Added PagesTitlesMixin.

utils/models/pages.py

@@ -0,0 +1,64 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+# Erik Stein <code@classlibrary.net>, 2017
+
+
+from django.db import models
+from django.utils.encoding import python_2_unicode_compatible
+from django.utils.text import normalize_newlines
+from django.utils.translation import ugettext_lazy as _
+from utils.functional import firstof
+
+from ..fields import AutoSlugField
+
+
+# TODO Use translatable fields by default
+@python_2_unicode_compatible
+class PageTitlesMixin(models.Model):
+    """
+    A model mixin containg title and slug field for models serving as website
+    pages with an URL.
+    """
+    short_title = models.CharField(_("Name"), max_length=50)
+    slug = AutoSlugField(_("URL-Name"), max_length=200, populate_from='short_title', unique_slug=True)
+    title = models.TextField(_("Titel (Langform)"), null=True, blank=True, max_length=300)
+    window_title = models.CharField(_("Fenster-/Suchmaschinentitel"), null=True, blank=True, max_length=300)
+
+    class Meta:
+        abstract = True
+
+    def __str__(self):
+        return self.short_title
+
+    def get_title(self):
+        return firstof(
+            self.title,
+            self.short_title
+        )
+
+    def get_window_title(self):
+        return firstof(
+            self.window_title,
+            self.short_title,
+            self.get_first_title_line(),
+        )
+
+    def get_first_title_line(self):
+        """
+        First line of title field.
+        """
+        return normalize_newlines(self.get_title()).partition("\n")[0]
+
+    def get_subtitle_lines(self):
+        """
+        All but first line of the long title field.
+        """
+        return normalize_newlines(self.title).partition("\n")[2]
+
+
+class PageTitleAdminMixin(object):
+    search_fields = ['short_title', 'title', 'window_title']
+    list_display = ['short_title', 'slug']
+    prepopulated_fields = {
+        'slug': ('short_title',),
+    }