Fixed #12410 -- Added LineLocatePoint GIS function.

docs/ref/contrib/gis/db-api.txt

@@ -386,6 +386,7 @@ Function                              PostGIS  Oracle          MySQL        Spat
 :class:`Intersection`                 X        X               X (≥ 5.6.1)  X
 :class:`IsValid`                      X        X               X (≥ 5.7.5)  X (LWGEOM)
 :class:`Length`                       X        X               X            X
+:class:`LineLocatePoint`              X                                     X
 :class:`MakeValid`                    X                                     X (LWGEOM)
 :class:`MemSize`                      X
 :class:`NumGeometries`                X        X               X            X

docs/ref/contrib/gis/functions.txt

@@ -358,6 +358,19 @@ resource-intensive) with the ``spheroid`` keyword argument.
     In older versions, a raw value was returned on MySQL when used on
     projected SRS.
 
+``LineLocatePoint``
+===================
+
+.. class:: LineLocatePoint(linestring, point, **extra)
+
+.. versionadded:: 2.0
+
+*Availability*: `PostGIS <https://postgis.net/docs/ST_LineLocatePoint.html>`__,
+SpatiaLite
+
+Returns a float between 0 and 1 representing the location of the closest point on
+``linestring`` to the given ``point``, as a fraction of the 2D line length.
+
 ``MakeValid``
 =============
 

docs/releases/2.0.txt

@@ -68,6 +68,9 @@ Minor features
   :class:`~django.contrib.gis.db.models.functions.IsValid` function, and
   :lookup:`isvalid` lookup.
 
+* Added the :class:`~django.contrib.gis.db.models.functions.LineLocatePoint`
+  function, supported on PostGIS and SpatiaLite.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~