Flex: Process untagged objects in their own callbacks

This happens regardless of whether the -x/--extra-attributes option is
set.

flex-config/untagged.lua

@@ -0,0 +1,44 @@
+-- This config example file is released into the Public Domain.
+--
+-- Most of the time we are only interested in nodes, ways, and relations that
+-- have tags. But we can also get the untagged ones if necessary by using
+-- the processing functions 'process_untagged_node', 'process_untagged_way',
+-- and 'process_untagged_relation', respectively.
+
+local nodes = osm2pgsql.define_node_table('nodes', {
+    { column = 'tags', type = 'jsonb' },
+    { column = 'geom', type = 'point' },
+})
+
+local ways = osm2pgsql.define_way_table('ways', {
+    { column = 'tags', type = 'jsonb' },
+    { column = 'geom', type = 'linestring' },
+})
+
+function osm2pgsql.process_node(object)
+    nodes:insert({
+        tags = object.tags,
+        geom = object:as_point(),
+    })
+end
+
+function osm2pgsql.process_untagged_node(object)
+    nodes:insert({
+        geom = object:as_point(),
+    })
+end
+
+-- If you want to use the same function in both cases, that's also quite easy.
+-- For instance like this:
+
+function do_way(object)
+    ways:insert({
+        tags = object.tags,
+        geom = object:as_linestring(),
+    })
+end
+
+osm2pgsql.process_way = do_way
+osm2pgsql.process_untagged_way = do_way
+
+

src/osmdata.cpp

@@ -31,7 +31,9 @@ osmdata_t::osmdata_t(std::shared_ptr<middle_t> mid,
 : m_mid(std::move(mid)), m_output(std::move(output)),
   m_connection_params(options.connection_params), m_bbox(options.bbox),
   m_num_procs(options.num_procs), m_append(options.append),
-  m_droptemp(options.droptemp), m_with_extra_attrs(options.extra_attributes)
+  m_droptemp(options.droptemp),
+  m_with_extra_attrs(options.extra_attributes ||
+                     options.output_backend == "flex")
 {
     assert(m_mid);
     assert(m_output);

src/output-flex.cpp

@@ -1047,36 +1047,45 @@ void output_flex_t::wait()
 
 void output_flex_t::node_add(osmium::Node const &node)
 {
-    if (!m_process_node) {
+    auto const &func =
+        node.tags().empty() ? m_process_untagged_node : m_process_node;
+
+    if (!func) {
         return;
     }
 
     m_context_node = &node;
-    get_mutex_and_call_lua_function(m_process_node, node);
+    get_mutex_and_call_lua_function(func, node);
     m_context_node = nullptr;
 }
 
 void output_flex_t::way_add(osmium::Way *way)
 {
     assert(way);
 
-    if (!m_process_way) {
+    auto const &func =
+        way->tags().empty() ? m_process_untagged_way : m_process_way;
+
+    if (!func) {
         return;
     }
 
     m_way_cache.init(way);
-    get_mutex_and_call_lua_function(m_process_way, m_way_cache.get());
+    get_mutex_and_call_lua_function(func, m_way_cache.get());
 }
 
 void output_flex_t::relation_add(osmium::Relation const &relation)
 {
-    if (!m_process_relation) {
+    auto const &func = relation.tags().empty() ? m_process_untagged_relation
+                                               : m_process_relation;
+
+    if (!func) {
         return;
     }
 
     m_relation_cache.init(relation);
     select_relation_members();
-    get_mutex_and_call_lua_function(m_process_relation, relation);
+    get_mutex_and_call_lua_function(func, relation);
 }
 
 void output_flex_t::delete_from_table(table_connection_t *table_connection,
@@ -1171,6 +1180,9 @@ output_flex_t::output_flex_t(output_flex_t const *other,
   m_area_buffer(1024, osmium::memory::Buffer::auto_grow::yes),
   m_process_node(other->m_process_node), m_process_way(other->m_process_way),
   m_process_relation(other->m_process_relation),
+  m_process_untagged_node(other->m_process_untagged_node),
+  m_process_untagged_way(other->m_process_untagged_way),
+  m_process_untagged_relation(other->m_process_untagged_relation),
   m_select_relation_members(other->m_select_relation_members),
   m_after_nodes(other->m_after_nodes), m_after_ways(other->m_after_ways),
   m_after_relations(other->m_after_relations)
@@ -1402,9 +1414,19 @@ void output_flex_t::init_lua(std::string const &filename,
         lua_state(), calling_context::process_way, "process_way"};
     m_process_relation = prepared_lua_function_t{
         lua_state(), calling_context::process_relation, "process_relation"};
+
+    m_process_untagged_node = prepared_lua_function_t{
+        lua_state(), calling_context::process_node, "process_untagged_node"};
+    m_process_untagged_way = prepared_lua_function_t{
+        lua_state(), calling_context::process_way, "process_untagged_way"};
+    m_process_untagged_relation =
+        prepared_lua_function_t{lua_state(), calling_context::process_relation,
+                                "process_untagged_relation"};
+
     m_select_relation_members = prepared_lua_function_t{
         lua_state(), calling_context::select_relation_members,
         "select_relation_members", 1};
+
     m_after_nodes = prepared_lua_function_t{lua_state(), calling_context::main,
                                             "after_nodes"};
     m_after_ways = prepared_lua_function_t{lua_state(), calling_context::main,

src/output-flex.hpp

@@ -301,7 +301,13 @@ class output_flex_t : public output_t
     prepared_lua_function_t m_process_node{};
     prepared_lua_function_t m_process_way{};
     prepared_lua_function_t m_process_relation{};
+
+    prepared_lua_function_t m_process_untagged_node{};
+    prepared_lua_function_t m_process_untagged_way{};
+    prepared_lua_function_t m_process_untagged_relation{};
+
     prepared_lua_function_t m_select_relation_members{};
+
     prepared_lua_function_t m_after_nodes{};
     prepared_lua_function_t m_after_ways{};
     prepared_lua_function_t m_after_relations{};