Merge pull request #1465 from joto/attributes-lua-example

Add flex config example showing how to access attributes in Lua

Author: lonvia

flex-config/README.md

@@ -24,6 +24,7 @@ After that you can dive into more advanced topics:
 * [unitable.lua](unitable.lua) -- Put all OSM data into a single table
 * [places.lua](places.lua) -- Creating JSON/JSONB columns
 * [with-schema.lua](with-schema.lua) -- Use a database schema
+* [attributes.lua](attributes.lua) -- How to access OSM object attributes
 
 The "generic" configuration is a full-featured but simple configuration that
 is a good starting point for your own real-world configuration:

flex-config/attributes.lua

@@ -0,0 +1,78 @@
+-- This config example file is released into the Public Domain.
+
+-- This config shows how to access the attributes of OSM objects: the version,
+-- changeset id, timestamp, user id and user name. For this to work the
+-- command line option --extra-attributes/-x must be set, otherwise those
+-- fields will be empty.
+
+-- Set this to the projection you want to use
+local srid = 4326
+
+local tables = {}
+
+tables.points = osm2pgsql.define_node_table('points', {
+    { column = 'tags', type = 'hstore' },
+    { column = 'geom', type = 'point', projection = srid },
+    { column = 'version', type = 'int' },
+    { column = 'changeset', type = 'int' },
+    { column = 'created', type = 'timestamp' },
+    { column = 'uid', type = 'int' },
+    { column = 'user', type = 'text' },
+})
+
+tables.lines = osm2pgsql.define_way_table('lines', {
+    { column = 'tags', type = 'hstore' },
+    { column = 'geom', type = 'linestring', projection = srid },
+    { column = 'version', type = 'int' },
+    { column = 'changeset', type = 'int' },
+    { column = 'created', type = 'timestamp' },
+    { column = 'uid', type = 'int' },
+    { column = 'user', type = 'text' },
+})
+
+tables.relations = osm2pgsql.define_relation_table('relations', {
+    { column = 'tags', type = 'hstore' },
+    { column = 'version', type = 'int' },
+    { column = 'changeset', type = 'int' },
+    { column = 'created', type = 'timestamp' },
+    { column = 'uid', type = 'int' },
+    { column = 'user', type = 'text' },
+})
+
+function osm2pgsql.process_node(object)
+    if next(object.tags) == nil then
+        return
+    end
+
+    tables.points:add_row({
+        tags = object.tags,
+        version = object.version,
+        changeset = object.changeset,
+        created = os.date('!%Y-%m-%dT%TZ', object.timestamp),
+        uid = object.uid,
+        user = object.user
+    })
+end
+
+function osm2pgsql.process_way(object)
+    tables.lines:add_row({
+        tags = object.tags,
+        version = object.version,
+        changeset = object.changeset,
+        created = os.date('!%Y-%m-%dT%TZ', object.timestamp),
+        uid = object.uid,
+        user = object.user
+    })
+end
+
+function osm2pgsql.process_relation(object)
+    tables.relations:add_row({
+        tags = object.tags,
+        version = object.version,
+        changeset = object.changeset,
+        created = os.date('!%Y-%m-%dT%TZ', object.timestamp),
+        uid = object.uid,
+        user = object.user
+    })
+end
+