apps/catalogue/fields.py

   1 # -*- coding: utf-8 -*-
   2 import datetime
   3
   4 from django.conf import settings
   5 from django.db import models
   6 from django.db.models import signals
   7 from django.dispatch import dispatcher
   8 from django import forms
   9 from django.forms.widgets import flatatt
  10 from django.forms.util import smart_unicode
  11 from django.utils import simplejson as json
  12 from django.utils.html import escape
  13 from django.utils.safestring import mark_safe
  14
  15
  16 class JSONEncoder(json.JSONEncoder):
  17     def default(self, obj):
  18         if isinstance(obj, datetime.datetime):
  19             return obj.strftime('%Y-%m-%d %H:%M:%S')
  20         elif isinstance(obj, datetime.date):
  21             return obj.strftime('%Y-%m-%d')
  22         elif isinstance(obj, datetime.time):
  23             return obj.strftime('%H:%M:%S')
  24         return json.JSONEncoder.default(self, obj)
  25
  26
  27 def dumps(data):
  28     return JSONEncoder().encode(data)
  29
  30
  31 def loads(str):
  32     return json.loads(str, encoding=settings.DEFAULT_CHARSET)
  33
  34
  35 class JSONField(models.TextField):
  36     def db_type(self):
  37         return 'text'
  38
  39     def get_internal_type(self):
  40         return 'TextField'
  41
  42     def pre_save(self, model_instance, add):
  43         value = getattr(model_instance, self.attname, None)
  44         return dumps(value)
  45
  46     def contribute_to_class(self, cls, name):
  47         super(JSONField, self).contribute_to_class(cls, name)
  48         dispatcher.connect(self.post_init, signal=signals.post_init, sender=cls)
  49
  50         def get_json(model_instance):
  51             return dumps(getattr(model_instance, self.attname, None))
  52         setattr(cls, 'get_%s_json' % self.name, get_json)
  53
  54         def set_json(model_instance, json):
  55             return setattr(model_instance, self.attname, loads(json))
  56         setattr(cls, 'set_%s_json' % self.name, set_json)
  57
  58     def post_init(self, instance=None):
  59         value = self.value_from_object(instance)
  60         if (value):
  61             setattr(instance, self.attname, loads(value))
  62         else:
  63             setattr(instance, self.attname, None)
  64
  65
  66 class JQueryAutoCompleteWidget(forms.TextInput):
  67     def __init__(self, source, options=None, *args, **kwargs):
  68         self.source = source
  69         self.options = None
  70         if options:
  71             self.options = dumps(options)
  72         super(JQueryAutoCompleteWidget, self).__init__(*args, **kwargs)
  73
  74     def render_js(self, field_id):
  75         source = "'%s'" % escape(self.source)
  76         options = ''
  77         if self.options:
  78             options += ', %s' % self.options
  79
  80         return u'$(\'#%s\').autocomplete(%s%s);' % (field_id, source, options)
  81
  82     def render(self, name, value=None, attrs=None):
  83         final_attrs = self.build_attrs(attrs, name=name)
  84         if value:
  85             final_attrs['value'] = smart_unicode(value)
  86
  87         if not self.attrs.has_key('id'):
  88             final_attrs['id'] = 'id_%s' % name
  89
  90         html = u'''<input type="text" %(attrs)s/>
  91             <script type="text/javascript">//<!--
  92             %(js)s//--></script>
  93             ''' % {
  94                 'attrs' : flatatt(final_attrs),
  95                 'js' : self.render_js(final_attrs['id']),
  96             }
  97
  98         return mark_safe(html)
  99
 100
 101 class JQueryAutoCompleteField(forms.CharField):
 102     def __init__(self, source, options=None, *args, **kwargs):
 103         if 'widget' not in kwargs:
 104             kwargs['widget'] = JQueryAutoCompleteWidget(source, options)
 105
 106         super(JQueryAutoCompleteField, self).__init__(*args, **kwargs)
 107