Client-side interaction

This guide explains how to leverage the Python client to interact with the solution REST API (backend) from the Dash server (frontend).

Project injection in callbacks

To access the solution project instance within a Dash callback, you need to pass the project via the pathname property of the dcc.Location component, usually tagged with the "url" identifier, as an input or state in the callback decorator.

Basic usage

Here’s how to inject the project instance into your callback:

from ansys.saf.glow.client import callback
from ansys.solutions.minimal.solution.definition import MyMinimalSolution
from dash_extensions.enrich import Input, State, Output


@callback(..., Input("button", "n_clicks"), State("url", "pathname"))  # Your output here
def my_callback(n_clicks: int, project: MyMinimalSolution):
    # Your callback logic here
    pass

The project parameter will be automatically injected with the current project instance, allowing you to interact with the solution backend.

Access the solution backend

Once you have the project instance injected into your callback, you can access various solution components:

Access steps

Use the project.steps attribute to access and interact with the solution steps:

from ansys.saf.glow.client import callback
from ansys.solutions.minimal.solution.definition import MyMinimalSolution
from dash_extensions.enrich import Input, State, Output


@callback(..., Input("button", "n_clicks"), State("url", "pathname"))  # Your output here
def my_callback(n_clicks: int, project: MyMinimalSolution):
    # Access a specific step
    my_step = project.steps.my_step_name

    # Execute a transaction method in the step
    my_step.my_transaction()

    # Set a step field
    my_step.field_name = new_value

    ...

Access storage scope

Use the project.storage_scope attribute to manage data persistence and storage:

from ansys.saf.glow.client import callback
from ansys.solutions.minimal.solution.definition import MyMinimalSolution
from dash_extensions.enrich import Input, State, Output


@callback(..., Input("button", "n_clicks"), State("url", "pathname"))  # Your output here
def my_callback(n_clicks: int, project: MyMinimalSolution):
    # Access the storage scope
    storage = project.storage_scope

Troubleshooting

If the project instance is not injected as expected into your callbacks, see Project injection in Dash callbacks in the Troubleshooting guide guide.