v0: Android and iOS: allow passing src_bytes in FilePicker.save_file() call

[FeodorFitsner]

This PR depends on ((includes) #5377

Updated example:

import flet
from flet import (
    ElevatedButton,
    FilePicker,
    FilePickerResultEvent,
    Icons,
    Page,
    PagePlatform,
    Row,
    Text,
)


def main(page: Page):
    # Pick files dialog
    def pick_files_result(e: FilePickerResultEvent):
        selected_files.value = (
            ", ".join(map(lambda f: f.name, e.files)) if e.files else "Cancelled!"
        )
        selected_files.update()

    pick_files_dialog = FilePicker(on_result=pick_files_result)
    selected_files = Text()

    def save_file(e):
        bytes = None
        if page.platform == PagePlatform.ANDROID:
            bytes = b"Hello world!"
        save_file_dialog.save_file(src_bytes=bytes)

    # Save file dialog
    def save_file_result(e: FilePickerResultEvent):
        save_file_path.value = (
            e.path if e.path else e.error if e.error else "Cancelled!"
        )
        save_file_path.update()

    save_file_dialog = FilePicker(on_result=save_file_result)
    save_file_path = Text()

    # Open directory dialog
    def get_directory_result(e: FilePickerResultEvent):
        directory_path.value = e.path if e.path else "Cancelled!"
        directory_path.update()

    get_directory_dialog = FilePicker(on_result=get_directory_result)
    directory_path = Text()

    # hide all dialogs in overlay
    page.overlay.extend([pick_files_dialog, save_file_dialog, get_directory_dialog])

    page.add(
        Row(
            [
                ElevatedButton(
                    "Pick files",
                    icon=Icons.UPLOAD_FILE,
                    on_click=lambda _: pick_files_dialog.pick_files(
                        allow_multiple=True
                    ),
                ),
                selected_files,
            ]
        ),
        Row(
            [
                ElevatedButton(
                    "Save file",
                    icon=Icons.SAVE,
                    on_click=save_file,
                    disabled=page.web,
                ),
                save_file_path,
            ]
        ),
        Row(
            [
                ElevatedButton(
                    "Open directory",
                    icon=Icons.FOLDER_OPEN,
                    on_click=lambda _: get_directory_dialog.get_directory_path(),
                    disabled=page.web,
                ),
                directory_path,
            ]
        ),
    )


flet.app(target=main)

[sourcery-ai]

We've reviewed this pull request using the Sourcery rules engine

[sourcery-ai]

security (opengrep-rules.python.lang.security.audit.dangerous-subprocess-use-audit): Detected subprocess function 'run' without a static string. If this data can be controlled by a malicious actor, it may be an instance of command injection. Audit the use of this call to ensure it is not controllable by an external resource. You may consider using 'shlex.escape()'.

Source: opengrep