Avoid duplicates in select menus (with yadcf)

README.rst

@@ -8,6 +8,45 @@ It is framework agnostic, tested with `Pyramid <http://www.pylonsproject.org/>`_
 
 It only depends on SQLAlchemy, and is compatible with version **1.10.x** of DataTables.
 
+**Small contribution:**
+In this fork has been added a natural sort method for PostgreSQL models. It needs a custom function to be created in the db:
+
+.. code-block:: sql
+
+    --
+    -- This file replaces a previous one which is now available at
+    -- /junk/naturalsort-hack.sql which had certain drawbacks and
+    -- was far more complex. This approach is simpler, though it
+    -- has the drawback of not dealing with locales (all comparisons
+    -- end up made as if in C locale).
+    --
+    -- To use:
+    --
+    --  SELECT ... ORDER BY naturalsort(column);
+    --
+    -- +optionally,
+    --
+    --  CREATE INDEX ON yourtable (naturalsort(column));
+    --
+    -- (The basic method is to prefix each numeric substring with its
+    -- length, then sort as a bytea to get C locale and \x00 delimiters
+    -- between fragments)
+    --
+
+    create or replace function naturalsort(text)
+    returns bytea
+    language sql
+    immutable strict
+    as $f$
+    select string_agg(convert_to(coalesce(r[2],
+                                length(length(r[1])::text) || length(r[1])::text || r[1]),
+                                'SQL_ASCII'),'\x00')
+        from regexp_matches($1, '0*([0-9]+)|([^0-9]+)', 'g') r;
+    $f$;
+
+    -- end
+
+
 |Build Status| |PyPi Version| |Coverage|
 
 .. |Build Status| image:: https://travis-ci.org/Pegase745/sqlalchemy-datatables.svg?branch=master

datatables/__init__.py

@@ -143,7 +143,7 @@ def yadcf_multi_select(expr, value):
 ColumnTuple = namedtuple(
     'ColumnDT',
     ['sqla_expr', 'column_name', 'mData', 'search_method',
-     'nulls_order', 'global_search'])
+     'nulls_order', 'global_search', 'sort_method'])
 
 
 class InvalidParameter(Exception):
@@ -178,7 +178,7 @@ class ColumnDT(ColumnTuple):
 
     def __new__(cls, sqla_expr, column_name=None, mData=None,
                 search_method='string_contains', nulls_order=None,
-                global_search=True):
+                global_search=True, sort_method=None):
         """Set default values for mData and filter.
 
         On creation, sets default None values for mData and string value for
@@ -194,7 +194,7 @@ def __new__(cls, sqla_expr, column_name=None, mData=None,
 
         return super(ColumnDT, cls).__new__(
             cls, sqla_expr, column_name, mData, search_method,
-            nulls_order, global_search)
+            nulls_order, global_search, sort_method)
 
 
 class DataTables:
@@ -277,7 +277,7 @@ def _set_yadcf_data(self, query):
                     query=query, exclude=i)
                 v = filtered.add_columns(col.sqla_expr).distinct().all()
                 self.yadcf_params.append(
-                    ('yadcf_data_{:d}'.format(i), [r[0] for r in v]))
+                    ('yadcf_data_{:d}'.format(i), [r[0] for r in sorted(set(v))]))
 
     def run(self):
         """Launch filtering, sorting and paging to output results."""
@@ -374,6 +374,8 @@ def _set_sort_expressions(self):
             column = self.columns[column_nr]
             direction = self.params.get('order[{:d}][dir]'.format(i))
             sort_expr = column.sqla_expr
+            if column.sort_method is not None:
+                sort_expr = column.sort_method
             if direction == 'asc':
                 sort_expr = sort_expr.asc()
             elif direction == 'desc':

examples/flask_tut/flask_tut/__init__.py

@@ -1,6 +1,7 @@
 """Flask tutorial views."""
 from flask import render_template, request, jsonify
 from flask import Flask
+from sqlalchemy import func
 
 from datatables import ColumnDT, DataTables
 
@@ -33,7 +34,7 @@ def data():
     # defining columns
     columns = [
         ColumnDT(User.id),
-        ColumnDT(User.name),
+        ColumnDT(User.name, sort_method=func.public.naturalsort(User.name)),
         ColumnDT(Address.description),
         ColumnDT(User.created_at)
     ]

examples/pyramid_tut/pyramid_tut/views.py

@@ -62,7 +62,7 @@ def data(request):
     #    in the table
     columns = [
         ColumnDT(User.id),
-        ColumnDT(User.name),
+        ColumnDT(User.name, sort_method=func.public.naturalsort(User.name)),
         ColumnDT(Address.description),
         ColumnDT(func.strftime('%d-%m-%Y', User.birthday)),
         ColumnDT(User.age)