Inherit and modify a `Meta` class

Question

So I have a base ItemTable, and then a number of Tables that inherit from it. I don't seem to be able to modify the Meta class. I tried just including the meta class normally and it didn't work, then I found this bug report and implemented it below. It fails silently: the tables render only with the columns from the parent meta class.

class ItemTable(tables.Table):

    class Meta:
        model = Item
        attrs = {"class":"paleblue"}
        fields = ('name', 'primary_tech', 'primary_biz', 'backup_tech', 'backup_biz')

class ApplicationTable(ItemTable):

    def __init__(self, *args, **kwargs):
        super(ApplicationTable, self).__init__(*args, **kwargs)

    class Meta(ItemTable.Meta):
        model = Application
        fields += ('jira_bucket_name',)

EDIT: Code amended as shown. I now get a NameError that fields is not defined.

A class named `Meta` and `Metaclass` are two different things. — Ashwini Chaudhary, Feb 14 '14 at 19:35
ok... well, terminology aside--and I'll be sure to research that--what am I doing wrong? — thumbtackthief, Feb 14 '14 at 19:36

score 5 · Accepted Answer · answered Feb 14 '14 at 20:48

5

Try:

class ApplicationTable(ItemTable):
    class Meta:
        model = Application
        fields = ItemTable.Meta.fields + ('jira_bucket_name',)

You'll have the same problems extending Meta in a table, as you will in a normal Django model.

answered Feb 14 '14 at 20:48

bradley.ayers

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This fails silently, but does not add the new columns. FWIW, this is the first time I've ever tried extending `Meta`, so I don't know how it compares to a non-django-tables2 model. – thumbtackthief Feb 14 '14 at 21:20
There was an embarrassing level of idiocy on my part that kept this from working. This is the correct solution. Thanks! – thumbtackthief Feb 18 '14 at 19:54

ndpu · Answer 2 · 2014-02-14T21:25:27.990

4

You didnt add , (comma) to one-element tuple. Try to change this line Meta.attrs['fields'] += ('jira_bucket_name') in ApplicationTable to:

Meta.attrs['fields'] += ('jira_bucket_name',)

if it didnt help try to create Meta class outsite model class definition:

class ItemTableMeta:
    model = Item
    attrs = {"class":"paleblue"}
    fields = ('name', 'primary_tech', 'primary_biz', 'backup_tech', 'backup_biz')

class ApplicationTableMeta(ItemTableMeta):
    model = Application
    fields = ItemTableMeta.fields + ('jira_bucket_name',)


class ItemTable(tables.Table):
    #...
    Meta = ItemTableMeta

class ApplicationTable(ItemTable):
    #...
    Meta = ApplicationTableMeta

edited Feb 14 '14 at 21:25

answered Feb 14 '14 at 20:25

ndpu

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Good catch, but didn't help with this problem. – thumbtackthief Feb 14 '14 at 20:42
No dice: All the tables still are only recognizing the parent ItemTableMeta. No error messages. – thumbtackthief Feb 18 '14 at 17:56
1

@thumbtackthief it is a django-tables issue, found this in docs https://docs.djangoproject.com/en/dev/topics/db/models/#meta-inheritance – ndpu Feb 18 '14 at 19:22

score 0 · Answer 3 · answered Feb 14 '14 at 20:30

0

You may need to take this up with the django-tables author. This is not a problem with standard Django.

answered Feb 14 '14 at 20:30

Paul Bissex

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I've added to the known bug report (2 years old) but haven't gotten a response yet. – thumbtackthief Feb 14 '14 at 20:44

Inherit and modify a `Meta` class

3 Answers3