libseed-list Set uri of Gstreamer pipeline

[alsaf <alfraealba googlemail com>]

I've been trying to amend the Gstreamer video program from the set of
examples supplied with Seed to a play mp3 file specified in a command
line argument . I've googled and found a C example which works and it
uses GObject to set the uri properties of the Gst.Pipeline to use it
with the specified file. The C code is as follows:

g_object_set (G_OBJECT (pipeline), "uri", uri, NULL);


I can't find a property in the GST introspection file and the nearest
I've found in the GObject introspection file is the set_property
function but when I try to wrap the pipeline object to GObject via the
following code, I can't 'expose' the set_property function to use it
(apologies if I'm not using the correct terminology):

gst = imports.gi.Gst;
gst.init(null, null);
pipeline = new gst.Pipeline({name: "MusicTest"});
gobject = imports.gi.GObject;
var temp = new gobject.Object(pipeline);

I'm not sure I'm going about this the right way but I've been trying to
get this working on and off for the past week and going round in
circles. 

Has anybody else been successful in doing something similar?