From 68bbcac872249a8fd290b7d938643e09a4b13fc6 Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Fri, 1 Dec 2006 10:08:13 +0000
Subject: [PATCH] Reflect featureset and feature classes in Python. Featureset
 follows Python iterator protocol e.g:

    ds = Shapefile(file="/../..")
    for f in ds.features_at_point(Coord(-2,51)):
        print f
TODO:
    1.access to Feature properties
    2.feature_at_point to accept screen coordinates
    3.apply hit_test for geometries.
---
 bindings/python/mapnik_datasource.cpp | 29 +++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/bindings/python/mapnik_datasource.cpp b/bindings/python/mapnik_datasource.cpp
index ab14d8638..5263a35b4 100644
--- a/bindings/python/mapnik_datasource.cpp
+++ b/bindings/python/mapnik_datasource.cpp
@@ -27,6 +27,7 @@
 #include <sstream>
 // mapnik
 #include <mapnik/envelope.hpp>
+#include <mapnik/feature.hpp>
 #include <mapnik/datasource.hpp>
 #include <mapnik/datasource_cache.hpp>
 #include <mapnik/feature_layer_desc.hpp>
@@ -68,16 +69,44 @@ namespace
     }
 }
 
+inline object pass_through(object const& o) { return o; }
+
+inline mapnik::feature_ptr next(mapnik::featureset_ptr const& itr)
+{
+    mapnik::feature_ptr f = itr->next();
+    if (!f)
+    {
+        PyErr_SetString(PyExc_StopIteration, "No more features.");
+        boost::python::throw_error_already_set();
+    }
+    return f; 
+}
+
 void export_datasource()
 {
     using namespace boost::python;
     using mapnik::datasource;
+    using mapnik::Featureset;
+    using mapnik::Feature;
+
+    class_<Feature,boost::shared_ptr<Feature>,
+        boost::noncopyable>("Feature",no_init)
+        .def("id",&Feature::id)
+        .def("__str__",&Feature::to_string)
+        ;
+    
+    class_<Featureset,boost::shared_ptr<Featureset>,
+        boost::noncopyable>("Datasource",no_init)
+        .def("next",next)
+        .def("__iter__",pass_through)
+        ;
     
     class_<datasource,boost::shared_ptr<datasource>,
         boost::noncopyable>("Datasource",no_init)
         .def("envelope",&datasource::envelope)
         .def("descriptor",&datasource::get_descriptor) //todo
         .def("features",&datasource::features)
+        .def("features_at_point",&datasource::features_at_point)
         .def("params",&datasource::params,return_value_policy<copy_const_reference>(), 
              "The configuration parameters of the data source. "  
              "These vary depending on the type of data source.")