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How can I create a submit form in Django with a dropping down list?

I am just starting to work with Django and I have some problems with forms and dropping lists.
I have a model with two attributes, and I want to display one of the attributes in a dropping down list (this one will be unchangeable) and another one in a text field (this one will be changeable). Also, I have a submit button, so I want to change a second attribute in a text field and by pressing on the button. How can I do this? What would some examples be?

As you are starting to work with Django, you might or might not know about how Django handle forms.
In Django, forms can be handled in two ways:
User-created and managed forms (without any form class)
Class-managed forms (connected to Django models)
Documentation form Django Forms
Now let’s talk about the first type of forms (where you create your HTML form and manage the request sent to server):
These forms are simple to make and when there are only a few and are only suggested when you have a very small amount of inputs (I would say four or fewer inputs).
Here is a simple example of subscription of a newsletter with an email example.
<form id='sub-form' method="POST">
{% csrf_token %}
<div>
<input type="email" name="sub_email">
</div>
<input class="button" value="Subscribe" type="submit" id="subbutton">
</form>
So a very important thing to look at here is {% csrf_token %}, about which you can read more about here and about how it works and prevents cross-site request forgery. This token will be required when you make a request to Django server with any post request and data.
In this subscription form you see one <input> with name="sub_email". Take note of this as we will use this to get this value on the server as this is the key to its value, and then a simple Submit Button.
When you press Submit on a page let’s say url = "http://BASE_URL/home" you will receive a POST request on the view that handles that URL.
So now coming to the view.py, let’s say you only allow registered users to subscribe then the view will go something like this (assuming you are not expecting any other request from the home URL).
def home(request):
user=request.user
if request.method == "POST":
if user.is_authenticated:
email = request.POST['sub_email'] #Using name of input
#Logic to save this email
return HttpResponse("You are Subscribed",status=200)
else:
return HttpReposnse("You are not Authenticated",status=401)
else:
return render(request,"home.html")
Now as you are the expert of simple forms, let’s work with Django class-based forms.
These views are a little work when you have very few inputs, but they are a great help in manageability and when you have to work with large number of inputs.
You will request these Class Based Forms as in your question you are trying to send an instance of a model from your Models.py to a form to user.
I have a model of Posts that can be used for this example:
class Post(models.Model):
postTitle = models.CharField(max_length = 90,null=True)
subTitle = models.CharField(max_length = 160,null=True)
location = models.CharField(max_length = 3,default = 'IN',null=True)
Now according to your question, you are trying to let the user change one attribute, let’s say postTitle and for location you are not letting the user select one of the countries which is preselected and for your post.
Now we have to create a form for this. Forms in class based are created in Forms.py. If you don't have forms.py then you can create one right along models.py and views.py.
Now for the form, I would like to edit some existing data as you are saying one of the attributes (Fields) is fixed and another editable, but you get the value from the model.
class PostEditForm(ModelForm):
location = forms.CharField(label='Country ',widget=forms.Select(attrs={'class': 'Classes_HERE','placeholder':' Select a Country','disabled':'disabled'} ,choices=country_list),required=True)
class Meta:
model = Post
fields= ['postTitle','subTitle','location']
labels = {
'postTitle':'Title',
'subTitle':'Sub-Title',
}
widgets = {
'postTitle': forms.TextInput(attrs={'class': 'mention_class_here','placeholder':' Add Title'}),
'subTitle': forms.TextInput(attrs={'class': 'mention_class_here','placeholder':' Add Sub-Title'})
}
Attributes can be mentioned in forms fields the way I have mentioned them in the above example. I used disabled="disabled" to disable (not editable) location field and used forms.Select to make it drop down.
You might also see that I gave the location field a list to choose from. This is how you can create a list of your items. It's been quite some time when I wrote this, so there might be errors or it may not work for you, so just make sure you are referring to the current documentation and searching Stack Overflow for answers.
country_list = [
('', 'Select a Country'),
("AF", "Afghanistan"),
("AX", "Aland Islands"),
("AL", "Albania"),
("DZ", "Algeria"),
("AS", "American Samoa"),
("AD", "Andorra"),
("AO", "Angola"),
("AI", "Anguilla"),
("AQ", "Antarctica"),
("AG", "Antigua And Barbuda"),
("AR", "Argentina"),
("AM", "Armenia"),
("AW", "Aruba"),
.
.
.
Now this form can be passed as context in a view to an HTML page.
def editPost(request,post_id):
user=request.user
post = get_object_or_404(Post,id=post_id) #Getting the instance of Post
if user.is_authenticated:
formPost = PostEditForm(request.POST or None,instance=post)
if request.method=='POST':
if formPost.is_valid():
savedPost=formPost.save()
else:
return render(request,'postEdit.html',{'formPost':formPost})
else:
return HttpResponse("Not Authorized",status:401)
Now your HTML file postEdit.html should look something like this:
<form id="post-form" method="POST" enctype="multipart/form-data">
{% csrf_token %}
<div>
{{formPost}}
</div>
</form>
That is it and adding a submit button in the same form, you can now edit your instance of post that you passed along with this {{formPost}}. Combine your logic wherever you think needs a change to fit in what you want to do.
By no means I am saying all this code is in working condition, but it is shown only to illustrate the flow and working.

Pass data between different views in Django

I have a basic view that retrieves some data, renders my page and sends some data to this page:
def myview(request)
one = values.objects.get(user=request.user).address
two = values.objects.get(user=request.user).number
return render(request, "main/mytemplate.html",
context={'address': one, 'numbers': two})
So the values retrieved by those two queries are shown on my page.
Now, on the same page, called mytemplate.html, i'm using another view, which is supposed to handle a form and some other operations:
def secondview(request):
if request.method == 'POST':
if 'button1' in request.POST:
form = MyForm(request.POST)
# check whether it's valid:
if form.is_valid():
profile = form.save(commit=False)
profile.user = request.user
profile.save()
return HttpResponseRedirect(request.path_info)
else:
form = MyForm()
return HttpResponse('it works!')
How can i use the data retrieved by those two queries in the second view? The queries are executed when the page is loaded by the first view. Then, in the same page the second view is used. I want to use the two variables one and two in the second view. Is there a way to do this in Django?
Why don't you make the same queries in the second view? Because i would like the second form to be as fast as possible in terms of reload, without having to do a DB query each time that view is used. Also, since i already retrieved those values when the page is opened, it would be a waste to do that again.
I don't know if this question is clear enough, but the core of it is: can i pass variables/data between two views in django?

You have few options:
Simplest way: include this data in request to the second view (as part of the form data, see an example below). You might even use a single view: if POST was send - store data else do request and show it on a page.
Use cache for that (see an example below) - But I'd recommend to use Django built-in package. Here is a basic example how to use it
Use Django Sessions (see an example below) - it is working option despite of that they have another purpose. When customer is loaded Django will load full session record, so you'll have all data in request.session variable. But that is bad practice: you can get a lot of data duplication and increased database memory consumption.
Use API (e.g. using DjangoRestFramework) together with usual Django app. So you'll just get data you need, and when you need. These API requests can also be cached so it is fast solution.

Yes, you can use session to pass data across views. A session works like a temporary server storage and keeps the needed data in a dictionary form.
For instance, add the following lines to myview:
request.session['one'] = one
request.session['two'] = two
Then, retrieve the data in secondview by referring to the session:
one = request.session['one']
two = request.session['two']

you can use cookies. but if you want more secure your request i suggest to you using redis and the python client for redis
file settings.py
redis = redis.Redis(host='localhost', port=6379, db=0)
file views.py
def view1(request):
redis.set("foo", "boo")
def view2(request):
boo = redis.get("foo")

Why not just saving the results of the two queries as hidden fields in the form rendered by the first template ?
<form ...>
<input type="hidden" id="address" name="address" value="{{address}}">
<input type="hidden" id="numbers" name="numbers" value="{{numbers}}">
...
Then, you can either add 'address' and 'numbers' form fields to MyForm
address = forms.CharField(widget=forms.HiddenInput(), required=False)
...
or just retrieve the values from request.POST

How to render an html template with data from view?

I am new to django. I made a form. I want that if the form is filled successfully then django should redirect to a success page showing the name entered in the form but no parameters should be present in the url itself.
I searched on the internet and the solution I got was to redirect to url with pk as a get parameter which fetches the data and shows in the view. But I don't want to pass any thing in the url itself. and some websites say that http can't redirect with post data.
Here's my views.py
class UserRegistrationView(CreateView):
model = UserForm
template_name = 'userregistration.html'
form_class = UserForm
success_url = 'success'
def get_success_url(self):
return reverse('success',kwargs = {'name' : self.object.firstName})
and here's the template to which I want to redirect:
<h2>Congratualations for registering {{name}} </h2>
Basically what I want is that if the person fill form mentioning his/her firstName as "xyz" then the redirected success page should say that "Congratulations for registering xyz"

You can use django sessions, which I believe installed by default in 1.8
Look here
# Set a session value:
request.session["fav_color"] = "blue"
# Get a session value -- this could be called in a different view,
# or many requests later (or both):
fav_color = request.session["fav_color"]
# Clear an item from the session:
del request.session["fav_color"]
You can pass your pk via session and extract your object in another view without affecting your url.
Make sure you clean up after yourself.
Let me know if more help needed.

One of the possible ways of passing data between views is via sessions. So, in your UserRegistrationView you need to override the form_valid method as shown below.
class UserRegsitrationView(CreateView):
def form_valid(self,form):
self.request.session['name'] = self.object.firstName
return super(UserRegistrationView,self).form_valid(form)
class SuccessView(TemplateView):
template_name = "success_template.html"
def get_context_data(self,**kwargs):
context = super(SuccessView,self).get_context_data(**kwargs)
context['name'] = self.request.session.get('name')
del self.request.session['name']
return context
One more thing that you can modify in your code is that you need not declare success_url if you are overriding get_success_url

Using Django CBV's without overriding get_context_data

Is there anyway I can take advantage of Django's default CBV's without resulting to super calls on the get_context_data to send extra pieces of info.
For instance, I have a site where the CBV's handle 99% of the work on their own, but I'd like to send minor bits of static info such as page titles and it seems unnecessary to use get_context_data just to accomplish this.
I'm aware that I can do the following:
class Page(DetailView):
model: MyModel
template_name: 'something.html'
title: 'Some Page Title'
And reference title in my template as view.title. However I'd like the page title to be an attribute of my model. Which I'm able to do through the following:
get_context_data(self, **kwargs):
context = super(Page, self).get_context_data(**kwargs)
context['title'] = 'Page Title | %s' % (self.get_object().title)
return context
Is it possible for me to reference the individual model being called in the detail view without running a query or using get_context_data so I can get the model's title attribute and use access it as view.title in my template?

I can't see any reason to define this method just to get the title. The whole point of a DetailView is that you have access to the object in the template, via {{ object }}. So why not just do {{ object.title }}?

Decorate GET URL using forms

I have some question:
I use django form, and fields like MultipleChoiceField
in view.py I clean data and get GET URL like this
http://localhost:8000/?category=&style=&sex=&brand=ASICS&brand=Be+Positive&low_price=&high_price=
Give me advise, can I regroup brand field and hide empty.
I want getting something like this:
http://localhost:8000/?brand=1+2
And else one question:
How can I set empty value(empty_label) for forms.ModelMultipleChoiceFIeld
forms.py:
brand = forms.MultipleChoiceField(required=False,
widget=forms.SelectMultiple(attrs={'size':1})
)
def __init__(self,app_label=None, *args, **kwargs):
super(Search, self).__init__(*args, **kwargs)
self.fields['brand'].choices = [('', 'All brands')]+[(brand.name, brand) for brand in Brand.objects.all() ]
views.py:
if request.method == 'GET' and request.GET:
form = SearchForm(app_label, request.GET)
if form.is_valid():
brands = form.cleaned_data['brand']
kwargs.update({"brand__name__in": brands})

This is how the browser submits multiple data. It's part of the HTML specification, trying to change it would be folly and technically I can't understand why you would try to care about how your url GET data looks.
That being said, if you want to change the way it submits you'll need javascript to transform the data on form submit. Django has nothing to do with the matter.
Using jQuery for example:
$('#form').submit(function(){
//Get form data
//Transform into my custom set of vars
//Redirect to form's ACTION with my querystring appended.
});
Please keep in mind you will not get any automatic parsing of the values on the Django side. Normally it would turn it into a list for you, but now you're responsible for parsing the 'value+value+value' yourself.

For empty label in forms you could do this -
class SomeForm(forms.Form):
h=forms.CharField(label=u'',widget=forms.TextInput(attrs={'value':'Search'}))
By keeping label as '', you get the label as empty. The attrs are basically the HTML attributes of the form text field.
UPDATE: I didn't understand the first part of your Q, elaborate...