Re: Can Embedded Python Blocks have callbacks?

[Jameson Collins]

[image: image.png]
```
"""
Embedded Python Blocks:

Each time this file is saved, GRC will instantiate the first class it finds
to get ports and parameters of your block. The arguments to __init__  will
be the parameters. All of them are required to have default values!
"""

import numpy as np
from gnuradio import gr


class blk(gr.sync_block):  # other base classes are basic_block,
decim_block, interp_block
"""Embedded Python Block example - a simple multiply const"""

def __init__(self, example_param=1.0):  # only default arguments here
"""arguments to this function show up as parameters in GRC"""
gr.sync_block.__init__(
self,
name='Embedded Python Block',   # will show up in GRC
in_sig=[np.complex64],
out_sig=[np.complex64]
)
# if an attribute with the same name as a parameter is found,
# a callback is registered (properties work, too).
self.example_param = example_param

def work(self, input_items, output_items):
"""example: multiply with constant"""
output_items[0][:] = input_items[0] * self.example_param
return len(output_items[0])

def set_example_param(self, asdf):
print('here')
```


On Wed, Jun 19, 2024 at 12:12 PM Croizer Mathieu 
wrote:

> Hello,
>
> Can you post the rest of the code and a snapshot of your project in
> gnuradio?  Because with only your function, it's hard to say what happens
> in your python block :)
>
> Best Regards
>
> M. Croizer
>
>
> Le mer. 19 juin 2024 à 14:52, Jameson Collins 
> a écrit :
>
>> I'm trying to use a callback to set a variable in an embedded python
>> block.  Using the tutorial (
>> https://wiki.gnuradio.org/index.php/Embedded_Python_Block) as an example
>> I added the function below.  I've found that this callback never gets
>> called when I update this value from a GUI.  Should it be?
>>
>> def set_example_param(self, example_param):
>> print("here")
>>
>>
>>
>>
>>

Re: Can Embedded Python Blocks have callbacks?

[Jameson Collins]

This was my concern, and it does appear to behave that way.

On Wed, Jun 19, 2024 at 4:34 PM Daniel Estévez  wrote:

> On 19/06/2024 14:51, Jameson Collins wrote:
> > I'm trying to use a callback to set a variable in an embedded python
> > block.  Using the tutorial
> > (https://wiki.gnuradio.org/index.php/Embedded_Python_Block
> > ) as an
> > example I added the function below.  I've found that this callback never
> > gets called when I update this value from a GUI.  Should it be?
> >
> > |def set_example_param(self, example_param): print("here")|
>
> Hi Jameson,
>
> I think Embedded Python blocks can only have (automatically generated)
> callbacks for __init__() arguments that are assigned as
>
> self.foo = foo
>
> in the body of __init__() (the example template that you get when you
> create a new Embedded Python block shows how this works).
>
> If you need more complex callbacks, I think you need to create a regular
> Python block in an OOT module.
>
> Best,
> Daniel.
>
>
>