auf/django/export/admin.py

   1 # -*- encoding: utf-8 -*-
   2
   3 import csv
   4 from StringIO import StringIO
   5
   6 from odf.opendocument import OpenDocumentSpreadsheet
   7 from odf.style import Style, TextProperties, TableColumnProperties
   8 from odf.text import P
   9 from odf.table import Table, TableRow, TableCell
  10
  11 from django.core.urlresolvers import reverse
  12 from django.contrib import admin
  13 from django.utils.functional import update_wrapper
  14 from django.http import HttpResponse
  15
  16 # Create a notation similar to queryset filter
  17 SEPARATOR = u"__"
  18
  19 # String return if lookup property failed
  20 EMPTY = u""
  21
  22
  23 def txt(msg):
  24     text = msg
  25     if not isinstance(msg, unicode):
  26         try:
  27             text = unicode (msg, "utf-8")
  28         except TypeError:
  29             pass
  30     return text
  31
  32
  33 class ExportAdmin(admin.ModelAdmin):
  34     change_list_template = 'admin/export/change_list.html'
  35
  36     def changelist_view(self, request, extra_context=None):
  37         """
  38         Add export URL for the template
  39         """
  40         if extra_context is None:
  41             extra_context = {}
  42         extra_context.update({
  43             'export_csv_url' : reverse("admin:%s_%s_export_csv" % (self.model._meta.app_label, self.model._meta.module_name)),
  44             'export_ods_url' : reverse("admin:%s_%s_export_ods" % (self.model._meta.app_label, self.model._meta.module_name)),
  45         })
  46         return super(ExportAdmin, self).changelist_view(request, extra_context)
  47
  48
  49     def get_urls(self):
  50         from django.conf.urls.defaults import patterns, url
  51
  52         urls = super(ExportAdmin, self).get_urls()
  53         info = self.model._meta.app_label, self.model._meta.module_name
  54
  55         urlpatterns = patterns('',
  56             url(r'^export-csv/$',
  57                 self.admin_site.admin_view(self.export_csv),
  58                 name='%s_%s_export_csv' % info),
  59             url(r'^export-ods/$',
  60                 self.admin_site.admin_view(self.export_ods),
  61                 name='%s_%s_export_ods' % info),
  62         )
  63         return urlpatterns + urls
  64
  65     def get_object_value(self, obj, header):
  66         """
  67         Function which work as a queryset filter access :
  68         Father -- Kid (One2One father related_name = 'child')
  69         father__name
  70         father__child__name
  71         It tries to resolve the property from header string, through
  72         linked object if needed. If it can't load any value, empty
  73         string is return.
  74         """
  75         segments = header.split(SEPARATOR)
  76         segments.reverse()
  77         prop = segments.pop()
  78         if len(segments) == 0:
  79             return getattr(obj, prop, EMPTY)
  80         else:
  81             try:
  82                 child = getattr(obj, prop, None)
  83                 return self.get_object_value(child, ".".join(segments))
  84             except:
  85                 return EMPTY
  86
  87     def get_default_export_fields(self):
  88       fields_name = [f.name for f in  self.model._meta.fields]
  89       for fk in self.model._meta._related_objects_cache.keys():
  90           fields_name = fields_name + [u"%s%s%s" % (fk.var_name, SEPARATOR, f.name) for f in fk.model._meta.fields]
  91       return fields_name
  92
  93
  94     def get_export_fields(self):
  95         """
  96         This property is a list of string, which should have queryset filter notation style (with X2 underscore).
  97         If there is no fields, the models is full introspected, stop at 1 depth level.
  98         """
  99
 100         export_fields = getattr(self, 'export_fields', None)
 101
 102         if export_fields is None:
 103             export_fields = getattr(self, 'csv_fields', None)
 104
 105         if export_fields is None:
 106             export_fields = self.get_default_export_fields()
 107
 108         return export_fields
 109
 110     def export_ods(self, request):
 111         """
 112         Generate HTTP response as ODS file from export_fields property.
 113         """
 114         export_fields = self.get_export_fields()
 115
 116         qs = self.queryset(request)
 117
 118         response = HttpResponse(mimetype='application/vnd.oasis.opendocument.spreadsheet')
 119         response['Content-Disposition'] = 'attachment; filename=%s.ods' % unicode(self.model._meta.verbose_name_plural)
 120
 121         doc = OpenDocumentSpreadsheet()
 122         style = Style(name="Large number", family="table-cell")
 123         style.addElement(TextProperties(fontfamily="Arial", fontsize="15pt"))
 124         doc.styles.addElement(style)
 125         widewidth = Style(name="co1", family="table-column")
 126         widewidth.addElement(TableColumnProperties(columnwidth="2.8cm", breakbefore="auto"))
 127         doc.automaticstyles.addElement(widewidth)
 128
 129         table = Table()
 130         if len (export_fields) > 0:
 131             tr = TableRow ()
 132             table.addElement (tr)
 133             for item in export_fields:
 134                 tc = TableCell ()
 135                 tr.addElement (tc)
 136                 p = P(stylename = style, text = txt(item))
 137                 tc.addElement (p)
 138
 139         for o in qs:
 140             tr = TableRow ()
 141             table.addElement (tr)
 142
 143             for attr in export_fields:
 144                 value = self.get_object_value(o, attr)
 145                 tc = TableCell ()
 146                 tr.addElement (tc)
 147                 p = P (stylename = style, text = txt(value))
 148                 tc.addElement (p)
 149
 150         doc.spreadsheet.addElement(table)
 151         buffer = StringIO ()
 152         doc.write(buffer)
 153
 154         response.write(buffer.getvalue())
 155         return response
 156
 157     def export_csv(self, request):
 158         """
 159         Generate HTTP response as CSV file from export_fields property.
 160         """
 161         csv_fields = self.get_export_fields()
 162
 163         qs = self.queryset(request)
 164
 165         response = HttpResponse(mimetype='text/csv')
 166         response['Content-Disposition'] = 'attachment; filename=%s.csv' % unicode(self.model._meta.verbose_name_plural)
 167
 168         writer = csv.writer(response)
 169
 170         headers = []
 171         for attr in csv_fields:
 172             headers.append(attr.encode('utf-8') if isinstance(attr, unicode) else attr)
 173         writer.writerow(headers)
 174
 175         for o in qs:
 176             row = []
 177             for attr in csv_fields:
 178                 value = self.get_object_value(o, attr)
 179                 row.append(value.encode('utf-8') if isinstance(value, unicode) else value)
 180             writer.writerow(row)
 181
 182         return response