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from __future__ import annotations
import asyncio
import time
import uuid
from pathlib import Path
from typing import TYPE_CHECKING, Any, Awaitable, Callable, Dict, Iterable, List, Optional, Union
from fastapi import Request
from fastapi.responses import Response
from fastapi.templating import Jinja2Templates
from nicegui import json
from . import binding, globals, outbox # pylint: disable=redefined-builtin
from .dependencies import generate_resources
from .element import Element
from .favicon import get_favicon_url
from .version import __version__
if TYPE_CHECKING:
from .page import page
templates = Jinja2Templates(Path(__file__).parent / 'templates')
class Client:
def __init__(self, page: page, *, shared: bool = False) -> None:
self.id = str(uuid.uuid4())
self.created = time.time()
globals.clients[self.id] = self
self.elements: Dict[int, Element] = {}
self.next_element_id: int = 0
self.is_waiting_for_connection: bool = False
self.is_waiting_for_disconnect: bool = False
self.environ: Optional[Dict[str, Any]] = None
self.shared = shared
self.on_air = False
with Element('q-layout', _client=self).props('view="hhh lpr fff"').classes('nicegui-layout') as self.layout:
with Element('q-page-container') as self.page_container:
with Element('q-page'):
self.content = Element('div').classes('nicegui-content')
self.waiting_javascript_commands: Dict[str, Any] = {}
self.head_html = ''
self.body_html = ''
self.page = page
self.connect_handlers: List[Union[Callable[..., Any], Awaitable]] = []
self.disconnect_handlers: List[Union[Callable[..., Any], Awaitable]] = []
@property
def ip(self) -> Optional[str]:
"""Return the IP address of the client, or None if the client is not connected."""
return self.environ['asgi.scope']['client'][0] if self.environ else None # pylint: disable=unsubscriptable-object
@property
def has_socket_connection(self) -> bool:
"""Return True if the client is connected, False otherwise."""
return self.environ is not None
def __enter__(self):
self.content.__enter__()
return self
def __exit__(self, *_):
self.content.__exit__()
def build_response(self, request: Request, status_code: int = 200) -> Response:
prefix = request.headers.get('X-Forwarded-Prefix', request.scope.get('root_path', ''))
elements = json.dumps({
id: element._to_dict() for id, element in self.elements.items() # pylint: disable=protected-access
})
socket_io_js_query_params = {**globals.socket_io_js_query_params, 'client_id': self.id}
vue_html, vue_styles, vue_scripts, imports, js_imports = generate_resources(prefix, self.elements.values())
return templates.TemplateResponse('index.html', {
'request': request,
'version': __version__,
'elements': elements.replace('&', '&')
.replace('<', '&lt;')
.replace('>', '&gt;')
.replace('`', '&#96;'),
'head_html': self.head_html,
'body_html': '<style>' + '\n'.join(vue_styles) + '</style>\n' + self.body_html + '\n' + '\n'.join(vue_html),
'vue_scripts': '\n'.join(vue_scripts),
'imports': json.dumps(imports),
'js_imports': '\n'.join(js_imports),
'quasar_config': json.dumps(globals.quasar_config),
'title': self.page.resolve_title(),
'viewport': self.page.resolve_viewport(),
'favicon_url': get_favicon_url(self.page, prefix),
'dark': str(self.page.resolve_dark()),
'language': self.page.resolve_language(),
'prefix': prefix,
'tailwind': globals.tailwind,
'prod_js': globals.prod_js,
'socket_io_js_query_params': socket_io_js_query_params,
'socket_io_js_extra_headers': globals.socket_io_js_extra_headers,
'socket_io_js_transports': globals.socket_io_js_transports,
}, status_code, {'Cache-Control': 'no-store', 'X-NiceGUI-Content': 'page'})
async def connected(self, timeout: float = 3.0, check_interval: float = 0.1) -> None:
"""Block execution until the client is connected."""
self.is_waiting_for_connection = True
deadline = time.time() + timeout
while not self.has_socket_connection:
if time.time() > deadline:
raise TimeoutError(f'No connection after {timeout} seconds')
await asyncio.sleep(check_interval)
self.is_waiting_for_connection = False
async def disconnected(self, check_interval: float = 0.1) -> None:
"""Block execution until the client disconnects."""
if not self.has_socket_connection:
await self.connected()
self.is_waiting_for_disconnect = True
while self.id in globals.clients:
await asyncio.sleep(check_interval)
self.is_waiting_for_disconnect = False
async def run_javascript(self, code: str, *,
respond: bool = True, timeout: float = 1.0, check_interval: float = 0.01) -> Optional[Any]:
"""Execute JavaScript on the client.
The client connection must be established before this method is called.
You can do this by `await client.connected()` or register a callback with `client.on_connect(...)`.
If respond is True, the javascript code must return a string.
"""
request_id = str(uuid.uuid4())
command = {
'code': code,
'request_id': request_id if respond else None,
}
outbox.enqueue_message('run_javascript', command, self.id)
if not respond:
return None
deadline = time.time() + timeout
while request_id not in self.waiting_javascript_commands:
if time.time() > deadline:
raise TimeoutError('JavaScript did not respond in time')
await asyncio.sleep(check_interval)
return self.waiting_javascript_commands.pop(request_id)
def open(self, target: Union[Callable[..., Any], str], new_tab: bool = False) -> None:
"""Open a new page in the client."""
path = target if isinstance(target, str) else globals.page_routes[target]
outbox.enqueue_message('open', {'path': path, 'new_tab': new_tab}, self.id)
def download(self, url: str, filename: Optional[str] = None) -> None:
"""Download a file from the given URL."""
outbox.enqueue_message('download', {'url': url, 'filename': filename}, self.id)
def on_connect(self, handler: Union[Callable[..., Any], Awaitable]) -> None:
"""Register a callback to be called when the client connects."""
self.connect_handlers.append(handler)
def on_disconnect(self, handler: Union[Callable[..., Any], Awaitable]) -> None:
"""Register a callback to be called when the client disconnects."""
self.disconnect_handlers.append(handler)
def remove_elements(self, elements: Iterable[Element]) -> None:
"""Remove the given elements from the client."""
binding.remove(elements, Element)
element_ids = [element.id for element in elements]
for element_id in element_ids:
del self.elements[element_id]
for element in elements:
element._on_delete() # pylint: disable=protected-access
element._deleted = True # pylint: disable=protected-access
outbox.enqueue_delete(element)
def remove_all_elements(self) -> None:
"""Remove all elements from the client."""
self.remove_elements(self.elements.values())