AttributeError while using a value_class

[chadsaun]

• wagtail_cache_block version: 0.1.3
• Django version: 2.2
• Python version: 3..6
• Operating System: Linux

Description

I used the cache_block template tag{% cache_block 300 request block %}...

    {% for card in self.product_cards %}
      {% cache_block 300 request card %}
        {% include_block card with request=request block=card only %}
      {% endcache_block %}
    {% endfor %}

...and got the following error

AttributeError at /
'ProductCardValue' object has no attribute 'value'

The error happened on this line of code for k, v in block_obj.value.bound_blocks.items(): which is in the middle of the below code...

def extract_block(block_obj):
    """
    Extract block values to vary_on list
    """
    vary_on = []
    if isinstance(block_obj.block, StructBlock):
        tmp_dict = {}
        for k, v in block_obj.value.bound_blocks.items():
            tmp_dict[k] = extract_block(v)
        vary_on.append({block_obj.block.name: tmp_dict})
    elif isinstance(block_obj.block, StreamBlock):
        tmp_ls = []
        for child in block_obj.value:
            sub_value = extract_block(child)

The block_obj is a ProductCardValue object which is this below:

class ProductCardValue(StructValue):
    
    def review_aggregate_data(self):
        
        ...
        
        return {}
    
    def product_info(self):

        ...
        
        return {}

The ProductCardValue is used by the ProductCardBlock as seen below:

class ProductCardBlock(blocks.StructBlock):
    title_link = LinkBlock(help_text='The title of the product')
    image_link = LinkBlock(required=False, help_text='The main image with a link')
    body = blocks.RichTextBlock(required=False, features=RICH_TEXT_FEATURES)
    product_id = blocks.ChoiceBlock(required=False, choices=PRODUCT_CHOICES, help_text='The product')
    show_product_reviews = blocks.BooleanBlock(required=False, help_text='Do you want to show the product review stars?')
    
    class Meta:
        template = 'streams/product_card_block.html'
        icon = 'placeholder'
        label = 'Product Card'
        value_class = ProductCardValue

Does this not work if you are using a value_class?