feature IDs for views (and tables without PK)

config/pg_featureserv.toml.example

@@ -68,6 +68,9 @@ WriteTimeoutSec = 30
 # Publish functions from these schemas (default is publish postgisftw)
 # FunctionIncludes = [ "postgisftw", "schema2" ]
 
+# Designate a column as the feature ID (where primary key is not available e.g. views/functions)
+# IDColumn = "id"
+
 [Paging]
 # The default number of features in a response
 LimitDefault = 20

demo/initdb/02-functions.sql

@@ -19,7 +19,7 @@ BEGIN
     dlat := (lat_max - lat_min) / num_y;
     RETURN QUERY
         SELECT
-            x.x::text || '_' || y.y::text AS fid,
+            x.x::text || '_' || y.y::text AS id,
             ST_MakeEnvelope(
                 lon_min + (x.x - 1) * dlon, lat_min + (y.y - 1) * dlat,
                 lon_min + x.x * dlon,       lat_min + y.y * dlat, 4326
@@ -35,7 +35,7 @@ COMMENT ON FUNCTION postgisftw.us_grid IS 'Generates a grid of rectangles coveri
 CREATE OR REPLACE FUNCTION postgisftw.us_grid_noid(
     num_x integer DEFAULT 10,
     num_y integer DEFAULT 10)
-RETURNS TABLE(geom geometry)
+RETURNS TABLE(value text, geom geometry)
 AS $$
 DECLARE
     lon_min CONSTANT numeric := -128;
@@ -49,6 +49,7 @@ BEGIN
     dlat := (lat_max - lat_min) / num_y;
     RETURN QUERY
         SELECT
+            x.x::text || '_' || y.y::text AS value,
             ST_MakeEnvelope(
                 lon_min + (x.x - 1) * dlon, lat_min + (y.y - 1) * dlat,
                 lon_min + x.x * dlon,       lat_min + y.y * dlat, 4326

hugo/content/installation/configuration.md

@@ -119,6 +119,9 @@ WriteTimeoutSec = 30
 # Publish functions from these schemas (default is publish postgisftw)
 # FunctionIncludes = [ "postgisftw", "schema2" ]
 
+# Designate a column as the feature ID (where primary key is not available e.g. views/functions)
+# IDColumn = "id"
+
 [Paging]
 # The default number of features in a response
 LimitDefault = 20
@@ -243,6 +246,12 @@ Overrides items specified in `TableIncludes`.
 A list of the schemas to publish functions from.
 The default is to publish functions in the `postgisftw` schema.
 
+#### IDColumn
+
+The column to use as the feature ID in cases where a primary key is not available. The default is `id`.
+
+> NOTE: The presence of a primary key will supercede this setting.
+
 #### LimitDefault
 
 The default number of features in a response,

internal/conf/config.go

@@ -44,6 +44,7 @@ func setDefaultConfig() {
 	viper.SetDefault("Database.TableIncludes", []string{})
 	viper.SetDefault("Database.TableExcludes", []string{})
 	viper.SetDefault("Database.FunctionIncludes", []string{"postgisftw"})
+	viper.SetDefault("Database.IDColumn", "id")
 
 	viper.SetDefault("Paging.LimitDefault", 10)
 	viper.SetDefault("Paging.LimitMax", 1000)
@@ -94,6 +95,7 @@ type Database struct {
 	TableIncludes         []string
 	TableExcludes         []string
 	FunctionIncludes      []string
+	IDColumn              string
 }
 
 // Metadata config

internal/data/catalog_db.go

@@ -354,6 +354,13 @@ func scanTable(rows pgx.Rows) *Table {
 		colDesc[i] = props.Elements[elmPos+2].String
 	}
 
+	// detect ID column if primary key not defined.
+	if idColumn == "" && conf.Configuration.Database.IDColumn != "" {
+		if _, ok := datatypes[conf.Configuration.Database.IDColumn]; ok {
+			idColumn = conf.Configuration.Database.IDColumn
+		}
+	}
+
 	// Synthesize a title for now
 	title := id
 	// synthesize a description if none provided

internal/data/catalog_db_fun.go

@@ -26,7 +26,6 @@ import (
 )
 
 // FunctionIDColumnName is the name for a function-supplied ID
-const FunctionIDColumnName = "id"
 
 const SchemaPostGISFTW = "postgisftw"
 
@@ -116,6 +115,13 @@ func scanFunctionDef(rows pgx.Rows) *Function {
 
 	geomCol := geometryColumn(outNames, datatypes)
 
+	idColumn := ""
+	if conf.Configuration.Database.IDColumn != "" {
+		if _, ok := datatypes[conf.Configuration.Database.IDColumn]; ok {
+			idColumn = conf.Configuration.Database.IDColumn
+		}
+	}
+
 	funDef := Function{
 		ID:             id,
 		Schema:         schema,
@@ -131,6 +137,7 @@ func scanFunctionDef(rows pgx.Rows) *Function {
 		OutJSONTypes:   outJSONTypes,
 		Types:          datatypes,
 		GeometryColumn: geomCol,
+		IDColumn:       idColumn,
 	}
 	//fmt.Printf("DEBUG: Function definitions: %v\n", funDef)
 	return &funDef
@@ -191,7 +198,7 @@ func (cat *catalogDB) FunctionFeatures(ctx context.Context, name string, args ma
 		return nil, errArg
 	}
 	propCols := removeNames(param.Columns, fn.GeometryColumn, "")
-	idColIndex := indexOfName(propCols, FunctionIDColumnName)
+	idColIndex := indexOfName(propCols, fn.IDColumn)
 	sql, argValues := sqlGeomFunction(fn, args, propCols, param)
 	log.Debugf("Function features query: %v", sql)
 	log.Debugf("Function %v Args: %v", name, argValues)

internal/service/handler.go

@@ -636,7 +636,7 @@ func writeFunItemsHTML(w http.ResponseWriter, name string, query string, urlBase
 	context.Group = "Functions"
 	context.Title = fn.ID
 	context.Function = fn
-	context.IDColumn = data.FunctionIDColumnName
+	context.IDColumn = fn.IDColumn
 
 	// features are not needed for items page (page queries for them)
 	return writeHTML(w, nil, context, ui.PageFunctionItems())