apps/catalogue/fields.py

   1 # -*- coding: utf-8 -*-
   2 # This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
   3 # Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
   4 #
   5 import datetime
   6 from functools import wraps
   7
   8 from django.conf import settings
   9 from django.db import models
  10 from django.db.models.fields.files import FieldFile
  11 from django.db.models import signals
  12 from django import forms
  13 from django.forms.widgets import flatatt
  14 from django.utils.encoding import smart_unicode
  15 from django.utils import simplejson as json
  16 from django.utils.html import escape
  17 from django.utils.safestring import mark_safe
  18 from django.utils.translation import ugettext_lazy as _
  19
  20
  21 class JSONEncoder(json.JSONEncoder):
  22     def default(self, obj):
  23         if isinstance(obj, datetime.datetime):
  24             return obj.strftime('%Y-%m-%d %H:%M:%S')
  25         elif isinstance(obj, datetime.date):
  26             return obj.strftime('%Y-%m-%d')
  27         elif isinstance(obj, datetime.time):
  28             return obj.strftime('%H:%M:%S')
  29         return json.JSONEncoder.default(self, obj)
  30
  31
  32 def dumps(data):
  33     return JSONEncoder().encode(data)
  34
  35
  36 def loads(str):
  37     return json.loads(str, encoding=settings.DEFAULT_CHARSET)
  38
  39
  40 class JSONFormField(forms.CharField):
  41     widget = forms.Textarea
  42
  43     def clean(self, value):
  44         try:
  45             loads(value)
  46             return value
  47         except ValueError, e:
  48             raise forms.ValidationError(_('Enter a valid JSON value. Error: %s') % e)
  49
  50
  51 class JSONField(models.TextField):
  52     def formfield(self, **kwargs):
  53         defaults = {'form_class': JSONFormField}
  54         defaults.update(kwargs)
  55         return super(JSONField, self).formfield(**defaults)
  56
  57     def db_type(self, connection):
  58         return 'text'
  59
  60     def get_internal_type(self):
  61         return 'TextField'
  62
  63     def contribute_to_class(self, cls, name):
  64         super(JSONField, self).contribute_to_class(cls, name)
  65
  66         def get_value(model_instance):
  67             return loads(getattr(model_instance, self.attname, None))
  68         setattr(cls, 'get_%s_value' % self.name, get_value)
  69
  70         def set_value(model_instance, json):
  71             return setattr(model_instance, self.attname, dumps(json))
  72         setattr(cls, 'set_%s_value' % self.name, set_value)
  73
  74
  75 class JQueryAutoCompleteWidget(forms.TextInput):
  76     def __init__(self, options, *args, **kwargs):
  77         self.options = dumps(options)
  78         super(JQueryAutoCompleteWidget, self).__init__(*args, **kwargs)
  79
  80     def render_js(self, field_id, options):
  81         return u'$(\'#%s\').autocomplete(%s).result(autocomplete_result_handler);' % (field_id, options)
  82
  83     def render(self, name, value=None, attrs=None):
  84         final_attrs = self.build_attrs(attrs, name=name)
  85         if value:
  86             final_attrs['value'] = smart_unicode(value)
  87
  88         if not self.attrs.has_key('id'):
  89             final_attrs['id'] = 'id_%s' % name
  90
  91         html = u'''<input type="text" %(attrs)s/>
  92             <script type="text/javascript">//<!--
  93             %(js)s//--></script>
  94             ''' % {
  95                 'attrs': flatatt(final_attrs),
  96                 'js' : self.render_js(final_attrs['id'], self.options),
  97             }
  98
  99         return mark_safe(html)
 100
 101
 102 class JQueryAutoCompleteSearchWidget(JQueryAutoCompleteWidget):
 103     def __init__(self, *args, **kwargs):
 104         super(JQueryAutoCompleteSearchWidget, self).__init__(*args, **kwargs)
 105
 106     def render_js(self, field_id, options):
 107         return u"""
 108         $('#%s')
 109         .autocomplete($.extend({
 110           minLength: 0,
 111           select: autocomplete_result_handler,
 112           focus: function (ui, item) { return false; }
 113         }, %s))
 114         .data("autocomplete")._renderItem = autocomplete_format_item;
 115         """ % (field_id, options)
 116
 117
 118 class JQueryAutoCompleteField(forms.CharField):
 119     def __init__(self, source, options={}, *args, **kwargs):
 120         if 'widget' not in kwargs:
 121             options['source'] = source
 122             kwargs['widget'] = JQueryAutoCompleteWidget(options)
 123
 124         super(JQueryAutoCompleteField, self).__init__(*args, **kwargs)
 125
 126
 127 class JQueryAutoCompleteSearchField(forms.CharField):
 128     def __init__(self, source, options={}, *args, **kwargs):
 129         if 'widget' not in kwargs:
 130             options['source'] = source
 131             kwargs['widget'] = JQueryAutoCompleteSearchWidget(options)
 132
 133         super(JQueryAutoCompleteSearchField, self).__init__(*args, **kwargs)
 134
 135
 136 class OverwritingFieldFile(FieldFile):
 137     """
 138         Deletes the old file before saving the new one.
 139     """
 140
 141     def save(self, name, content, *args, **kwargs):
 142         leave = kwargs.pop('leave', None)
 143         # delete if there's a file already and there's a new one coming
 144         if not leave and self and (not hasattr(content, 'path') or
 145                                    content.path != self.path):
 146             self.delete(save=False)
 147         return super(OverwritingFieldFile, self).save(
 148                 name, content, *args, **kwargs)
 149
 150
 151 class OverwritingFileField(models.FileField):
 152     attr_class = OverwritingFieldFile
 153
 154
 155 try:
 156     # check for south
 157     from south.modelsinspector import add_introspection_rules
 158
 159     add_introspection_rules([], ["^catalogue\.fields\.JSONField"])
 160     add_introspection_rules([], ["^catalogue\.fields\.OverwritingFileField"])
 161 except ImportError:
 162     pass