phpy/docs/en/php/fn.md

Callback Function

You can use PHP callable objects as callback functions in Python. Simply wrap them with PyCore::fn(callable $fn).

$m = PyCore::import('app.user');
$uuid = uniqid();
$rs = $m->test_callback(PyCore::fn(function ($namespace) use ($uuid) {
    var_dump($namespace);
    return $uuid;
}));

• import app.user imports a custom Python package
• Calls a function test_callback in the package, which takes a parameter as a Python Callable object
• Wraps a Closure object as the callback using PyCore::fn(), supports both function name string and object method call
• The callback function returns a string, which will be a str type return value in the test_callback function

Example

Here, we use Python tkinter as an example:

<?php
$tkinter = PyCore::import('tkinter');
$root = $tkinter->Tk();
$root->title('My Window');
$root->geometry("500x500");
$root->resizable(False, False);

$button = $tkinter->Button($root, text: "Click Me!!", command: PyCore::fn(function () {
    var_dump(func_get_args());
    echo 'Click Me!!' . PHP_EOL;
}));
$button->pack();

$tkinter->mainloop();

PHP serves as the callback function for the Tk Button.