Redirect stdout to TextLog?

[victor-shepardson]

Conceptually I want to redirect all stdout/stderr to a TextLog, so I can incrementally move an app to Textual (and have error / debug statements show up within my TUI rather than being hidden until the app exits). But I don't literally want that since Textual itself needs to render the app to stdout (?) and seems to foil a global redirection of stdout here. Is there anything I can do if I want e.g. print calls in library code which I don't control to wind up in a TextLog?

Related to #190

my current approach is to add this to my TUI class:

def flush(self): pass
def write(self, s):
    """for redirecting stdout to a file-like"""
    if self.is_running:
        return self.call_from_anywhere(self.std_log.write, s) # std_log is a TextLog
    else:
        return sys.__stdout__.write(s)

def call_from_anywhere(self, f, *a, **kw):
    try:
        return self.call_from_thread(f, *a, **kw)
    except RuntimeError as e:
        return f(*a, **kw)

and set sys.stdout = my_tui_instance. This works if I use print(..., file=my_tui_instance) but fails to redirect unmodified print statements.

[victor-shepardson]

I found that I can monkey-patch print in some cases:

import some_module
from textual.app import App

MyTUI(App):
    def __init__(self):
        super().__init__()
        self.std_log = TextLog(id='std_log')

    def compose(self):
        yield Header()
        yield self.std_log
        yield Footer()

    def print(self, *a, **kw):
        """redirects to the UI's default std output log"""
        kw['file'] = self
        print(*a, **kw)

    def flush(self): pass
    def write(self, s):
        """for redirecting stdout to a file-like"""
        if self.is_running:
            return self.call_from_anywhere(self.std_log.write, s) # std_log is a TextLog
        else:
            return sys.__stdout__.write(s)

    def call_from_anywhere(self, f, *a, **kw):
        try:
            return self.call_from_thread(f, *a, **kw)
        except RuntimeError as e:
            return f(*a, **kw)

my_tui_instance = MyTUI()

some_module.print = my_tui_instance.print

my_tui_instance.run()

but it would be great to capture output from C extensions, logging frameworks, or any case where print can't just be replaced this way