adminutils (for django.contrib.admin)

adminutils.py

# -*- coding: utf-8 -*-

"""
Usage:

    from django.contrib import admin
    
    class MyModelAdmin(admin.ModelAdmin):
        list_display = ('trunc_name', 'value')
        
        trunc_name = truncate_field('name')
"""

from django.utils.text import capfirst


def attrs(**kwargs):
    def attrsetter(function):
        for key, value in kwargs.items():
            setattr(function, key, value)
        return function
    return attrsetter


def truncate_field(field_name, verbose_name=None, max_length=50):
    
    if hasattr(field_name, '__call__'):
        getter = (lambda fun: lambda obj: fun(obj))(field_name)
        
        if hasattr(field_name, 'verbose_name'):
            verbose_name = field_name.verbose_name
        elif hasattr(field_name, 'short_description'):
            verbose_name = field_name.short_description
        
        if hasattr(field_name, 'field_name'):
            field_name = field_name.field_name
        else:
            field_name = field_name.__name__
    
    else:
        getter = lambda obj: getattr(obj, field_name)
        
    if not verbose_name:
        verbose_name = capfirst(field_name.replace('_', ' '))
    
    @attrs(
        short_description=verbose_name,
        admin_order_field=field_name)
    def truncated(self, obj):
        field = getter(obj)
        if len(field) <= max_length:
            return field
        return field[:(max_length - 3)] + '...'
    
    return truncated