NAME

       mongoc_change_stream_t - mongoc_change_stream_t

SYNOPSIS

          #include <mongoc.h>

          typedef struct _mongoc_change_stream_t mongoc_change_stream_t;

       mongoc_change_stream_t  is  a handle to a change stream. A collection change stream can be
       obtained using mongoc_collection_watch.

       It is recommended to use a mongoc_change_stream_t and  its  functions  instead  of  a  raw
       aggregation  with a $changeStream stage. For more information see the MongoDB Manual Entry
       on Change Streams.

EXAMPLE

       example-collection-watch.c.INDENT 0.0

          #include <mongoc.h>

          int
          main ()
          {
             bson_t empty = BSON_INITIALIZER;
             const bson_t *doc;
             bson_t *to_insert = BCON_NEW ("x", BCON_INT32 (1));
             const bson_t *err_doc;
             bson_error_t err;
             mongoc_client_t *client;
             mongoc_collection_t *coll;
             mongoc_change_stream_t *stream;
             mongoc_write_concern_t *wc = mongoc_write_concern_new ();
             bson_t opts = BSON_INITIALIZER;
             bool r;

             mongoc_init ();

             client = mongoc_client_new ("mongodb://"
                                         "localhost:27017,localhost:27018,localhost:"
                                         "27019/db?replicaSet=rs0");
             if (!client) {
                fprintf (stderr, "Could not connect to replica set\n");
                return 1;
             }

             coll = mongoc_client_get_collection (client, "db", "coll");
             stream = mongoc_collection_watch (coll, &empty, NULL);

             mongoc_write_concern_set_wmajority (wc, 10000);
             mongoc_write_concern_append (wc, &opts);
             r = mongoc_collection_insert_one (coll, to_insert, &opts, NULL, &err);
             if (!r) {
                fprintf (stderr, "Error: %s\n", err.message);
                return 1;
             }

             while (mongoc_change_stream_next (stream, &doc)) {
                char *as_json = bson_as_relaxed_extended_json (doc, NULL);
                fprintf (stderr, "Got document: %s\n", as_json);
                bson_free (as_json);
             }

             if (mongoc_change_stream_error_document (stream, &err, &err_doc)) {
                if (!bson_empty (err_doc)) {
                   fprintf (stderr,
                            "Server Error: %s\n",
                            bson_as_relaxed_extended_json (err_doc, NULL));
                } else {
                   fprintf (stderr, "Client Error: %s\n", err.message);
                }
                return 1;
             }

             bson_destroy (to_insert);
             mongoc_write_concern_destroy (wc);
             bson_destroy (&opts);
             mongoc_change_stream_destroy (stream);
             mongoc_collection_destroy (coll);
             mongoc_client_destroy (client);
             mongoc_cleanup ();
          }

AUTHOR

       MongoDB, Inc

COPYRIGHT

       2018, MongoDB, Inc