Develop Reference

Django/Js: how to post a form without reloading whole page

My application currently flows through 3 pages:
User selects question in index page
User submits answer in answer page
User is presented with result in results page.
I want to compress that down to a single page where the user submits an answer to the question and result is shown on the same page.
The following django-template code separates questions with Bootstrap accordion. How do I post the form without refreshing the whole page? I want to be able to display the result on the page, update CSS styling with Javascript etc.
<h2>{{ category.title }}</h2>
<div class="accordion" id="accordion{{category.title}}">
{% for challenge in category.challenge_set.all %}
<div class="card">
<div class="card-header" id="heading{{challenge.id}}">
<h2 class="mb-0">
<button class="btn btn-link btn-block text-left" type="button" data-toggle="collapse" data-target="#collapse{{challenge.id}}" aria-expanded="true" aria-controls="collapse{{challenge.id}}">
{{ challenge.question_text }} - {{ challenge.point_value }} points
</button>
</h2>
</div>
<div id="collapse{{challenge.id}}" class="collapse in" aria-labelledby="heading{{challenge.id}}" data-parent="#accordion{{category.title}}">
<div class="card-body">
<p>{{ challenge.description }}</p>
<form action="{% url 'challenges:answer' challenge.id %}" method="post">
{% if challenge|is_answered:request %}
<label for="answered">Answer</label>
<input type="text" name="answered" id="answered" value="{{ challenge.answer_text }}" readonly>
{% else %}
{% csrf_token %}
<label for="answer">Answer</label>
<input type="text" name="answer" id="answer">
<input type="submit" value="Submit">
{% endif %}
</form>
</div>
</div>
{% endfor %}
</div>
Here is the view:
def index(request):
context = {'challenges_by_category_list': Category.objects.all()}
return render(request, 'challenges/index.html', context)
def detail(request, challenge_id):
challenge = get_object_or_404(Challenge, pk=challenge_id)
return render(request, 'challenges/detail.html', {'challenge': challenge})
def results(request, challenge_id, result):
challenge = get_object_or_404(Challenge, pk=challenge_id)
return render(request, 'challenges/results.html', {'challenge':challenge, 'result':result})
def answer(request, challenge_id):
challenge = get_object_or_404(Challenge, pk=challenge_id)
result = "Incorrect, try again!"
if challenge.answer_text.lower() == request.POST['answer'].lower():
current_user = request.user
session = User_Challenge(user=current_user, challenge=challenge, answered=True)
session.save()
points = Profile(user=current_user, points=challenge.point_value)
points.save()
result = "Correct!"
return HttpResponseRedirect(reverse('challenges:results', args=(challenge.id, result)))

You can try this:
Add the below script in your template:
<script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
write a script and a function inside it to submit the form data.
<script type="text/javascript">
function submitData( challenge_id ){
// Get answer from the input element
var answer = document.getElementById("answer").value;
// add the url over here where you want to submit form & challenge_id is also taken as a parameter.
var url = "<your_url>";
$.ajax({
url: url,
data: {
'answer': answer,
},
dataType: 'JSON',
success: function(data){
// show an alert message when form is submitted and it gets a response from the view where result is provided and if url is provided then redirect the user to that url.
alert(data.result);
if (data.url){
window.open(data.url, '_self');
}
}
});
}
</script>
Change type of the submit button and add an onclick event to call the submitData() function and pass the challenge id to it. And remove the action attr from the form.
see below:
<form method="post">
{% csrf_token %}
{% if challenge|is_answered:request %}
<label for="answered">Answer</label>
<input type="text" name="answered" id="answered" value="{{ challenge.answer_text }}" readonly>
{% else %}
<label for="answer">Answer</label>
<input type="text" name="answer" id="answer">
// over here
<button type="button" onclick="submitData({{ challenge.id }})">
Submit
</button>
{% endif %}
</form>
Return a JsonReponse to the ajax call from the views.
views.py
def answer(request, challenge_id):
answer = request.GET.get('answer', False)
url = False
if challenge.objects.filter(id=challenge_id).exists() and answer:
challenge = Challenge.objects.get(id=challenge_id)
if challenge.answer_text.lower() == answer.lower():
current_user = request.user
session = User_Challenge(user=current_user, challenge=challenge, answered=True)
session.save()
points = Profile(user=current_user, points=challenge.point_value)
points.save()
result = "Correct!"
# specify the url where you want to redirect the user after correct answer
url = ""
else:
result = "Incorrect, try again!"
data = {
'result': result,
'url': url
}
return JsonResponse(data)

ajax in django success function is not working

I am new in ajax as well as Django. I try to put ajax in my code to check that in the signup page if some user is already having one email then that email can't use for new users and disable the button else if the email does not exist then the user can be created.
ajaxCode
$(document).on('blur', 'input[name="email"]', function(){
$.ajax({
type:'POST',
url:'/stock/checkemail/',
data:{
email:$("#email").val(),
csrfmiddlewaretoken:$('input[name=csrfmiddlewaretoken]').val()
},
success:function(){
$('input[type="submit"]').attr('disabled', 'true')
},
failure:function(){
$('input[type="submit"]').removeAttr('disabled');
}
})
});
url.py
path('checkemail/',Emailser.as_view()),
views.py
class Emailser(View):
def post(self, request):
em = request.POST['email']
print(em)
try:
user = User.objects.get(email=em)
return HttpResponse('true')
except:
return HttpResponse('false')
In views.py print(em) is also printing mail that type in field but don't know why is not working.
template
{% extends 'base.html' %}
{% block content %}
{% load static %}
<div>
<h2>Sign Up</h2>
{% if error %}
{{error}}
<br/>
{% endif %}
<form method="post" id="signup" >
{% csrf_token %}
{{ form.as_p }}
<button type="submit" class="btn btn-primary" >Signup</button>
</form>
</div>
<script src="{% static 'assets/signup.js' %}" ></script>
{% endblock %}

try this inside succcess function
$('input[type="submit"]').disabled = true;

$(document).on('blur', 'input[name="email"]', function(){
$.ajax({
type:'POST',
url:'/stock/checkemail/',
data:{
email:$("#email").val(),
csrfmiddlewaretoken:$('input[name=csrfmiddlewaretoken]').val()
},
success:function(response){
response ? $('input[type="submit"]').attr('disabled', 'true') : $('input[type="submit"]').removeAttr('disabled');
},
failure:function(error){
console.log(error);
}
})
});

form wizard does not move to the next screen in a jquery dialog

I an using django-crispy forms and using that in a jquery dialog box to show a form wizard. the problem that I am facing is that when used in the dialog box the wizard never moves to the next screen.
So, my wizard is defined as follows:
class ContactWizard(SessionWizardView):
def get_template_names(self):
return "reviewdialog.html"
def done(self, form_list, **kwargs):
return HttpResponseRedirect('index')
And the template is defined as:
{% load crispy_forms_tags %}
{% load i18n %}
{% block content %}
<form action="." method="post">
{% csrf_token %}
<table>
{{ wizard.management_form }}
{% if wizard.form.forms %}
{{ wizard.form.management_form }}
{% for form in wizard.form.forms %}
{% crispy form %}
{% endfor %}
{% else %}
{% crispy wizard.form %}
{% endif %}
{% if wizard.steps.prev %}
<button name="wizard_goto_step" value="{{ wizard.steps.first }}">{% trans "first step" %}</button>
<button name="wizard_goto_step" value="{{ wizard.steps.prev }}">{% trans "prev step" %}</button>
{% endif %}
</table>
<input type="submit" class="btn btn-success" value = "NEXT">
</form>
{% endblock %}
Now, I show this in a jquery dialog where I have overridden the submit method to ensure that the dialog does not close on clicking the 'NEXT' button
<script>
function EditDialog(pk) {
$.ajax({
url: "{% url 'populatereviewform' %}",
method: 'GET',
data: {
pk: pk
},
success: function(formHtml){
//place the populated form HTML in the modal body
$('.modal-body').html(formHtml);
$( "#dialog" ).modal({width: 500, height: 500});
},
dataType: 'html'
});
$('#dialog').submit( function(e) {
return false;
});
return false;
}
</script>
The AJAX part just populates the form with some data and the dialog object is a standard jquery modal dialog. The form is shown at the first screen and is populated with the correct value but when I press NEXT nothing happens in the sense that the wizard does not transition.
The urls.py is configured as:
url(r'^review/(?P<pk>\d+)/$', views.ContactWizard.as_view([DummyForm, OtherForm]), name='review'),
Som, the form starts with the DummyForm (which is a ModalForm) but does not progress to the next wizard screen. I have a feeling it could be something to do with my javascript but could bit get to the bottom of this.
EDIT
So, based on #udi's answer, I tried the following:
$("#dialog").submit(function(e)
{
$.ajaxSetup({
beforeSend: function(xhr, settings) {
if (!csrfSafeMethod(settings.type) && !this.crossDomain) {
xhr.setRequestHeader("X-CSRFToken", csrftoken);
}
}
});
var postData = $(this).serializeArray();
var formURL = $(this).attr("action");
$.ajax(
{
url : formURL,
type: "POST",
data : postData,
success:function(data, textStatus, jqXHR)
{
$('.modal-body').html(data);
},
error: function(jqXHR, textStatus, errorThrown)
{
alert(errorThrown)
}
});
e.preventDefault(); //STOP default action
e.unbind(); //unbind. to stop multiple form submit.
});
return false;
}
However, the data that is returned here is not the next screen of the wizard but the underlying page on which the dialog is shown. So, perhaps it is the formURL or postdata variables that are not initialized properly?
The template for the wizard screen is:
{% load crispy_forms_tags %}
{% load i18n %}
{% block head %}
{{ wizard.form.media }}
{% endblock %}
{% block content %}
<form id="review-form" action="." method="post">
{% csrf_token %}
<table>
{{ wizard.management_form }}
{% if wizard.form.forms %}
{{ wizard.form.management_form }}
{% for form in wizard.form.forms %}
{% crispy form %}
{% endfor %}
{% else %}
{% crispy wizard.form %}
{% endif %}
{% if wizard.steps.prev %}
<button name="wizard_goto_step" class="btn btn-success" value="{{ wizard.steps.first }}">{% trans "first step" %}</button>
<button name="wizard_goto_step" class="btn btn-success" value="{{ wizard.steps.prev }}">{% trans "prev step" %}</button>
{% endif %}
</table>
<input type="submit" class="btn btn-success" value = "Hello">
</form>
{% endblock %}

You will need to get the html of the next form via jQuery and update it in the dialog.

jquery .click() event issue (django)

I have created a view that generates posts and each post have a comments_set which produces all the comments made by user. When new comment is posted, below function is executed.
$("#comment-post-button").click(function(){
var event_id = document.getElementById('event-id').value;
var url= '/post-comments/'+event_id +'/';
var data = {csrfmiddlewaretoken: document.getElementsByName('csrfmiddlewaretoken')[0].value,
content:document.getElementsByName('comment-post-content')[0].value
}
$.post(url , data, function(){
$("#refresh-comments").load("/comments/" + event_id + '/', function(){
$("#comment-post-content").val("");
});
});
$("#comment-post-content").val("");
return false;
});
The problem is that the page contains multiple posts and each comment submission button has the same id "comment-post-button". So the above function works only for the top post and not for the rest. I can see what the problem is but don't know how to solve this. Please help.
Here is the html markup:
{% for event in events %}
<div class="post">
<div class="post-right">
<div class="post-author">{{ event.author.first_name }}</div>
<div class="post-content">{{ event.description }}</div>
<div class="post-bar">
<div class="post-likes">{{ event.up_votes }}<img src="/site-media/static/images/like.png" /></div>
<div class="post-dislikes">{{ event.down_votes }}<img src="/site-media/static/images/dislike.png" /></div>
<div class="post-timestamp">{{ event.pub_date }}</div>
Comment
</div>
<div class="post-comment">
<form method="post" action="/post-comments/{{ event.id }}/">
{% csrf_token %}
<input type="text" id="comment-post-content" name="comment-post-content" maxlength="200" placeholder="Add a comment..." />
<input type="hidden" id="event-id" value="{{ event.id }}">
<input type="submit" id="comment-post-button" class="comment-post-button" value="Post comment" />
</form>
</div>
<div id="refresh-comments" class="comments">
{% include "comments.html" %}
</div>
</div>
<div class="post-left">
<img src="../FestJanta/site-media/static/images/post.jpg" />
</div>
</div>
{% endfor %}
comments.html:
{% for comment in event.comment_set.all|slice:"3" %}
<div class="comments-right">
{{ comment.author.first_name }}
{{ comment.content }}<br>
<div class="comment-timestamp">{{ comment.pub_date }}</div>
</div>
<div class="comments-left"><img src="../FestJanta/site-media/static/images/comment.jpg" /></div>
{% endfor %}
Final working solution:
$(".comment-post-button").click(function(){
var btn = $(this);
var currentPost = btn.parents('.post');
var event_id = currentPost.find('.event-id').val();
var url= '/post-comments/'+event_id +'/';
var data = {csrfmiddlewaretoken: document.getElementsByName('csrfmiddlewaretoken')[0].value,
content:currentPost.find('input[name="comment-post-content"]').val()
}
$.post(url , data, function(){
$(currentPost.find('.refresh-comments')).load("/comments/" + event_id + '/', function(){
$(currentPost.find('.comment-post-content')).val("");
});
});
return false;
});

Remove id and add class:
<input type="hidden" class="event-id" value="{{ event.id }}">
Do something like this:
$('.comment-post-button').click(function(){
var $btn = $(this);
var $currentPost = $btn.parents('.post');
var event_id = $currentPost.find('.event-id').val();
//...
});
Find each element in $currentPost scope:
Instead of this:
content: document.getElementsByName('comment-post-content')[0].value
Do this:
content: $currentPost.find('input[name="comment-post-content"]').val()

You could do the following:
Identify all post buttons, e.g. by a class like .comment-button
Use the .on() notation of jQuery
Pass the event and use its target property to identify the DOM element that triggered the event
Use traversion to get the correct DOM element of the post
The result should look something like this (untested):
Markup (I basically just got rid of the IDs; not sure how/if django handles this automatically):
{% for event in events %}
<div class="post">
<div class="post-right">
<div class="post-author">{{ event.author.first_name }}</div>
<div class="post-content">{{ event.description }}</div>
<div class="post-bar">
<div class="post-likes">{{ event.up_votes }}<img src="/site-media/static/images/like.png" /></div>
<div class="post-dislikes">{{ event.down_votes }}<img src="/site-media/static/images/dislike.png" /></div>
<div class="post-timestamp">{{ event.pub_date }}</div>
Comment
</div>
<div class="post-comment">
<form method="post" action="/post-comments/{{ event.id }}/">
{% csrf_token %}
<input type="text" name="comment-post-content" maxlength="200" placeholder="Add a comment..." />
<input type="hidden" name="event-id" value="{{ event.id }}">
<input type="submit" class="comment-post-button" value="Post comment" />
</form>
</div>
<div class="comments">
{% include "comments.html" %}
</div>
</div>
<div class="post-left">
<img src="../FestJanta/site-media/static/images/post.jpg" />
</div>
</div>
{% endfor %}
Javascript:
$("body") // Could be any ancestor, body is not the best option
.on('click', '.comment-post-button' function(ev){
var clickTarget = ev.target, // The element clicked on
postElement = $(clickTarget).closest('.post'), // the div enclosing a post
commentSection = $(postElement).find(".comments"), // the div enclosing the comments
commentInputField = $(clickTarget).siblings("[name='comment-post-content']"),
event_id = $(clickTarget).siblings("[name='event-id']").val(),
url= '/post-comments/'+event_id +'/';
// Not sure what this token is, so I will not change that part
var data = {csrfmiddlewaretoken: document.getElementsByName('csrfmiddlewaretoken')[0].value,
content: commentInputField.val()
}
$.post(url , data, function(){
$(commentSection).load("/comments/" + event_id + '/', function(){
$(commentInputField ).val("").prop('disabled', false); // In the callback, empty and reenable
});
});
$(commentInputField ).prop('disabled', true); // I guess disabling the field makes sense
return false;
});
An additional advantage is that you will end up with only one click handler. Note that the solution could be optimized (e.g. by improving the selectors). In addition, jslint will give some warnings.

to give each post & post_Comment_button a unique id, as suggested by someone, change the markup as follows:
{% for event in events %}
<div class="post" id="post_{{forloop.counter}}">
[...]
<input type="submit" id="comment-post-button_{{forloop.counter}}" class="comment-post-button" value="Post comment" />
then change the js function as follows:
$("#comment-post-button").click(function(event){
var buttonNr = event.target.id.replace('comment-post-button_', '');
var postId = 'post_' + buttonNr;
$("#" + postId)... --> and do whatever with it..

Send only specific value to server in Django

I have a html code like this:
{% for i, j, k in full_name %}
{{ i }} {{ j }}
<input type="text" name="follow_id" value="{{ k }}" />
<input type="submit" value="Follow"><br /> <br />
{% endfor %}
The output looks like this:
user1 user_id_of_user1 follow_button
user2 user_id_of_user2 follow_button
user3 user_id_of_user3 follow_button
If I press the follow button of user3 I want to send the id of user3 only so that I can access it in server like this:
followed_user = request.POST['follow_id']
# Process
But, no matter which follow_button I press, I get the user id of only user1. How to fix this?

This is not a Django issue, but a HTML issue. Here is the work around: 1 form for each user:
{% for i, j, k in full_name %}
<form action="mydomain.com/mysubmiturl/" method="POST"><!-- Leave action empty to submit to this very same html -->
{% csrf_token %} <!-- Django server only accept POST requests with a CSRF token -->
{{ i }} {{ j }}
<input type="text" name="follow_id" value="{{ k }}" />
<input type="submit" value="Follow"><br /> <br />
</form>
{% endfor %}
Note that all the forms submit to the same URL, and thus the same view function !

Just my 2 cents, I would use some jQuery for this job.
In your template:
{% for i, j, k in full_name %}
{{ i }} {{ j }}
Follow
{% endfor %}
Then submit the data using AJAX:
$('.follow-button').click(function (e) {
e.preventDefault();
var this_id = $(this).attr('id').replace('js-follow-', '');
$.ajax({
type: 'POST',
url: 'path/to/view',
data: {'follow_id': this_id},
success: function (resp) {
// do something with response here?
}
});
});