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How can I render a Django render() response in an ajax function?

In my view, I return html if a form is valid:
if form_valid():
return render(request, 'home.html', context=context)
else:
return HttpResponse(status=204)
I'm submitting multiple forms via ajax and want to render the response, if the status code is not 204:
$.ajax({
data: $(this).serialize(),
type: $(this).attr('method'),
url: $(this).attr('action'),
success: function (response, status, jqXHR) {
if (jqXHR.status !== 204) {
document.write(response); // this works, but I lose some functionality. Some buttons stop working.
// How can I render the response correctly?
}
}
});
EDIT: The buttons that don't work anymore. It's a form using bootstrap collapse with some workarounds
main.html
<form action="." method="post">
{% csrf_token %}
{% include 'collapse_form.html' with form=mysql_form %}
{% include 'collapse_form.html' with form=postgres_form %}
{% include 'collapse_form.html' with form=sqlite_form %}
<input type="hidden" name="databases-section"/>
<a id="download-btn" class="btn btn-success">Download</a>
<a id="hidden-download-link" class="js-scroll-trigger" href="#download"></a>
</form>
collapse_form.html
{% load crispy_forms_filters %}
<div class="collapseForm">
<div class="collapseFormButton">
<button id="collapseBtn" class="d-none btn btn-check p-0 m-0" type="button" data-toggle="collapse"
data-target="#{{ form.prefix }}-collapseTarget"
aria-expanded="false">
</button>
{{ form.active|as_crispy_field }}
</div>
<div class="collapse" id="{{ form.prefix }}-collapseTarget">
<div class="card card-body">
{{ form|as_crispy_errors }}
{% for field in form.visible_fields|slice:"1:" %}
{{ field|as_crispy_field }}
{% endfor %}
</div>
</div>
</div>
js
$('.collapseFormButton').find("input").change(function () {
toggleCollapseForm()
});
function toggleCollapseForm() {
let collapseForm = $(".collapseForm");
collapseForm.each(function () {
let collapseCheckbox = $(this).find("input[id*='active']");
let collapseTarget = $(this).find("div[id*='collapseTarget']");
if (collapseCheckbox.is(':checked')) {
collapseTarget.collapse('show');
} else {
collapseTarget.collapse('hide');
}
});
}

instead of document.write there is more functions like append, you could use that to append the rendered htmls cooming to ajax as a response to a specific element selected by id to avoid any problem like lossing the documents html tags(html, body, header) .
and there is big point!
javascript has different behavior regarding dynamically added elements!
to be more clear, I think js and/or jQuery has different behavior for keword this which doesn't work on dynamically added elements. so you sould use another query-selector like $(document).on('click', element, function (){....} and this would work as expected.

Progress Bar Upload to S3 Django

I would like to show an upload progress bar for S3 uploads from a Django site. Currently without the progress bar being manipulated by JQuery, the uploads are working direct to S3. Once I try to implement the progress bar using JQuery, the upload form still functions as far accepting input and the file, but will not communicate the file to S3.
Here is the upload view:
from .forms import UploadForm
def upload(request):
if request.method == 'POST':
form = UploadForm(request.POST, request.FILES)
if form.is_valid():
form.save()
return redirect('upload')
else:
form = UploadForm()
context = {
'form': form
}
return render(request, 'content/upload.html', context)
Here is the HTML:
{% extends "about/base.html" %}
{% load crispy_forms_tags %}
{% block content %}
{% block navbar %}{% endblock %}
<div class="site-section mb-5">
<div class="container">
<div class="form-register">
<form method="POST" enctype="multipart/form-data">
{% csrf_token %}
<legend>Upload Content</legend>
<div class="form-group">
{{ form | crispy }}
</div>
<button class="btn btn-outline-info" type="submit">Upload</button>
</form>
<div class="progress">
<div id="progressBar" class="progress-bar" role="progressbar" aria-valuenow="0" aria-valuemin="0" aria-valuemax="100" style="width: 0%;">
0%
</div>
</div>
</div>
</div>
{% endblock %}
Here is the JQuery:
$(document).ready(function() {
$('form').on('submit', function(event) {
event.preventDefault();
var formData = new FormData($('form')[0]);
$.ajax({
xhr : function() {
var xhr = new window.XMLHttpRequest();
xhr.upload.addEventListener('progress', function(e) {
if (e.lengthComputable) {
console.log('Bytes Loaded: ' + e.loaded);
console.log('Total Size: ' + e.total);
console.log('Percentage Uploaded: ' + (e.loaded / e.total))
var percent = Math.round((e.loaded / e.total) * 100);
$('#progressBar').attr('aria-valuenow', percent).css('width', percent + '%').text(percent + '%');
}
});
return xhr;
},
type : 'POST',
url : '/upload',
data : formData,
processData : false,
contentType : false,
success : function() {
alert('File uploaded!');
}
});
});
});
I assume there is something I need to change in the JQuery since I am overriding the default submit button action, but I am not sure what exactly to change in order to make sure the file goes to S3 via django-storages and boto3, the packages being used to communicate with S3.

how to add ajax to django webpage

I am working on a django application. This application hold two forms. In the first form (image_form) the user can upload an image. In the second form (image_description) the user can fill some description about the image. when the image is uploaded in the first form, an image classifier runs on the image tries to fill parts of the image_description form. Once the second form is submitted the item is displayed in a new page (item_list). This is the urlpatterns for the application.
urls.py
urlpatterns = [
path('', views.index, name='home'),
path('accounts/', include('django.contrib.auth.urls')),
path('signup/', views.signup, name='signup'),
path('items/', views.item_list, name='item_list'),
path('items/upload/description/', views.upload_item, name='upload_item'),
path('items/<int:pk>/', views.delete_item, name='delete_item'),
path('items/upload/image_classification/', views.image_classification, name='image_classification'),
]
here item_list is the page where all items are displayed. This page is displayed once the image_description form is submitted.
upload_item page contains both the forms.
image_classification runs when upload image button in the first form is clicked. This happens in the upload_item page.
views.py
def item_list(request):
items = Item.objects.all()
return render(request, 'item_list.html', {'items':items})
def upload_item(request):
if request.method == 'POST':
form_des = ItemForm(request.POST, request.FILES)
if form_des.is_valid():
form_des.save()
return redirect('item_list')
else:
form_des = ItemForm()
return render(request, 'upload_item.html', {'form_des': form_des})
def image_classification(request):
form_des = ItemForm()
if request.method == 'POST':
if 'file' in request.FILES:
handle_uploaded_file(request.FILES['file'], str(request.FILES['file']))
img = np.expand_dims(cv2.resize(cv2.imread(os.path.join('./media/item/img/', str(request.FILES['file']))), (170, 100)), axis=0)
cat_prediction = cat_classifier.predict_classes(img)[0]
pattern_prediction = pat_classifier.predict_classes(img)[0]
form_des.fields['title'].widget.attrs['value'] = cat_prediction
form_des.fields['pattern'].widget.attrs['value'] = pattern_prediction
form_des.fields['user'].widget.attrs['value'] = request.user
form_des.fields['user'].widget.attrs['readonly'] = True
return render(request, 'upload_item.html', {'form_des': form_des})
else:
return redirect('upload_item')
upload_item.html template
<div class="container">
<div class="row justify-content-center">
<div class="col-7">
<center>
<h2>Upload image</h2>
<!-- <div class="row justify-content-center"> -->
<div class="upload-btn-wrapper">
<form action="{% url 'image_classification' %}" method="POST" enctype="multipart/form-data" data-url="image_classification/" class="my_form">
{% csrf_token %}
<input type="file" name="file" id="file" class="inputfile" multiple/>
<label for="file" class="btn btn-outline-dark btn-lg mt-5 select">Choose a file</label>
<input class='btn btn-primary btn-lg btn-block upload_image_button' type="submit" value="Upload image" disabled/>
</form>
</div>
<!-- </div> -->
<center>
<p class='font-weight-bold mt-5 mb-5 text-danger'>Step: 1 of 2</p>
</center>
<div class="separation"></div>
<h2>Item description</h2>
</center>
<div class="card mb-2 mt-3">
<div class="card-body">
<form method="post" enctype="multipart/form-data" action="{% url 'upload_item' %}" id='item_des'>
{% csrf_token %}
{{form_des.title|as_crispy_field}}
{{form_des.pattern|as_crispy_field}}
{{form_des.color|as_crispy_field}}
{{form_des.user|as_crispy_field}}
<button type="submit" class='btn btn-primary btn-lg btn-block save_btn'>Save item</button>
</form>
</div>
</div>
<center>
<p class='font-weight-bold mt-2 mb-5 text-danger'>Step: 2 of 2</p>
</center>
</div>
</div>
</div>
My problem is when the upload image button is clicked in the first form the url changes from items/upload/description/ to items/upload/image_classification/ and the page reloads with the auto filled sections in the second form.
I want to use AJAX to auto-fill the second form without reloading the page but am not sure how to do it. I followed a few tutorials but am not able to achieve this.
Please help me
Thank you
[EDIT1]
Based on Adeel Siddiqui's answer, I made a few changes to views.py
views.py
def image_classification(request):
form_des = ItemForm()
user =str(request.user)
if request.method == 'POST':
if 'file' in request.FILES:
handle_uploaded_file(request.FILES['file'], str(request.FILES['file']))
img = np.expand_dims(cv2.resize(cv2.imread(os.path.join('./media/item/img/', str(request.FILES['file']))), (170, 100)), axis=0)
cat_prediction = cat_classifier.predict_classes(img)[0]
pattern_prediction = pat_classifier.predict_classes(img)[0]
form_des.fields['title'].widget.attrs['value'] = cat_prediction
form_des.fields['pattern'].widget.attrs['value'] = pattern_prediction
form_des.fields['user'].widget.attrs['value'] = request.user
form_des.fields['user'].widget.attrs['readonly'] = True
context = {
'tops_prediction' :tops_prediction,
'pattern_prediction':pattern_prediction,
'user' :user,
}
return HttpResponse(json.dumps(context))
else:
return redirect('upload_item')
How do I access this context from fillImageDescriptionText in jquery and auto-fill the second form in the upload_item page?
[EDIT-2] screenshot of the output after using the updated answer

You could prevent the default event happening when the form is submitted. Suppose your image classification form has the id image-classify-form, then:
$("#image-classify-form").submit(function(event) {
event.preventDefault();
imageClassifyAjax();
}
where your imageClassifyAjax function does this (i previously forgot to create the FormData object on line 2 which was causing the POST request to fail):
function imageClassifyAjax() {
let $form = $("#image-classify-form");
let form_data = new FormData($form[0]);
$.ajax({
url: $form.attr('action'),
type: $form.attr('method'),
data: form_data,
processData: false,
contentType: false,
dataType: 'json',
success: function (data) {
fillImageDescriptionText(data);
},
error: function (xhr) {
console.log("Something went wrong: " + xhr.responseText);
}
});
}
and fillImageDescriptionText uses the json data returned by the view to fill up the form for the image description. So you have to modify what your view does on the POST method. You have to return an HttpResponse instead of doing a render template:
import json
from django.http import HttpResponse
def image_classification(request):
form_des = ItemForm()
if request.method == 'POST':
...
...
return HttpResponse(json.dumps({'title': cat_prediction, 'pattern': pattern_prediction, 'user': request.user.email}))
fillImageDescriptionText receives this json object as input, so you can basically:
function fillImageDescriptionText(data) {
$("#item_des #id_title").val(data.title);
$("#item_des #id_pattern").val(data.pattern);
$("#item_des #id_user").val(data.user);
$("#item_des #id_user").prop('readonly', true);
}
where id_ is the id generated for the elements by django crispy forms or whatever package you are using for the forms. It is mostly prefixed with an "id_". You can check it up by inspecting elements from the browser.

Not Found url in django class based view with ajax

I have a problem with "like" functionality. I want to make it possible to like the post, without overloading the whole page. So I used CBV django connected to ajax.
My problem is that it receives: Not Found: /like/ by pressing the "Like" button.
My view:
class PostLikeView(generic.View):
def post(self, request):
post = get_object_or_404(Post, id=request.POST.get('id'))
is_liked = False
if post.likes.filter(id=request.user.id).exists():
post.likes.remove(request.user)
is_liked = False
else:
post.likes.add(request.user)
is_liked = True
context = {
'post': post,
'is_liked': is_liked,
'total_likes': post.total_likes(),
}
if request.is_ajax():
html = render_to_string('post/like_section.html', context, request=request)
return JsonResponse({'form': html})
Below is jquery code:
<script type="text/javascript">
$(document).ready(function(event){
$(document).on('click', '#like', function(event){
event.preventDefault;
var pk = $(this).attr('value');
$.ajax({
type: 'POST',
url: "{% url 'post:post_like' %}",
data: {'id': pk, 'csrfmiddlewaretoken': '{{ csrf_token }}'},
dataType: 'json',
success: function(response){
$('#like-section').html(response['form'])
console.log($('#like-section').html(response['form']))
},
error: function(rs, e){
console.log(rs.responseText);
},
});
});
});
</script>
url to view:
url(r'^like/$', login_required(PostLikeView.as_view()), name='post_like'),
code in html:
<form action="{% url 'post:post_like' %}" method="post">
{% csrf_token %}
{% if is_liked %}
<button type="submit" id="like" name="post_id" value="{{ post.id }}" class="btn btn-danger">Dislike</button>
{% else %}
<button type="submit" id="like" name="post_id" value="{{ post.id }}" class="btn btn-primary">Like</button>
{% endif %}
</form>
I would like the button to work on the principle of not reloading the whole page.

The issue I think is that you've not actually called event.preventDefault in your click event handler (you're missing the brackets). That means that the submit button submits the form, but the form doesn't contain a parameter named id and so get_object_or_404(Post, id=request.POST.get('id')) raises a 404.
Add the missing brackets to event.preventDefault, and also note that the value of id= attributes on HTML elements should be unique within the page. Change the values of the id= attributes on the <button> elements so that they are unique.

HTML/Django/Jinja/Python : How to post a fixed value back

This is a HTML template that displays all of the proposals in a database (passed through views.py as a list in the dictionary parameter). I then use a jinja for-loop to go through all the proposals in the database and display their attributes.
How can I Post-request the {{ proposal.id }} back to my python code when the "Learn more" button is clicked? I need this to allow me to display the corresponding values in my other html template.
Sorry if this is a basic question, i'm a high school student and extremely new to django! Thanks alot in advance!
{% block body %}
{% for proposal in proposals %}
<div class="jumbotron">
<h2> Proposal : {{ proposal.title }} </h2>
<h4> Status : {{ proposal.status }} </h4>
<h4> Out of --- Votes: </h4>
<div class="progress">
<div class="progress-bar progress-bar-success" style="width: {{ proposal.votes_for }}%">
<span class="sr-only">35% Complete (success)</span>
{{ proposal.votes_for }}% For
</div>
<div class="progress-bar progress-bar-danger" style="width: {{ proposal.votes_against }}%">
<span class="sr-only">10% Complete (danger)</span>
{{ proposal.votes_against }}% Against
</div>
</div>
<p><a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a></p>
</div>

If you just want to go to the Proposal details you should definitely look to a class-based DetailView.
You can make it with AJAX request or you can make it with form. For the both of types you should have a View to catch it.
HTML Form:
In your template you should have:
<form id="formId" method="post" action="{% url 'catch-proposal' %}">
{% csrf_token %}
<input type="hidden" name="proposal_id" value="{{ proposal.id }}"/>
<p><button type="submit" class="btn btn-primary btn-lg">Learn more</a></p>
<!-- <input type="submit" class="btn btn-primary btn-lg" value="Learn more"/> -->
</form>
It will go to your View from urls.py:
url(r'^post/for/proposal/$', catch_proposal, name='catch-proposal'),
# if your view class-based
# url(r'^post/for/proposal/$', CatchProposal.as_view(), name='catch-proposal')
Then in your view you will catch POST data:
def catch_proposal(request):
if request.method == "POST":
print(request.POST) # have a look for your post params
return reverse_lazy('index') # your response, you can make it on your own
AJAX:
Check it! AJAX and Django
Page uses AJAX without any HTML form
A page makes a POST request via AJAX, and the page does not have an HTML form with a csrf_token that would cause the required CSRF cookie to be sent.
Solution: use ensure_csrf_cookie() on the view that sends the page.
In your scripts define:
function sendPost(proposalId) {
$.ajax({
url: '{% url 'catch-proposal' %}', // or just /ajax/catch/proposal/
method : "POST",
data: {
// your data to send key => val
'id': proposalId
},
dataType: 'json', // it can be xml, json, script, html
success: function (result) {
// Do something if your request was successful (code=200)
// All response data stored in result
console.log(result)
},
error : function(xhr,errmsg,err) {
// Error case
console.log(xhr.status + ": " + xhr.responseText);
}
});
}
For your Learn More button:
<p><button class="btn btn-primary btn-lg" role="button" onclick="sendPost({{ proposal.id }})">Learn more</button></p>
And you will catch it in your View:
#ensure_csrf_cookie # Since you sending POST request without form tag
def catch_proposal(request):
response_data = {} # your response
if request.method == 'POST':
# your post request
if 'id' not in request.POST: # check the param from POST
# Provide error message
response_data['error_message'] = "Can't find ID in POST params..."
else:
# Do whatever
proposal_id = int(request.POST.get('id'))
try:
proposal = Proposal.objects.get(id=transport_id)
response_data['success'] = True
except Proposal.DoesNotExist:
response_data['success'] = False
return JsonResponse(response_data)
else:
response_data = {
'error_message': 'Something is going very strange and wrong...'
}
return JsonResponse(response_data)
Adding created View to urls.py:
from .views import catch_proposal # or yourapp.views
....
url(r'^ajax/catch/proposal/$', catch_proposal, name='catch_proposal'),
....