Django, Ajax- HttpResponse does not send json - ajax

Question

Django 1.7.2/ python 3.4
this code is about 'like'.
if user click the 'like' button, ajax calls 'pushLike'.
if the user has liked the article before(saved inside Mysql), delete the row on table(DB).
or if the user is not liking the article, create a row and insert it on the table(DB).
after that, count how many like has beed clicked on that article.
I would like to pass the likeCnt(count) to ajax, and write it on the button.
The likeCnt has the right value(I checked it on the server mysql table).
The button color does change(white to blue, and vise versa), but the text does not change.
It seems like json does not pass to ajax. I tried passing data by 'text' type and it did worked, but i want it by json.
I've tried simplejson, json, mimetype, content_type on HttpResponse.
please help me.
view
#login_required
def pushLike(request):
pk = request.GET['writing_id']
try:
la = LikeArticles.objects.get(user = User.objects.get(username=request.user.username), article_id=pk)
if(la.is_like()):
la.delete()
likeCnt = LikeArticles.objects.filter(article_id=pk).count()
FreeBoards.objects.filter(id=pk).update(like = likeCnt)
else: #Never happens
la.like = True
la.save()
likeCnt = LikeArticles.objects.filter(article_id=pk).count()
FreeBoards.objects.filter(id=pk).update(like = likeCnt)
except ObjectDoesNotExist:
la = LikeArticles(user = User.objects.get(username=request.user.username),
article = FreeBoards.objects.get(id=pk),
like = True,
)
la.save()
likeCnt = LikeArticles.objects.filter(article_id=pk).count()
FreeBoards.objects.filter(id=pk).update(like = likeCnt)
data = {'likeCnt': likeCnt}
# return render(request, url, context)
return HttpResponse(simplejson.dumps(data), mimetype='application/javascript')
javascript
<script type="text/javascript">
$(document).ready(function(){
$('#btn-like').click(function(){
var e = $('#btn-like').css('background-color');
$.ajax({
url : '/sle/freeboards/pushLike/',
data : {'writing_id':{{writing_id}},
},
dataType : "json",
success:function(data){
alert(data.likeCnt);
if(e == 'rgb(59, 89, 152)') {
$('#btn-like').css('background-color', '#ffffff').css('color', '#000000');
$('#btn-like').text(data.likeCnt);
} else {
$('#btn-like').css('background-color', '#3b5998').css('color', '#ffffff');
$('#btn-like').text(data.likeCnt);
}
},
failure: function(data){
alert('fail!!')
}
});
});
});
</script>

Answer 1

you'll want to be sure to set the proper mimetype in your HttpResponse
#login_required
def pushLike(request):
...
# return json -- !!not javascript!!
return HttpResponse(simplejson.dumps(...), mimetype="application/json")
--or--
#login_required
def pushLike(request):
...
# return json -- !!not javascript!!
return JsonResponse({"your": "context dictionary"})
If that doesn't work, have you tried parsing the json with your Jquery code?
ie:
$.ajax({
...
success: function(data){
var response = $.parseJSON(data);
...
}
});
javascript might actually receiving bytes back from whatever you are serving your django app with... so instead of getting JSON back, you're actually getting string that looks like JSON. http://api.jquery.com/jquery.parsejson/