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1 from datetime import datetime, timedelta |
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2 |
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3 from django.core.exceptions import ImproperlyConfigured, ObjectDoesNotExist |
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4 from django.template import loader, Template, TemplateDoesNotExist |
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5 from django.contrib.sites.models import Site, RequestSite |
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6 from django.utils import feedgenerator |
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7 from django.utils.tzinfo import FixedOffset |
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8 from django.utils.encoding import smart_unicode, iri_to_uri |
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9 from django.conf import settings |
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10 from django.template import RequestContext |
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11 |
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12 def add_domain(domain, url): |
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13 if not (url.startswith('http://') or url.startswith('https://')): |
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14 # 'url' must already be ASCII and URL-quoted, so no need for encoding |
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15 # conversions here. |
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16 url = iri_to_uri(u'http://%s%s' % (domain, url)) |
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17 return url |
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18 |
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19 class FeedDoesNotExist(ObjectDoesNotExist): |
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20 pass |
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21 |
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22 class Feed(object): |
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23 item_pubdate = None |
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24 item_enclosure_url = None |
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25 feed_type = feedgenerator.DefaultFeed |
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26 feed_url = None |
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27 title_template = None |
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28 description_template = None |
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29 |
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30 def __init__(self, slug, request): |
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31 self.slug = slug |
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32 self.request = request |
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33 self.feed_url = self.feed_url or request.path |
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34 self.title_template_name = self.title_template or ('feeds/%s_title.html' % slug) |
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35 self.description_template_name = self.description_template or ('feeds/%s_description.html' % slug) |
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36 |
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37 def item_link(self, item): |
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38 try: |
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39 return item.get_absolute_url() |
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40 except AttributeError: |
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41 raise ImproperlyConfigured, "Give your %s class a get_absolute_url() method, or define an item_link() method in your Feed class." % item.__class__.__name__ |
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42 |
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43 def __get_dynamic_attr(self, attname, obj, default=None): |
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44 try: |
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45 attr = getattr(self, attname) |
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46 except AttributeError: |
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47 return default |
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48 if callable(attr): |
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49 # Check func_code.co_argcount rather than try/excepting the |
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50 # function and catching the TypeError, because something inside |
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51 # the function may raise the TypeError. This technique is more |
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52 # accurate. |
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53 if hasattr(attr, 'func_code'): |
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54 argcount = attr.func_code.co_argcount |
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55 else: |
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56 argcount = attr.__call__.func_code.co_argcount |
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57 if argcount == 2: # one argument is 'self' |
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58 return attr(obj) |
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59 else: |
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60 return attr() |
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61 return attr |
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62 |
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63 def feed_extra_kwargs(self, obj): |
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64 """ |
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65 Returns an extra keyword arguments dictionary that is used when |
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66 initializing the feed generator. |
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67 """ |
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68 return {} |
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69 |
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70 def item_extra_kwargs(self, item): |
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71 """ |
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72 Returns an extra keyword arguments dictionary that is used with |
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73 the `add_item` call of the feed generator. |
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74 """ |
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75 return {} |
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76 |
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77 def get_object(self, bits): |
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78 return None |
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79 |
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80 def get_feed(self, url=None): |
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81 """ |
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82 Returns a feedgenerator.DefaultFeed object, fully populated, for |
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83 this feed. Raises FeedDoesNotExist for invalid parameters. |
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84 """ |
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85 if url: |
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86 bits = url.split('/') |
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87 else: |
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88 bits = [] |
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89 |
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90 try: |
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91 obj = self.get_object(bits) |
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92 except ObjectDoesNotExist: |
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93 raise FeedDoesNotExist |
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94 |
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95 if Site._meta.installed: |
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96 current_site = Site.objects.get_current() |
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97 else: |
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98 current_site = RequestSite(self.request) |
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99 |
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100 link = self.__get_dynamic_attr('link', obj) |
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101 link = add_domain(current_site.domain, link) |
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102 |
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103 feed = self.feed_type( |
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104 title = self.__get_dynamic_attr('title', obj), |
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105 subtitle = self.__get_dynamic_attr('subtitle', obj), |
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106 link = link, |
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107 description = self.__get_dynamic_attr('description', obj), |
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108 language = settings.LANGUAGE_CODE.decode(), |
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109 feed_url = add_domain(current_site.domain, |
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110 self.__get_dynamic_attr('feed_url', obj)), |
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111 author_name = self.__get_dynamic_attr('author_name', obj), |
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112 author_link = self.__get_dynamic_attr('author_link', obj), |
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113 author_email = self.__get_dynamic_attr('author_email', obj), |
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114 categories = self.__get_dynamic_attr('categories', obj), |
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115 feed_copyright = self.__get_dynamic_attr('feed_copyright', obj), |
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116 feed_guid = self.__get_dynamic_attr('feed_guid', obj), |
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117 ttl = self.__get_dynamic_attr('ttl', obj), |
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118 **self.feed_extra_kwargs(obj) |
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119 ) |
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120 |
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121 try: |
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122 title_tmp = loader.get_template(self.title_template_name) |
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123 except TemplateDoesNotExist: |
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124 title_tmp = Template('{{ obj }}') |
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125 try: |
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126 description_tmp = loader.get_template(self.description_template_name) |
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127 except TemplateDoesNotExist: |
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128 description_tmp = Template('{{ obj }}') |
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129 |
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130 for item in self.__get_dynamic_attr('items', obj): |
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131 link = add_domain(current_site.domain, self.__get_dynamic_attr('item_link', item)) |
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132 enc = None |
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133 enc_url = self.__get_dynamic_attr('item_enclosure_url', item) |
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134 if enc_url: |
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135 enc = feedgenerator.Enclosure( |
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136 url = smart_unicode(enc_url), |
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137 length = smart_unicode(self.__get_dynamic_attr('item_enclosure_length', item)), |
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138 mime_type = smart_unicode(self.__get_dynamic_attr('item_enclosure_mime_type', item)) |
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139 ) |
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140 author_name = self.__get_dynamic_attr('item_author_name', item) |
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141 if author_name is not None: |
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142 author_email = self.__get_dynamic_attr('item_author_email', item) |
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143 author_link = self.__get_dynamic_attr('item_author_link', item) |
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144 else: |
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145 author_email = author_link = None |
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146 |
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147 pubdate = self.__get_dynamic_attr('item_pubdate', item) |
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148 if pubdate and not pubdate.tzinfo: |
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149 now = datetime.now() |
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150 utcnow = datetime.utcnow() |
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151 |
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152 # Must always subtract smaller time from larger time here. |
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153 if utcnow > now: |
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154 sign = -1 |
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155 tzDifference = (utcnow - now) |
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156 else: |
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157 sign = 1 |
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158 tzDifference = (now - utcnow) |
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159 |
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160 # Round the timezone offset to the nearest half hour. |
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161 tzOffsetMinutes = sign * ((tzDifference.seconds / 60 + 15) / 30) * 30 |
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162 tzOffset = timedelta(minutes=tzOffsetMinutes) |
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163 pubdate = pubdate.replace(tzinfo=FixedOffset(tzOffset)) |
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164 |
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165 feed.add_item( |
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166 title = title_tmp.render(RequestContext(self.request, {'obj': item, 'site': current_site})), |
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167 link = link, |
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168 description = description_tmp.render(RequestContext(self.request, {'obj': item, 'site': current_site})), |
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169 unique_id = self.__get_dynamic_attr('item_guid', item, link), |
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170 enclosure = enc, |
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171 pubdate = pubdate, |
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172 author_name = author_name, |
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173 author_email = author_email, |
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174 author_link = author_link, |
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175 categories = self.__get_dynamic_attr('item_categories', item), |
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176 item_copyright = self.__get_dynamic_attr('item_copyright', item), |
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177 **self.item_extra_kwargs(item) |
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178 ) |
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179 return feed |