Add spreadsheet export functionality to ModelAdmin

wagtail/admin/views/reports.py

@@ -1,4 +1,6 @@
 import csv
+import datetime
+
 from xlsxwriter.workbook import Workbook
 
 from collections import OrderedDict
@@ -51,7 +53,10 @@ class SpreadsheetExportMixin:
         
     def write_xlsx_row(self, worksheet, row_dict, row_number):
         for col_number, (field, value) in enumerate(row_dict.items()):
-            preprocess_function = self.custom_xlsx_field_preprocess.get(field, force_str)
+            if not isinstance(value, (datetime.date, datetime.time)):
+                preprocess_function = self.custom_xlsx_field_preprocess.get(field, force_str)
+            else:
+                preprocess_function = self.custom_xlsx_field_preprocess.get(field)
             processed_value = preprocess_function(value) if preprocess_function else value
             worksheet.write(row_number, col_number, processed_value)
     
@@ -143,7 +148,6 @@ class LockedPagesView(ReportView):
     title = _('Locked Pages')
     header_icon = 'locked'
     export_heading_overrides = {'latest_revision_created_at': _("Updated"), 'status_string': _("Status"), 'content_type.model_class._meta.verbose_name.title': _("Type")}
-    custom_xlsx_field_preprocess = {'latest_revision_created_at': None, 'locked_at': None}
     list_export = ['title', 'latest_revision_created_at', 'status_string', 'content_type.model_class._meta.verbose_name.title', 'locked_at', 'locked_by']
 
     def get_queryset(self):

wagtail/contrib/modeladmin/options.py

@@ -74,6 +74,7 @@ class ModelAdmin(WagtailRegisterable):
     menu_order = None
     list_display = ('__str__',)
     list_display_add_buttons = None
+    list_export = ()
     inspect_view_fields = []
     inspect_view_fields_exclude = []
     inspect_view_enabled = False
@@ -202,6 +203,13 @@ class ModelAdmin(WagtailRegisterable):
         return self.list_display_add_buttons or self.get_list_display(
             request)[0]
 
+    def get_list_export(self, request):
+        """
+        Return a sequence containing the fields/method output to be displayed
+        in spreadsheet exports.
+        """
+        return self.list_export
+
     def get_empty_value_display(self, field_name=None):
         """
         Return the empty_value_display value defined on ModelAdmin

wagtail/contrib/modeladmin/templates/modeladmin/index.html

@@ -24,13 +24,13 @@
                     {% block search %}{% search_form %}{% endblock %}
                 </div>
                 {% block header_extra %}
-                    {% if user_can_create %}
-                        <div class="right">
-                            <div class="addbutton">
+                    <div class="right">
+                        {% if user_can_create %}
+                            <span class="addbutton">
                                 {% include 'modeladmin/includes/button.html' with button=view.button_helper.add_button %}
-                             </div>
-                         </div>
-                     {% endif %}
+                            </span>
+                        {% endif %}
+                    </div>
                 {% endblock %}
             </div>
         </header>
@@ -86,6 +86,13 @@
                         </nav>
                     {% endblock %}
 
+                    {% if view.list_export %}
+                        <div class="nice-padding col9">
+                            <a href="?export=base&{{ request.GET.urlencode }}" class="button bicolor icon icon-download">{% trans 'Download all' %}</a>
+                            <a href="?export=base&{{ request.GET.urlencode }}" class="button bicolor icon icon-download">{% trans 'Download filtered' %}</a>
+                        </div>
+                    {% endif %}
+
                 {% endblock %}
             </div>
         </div>

wagtail/contrib/modeladmin/views.py

@@ -24,6 +24,7 @@ from django.views.generic import TemplateView
 from django.views.generic.edit import FormView
 
 from wagtail.admin import messages
+from wagtail.admin.views.reports import SpreadsheetExportMixin
 
 from .forms import ParentChooserForm
 
@@ -212,14 +213,15 @@ class InstanceSpecificView(WMABaseView):
         return super().get_context_data(**context)
 
 
-class IndexView(WMABaseView):
+class IndexView(SpreadsheetExportMixin, WMABaseView):
 
     ORDER_VAR = 'o'
     ORDER_TYPE_VAR = 'ot'
     PAGE_VAR = 'p'
     SEARCH_VAR = 'q'
     ERROR_FLAG = 'e'
-    IGNORED_PARAMS = (ORDER_VAR, ORDER_TYPE_VAR, SEARCH_VAR)
+    EXPORT_VAR = 'export'
+    IGNORED_PARAMS = (ORDER_VAR, ORDER_TYPE_VAR, SEARCH_VAR, EXPORT_VAR)
 
     # sortable_by is required by the django.contrib.admin.templatetags.admin_list.result_headers
     # template tag as of Django 2.1 - see https://docs.djangoproject.com/en/2.1/ref/contrib/admin/#django.contrib.admin.ModelAdmin.sortable_by
@@ -231,12 +233,14 @@ class IndexView(WMABaseView):
         if not self.permission_helper.user_can_list(request.user):
             raise PermissionDenied
 
+        self.list_export = self.model_admin.get_list_export(request)
         self.list_display = self.model_admin.get_list_display(request)
         self.list_filter = self.model_admin.get_list_filter(request)
         self.search_fields = self.model_admin.get_search_fields(request)
         self.items_per_page = self.model_admin.list_per_page
         self.select_related = self.model_admin.list_select_related
         self.search_handler = self.model_admin.get_search_handler(request, self.search_fields)
+        self.export = (request.GET.get(self.EXPORT_VAR))
 
         # Get search parameters from the query string.
         try:
@@ -249,12 +253,27 @@ class IndexView(WMABaseView):
             del self.params[self.PAGE_VAR]
         if self.ERROR_FLAG in self.params:
             del self.params[self.ERROR_FLAG]
+        if self.EXPORT_VAR in self.params:
+            del self.params[self.EXPORT_VAR]        
 
         self.query = request.GET.get(self.SEARCH_VAR, '')
+
+        if self.export == 'base':
+            return self.as_spreadsheet(self.get_base_queryset(request=request))
+
         self.queryset = self.get_queryset(request)
 
+        if self.export == 'current':
+            return self.as_spreadsheet(self.queryset)
+
         return super().dispatch(request, *args, **kwargs)
 
+    def get_heading(self, queryset, field):
+        heading_override = self.export_heading_overrides.get(field)
+        if heading_override:
+            return force_str(heading_override)
+        return force_str(label_for_field(field, model=self.model))
+
     @property
     def media(self):
         return forms.Media(