endif %}
{% for form in formset.forms %}
{% if form.errors %}
Form number {{ forloop.counter }}:
<ul class="errorlist">
{% for key, error in form.errors.items %}
<li>{{form.fields|get_label:key}}
<ul class="errorlist">
<li>{{error}}</li>
</ul>
</li>
{% endfor %}
</ul>
{% endif %}
{% endfor %}
</div>
</div>
{% endif %}
form_tags.py
from django import template
register = template.Library()
def get_label(a_dict, key):
return getattr(a_dict.get(key), 'label', 'No label')
register.filter("get_label", get_label)
One caveat: In contrast to forms Formset.errors does not include non_field_errors.
def some_view(request):
if request.method == 'POST':
form = SomeForm(request.POST)
if form.is_valid():
return HttpResponseRedirect('/thanks'/)
else:
form = SomeForm()
return render(request, 'some_form.html', {'form': form})
This answer is correct but has a problem: fields not defined.
If you have more then one field, you can not recognize which one has error.
with this change you can display field name:
{% if form.errors %}
{% for field in form %}
{% for error in field.errors %}
<div class="alert alert-danger">
<strong>{{ field.label }}</strong><span>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endfor %}
{% for error in form.non_field_errors %}
<div class="alert alert-danger">
<strong>{{ error|escape }}</strong>
</div>
{% endfor %}
{% endif %}
#AamirAdnan's answer missing field.label; the other way to show the errors in few lines.
{% if form.errors %}
<!-- Error messaging -->
<div id="errors">
<div class="inner">
<p>There were some errors in the information you entered. Please correct the following:</p>
<ul>
{% for field in form %}
{% if field.errors %}<li>{{ field.label }}: {{ field.errors|striptags }}</li>{% endif %}
{% endfor %}
</ul>
</div>
</div>
<!-- /Error messaging -->
{% endif %}
simply you can do like this because when you initialized the form in contains form data and invalid data as well:
def some_func(request):
form = MyForm(request.POST)
if form.is_valid():
//other stuff
return render(request,template_name,{'form':form})
if will raise the error in the template if have any but the form data will still remain as :
error_demo_here
You can put simply a flag variable, in this case is_successed.
def preorder_view(request, pk, template_name='preorders/preorder_form.html'):
is_successed=0
formset = PreorderHasProductsForm(request.POST)
client= get_object_or_404(Client, pk=pk)
if request.method=='POST':
#populate the form with data from the request
# formset = PreorderHasProductsForm(request.POST)
if formset.is_valid():
is_successed=1
preorder_date=formset.cleaned_data['preorder_date']
product=formset.cleaned_data['preorder_has_products']
return render(request, template_name, {'preorder_date':preorder_date,'product':product,'is_successed':is_successed,'formset':formset})
return render(request, template_name, {'object':client,'formset':formset})
afterwards in your template you can just put the code below
{%if is_successed == 1 %}
<h1>{{preorder_date}}</h1>
<h2> {{product}}</h2>
{%endif %}
Related
The form does not show any errors when i try to submit it, it just reload the sign up page even though there are errors in my input, i used an if statement to see there are errors and the for loop to display each error but they do not seem to be working. what am i doing wrong and how can i solve it?
main.py
from flask import Flask, render_template, request
from flask_wtf import FlaskForm
from wtforms.fields import StringField, EmailField, PasswordField, SubmitField, TextAreaField, BooleanField
from wtforms.validators import Length, DataRequired, Email, EqualTo, Optional
class SignUp(FlaskForm):
username = StringField(label="username", validators=[Length(min=5, max=20), DataRequired(message="enter a name")])
first_name = StringField(label="first name", validators=[Length(min=5, max=20), DataRequired()])
last_name = StringField(label="last name", validators=[Length(min=5, max=20), DataRequired()])
email = EmailField(label="email", validators=[DataRequired(), Length(min=6)])
password = PasswordField(label="password", validators=[Length(min=8, max=40), DataRequired()])
confirm_password = PasswordField(label="confirm password", validators=[EqualTo(password), DataRequired()])
message = TextAreaField(label="message", validators=[Length(min=10, max=120), Optional()])
agree = BooleanField(label="I agree to the terms and conditions")
submit = SubmitField(label="Sign Up")
app = Flask(__name__)
app.config["SECRET_KEY"] = "uhr78hv98n4n8y7b6em98x8794c87x3m98xtmmsce9n8ce"
#app.route("/")
#app.route("/home")
def home():
return render_template("index.html")
#app.route("/signup", methods=["POST", "GET"])
#app.route("/register", methods=["POST", "GET"])
def sign_up():
form = SignUp()
if request.method == "POST":
if form.validate_on_submit():
pass
return render_template("signup.html", form=form)
if __name__ == "__main__":
app.run(debug=True)
signup.html
{% extends "base.html" %} {% block head %}
<title>Sign UP</title>
{% endblock head %} {% block body %}
<h1>Sign Up</h1>
<form method="POST" action="{{ url_for('sign_up') }}" novalidate>
{{ form.csrf_token }}
<div class="field">
{{ form.username.label }} {{ form.username }} {% if form.username.errors %}
{% for error in form.username.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.first_name.label }} {{ form.first_name }} {% if
form.first_name.errors %} {% for error in form.first_name.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.last_name.label }} {{ form.last_name }} {% if form.last_name.errors
%} {% for error in form.last_name.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.email.label }} {{ form.email }} {% if form.email.errors %} {% for
error in form.email.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.password.label }} {{ form.password }} {% if form.password.errors %}
{% for error in form.password.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.confirm_password.label }} {{ form.confirm_password }} {% if
form.confirm_password.errors %} {% for error in form.confirm_password.error
%}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
<div class="field">
{{ form.message.label }} {{ form.message }} {% if form.message.errors %} {%
for error in form.message.error %}
<p style="color: red">{{ error }}</p>
{% endfor %} {% endif %}
</div>
{{ form.agree }} <br />
{{ form.submit }}
</form>
{% endblock body %}
I have been working on a website for the past while using flask, python and bootstrap. I added footer to my website and I would like a "contact me" form in the footer. Below is my current code for creating a contact form and displaying this form.
class ContactForm(FlaskForm):
email = StringField("", validators=[DataRequired(), Email()])
content = TextAreaField("", validators=[DataRequired(), length(min=2, max=500)])
submit = SubmitField("Submit")
<form method="POST" action="">
<div class="form-group">
{{ form.email.label(class="form-control-label") }}
{% if form.email.errors %}
{{ form.email(class="form-control form-control-lg is-invalid") }}
<div class="invalid-feedback">
{% for error in form.email.errors %}
<span>{{ error }}</span>
{% endfor %}
</div>
{% else %}
{{ form.email(class="form-control form-control-lg") }}
{% endif %}
</div>
<div class="form-group">
{{ form.content.label(class="form-control-label") }}
{% if form.content.errors %}
{{ form.content(class="form-control form-control-lg is-invalid") }}
<div class="invalid-feedback">
{% for error in form.content.errors %}
<span>{{ error }}</span>
{% endfor %}
</div>
{% else %}
{{ form.content(class="form-control form-control-lg") }}
{% endif %}
</div>
<div class="form-group">
{{ form.submit(class="btn btn-outline-info") }}
</div>
</form>
I created this footer in my "layout.html" file which is the base file that all other html documents extend from so that all pages will have this same footer.
The issue is that then I need to create and instance of this form object on every page of my application and handle the validate_on_submit on every page. (Sample code below)
#app.route("/random_page", methods=["GET", "POST"])
def random_page():
form = ContactForm()
if form.validate_on_submit():
# code to send the email goes here
return render_template("random_page")
I am looking for an easier way to do this so that I don't need to repeat code on every page and so that It can be considerably simpler. I am not very experienced with flask and would highly appreciate the help.
Use the #app.context_processor decorator, documentation to inject an instance of your contact form into the template context for all templates. For example:
#app.context_processor
def inject():
return dict(
contact_form=ContactForm(),
)
Then re-write the form's HTML to use the contact_form template variable, also adding in an appropriate action route.
<form method="POST" action="{{url_for('contact')}}">
<div class="form-group">
{{ contact_form.email.label(class="form-control-label") }}
{% if contact_form.email.errors %}
{{ contact_form.email(class="form-control form-control-lg is-invalid") }}
<div class="invalid-feedback">
{% for error in form.email.errors %}
<span>{{ error }}</span>
{% endfor %}
</div>
{% else %}
{{ contact_form.email(class="form-control form-control-lg") }}
{% endif %}
</div>
<div class="form-group">
{{ contact_form.content.label(class="form-control-label") }}
{% if contact_form.content.errors %}
{{ contact_form.content(class="form-control form-control-lg is-invalid") }}
<div class="invalid-feedback">
{% for error in contact_form.content.errors %}
<span>{{ error }}</span>
{% endfor %}
</div>
{% else %}
{{ contact_form.content(class="form-control form-control-lg") }}
{% endif %}
</div>
<div class="form-group">
{{ contact_form.submit(class="btn btn-outline-info") }}
</div>
</form>
Then add a route to solely handle this form's postback:
#app.route("/contact", methods=["POST"])
def contact():
form = ContactForm()
if form.validate_on_submit():
# code to send the email goes here
# blah blah
I have designed a form to update a task. The form will get the details of the task into the update form and while submitting that form the form.validate_on_submit does not work and redirects again to the same form with the previous values. Here are my routes and template code. I have used {{ form.csrf_token }}. But similar logic works with the newTask route.
Update Route
#main.route('/update/<int:id>',methods=['POST','GET'])
#login_required
def update(id):
if form.validate_on_submit():
t.task_name = form.task_name.data
t.assignee = form.assignee.data
t.deal_size = form.deal_size.data
t.lead_status = form.lead_status.data
t.stage = form.stage.data
t.priority = form.priority.data
t.submission_date = form.date.data
db.session.add(t)
db.session.commit()
return redirect('/')
form = NewTaskForm()
t = Tasks.query.get_or_404(id)
return render_template("update.html",form = form , t = t)
update.html
<form method="POST" action="/update/{{ t.id }}">
{{ form.csrf_token }}
<div class="form-group">
{{ form.task_name.label }}{{ form.task_name(class='form-control',value = t.task_name ) }}
{% if form.task_name.errors %}
{% for error in form.task_name.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
<div class="form-group">
{{ form.assignee.label }}{{ form.assignee(class='form-control',value = t.assignee) }}
{% if form.assignee.errors %}
{% for error in form.assignee.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
<div class="form-group">
{{ form.deal_size.label }}{{ form.deal_size(class='form-control',value = t.deal_size) }}
{% if form.deal_size.errors %}
{% for error in form.deal_size.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
<div class="form-group">
{{ form.lead_status.label }}{{ form.lead_status(class='form-control',value = t.lead_status) }}
{% if form.lead_status.errors %}
{% for error in form.lead_status.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
<div class="form-check padding-none">
{{ form.stage.label(class='form-check-label') }}{{ form.stage(class='form-check-input customRadio',value = t.stage.data) }}
{% if form.stage.errors %}
{% for error in form.stage.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
<div class="form-group">
{{ form.date.label }}{{ form.date(class='form-control',value = t.submission_date.date()) }}
{% if form.date.errors %}
{% for error in form.date.errors %}
<div class="alert alert-danger" role="alert">
{{ error }}
</div>
{% endfor %}
{% endif %}
</div>
{{ form.submit(class="btn btn-outline-primary btn-block") }}
</form>
newTask route
#main.route('/new-task',methods=['POST','GET'])
#login_required
def newTask():
form = NewTaskForm()
if form.validate_on_submit():
t = Tasks()
t.task_name = form.task_name.data
t.assignee = form.assignee.data
t.deal_size = form.deal_size.data
t.lead_status = form.lead_status.data
t.stage = form.stage.data
t.priority = form.priority.data
t.submission_date = form.date.data
db.session.add(t)
db.session.commit()
return redirect('/')
return render_template("newtask.html",form = form)
If you want to redirect the user to the new form use:
#main.route('/update/<int:id>',methods=['POST','GET'])
#login_required
def update(id):
if form.validate_on_submit():
# do something and then redirect
return redirect(url_for('confirm'))
return render_template("update.html",form = form , t = t)
Probably, you need to create a new function for the 'confirmation site' if you haven't done already.
You can look up the flask documentation if you want to have a better understanding of
url_for :
It accepts the name of the function as its first argument and any number of keyword arguments, each corresponding to a variable part of the URL rule. Unknown variable parts are appended to the URL as query parameters.
Here you can find a good explanation as well:
create-dynamic-urls-in-flask
I needed some validation on a Django ModelForm field. So I changed 2 lines in my models.py (just below). The validation is blocking as necessary, but I can't find the proper way to display the ValidationError. Maybe there is a cleaner way to do this in the model form ?
models.py
class Lexicon(models.Model):
[...]
alphanumeric = RegexValidator(r'^[0-9a-zA-Z]*$', _('Only alphanumeric characters are allowed'))
filename = models.CharField(_("Filename"), max_length=40, validators=[alphanumeric])
forms.py
class LexiconForm(forms.ModelForm):
class Meta:
model = Lexicon
fields = ['filename', 'language', 'comment', 'alphabet', 'case_sensitive', 'diacritics']
views.py
#login_required
def new_pls_view(request):
if request.method == 'POST':
form = LexiconForm(request.POST)
if form.is_valid():
obj = form.save(commit=False)
obj.user = request.user
obj.save()
return redirect('pls_edit')
else:
form = LexiconForm()
return render(request, 'main/new_pls.html', {
'form': form,
})
template.html
<form class="form-horizontal" method="post" action="{% url 'new_pls' %}">
{% csrf_token %}
{% if form.non_field_errors %}
<div class="alert alert-danger" role="alert">
{% for error in form.non_field_errors %}
{{ error }}
{% endfor %}
</div>
{% endif %}
[...]
{% if form.is_bound %}
{% if form.filename.errors %}
{% for error in form.filename.errors %}
<div class="invalid-feedback">
{{ error }}
</div>
{% endfor %}
{% endif %}
{% if form.filename.help_text %}
<small class="form-text text-muted">{{ form.filename.help_text }}</small>
{% endif %}
{% endif %}
{% render_field form.filename type="text" class+="form-control" id="plsFilename" placeholder=form.filename.label %}
Replacing my entire form by {{ form }} as #Alasdair suggested is working, so I guess something is wrong with my template rendering.
I've simply replaced my error printing by this and the error prints!
<form class="form-horizontal" method="post" action="{% url 'new_pls' %}">
{% csrf_token %}
{{ form.non_field_errors }}
[...]
{{ form.filename.errors }}
{% render_field form.filename type="text" class+="form-control" id="plsFilename" placeholder=form.filename.label %}
I got a question regarding the validation of a dynamically added inline formset in Django. It seems like I am missing something in my implementation.
Here is my case:
My project is a team management platform. A team is called Crew and can have several time Schedules. Each Schedule can have several Shifts. Please take a look at my code. At the moment I am able to create a schedule with several, dynamically added forms of the formset for the Shifts, if all fields are valid.
If not, the error for the Shift forms is not displayed and it is filled with the initial data again. It looks like the data of the shift forms is not bound after sending the POST request (because form.is_bound() is false). Moreover the data of Shift forms is not populated again after the POST request.
What do you think is the cause of this behaviour? Do I have to overwrite the is_valid function? I dont know, because it looks like the function works fine - the data is just not bound correctly to the new forms.
Views.py
def schedule_add(request, crew_id):
if request.method == "GET":
form = ScheduleForm()
ShiftFormSet = formset_factory(ShiftForm)
return render(request, 'schedule_add2.html', {'form': form, 'formset': ShiftFormSet, 'title':"Zeitplan hinzufügen"})
elif request.method == "POST":
form = ScheduleForm(request.POST)
numberOfShifts = int(request.POST['form-TOTAL_FORMS'])
ShiftFormSet = formset_factory(ShiftForm, extra=numberOfShifts)
shift_formset = ShiftFormSet(request.POST, prefix='form')
print(request.POST)
if form.is_valid() and shift_formset.is_valid():
schedule = Schedule()
schedule.name = form.cleaned_data.get('name')
schedule.crew = Crew.objects.get(pk=crew_id)
schedule.location = form.cleaned_data.get('location')
schedule.subperiod = form.cleaned_data.get('sub_period')
schedule.save()
for shift_form in shift_formset:
if shift_form.is_valid():
shift = Shift()
shift.min_user_count = shift_form.cleaned_data.get('min_user_count')
shift.max_user_count = shift_form.cleaned_data.get('max_user_count')
shift.start_datetime = shift_form.cleaned_data.get('start_time')
shift.end_datetime = shift_form.cleaned_data.get('end_time')
shift.schedule = schedule
shift.save()
messages.success(request, 'Zeitplan & Schichten angelegt.')
return redirect('shifter:crew_view', crew_id=crew_id)
else:
messages.error(request, 'Fehler')
return render(request, 'schedule_add2.html', {'form': form, 'formset': ShiftFormSet, 'title':"Zeitplan hinzufügen"})
else:
return redirect('shifter:index')
forms.py
class ScheduleForm(forms.ModelForm):
name = forms.CharField(max_length=30, required=True, help_text='', label="Name")
sub_period = forms.ModelChoiceField(queryset=SubPeriod.objects.all(), empty_label=None, label="Tag")
location = forms.ModelChoiceField(queryset=Location.objects.all(), empty_label=None, label="Einsatzort")
class Meta:
model = Schedule
fields = ('name', 'sub_period', 'location',)
class ShiftForm(forms.ModelForm):
min_user_count = forms.IntegerField(required=True, help_text='', label="Min Count", initial=2)
max_user_count = forms.IntegerField(required=True, help_text='', label="Max Count", initial=4)
start_time = forms.DateTimeField(required=True, help_text='', label="Shift start", initial=datetime.now)
end_time = forms.DateTimeField(required=True, help_text='', label="Shift end", initial=datetime.now)
class Meta:
model = Shift
fields = ('start_time','end_time','min_user_count','max_user_count',)
Template
<form method="post">
{% csrf_token %}
{% if form.non_field_errors %}
<div class="alert alert-danger" role="alert">
{% for error in form.non_field_errors %}
{{ error }}
{% endfor %}
</div>
{% endif %}
{% for field in form.visible_fields %}
{{ field.label_tag }}
{% if form.is_bound %}
{% if field.errors %}
{% render_field field class="form-control is-invalid" %}
{% for error in field.errors %}
<div class="invalid-feedback">
{{ error }}
</div>
{% endfor %}
{% else %}
{% render_field field class="form-control is-valid" %}
{% endif %}
{% else %}
{% render_field field class="form-control" %}
{% endif %}
{% if field.help_text %}
<small class="form-text text-muted">{{ field.help_text }}</small>
{% endif %}
{% endfor %}
<h2 class="mt-5">Shifts</h2>
<table class="table">
{{ formset.management_form }}
{% for form in formset.forms %}
{% if forloop.first %}
<thead>
<tr>
{% for field in form.visible_fields %}
<th>{{ field.label|capfirst }}</th>
{% endfor %}
<th></th>
</tr>
</thead>
{% endif %}
<tr class="formset_row">
{% for field in form.visible_fields %}
<td>
{# Include the hidden fields in the form #}
{% if forloop.first %}
{% for hidden in form.hidden_fields %}
{{ hidden }}
{% endfor %}
{% endif %}
{% if form.is_bound %}
{% if form.errors %}
{% render_field field class="form-control is-invalid" %}
{% for error in form.errors %}
<div class="invalid-feedback">
{{ error }}
</div>
{% endfor %}
{% else %}
{% render_field field class="form-control is-valid" %}
{% endif %}
{% else %}
{% render_field field class="form-control" %}
{% endif %}
</td>
{% endfor %}
<td></td>
</tr>
{% endfor %}
</table>
<button type="submit" class="btn btn-primary">Save</button>
</form>
Thanks in advance,
Christopher
You're returning the class, ShiftFormSet, to the template (in the third-from-last line of your code) instead of the instance, shift_formset.