From 00e56dd09604fbd680fe911cf6893d1cfd544de8 Mon Sep 17 00:00:00 2001
From: Erik Stein <erik@classlibrary.net>
Date: Mon, 24 Dec 2018 10:39:56 +0100
Subject: [PATCH] AdminActionBase.

---
 CHANGES                                       |  2 +
 shared/utils/admin_actions.py                 | 75 +++++++++++++++++++
 .../admin/action_forms/admin_action_base.html | 30 ++++++++
 3 files changed, 107 insertions(+)
 create mode 100644 shared/utils/admin_actions.py
 create mode 100644 shared/utils/templates/admin/action_forms/admin_action_base.html

diff --git a/CHANGES b/CHANGES
index 4a46d3d..1b6011d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,6 @@
 - Added dispatch_slug_path.
+- Added AdminActionBase.
+
 0.2.17 2018-12-17
 - PageTitlesMixin: Slimdown name for get_short_title.
 - Daytime utils.
diff --git a/shared/utils/admin_actions.py b/shared/utils/admin_actions.py
new file mode 100644
index 0000000..54b4f52
--- /dev/null
+++ b/shared/utils/admin_actions.py
@@ -0,0 +1,75 @@
+
+from django import forms
+from django.contrib import admin
+from django.http import HttpResponseRedirect
+from django.shortcuts import render
+
+
+class AdminActionBase:
+    action_name = None
+    options_template_name = 'admin/action_forms/admin_action_base.html'
+    title = None
+    queryset_action_label = None
+    action_button_label = None
+
+    def apply(self, queryset, form):
+        raise NotImplementedError
+
+    def get_message(self, count):
+        raise NotImplementedError
+
+    def get_failure_message(self, count, failure_count):
+        raise NotImplementedError
+
+    class BaseForm(forms.Form):
+        _selected_action = forms.CharField(widget=forms.MultipleHiddenInput)
+
+    def get_form_class(self, modeladmin, request, queryset):
+        """
+        Example:
+
+        class CustomForm(BaseForm)
+            chosen_target = forms.ModelChoiceField(
+                label=_("Choose target itembundle"),
+                queryset=ItemBundle.objects.exclude(pk__in=queryset),
+                widget=ForeignKeyRawIdWidget(modeladmin.model._meta.get_field('parent').rel, modeladmin.admin_site),
+                empty_label=_("Root level"), required=False)
+        return CustomForm
+        """
+        raise NotImplementedError
+
+    def __call__(self, modeladmin, request, queryset):
+        form_class = self.get_form_class(modeladmin, request, queryset)
+
+        form = None
+        if 'apply' in request.POST:
+            form = form_class(request.POST)
+            if form.is_valid():
+                queryset_count = queryset.count()
+                count = self.apply(queryset, form)
+                failure_count = queryset_count - count
+                if failure_count > 0:
+                    message = self.get_failure_message(form, count, failure_count)
+                else:
+                    message = self.get_message(form, count)
+                modeladmin.message_user(request, message)
+                return HttpResponseRedirect(request.get_full_path())
+
+        if 'cancel' in request.POST:
+            return HttpResponseRedirect(request.get_full_path())
+
+        if not form:
+            form = form_class(initial={
+                '_selected_action': request.POST.getlist(
+                    admin.ACTION_CHECKBOX_NAME),
+            })
+
+        return render(request, self.options_template_name, context={
+            'action_name': self.action_name,
+            'title': self.title,
+            'queryset_action_label': self.queryset_action_label,
+            'action_button_label': self.action_button_label,
+            'queryset': queryset,
+            'action_form': form,
+            'opts': modeladmin.model._meta,
+        })
diff --git a/shared/utils/templates/admin/action_forms/admin_action_base.html b/shared/utils/templates/admin/action_forms/admin_action_base.html
new file mode 100644
index 0000000..cf2dd59
--- /dev/null
+++ b/shared/utils/templates/admin/action_forms/admin_action_base.html
@@ -0,0 +1,30 @@
+{% extends "admin/change_form.html" %}{# Needed for admin javascripts #}
+{% load i18n static %}
+
+
+{% block title %}{{ title }}{% endblock %}
+
+
+{% block content %}
+	<div id="content-main">
+		<form action="" method="post">{% csrf_token %}
+			<div>
+				{{ action_form.as_p }}
+				{% for obj in queryset %}
+				<input type="hidden" name="_selected_action" value="{{ obj.id }}">
+				{% endfor %}
+
+				<p>{{ queryset_action_label }}</p>
+
+				<ul>
+					{{ queryset|unordered_list }}
+				</ul>
+
+				<input type="hidden" name="action" value="{{ action_name }}">
+				<input type="submit" name="apply" value="{{ action_button_label }}">
+				<input class="button cancel-link" type="submit" name="cancel" value="{% trans "Cancel" %}">
+				{# <a href="#" class="button cancel-link">{% trans "No, take me back" %}</a> #}
+			</div>
+		</form>
+	</div>
+{% endblock %}