Allow separate accessor for sort field on columns (code attached)

[chriscrowe]

In my code I use an accessor for a column that points to a function in my model (the function translates a ManyToMany field into a comma-separated string). But when trying to sort on said column, it will fail because the accessor does not resolve to an actual field on my model. So I added an extra kwarg to the Column initializer so you can specify an optional sort_accessor, which instead of pointing to my model function it points to one of the fields:

In columns.py - modified Column and BoundColumn to accept sort_accessor kwarg
http://dpaste.com/579958/

In tables.py - modified _translate_order_by function
http://dpaste.com/579959/

Sorry-- I would submit a pull request but I haven't forked you project (plus the version I'm using is a few months old), and I don't really have time to set all that up right now.

[bradleyayers]

Hi thanks for the suggestion, but I'm hesitant to add this feature. As it stands I feel like there's already too many configuration options. This functionality can be achieved by using a render_FOO method, e.g.

def render_m2m_field(self, record):
    return record.m2m_pretty_method()

[thibault]

I think this feature would be really useful. Let's they thay I've got a table displaying a list of products. There's a column displaying the first and last name of the product's buyer. I should be able to sort by last name.

Anyway, this is a recurrent need I meet using this application.

[bradleyayers]

Thanks for the input @thibault. What's your feeling about the approach using the render_FOO method? Too verbose for such a common pattern?

def render_m2m_field(self, record):
return record.m2m_pretty_method()

If I were to add this I'm leaning toward calling the argument order_by_accessor or just order_by.

[chriscrowe]

I fell back to using the render_FOO methods after you shot down my idea... But I do think that it's a bit verbose if you've got lots of columns referring to fields on a foreign key object.

[bradleyayers]

Okay well this isn't an issue that I've come across personally, but since both @skandocious and @thibault have, and contributed to this ticket it means there's probably a bunch of other people that would want this too. I'll look into adding it.

[thibault]

Hi, and thank you for your fast reply. Since you ask, I think the render_FOO is ok. Verbose, maybe, but do we really need something shorter, I'm not sure.

An order_by accessor, which would allow me to order a queryset by any field, including in a foreign table would be great.

[twoolie]

I remember that there used to be a property you could add to instance methods which would tell the admin interface which field to order with respect to when ordering by that generated value. I can't seem to find it in the docs, but maybe someone else can?