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 import forms
   8 from django.forms.widgets import flatatt
   9 from django.forms.util import smart_unicode
  10 from django.utils import simplejson as json
  11 from django.utils.html import escape
  12 from django.utils.safestring import mark_safe
  13
  14
  15 class JSONEncoder(json.JSONEncoder):
  16     def default(self, obj):
  17         if isinstance(obj, datetime.datetime):
  18             return obj.strftime('%Y-%m-%d %H:%M:%S')
  19         elif isinstance(obj, datetime.date):
  20             return obj.strftime('%Y-%m-%d')
  21         elif isinstance(obj, datetime.time):
  22             return obj.strftime('%H:%M:%S')
  23         return json.JSONEncoder.default(self, obj)
  24
  25
  26 def dumps(data):
  27     return JSONEncoder().encode(data)
  28
  29
  30 def loads(str):
  31     return json.loads(str, encoding=settings.DEFAULT_CHARSET)
  32
  33
  34 class JSONFormField(forms.CharField):
  35     widget = forms.Textarea
  36
  37     def clean(self, value):
  38         try:
  39             loads(value)
  40             return value
  41         except ValueError, e:
  42             raise forms.ValidationError('Enter a valid JSON value. Error: %s' % e)
  43
  44
  45 class JSONField(models.TextField):
  46     def formfield(self, **kwargs):
  47         defaults = {'form_class': JSONFormField}
  48         defaults.update(kwargs)
  49         return super(JSONField, self).formfield(**defaults)
  50
  51     def db_type(self):
  52         return 'text'
  53
  54     def get_internal_type(self):
  55         return 'TextField'
  56
  57     def contribute_to_class(self, cls, name):
  58         super(JSONField, self).contribute_to_class(cls, name)
  59
  60         def get_value(model_instance):
  61             return loads(getattr(model_instance, self.attname, None))
  62         setattr(cls, 'get_%s_value' % self.name, get_value)
  63
  64         def set_value(model_instance, json):
  65             return setattr(model_instance, self.attname, dumps(json))
  66         setattr(cls, 'set_%s_value' % self.name, set_value)
  67
  68
  69 class JQueryAutoCompleteWidget(forms.TextInput):
  70     def __init__(self, source, options=None, *args, **kwargs):
  71         self.source = source
  72         self.options = None
  73         if options:
  74             self.options = dumps(options)
  75         super(JQueryAutoCompleteWidget, self).__init__(*args, **kwargs)
  76
  77     def render_js(self, field_id):
  78         source = "'%s'" % escape(self.source)
  79         options = ''
  80         if self.options:
  81             options += ', %s' % self.options
  82
  83         return u'$(\'#%s\').autocomplete(%s%s);' % (field_id, source, options)
  84
  85     def render(self, name, value=None, attrs=None):
  86         final_attrs = self.build_attrs(attrs, name=name)
  87         if value:
  88             final_attrs['value'] = smart_unicode(value)
  89
  90         if not self.attrs.has_key('id'):
  91             final_attrs['id'] = 'id_%s' % name
  92
  93         html = u'''<input type="text" %(attrs)s/>
  94             <script type="text/javascript">//<!--
  95             %(js)s//--></script>
  96             ''' % {
  97                 'attrs' : flatatt(final_attrs),
  98                 'js' : self.render_js(final_attrs['id']),
  99             }
 100
 101         return mark_safe(html)
 102
 103
 104 class JQueryAutoCompleteField(forms.CharField):
 105     def __init__(self, source, options=None, *args, **kwargs):
 106         if 'widget' not in kwargs:
 107             kwargs['widget'] = JQueryAutoCompleteWidget(source, options)
 108
 109         super(JQueryAutoCompleteField, self).__init__(*args, **kwargs)
 110