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Getting the error when trying to open the modal with product details after products were queried with help of ajax

Error itself:

Uncaught SyntaxError: Unexpected end of JSON input
at JSON.parse (<anonymous>)
at HTMLButtonElement.<anonymous> (scripts.js:54)
at HTMLDocument.dispatch (jquery-3.3.1.js:5183)
at HTMLDocument.elemData.handle (jquery-3.3.1.js:4991)

To be clear: I have some filters, result of which is filtered in the python filter_items function then it uses JSONResponse to send it to the front-end in form of a dictionary(as_dict() function in Item model) were they are added to hidden input value. JS function takes that hidden input value and renders the results of filtering using the data from that input.

Item Model which is queried with help of filter function:

class Item(models.Model):

ITEM_TYPES = (
    ('UM', 'Umbrella'),
    ('SK', 'Skirt'),
    ('TR', 'Trousers'),
    ('OT', 'Other')
)

BRANDS = (
    ('VS', 'Versace'),
    ('SP', 'Supreme'),
    ('SI', 'Stone Island'),
    ('FP', 'Fred Perry'),
)

title = models.CharField(max_length=256)
image = models.ImageField(upload_to='img/')
brand = models.CharField(max_length=256)
type = models.CharField(choices=ITEM_TYPES, max_length=2)
description = models.TextField(blank=True, null=True)
season = models.TextField(blank=True, null=True)
discount = models.FloatField(blank=True, null=True)
price = models.FloatField()

def __str__(self):
    return self.title + ' ' + self.type

def as_dict(self):
    data = {"title": self.title, "image": self.image.url, "brand": self.brand, "type": self.type,
            "discount": self.discount, "price": self.price, "rus_representation": self.rus_representation,
            "description": self.description, "season": self.season, "images": [self.image.url]}

    if self.images:
        for image in self.images.all():
            data['images'].append(image.image.url)

    # data['dumped'] = json.dumps(data)
    # print(data['dumped'])
    return data

def dumped_as_dict(self):
    return json.dumps(self.as_dict())

@property
def rus_representation(self):

    if self.type == 'UM':
        return 'Зонтик'
    elif self.type == 'SK':
        return 'Юбка'
    elif self.type == 'TR':
        return 'Штаны'
    elif self.type == 'OT':
        return 'Другое'

Class based view with filter function inside of it:

class ProductsListView(ListView):
model = Item
types = Item.ITEM_TYPES
brands = Item.BRANDS

def get_context_data(self, **kwargs):
    context = super().get_context_data(**kwargs)
    context['types'] = self.types
    context['brands'] = self.brands
    return context

@classmethod
def filter_items(cls, request, *args, **kwargs):
    if request.is_ajax():
        data = request.GET

        queryset = Item.objects.all()

        if not data['type'] == 'ALL':
            queryset = queryset.filter(type=data['type'])

        if not data['brand'] == 'ALL':
            queryset = queryset.filter(brand__contains=data['brand'])
        return JsonResponse({'result': [item.as_dict() for item in queryset]})

JavaScript filter function:

    $('.choice-link').click(function () {
    var choice = $(this).text();

    $(this).siblings().attr('id', '');

    $(this).attr('id', 'active');

    $(this).parent().parent().children('button').text(choice);

    var data = {
        'brand': $('.brand-dropdown').children('#active').attr('data-choice'),
        'type': $('.type-dropdown').children('#active').attr('data-choice')
    };

    $.ajax({
        url: '../ajax/filter/',
        data: data,
        success: function (data) {
            $('.item-block').remove();
            $.each(data.result, function (index, item) {
                if (!item.discount) {
                    var el = '<div class="item-block flex" style="flex-direction: column"><input type="hidden" value='+ JSON.stringify(item) +'><img class="img-fluid" style="box-shadow: 0 0 10px rgba(0,0,0,0.5);" src="' + item.image + '"><h6 class="item-title">' + item.rus_representation + ' "' + item.brand + '"<hr></h6><p class="flex" style="align-items: flex-start"><span class="price-tag">' + item.price + ' $</span></p><button type="button" class="item-btn btn-sm btn btn-outline-info" data-toggle="modal" data-target=".details-modal">Подробней <img style="height: 10px" "></button></div>';
                } else {
                    var el = '<div class="item-block flex" style="flex-direction: column"><input type="hidden" value='+ JSON.stringify(item) +'><img class="img-fluid" style="box-shadow: 0 0 10px rgba(0,0,0,0.5);" src="' + item.image + '"><h6 class="item-title">' + item.rus_representation + ' "' + item.brand + '"<hr></h6><p class="flex" style="align-items: flex-start"><span class="price-tag">' + item.price + ' $</span><span class="discount badge badge-danger">' + item.discount + ' $</span></p><button type="button" class="item-btn btn-sm btn btn-outline-info" data-toggle="modal" data-target=".details-modal">Подробней <img style="height: 10px" "></button></div>';
                }
                $('.items-list').children('hr').after(el)
            });

        }
    })
});

Java Script function which fills the modal with related data:

$(document).on('click', '.item-btn', function () {
var data = JSON.parse($(this).siblings('input').val()); (line 54 where error message points)

$('.product-title').html(data.rus_representation + ' "<i>' + data.brand + '</i>"' + '<hr>');

if(data.description) {
    $('.product-description').text(data.description);
}else{
    $('.product-description').html('<h4>Описнаие пока не добавлено</h4>')
}

$('.carousel-inner').empty();
$.each(data.images, function (index, img) {
    if(index === 0){
        var el = '<div class="carousel-item active"><img class="d-block w-100" src="'+ img +'"></div>'
    } else {
        var el = '<div class="carousel-item"><img class="d-block w-100" src="'+ img +'"></div>'
    }

    $('.carousel-inner').append(el)
});

$('.product-brand').html('<i>' + data.brand + '</i>');
$('.product-type').text(data.rus_representation);
$('.product-season').text(data.season);

if (data.discount){
    $('.discount-in-modal').html('<span class="discount badge badge-danger" style="position: relative; top: -5px">'+ data.discount +' $</span>');
}

$('.product-price').text(data.price);

});

HTML:

            {% for item in object_list %}
            <div class="item-block flex" style="flex-direction: column">
                <input type="hidden" value="{{ item.dumped_as_dict }}">
                <img class="img-fluid" style="box-shadow: 0 0 10px rgba(0,0,0,0.5); max-height: 300px" src="{{ item.image.url }}">
                <h6 class="item-title">
                    {{item.rus_representation}} "{{item.brand}}"
                    <hr>
                </h6>
                <p class="flex" style="align-items: flex-start">
                    <span class="price-tag">{{ item.price }} $</span>
                    {% if item.discount %}
                        <span class="discount badge badge-danger">{{ item.discount }} $</span>
                    {% endif %}
                </p>
                <button type="button" class="item-btn btn-sm btn btn-outline-info" data-toggle="modal" data-target=".details-modal">Подробней <img style="height: 10px" src="{% static 'img/arrow.png' %}"></button>
            </div>
        {% endfor %}

IF do console.log(JSON.stringify(item));:

{"title":"tst","image":"/media/img/_58A1259_sm.jpg","brand":"GUCCI","type":"SK","discount":9000000,"price":9,"rus_representation":"Юбка","description":"LoL Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.","season":"","images":["/media/img/_58A1259_sm.jpg","/media/img/_58A7975_sm.jpg"]}

How it should look like:

opening the modal on initial load

What I have:

if use filtering and them trying to open details modal

Adding view from Inspector: For some reasons string is not fully added to value attr

Vlad Ivanyk
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    What we need to see here is the html that the JSON.parse line is operating on - it looks like it doesn't contain valid json. – snakecharmerb Dec 29 '18 at 15:55
  • `JavaScript filter function` part, you can see the variable `el` there, which holds the html for just filtered results Will aslo add html on how it looks like on initial load – Vlad Ivanyk Dec 29 '18 at 15:58
  • [This](https://stackoverflow.com/a/8542786/5320906) might be a better approach - json in the value attribute may not be parsed correctly. – snakecharmerb Dec 29 '18 at 16:09
  • @VladIvanyk the problem is that whatever is in the `.value` of the `` is not valid JSON, but you did not post what the `.value` actually looks like. – Pointy Dec 29 '18 at 16:17
  • @Pointy As I said above it is visible in the js function responsible for filtering `$('.choice-link').click(function () {` where I have variable `el` inside the `$.each` loop. `var el = '
    ` If I got you right of coursse
    – Vlad Ivanyk Dec 29 '18 at 16:27
  • @snakecharmerb trying to implement method you shared but for current moment no luck – Vlad Ivanyk Dec 29 '18 at 16:28
  • What I mean is that we cannot see the output of that `JSON.stringify()` call. In particular, if there is a `'` character in the string that will break the HTML syntax. You can encode special HTML characters like `<`, `>`, and the quote characters with a separate function to do a simple search/replace with HTML entities. – Pointy Dec 29 '18 at 16:32
  • @Pointy check this screen from inspector please on the bottom of my question, it named `Adding view from Inspector: For some reasons string is not fully added to value attr` – Vlad Ivanyk Dec 29 '18 at 16:36
  • I see that screen shot, yes, but that's still confusing because you're seeing the result of what happened when the HTML was parsed; in other words, that's the evidence that the problem happened, but the actual input text is where the problem actually is. – Pointy Dec 29 '18 at 16:37
  • updated the quetion with `IF do console.log(JSON.stringify(item));` That is what you meant? – Vlad Ivanyk Dec 29 '18 at 16:40

1 Answers1

0

When you build that HTML string, your code does something like this:

var el = '<div ... value=' + JSON.stringify(x) + ' ... >';

The HTML result will therefore be

var el = '<div ... value={ ... } ... >';

Because the attribute value for "value" is not quoted in the resulting HTML source, the first space character in the JSON is the end of the attribute value, as far as the HTML parser is concerned.

You need to include quotes at least:

var el = '<div ... value=\'' + JSON.stringify(x) + '\' ... >';

I would also strongly suggest that you use an HTML entity encoder to encode any HTML metacharacters in the string, something like

function scrubHtml(s) {
  return s.replace(/[<>'"&]/g, function(meta) {
    return "&#" + meta.charCodeAt(0) + ";";
  });
}
Pointy
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  • That part you added after editing it replaces `/[<>'"&]/g` symbols with `"&" + meta.charCodeAt(0) + ";";` but what is that symbol ? – Vlad Ivanyk Dec 29 '18 at 16:56
  • HTML entity notation: `&nnn;` where the *nnn* part is a character code. That protects embedded HTML special characters from confusing the HTML parser. The resulting attribute values will be plain strings; those symbols are "digested" by HTML into simple characters. – Pointy Dec 29 '18 at 18:45
  • @VladIvanyk oops except I forgot something important!! It should be `` not just `&` - fixing the answer now. My apologies. – Pointy Dec 29 '18 at 18:56