[Discuss-gnuradio] gr_top_block adding new block while running

[Engin Karabulut]

hi all,

I want to record for example a fir filter output
to file when I want. I have develop basic application,
given some parts below

.....
.....
def start_record_samples (self):
        self.stop()
        self.utfil = gr.file_sink(gr.sizeof_float,"capture.cfile")
        self.connect(self.chan_filt,self.utfil)
        self.start()
              
def stop_record_samples (self):
        self.stop()
        self.disconnect(self.chan_filt,self.utfil)
        self.start()

.....
.....

these functions are controlled with two buttons. "start" button calls 
start_record_samples and "stop" button calls stop_record_samples.

but they don't work properly.

start_record_samples gives error given below,

Traceback (most recent call last):
  File "/usr/local/lib/python2.5/site-packages/gnuradio/wxgui/form.py", line 
33, in <lambda>
    wx.EVT_BUTTON(parent, new_id, lambda evt: callback())
  File "usrp_snby_rcv.py", line 219, in record_samples
    self.start_record_samples()
  File "usrp_snby_rcv.py", line 227, in start_record_samples
    self.start()
  File "/usr/local/lib/python2.5/site-packages/gnuradio/gr/top_block.py", 
line 72, in start
    self._tb.start()
  File "/usr/local/lib/python2.5/site-
packages/gnuradio/gr/gnuradio_swig_py_runtime.py", line 1411, in start
    return _gnuradio_swig_py_runtime.gr_top_block_sptr_start(*args, 
**kwargs)
RuntimeError: top_block::start: top block already running or wait() not 
called after previous stop()

how can  I add new block temporarily to a running gr_top_block scheduler? 
because after stop it can't start anymore.

regards.