Add filter for layer

This lets us for example exclude all features that are at a too high
level (e.g. country or continent) by explicitly specifying all the
layers that we care about and only getting results from those layers.

Author: c-w

controllers/features.js

@@ -24,6 +24,7 @@ exports.getById = function(req, res) {
     let query = {
         id: req.params.id.split(','),
         filter_namespace: req.query.filter_namespace,
+        filter_layer: req.query.filter_layer,
         include: req.query.include
     };
 
@@ -39,6 +40,7 @@ exports.getByPoint = function(req, res) {
         latitude: parseFloat(req.params.latitude),
         longitude: parseFloat(req.params.longitude),
         filter_namespace: req.query.filter_namespace,
+        filter_layer: req.query.filter_layer,
         include: req.query.include
     };
 
@@ -57,6 +59,7 @@ exports.getByName = function(req, res) {
     let query = {
         name: req.params.name.split(/,(?=[^ ])/),
         filter_namespace: req.query.filter_namespace,
+        filter_layer: req.query.filter_layer,
         include: req.query.include
     };
 
@@ -79,6 +82,7 @@ exports.getByBoundingBox = function(req, res) {
         east: parseFloat(req.params.east),
         filter_name: req.query.filter_name,
         filter_namespace: req.query.filter_namespace,
+        filter_layer: req.query.filter_layer,
         include: req.query.include
     };
 

schema.sql

@@ -26,6 +26,7 @@ CREATE TABLE features
 CREATE INDEX features_hull_index ON features USING gist (hull);
 CREATE INDEX features_name_lower_index ON features(lower(name));
 CREATE INDEX features_namespace_index ON features(lower(split_part(id, '-', 1)));
+CREATE INDEX features_layer_lower_index ON features(lower(layer));
 
 GRANT SELECT, UPDATE, INSERT, DELETE ON features TO frontend;
 

services/features.js

@@ -135,6 +135,10 @@ function addQueryPredicates(sql, query) {
         sql += ` AND lower(split_part(id, '-', 1)) = lower(${escapeSql(query.filter_namespace)})`;
     }
 
+    if (query.filter_layer) {
+        sql += ` AND lower(layer) IN (${query.filter_layer.split(',').map(layer => `lower(${escapeSql(layer)})`).join(',')})`;
+    }
+
     return sql;
 }