multiple outputs

[George-bai]

@idling-mind

I have functions that have multiple outputs, and Flowfunc can render all outputs as expected. However, when connect second / third output port with other node inputs, all connections will automatically change to only the FIRST output port and other node inputs:

How to fix this? also, is there a way to naming the outputs (similar to the parameter name in the function inputs), so the output port can use its name as label. Easy to know which port is which output.

Thanks for updating the component.

[idling-mind]

Hmm, you're right. This seems to be a bug! My gut feeling is that there is something going on with the underlying js package (flume).

Regarding naming your output ports, you can access each 'Node' object from the config object. below is a modified version of the usage.py

from typing import Dict
import dash
from dash import html, Input, Output, State
from flowfunc import Flowfunc
from flowfunc.config import Config
from flowfunc.jobrunner import JobRunner
from flowfunc.models import OutNode

app = dash.Dash(__name__)

# Functions can be converted to nodes
def add(a: int, b: int) -> int:
    """Add two numbers"""
    return a + b

def subtract(a: int, b: int) -> int:
    """Find difference between two numbers"""
    return a - b

def swap_numbers(a: int, b: int) -> tuple[int, int]:
    """Swap the given numbers"""
    return b, a


# A Config object contains info about the nodes and ports available in the node editor
nodeeditor_config = Config.from_function_list([add, subtract, swap_numbers])
nodeeditor_config.nodes[-1].outputs[0].label = "First number"
nodeeditor_config.nodes[-1].outputs[1].label = "Second number"

# A JobRunner object helps evaluate the nodes created using the node editor
runner = JobRunner(nodeeditor_config)

nodeeditor_config.nodes[0].outputs[0].label = "Sum of numbers"

app.layout = html.Div(
    [
        html.Button(id="btn_run", children="Run"),
        Flowfunc(id="nodeeditor", config=nodeeditor_config.dict()),
        html.Div(id="output"),
    ], style={"height": "600px"}
)


@app.callback(
    Output("output", "children"),
    Input("btn_run", "n_clicks"),
    State("nodeeditor", "nodes"),
    prevent_intial_call=True,
)
def run_nodes(nclicks: int, output_nodes: Dict[str, OutNode]):
    """Run the node layout"""
    # The result is a dictionary of OutNode objects
    result = runner.run(output_nodes)
    output = []
    for node in result.values():
        # node.result contains the result of the node
        output.append(
            html.Div([html.H1(f"{node.type}: {node.id}"), html.P(str(node.result))])
        )
    return output

if __name__ == "__main__":
    app.run(debug=True) 

You can create a node/port from scratch also using the classes if you want. Here is an example

[George-bai]

Thanks for your quick response @idling-mind

Is this a quick fix or need Flume to make changes to support this? I also tried to fork this project and setup the developer environment to work on the Flume part. But seems like there are some depending JS modules/ components are quite old and need older versions when doing npm install. The new version of Flume is rewritten in Typescript may worth to update.

A detailed guide for develop / contribute would be much appreciated.

[idling-mind]

I think I found the issue and it's not in flume. Each output node needs a unique name and as of now, it was setting it as the annotation of the output. For the timebeing, you can set the name manually just like how you set the label.

...
nodeeditor_config.nodes[-1].outputs[0].name= "first_number"
nodeeditor_config.nodes[-1].outputs[1].name= "second_number"
...

The bug is happening in this function

I have been meaning to re-write the whole processing of functions utilizing latest pydantic methods (or may be using better features of newer python).

[George-bai]

Thanks @idling-mind. looking forward to seeing the new version. Any plan or roadmap?

[George-bai]

For anyone don't want to do manual naming, can add below code for the process_output function:

[idling-mind]

Fixed in the new release