Multi-server setup

[DavidBerger98]

Hi,
Since Trame 2.0 it is possible to run multiple Trame servers in parallel each with its own state and controller.
I wrote a simple example to show how to set up two servers listening on different ports and have them communicate with each other.

One can for example imagine having a custom application and then hooking up ParaView Visualizer for visualization in an iframe. However, this is much more powerful than an external application in an iframe, since both servers can have access to the other's Trame state and controller.

See a simple example below:

r"""
Multi-server setup
"""

import asyncio

from trame.app import get_server
from trame.ui.vuetify import SinglePageLayout
from trame.widgets import vuetify


server1 = get_server("server1")
state1 = server1.state
state1.trame__title = "Server1"

server2 = get_server("server2")
state2 = server2.state
state2.trame__title = "Server2"


def send_to_server1(message):
    with state1:
        state1.received = message


def send_to_server2(message):
    with state2:
        state2.received = message


with SinglePageLayout(server1) as layout:
    layout.title.set_text("Server1")

    with layout.content:
        with vuetify.VCard(classes="pa-4"):
            vuetify.VTextField(
                v_model=("message", "Hi from server 1"),
            )
            vuetify.VBtn(
                "Send message to server 2",
                click=(send_to_server2, "[message]"),
            )
            vuetify.VTextField(readonly=True, v_model=("received", "<message here>"))

with SinglePageLayout(server2) as layout:
    layout.title.set_text("Server2")

    with layout.content:
        with vuetify.VCard(classes="pa-4"):
            vuetify.VTextField(
                v_model=("message", "Hi from server 2"),
            )
            vuetify.VBtn(
                "Send message to server 1",
                click=(send_to_server1, "[message]"),
            )
            vuetify.VTextField(
                readonly=True,
                v_model=("received", "<message here>"),
            )


if __name__ == "__main__":
    task1 = server1.start(exec_mode="task", port=8080)
    task2 = server2.start(exec_mode="task", port=8081)
    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.gather(task1, task2))