New tab using url_target="_blank" uses same session

[gbrandt]

If I have a button that opens a new page on the same app, or the app itself, it uses the same session and any changes on the new tab reflect in the original tab.

Code example to reproduce the issue:

Start the app, click the new tab button. Any action to increase the value in the first tab are also shown in the second tab

import flet as ft


def main(page: ft.Page):
    page.title = "Flet counter example"
    page.vertical_alignment = ft.MainAxisAlignment.CENTER

    txt_number = ft.TextField(value="0", text_align="right", width=100)

    def minus_click(e):
        txt_number.value = str(int(txt_number.value) - 1)
        page.update()

    def plus_click(e):
        txt_number.value = str(int(txt_number.value) + 1)
        page.update()

    page.add(
        ft.Row(
            [
                ft.IconButton(ft.icons.REMOVE, on_click=minus_click),
                txt_number,
                ft.IconButton(ft.icons.ADD, on_click=plus_click),
            ],
            alignment=ft.MainAxisAlignment.CENTER,
        )
    )

    page.add(ft.ElevatedButton("new tab", url="http://127.0.0.1:3000", url_target="_blank"))


ft.app(target=main, view=ft.WEB_BROWSER)

Describe the results you received:

Any action to increase the value in the first tab are also shown in the second tab

Describe the results you expected:

The new tab should start a new session, not use the existing session. If I just open a new tab and type the address in the URL, a new session is started.

Additional information you deem important (e.g. issue happens only occasionally):

Flet version (pip show flet):

Name: flet
Version: 0.8.2
Summary: Flet for Python - easily build interactive multi-platform apps in Python
Home-page: 
Author: Appveyor Systems Inc.

Operating system:

macOS, tested in Safari and Firefox

Additional environment details:

[FeodorFitsner]

I found this which looks like our case: https://stackoverflow.com/questions/20879714/how-to-prevent-sessionstorage-being-inherited-when-using-target-blank-window

I could be mistaken, but url_launcher, the package we use in Flet to follow URLs, uses window.open. Someone suggests adding 'noopener=true' which could be a solution. We can try that. Let's mark this issue as a bug.

[FeodorFitsner]

...and this could be a solution from a different angle - store session data in window.name. Could work for Flet as it stores only session ID in a tab session.