failed to render field for a new added attribute

[Jasper Yang]

hi All:

I'm getting crazy with this little thing.

1)I override StockRecord by adding a new attribute like

/apps/partner/models.py

class StockRecord(AbstractStockRecord):

    num_in_stock_default = models.PositiveIntegerField(

                    _("Number in stock default value"), blank=True, null=True)

make migration and very sure this has been added to database.

2)I add this new attribute to StockRecordForm

apps/dashboard/catalogue/forms.py

class StockRecordForm(CoreStockRecordForm):

    class Meta:

        model = StockRecord

        fields = [

            'partner', 'partner_sku',

            'price_currency', 'price_excl_tax', 'price_retail', 'cost_price',

            'num_in_stock', 'num_in_stock_default', 'low_stock_threshold',

        ]

3)change the template to show this attribute.

templates/dashboard/catalogue/product_update.html

<td>{% include "dashboard/partials/form_field.html" with field=stockrecord_form.num_in_stock_default nolabel=True %}</td>

finally, I get failure with nothing render for this attribute. the html generated for this attribute like this:

<div class="form-group ">      

                <div class="">

                </div>            

        </div>

anything wrong or missed??

and i try to find out in templates/oscar/dashboard/partials/form_field.html and guess it get something wrong within 'render_field'.

but unfortunately, I found little info with this tag. what is 'render_field'? 

{%else%}
	{% render_field field class+="form-control" %}
	{% endif %}

BR//Jasper