Add templatefilter joinandor

This filter takes a list of a,b,c,d and turns it into "a, b, c and d"
or "a, b, c or d" depending on parameter given.

Author: mhagander

pgweb/core/templatetags/pgfilters.py

@@ -80,3 +80,16 @@ def release_notes_pg_minor_version(minor_version, major_version):
     if str(major_version) in ['0', '1']:
         return str(minor_version)[2:4]
     return minor_version
+
+
+@register.filter()
+def joinandor(value, andor):
+    # Value is a list of objects. Join them on comma, add "and" or "or" before the last.
+    if len(value) == 1:
+        return str(value)
+
+    if not isinstance(value, list):
+        # Must have a list to index from the end
+        value = list(value)
+
+    return ", ".join([str(x) for x in value[:-1]]) + ' ' + andor + ' ' + str(value[-1])