How to determine whether the current connection is secure

[weinibuliu]

Question

Hi erveyone.

I use the function ui.clipboard.read() to read clipboard.However,I encountered some difficulties.
This function only works in secure contexts (HTTPS or localhost). That's no problems. But I have no way of knowing if the user is on a secure connection in advance.
I read the source code,I find this function always return str(if result is None,return "").This caused some confusion,because when the clipboard is empty,this function also return "".I have no way of determining whether the user is in an unsecured connection or because the clipboard is empty, so return "".Therefore,I can't show specific notifications to users.

I tried to modify this part of the source code https://github.com/zauberzeug/nicegui/blob/main/nicegui/functions/clipboard.py#L15-L30 :

async def read() -> str | None:
    """Read text from the clipboard.

    Note: This function only works in secure contexts (HTTPS or localhost).
    """
    result = await run_javascript('''
        if (navigator.clipboard) {
            return navigator.clipboard.readText()
        }
        else {
            console.error('Clipboard API is only available in secure contexts (HTTPS or localhost).')
        }
    ''')
    if result is None:
        log.warning('Clipboard API is only available in secure contexts (HTTPS or localhost).')
    return result

When result is None,return None instead of '' to distinguish the above two situations.When clipboard is empty,we will get '';When user not in Https or loaclhost,we will get None.

However,This means I need to modify the package before use pyinstaller build my exe.

Is there a better way to handle this?

[weinibuliu]

By the way,this is my code to show specific notifications to users.

async def on_cb_click():
    data = await ui.clipboard.read()
    print(data)
    if type(data) == str and data:
        own_input.set_value(data)
        ui.notify(
            "Succeed: ", position="bottom-right", type="positive"
        )
    elif data is None: # Unluckly we couldn't get None now.
        ui.notify(
            "Failed: Not in Https or localhost",
            position="bottom-right",
            type="warning",
        )
    else:
        ui.notify(
            "Failed: Cilpboard is empty",
            position="bottom-right",
            type="warning",
        )

[weinibuliu]

When I use ui.clipboard.write() function,I encountered same difficulties.Unluckly,this function doesn't return value(Alaways None).Maybe we should find a way to determine whether the current connection is secure instead of judging statu by return value.

[falkoschindler]

Good question, @weinibuliu! Maybe it would be better to raise an exception instead of printing a warning and returning an empty string. But because it would break the API, we would need to wait for version 3.0 before changing it.

Your custom read() function seems like a good workaround. You can use it without modifying the library. This way you don't have to wait for 3.0.

To check whether the clipboard is available, you can use a function like this:

async def can_access_clipboard() -> bool:
    return await ui.run_javascript('navigator.clipboard') is not None

[weinibuliu]

Thank you very much, I will use it in my project. At the same time, I look forward to the 3.0 update. Thanks again.

[falkoschindler]

See issue #4237.