examples: add aggregation example with compile time checks.

Now we can just include it in the generated docs and ensure it compiles
correctly like the others.

Author: Christian Hergert

.gitignore

@@ -1,6 +1,7 @@
 *~
 *.a
 aclocal.m4
+aggregation1
 AUTHORS
 autom4te.cache
 bulk1

doc/aggregate.page

@@ -62,35 +62,7 @@ connecting to: test</output>
   <section>
     <title>States with Populations Over 10 Million</title>
     <p>To get all states with a population greater than 10 million, use the following aggregation pipeline:</p>
-    <synopsis><code mime="text/x-csrc"><![CDATA[#include <mongoc.h>
-#include <bcon.h>
-#include <stdio.h>
-
-static void
-print_pipeline (mongoc_collection_t *collection)
-{
-   bson_t *pipeline;
-   mongoc_cursor_t *cursor;
-   const bson_t *doc;
-
-   pipeline = BCON_NEW ("pipeline", "[",
-      "{", "$group", "{", "_id", "$state", "total_pop", "{", "$sum", "$pop", "}", "}", "}",
-      "{", "$match", "{", "total_pop", "{", "$gte", BCON_INT32 (10000000), "}", "}", "}",
-   "]");
-
-   cursor = mongoc_collection_aggregate (collection, MONGOC_QUERY_NONE, pipeline, NULL, NULL);
-
-   while (mongoc_cursor_next (cursor, &doc)) {
-      char *str;
-
-      str = bson_as_json (doc, NULL);
-      printf ("%s\n", str);
-      bson_free (str);
-   }
-
-   mongoc_cursor_destroy (cursor);
-   bson_destroy (pipeline);
-}]]></code></synopsis>
+    <synopsis><code mime="text/x-csrc"><include parse="text" href="../examples/aggregation/aggregation1.c" xmlns="http://www.w3.org/2001/XInclude" /></code></synopsis>
 
     <p>You should see a result like the following:</p>
 

examples/Makefile.am

@@ -68,3 +68,8 @@ noinst_PROGRAMS += bulk3
 bulk3_SOURCES = examples/bulk/bulk3.c
 bulk3_CFLAGS = $(EXAMPLE_CFLAGS)
 bulk3_LDADD = $(EXAMPLE_LDADD)
+
+noinst_PROGRAMS += aggregation1
+aggregation1_SOURCES = examples/aggregation/aggregation1.c
+aggregation1_CFLAGS = $(EXAMPLE_CFLAGS)
+aggregation1_LDADD = $(EXAMPLE_LDADD)

examples/aggregation/aggregation1.c

@@ -0,0 +1,54 @@
+#include <mongoc.h>
+#include <stdio.h>
+
+static void
+print_pipeline (mongoc_collection_t *collection)
+{
+   mongoc_cursor_t *cursor;
+   bson_error_t error;
+   const bson_t *doc;
+   bson_t *pipeline;
+   char *str;
+
+   pipeline = BCON_NEW ("pipeline", "[",
+      "{", "$group", "{", "_id", "$state", "total_pop", "{", "$sum", "$pop", "}", "}", "}",
+      "{", "$match", "{", "total_pop", "{", "$gte", BCON_INT32 (10000000), "}", "}", "}",
+   "]");
+
+   cursor = mongoc_collection_aggregate (collection, MONGOC_QUERY_NONE, pipeline, NULL, NULL);
+
+   while (mongoc_cursor_next (cursor, &doc)) {
+      str = bson_as_json (doc, NULL);
+      printf ("%s\n", str);
+      bson_free (str);
+   }
+
+   if (mongoc_cursor_error (cursor, &error)) {
+      fprintf (stderr, "Cursor Failure: %s\n", error.message);
+   }
+
+   mongoc_cursor_destroy (cursor);
+   bson_destroy (pipeline);
+}
+
+int
+main (int argc,
+      char *argv[])
+{
+   mongoc_client_t *client;
+   mongoc_collection_t *collection;
+
+   mongoc_init ();
+
+   client = mongoc_client_new ("mongodb://localhost:27017");
+   collection = mongoc_client_get_collection (client, "test", "zipcodes");
+
+   print_pipeline (collection);
+
+   mongoc_collection_destroy (collection);
+   mongoc_client_destroy (client);
+
+   mongoc_cleanup ();
+
+   return 0;
+}