Sendmail: Keep uploaded attachment when preview is used

src/pretix/base/templates/pretixbase/forms/widgets/thumbnailed_file_input.html

@@ -4,3 +4,4 @@
     <label for="{{ widget.checkbox_id }}">{{ widget.clear_checkbox_label }}</label>{% endif %}{% if widget.value.is_img %}<br><a href="{{ widget.value.url }}" data-lightbox="{{ widget.value.name }}"><img src="{{ widget.value|thumb:"200x100" }}" /></a>{% endif %}<br>
     {{ widget.input_text }}:{% endif %}
 <input type="{{ widget.type }}" name="{{ widget.name }}"{% include "django/forms/widgets/attrs.html" %}>
+{% if widget.cachedfile %}<input type="hidden" name="{{ widget.hidden_name }}" value="{{ widget.cachedfile.id }}">{% endif %}

src/pretix/control/forms/__init__.py

@@ -7,6 +7,7 @@ from django.core.exceptions import ValidationError
 from django.core.files import File
 from django.core.files.uploadedfile import UploadedFile
 from django.forms.utils import from_current_timezone
+from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 
 from ...base.forms import I18nModelForm
@@ -77,6 +78,8 @@ class ClearableBasenameFileInput(forms.ClearableFileInput):
 
         @property
         def name(self):
+            if hasattr(self.file, 'display_name'):
+                return self.file.display_name
             return self.file.name
 
         @property
@@ -84,6 +87,8 @@ class ClearableBasenameFileInput(forms.ClearableFileInput):
             return any(self.file.name.lower().endswith(e) for e in ('.jpg', '.jpeg', '.png', '.gif'))
 
         def __str__(self):
+            if hasattr(self.file, 'display_name'):
+                return self.file.display_name
             return os.path.basename(self.file.name).split('.', 1)[-1]
 
         @property
@@ -93,6 +98,48 @@ class ClearableBasenameFileInput(forms.ClearableFileInput):
     def get_context(self, name, value, attrs):
         ctx = super().get_context(name, value, attrs)
         ctx['widget']['value'] = self.FakeFile(value)
+        ctx['widget']['cachedfile'] = None
+        return ctx
+
+
+class CachedFileInput(forms.ClearableFileInput):
+    template_name = 'pretixbase/forms/widgets/thumbnailed_file_input.html'
+
+    class FakeFile(File):
+        def __init__(self, file):
+            self.file = file
+
+        @property
+        def name(self):
+            return self.file.filename
+
+        @property
+        def is_img(self):
+            return any(self.file.filename.lower().endswith(e) for e in ('.jpg', '.jpeg', '.png', '.gif'))
+
+        def __str__(self):
+            return self.file.filename
+
+        @property
+        def url(self):
+            return self.file.file.url
+
+    def value_from_datadict(self, data, files, name):
+        from ...base.models import CachedFile
+        v = super().value_from_datadict(data, files, name)
+        if v is None and data.get(name + '-cachedfile'):  # An explicit "[x] clear" would be False, not None
+            return CachedFile.objects.filter(id=data[name + '-cachedfile']).first()
+        return v
+
+    def get_context(self, name, value, attrs):
+        from ...base.models import CachedFile
+        if isinstance(value, CachedFile):
+            value = self.FakeFile(value)
+
+        ctx = super().get_context(name, value, attrs)
+        ctx['widget']['value'] = value
+        ctx['widget']['cachedfile'] = value.file if isinstance(value, self.FakeFile) else None
+        ctx['widget']['hidden_name'] = name + '-cachedfile'
         return ctx
 
 
@@ -129,7 +176,7 @@ class ExtFileField(SizeFileField):
 
     def clean(self, *args, **kwargs):
         data = super().clean(*args, **kwargs)
-        if data:
+        if isinstance(data, File):
             filename = data.name
             ext = os.path.splitext(filename)[1]
             ext = ext.lower()
@@ -138,6 +185,49 @@ class ExtFileField(SizeFileField):
         return data
 
 
+class CachedFileField(ExtFileField):
+    widget = CachedFileInput
+
+    def to_python(self, data):
+        from ...base.models import CachedFile
+
+        if isinstance(data, CachedFile):
+            return data
+
+        return super().to_python(data)
+
+    def bound_data(self, data, initial):
+        from ...base.models import CachedFile
+
+        if isinstance(data, File):
+            cf = CachedFile.objects.create(
+                expires=now() + datetime.timedelta(days=1),
+                date=now(),
+                filename=data.name,
+                type=data.content_type,
+            )
+            cf.file.save(data.name, data.file)
+            cf.save()
+            return cf
+        return super().bound_data(data, initial)
+
+    def clean(self, *args, **kwargs):
+        from ...base.models import CachedFile
+
+        data = super().clean(*args, **kwargs)
+        if isinstance(data, File):
+            cf = CachedFile.objects.create(
+                expires=now() + datetime.timedelta(days=1),
+                date=now(),
+                filename=data.name,
+                type=data.content_type,
+            )
+            cf.file.save(data.name, data.file)
+            cf.save()
+            return cf
+        return data
+
+
 class SlugWidget(forms.TextInput):
     template_name = 'pretixcontrol/slug_widget.html'
     prefix = ''

src/pretix/plugins/sendmail/forms.py

@@ -9,7 +9,7 @@ from pretix.base.email import get_available_placeholders
 from pretix.base.forms import PlaceholderValidator
 from pretix.base.forms.widgets import SplitDateTimePickerWidget
 from pretix.base.models import CheckinList, Item, Order, SubEvent
-from pretix.control.forms import ExtFileField
+from pretix.control.forms import CachedFileField
 from pretix.control.forms.widgets import Select2, Select2Multiple
 
 
@@ -23,7 +23,7 @@ class MailForm(forms.Form):
     sendto = forms.MultipleChoiceField()  # overridden later
     subject = forms.CharField(label=_("Subject"))
     message = forms.CharField(label=_("Message"))
-    attachment = ExtFileField(
+    attachment = CachedFileField(
         label=_("Attachment"),
         required=False,
         ext_whitelist=(

src/pretix/plugins/sendmail/views.py

@@ -1,5 +1,4 @@
 import logging
-from datetime import timedelta
 
 import bleach
 import dateutil
@@ -13,7 +12,7 @@ from django.views.generic import FormView, ListView
 
 from pretix.base.email import get_available_placeholders
 from pretix.base.i18n import LazyI18nString, language
-from pretix.base.models import CachedFile, LogEntry, Order, OrderPosition
+from pretix.base.models import LogEntry, Order, OrderPosition
 from pretix.base.models.event import SubEvent
 from pretix.base.services.mail import TolerantDict
 from pretix.base.templatetags.rich_text import markdown_compile_email
@@ -124,7 +123,6 @@ class SenderView(EventPermissionRequiredMixin, FormView):
 
         if self.request.POST.get("action") == "preview":
             for l in self.request.event.settings.locales:
-
                 with language(l):
                     context_dict = TolerantDict()
                     for k, v in get_available_placeholders(self.request.event, ['event', 'order',
@@ -146,17 +144,6 @@ class SenderView(EventPermissionRequiredMixin, FormView):
 
             return self.get(self.request, *self.args, **self.kwargs)
 
-        attachment = None
-        if 'attachment' in self.request.FILES:
-            attachment = self.request.FILES['attachment']
-            cf = CachedFile.objects.create(
-                expires=now() + timedelta(days=1),
-                date=now(),
-                filename=attachment.name,
-                type=attachment.content_type,
-            )
-            cf.file.save(attachment.name, attachment.file)
-            cf.save()
         kwargs = {
             'recipients': form.cleaned_data['recipients'],
             'event': self.request.event.pk,
@@ -169,8 +156,8 @@ class SenderView(EventPermissionRequiredMixin, FormView):
             'checkin_lists': [i.pk for i in form.cleaned_data.get('checkin_lists')],
             'filter_checkins': form.cleaned_data.get('filter_checkins'),
         }
-        if attachment is not None:
-            kwargs['attachments'] = [cf.id]
+        if form.cleaned_data.get('attachment') is not None:
+            kwargs['attachments'] = [form.cleaned_data['attachment'].id]
 
         send_mails.apply_async(
             kwargs=kwargs