helpers.format makes sorting work as if column is text rather than numeric

[bmatzelle]

I am using the helpers.format function to return numbers with commas included, helpers.format("{0:,}") to be specific, but I'm having an issue because if I click the column to sort the results they are getting returned as if the column were a text (non-numeric) field. Below is the order that the results are getting returned. Here is a screenshot of the table results.

• 7,786
• 52
• 5,406
• 43
• 4,692
• 4
• 318
• 2,857
• 158
• 1,676

What can I do to have them be returned in the correct order (7,786 > 5,406 > 4692, and so on)?

My development environment is the following:

• Django 1.6.5
• Python 2.7.5
• django-datatable-view 0.7.1

[tiliv]

Hm... does the middle argument of the column definition correctly reflect a database value, or is it computed via a method?

It sounds like the code is deciding it's not a real database field, and it's manually sorting by post-processed version of the data.

To prevent this, make sure the value's model field is correctly specified as part of the column definition:

datatable_options = {
    'columns': [ ('My Field', 'path__field', helpers.callback("{0:,}")) ],
}

If the field is calculated and not actually available at the query level, you can specify a model method/property name, and then you'll have to return a 2-tuple of data from your datatable callback so that it knows what is "formatted" and what is "raw":

datatable_options = {
    'columns': [ ('My Field', 'path__field', helpers.callback("{0:,}")) ],
}
def get_column_My_Field_data(self, obj, *args, **kwargs):
    text = "{0:,}".format(obj.path.field)
    return (text, obj.path.field)

I think this managed to escape full documentation. I'll see what I can do to add that in. It's not the kind of thing you want to be forced into doing often, but let me know if it changes anything.

[bmatzelle]

Hm... does the middle argument of the column definition correctly reflect a database value, or is it computed via a method?

It's computed by a method.

If the field is calculated and not actually available at the query level, you can specify a model method/property name, and then you'll have to return a 2-tuple of data from your datatable callback so that it knows what is "formatted" and what is "raw"

Excellent! Thanks for the help!