From 82465ebc12a2607a66abc5af4f56066e9b7e678c Mon Sep 17 00:00:00 2001
From: "Andrew G. Brown" <andrew.g.brown@usda.gov>
Date: Wed, 6 Dec 2023 21:35:19 -0800
Subject: [PATCH] Add toggle for gdal_spatialite_computed_geom_column entries
 for #6

---
 R/gpkg-view.R                   |  9 +++++++++
 man/gpkg_create_spatial_view.Rd | 14 ++++++++++----
 misc/gpkg-view-voronoi.R        |  3 ++-
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/R/gpkg-view.R b/R/gpkg-view.R
index 1c2f89a..4b46ed8 100644
--- a/R/gpkg-view.R
+++ b/R/gpkg-view.R
@@ -5,6 +5,10 @@
 #' @param viewquery _character_. Query for view contents. 
 #' @param geom_column _character_. Column name of view geometry. Default: `"geom"`
 #' @param geometry_type_name _character_. View geometry type. Default: `"GEOMETRY"`
+#' @param spatialite_computed _logical_. Register definition of `geom_column` as
+#'                            the result of a Spatialite spatial function via 
+#'                            `"gdal_spatialite_computed_geom_column"` extension. 
+#'                            Default: `FALSE`
 #' @param data_type _character_. View data type. Default `"features"`
 #' @param srs_id _integer_. Spatial Reference System ID. Default: `4326` (WGS84)
 #' @param z _integer_. Default: `0`
@@ -18,6 +22,7 @@ gpkg_create_spatial_view <- function(g,
                                      viewquery, 
                                      geom_column = "geom",
                                      geometry_type_name = "GEOMETRY",
+                                     spatialite_computed = FALSE,
                                      data_type = "features",
                                      srs_id = 4326,
                                      z = 0,
@@ -29,4 +34,8 @@ gpkg_execute(g, sprintf("INSERT INTO gpkg_contents (table_name, identifier, data
 gpkg_execute(g, sprintf("INSERT INTO gpkg_geometry_columns (table_name, column_name, geometry_type_name, srs_id, z, m) 
                         VALUES ('%s', '%s', '%s', %s, %s, %s)",
                                 viewname, geom_column, geometry_type_name, srs_id, z, m))
+if (spatialite_computed)
+  gpkg_execute(g, sprintf("INSERT INTO gpkg_extensions (table_name, column_name, extension_name, definition, scope) 
+                        VALUES ('%s', '%s', 'gdal_spatialite_computed_geom_column', 'https://gdal.org/drivers/vector/gpkg_spatialite_computed_geom_column.html', 'read-write');",
+                                viewname, geom_column))
 }
\ No newline at end of file
diff --git a/man/gpkg_create_spatial_view.Rd b/man/gpkg_create_spatial_view.Rd
index 91d3089..688c60c 100644
--- a/man/gpkg_create_spatial_view.Rd
+++ b/man/gpkg_create_spatial_view.Rd
@@ -10,6 +10,7 @@ gpkg_create_spatial_view(
   viewquery,
   geom_column = "geom",
   geometry_type_name = "GEOMETRY",
+  spatialite_computed = FALSE,
   data_type = "features",
   srs_id = 4326,
   z = 0,
@@ -27,16 +28,21 @@ gpkg_create_spatial_view(
 
 \item{geometry_type_name}{\emph{character}. View geometry type. Default: \code{"GEOMETRY"}}
 
+\item{spatialite_computed}{\emph{logical}. Register definition of \code{geom_column} as
+the result of a Spatialite spatial function via
+\code{"gdal_spatialite_computed_geom_column"} extension.
+Default: \code{FALSE}}
+
 \item{data_type}{\emph{character}. View data type. Default \code{"features"}}
 
-\item{srs_id}{integer. Spatial Reference System ID. Default: \code{4326} (WGS84)}
+\item{srs_id}{\emph{integer}. Spatial Reference System ID. Default: \code{4326} (WGS84)}
 
-\item{z}{integer. Default: \code{0}}
+\item{z}{\emph{integer}. Default: \code{0}}
 
-\item{m}{integer. Default: \code{0}}
+\item{m}{\emph{integer}. Default: \code{0}}
 }
 \value{
-\code{1} if a new record in \code{gpkg_geometry_columns} is successfully made.
+\emph{integer}. Returns \code{1} if a new record in \code{gpkg_geometry_columns} is successfully made.
 }
 \description{
 Create a Spatial View
diff --git a/misc/gpkg-view-voronoi.R b/misc/gpkg-view-voronoi.R
index e15f850..04610da 100644
--- a/misc/gpkg-view-voronoi.R
+++ b/misc/gpkg-view-voronoi.R
@@ -17,7 +17,8 @@ gpkg_create_spatial_view(g, "my_vor", "SELECT lux.fid AS OGC_FID,
                                               ST_VoronojDiagram(geom) AS geom2 
                                        FROM lux WHERE ID_2 <= 3", 
                          geom_column = "geom2", 
-                         geometry_type_name = "MULTIPOLYGON") 
+                         geometry_type_name = "MULTIPOLYGON",
+                         spatialite_computed = TRUE) 
                          # NB: terra::vect() sensitive to geom type
 gpkg_contents(g)