Introduce documentation redirects for doc pages that are renamed

The web documentation used to suffer from a problem that if a
documentation page were renamed in a newer version, any references
pointing to said documentation would be lost. For example, the feature
known as "Default Roles" was renamed to "Privileged Roles" but caused
a change in the URL.

This patch introduces the ability to create a "DocPageRedirect" by
specifying the previous name of the documentation page (e.g.
"default-roles.html") and the new name (e.g. "privileged-roles.html")
such that the continuity is preserved between versions.

1 files changed, 11 insertions, 0 deletions

diff --git a/pgweb/docs/models.py b/pgweb/docs/models.py
index 87afe1ca..a4558a68 100644
--- a/pgweb/docs/models.py
+++ b/pgweb/docs/models.py
@@ -33,3 +33,14 @@ class DocPageAlias(models.Model):
     class Meta:
         db_table = 'docsalias'
         verbose_name_plural = 'Doc page aliases'
+
+
+class DocPageRedirect(models.Model):
+    """DocPageRedirect offers the ability to redirect from a page that has been
+    completely removed from the PostgreSQL documentation
+    """
+    redirect_from = models.CharField(max_length=64, null=False, blank=False, unique=True, help_text='Page to redirect from, e.g. "old_page.html"')
+    redirect_to = models.CharField(max_length=64, null=False, blank=False, unique=True, help_text='Page to redirect from, e.g. "new_page.html"')
+
+    class Meta:
+        verbose_name_plural = "Doc page redirects"