File: C:/Users/fred/anaconda3/Lib/site-packages/panel/io/pyodide.py
from __future__ import annotations
import asyncio
import functools
import io
import json
import os
import sys
import uuid
from typing import Any, Callable
import bokeh
import js
import param
import pyodide # isort: split
from bokeh import __version__
from bokeh.core.serialization import Buffer, Serialized, Serializer
from bokeh.document import Document
from bokeh.document.json import PatchJson
from bokeh.embed.elements import script_for_render_items
from bokeh.embed.util import standalone_docs_json_and_render_items
from bokeh.embed.wrappers import wrap_in_script_tag
from bokeh.events import DocumentReady
from bokeh.io.doc import set_curdoc
from bokeh.model import Model
from bokeh.settings import settings as bk_settings
from js import JSON, XMLHttpRequest
from ..config import config
from ..util import edit_readonly, isurl
from . import resources
from .document import MockSessionContext
from .loading import LOADING_INDICATOR_CSS_CLASS
from .mime_render import WriteCallbackStream, exec_with_return, format_mime
from .state import state
resources.RESOURCE_MODE = 'CDN'
os.environ['BOKEH_RESOURCES'] = 'cdn'
try:
from js import document as js_document # noqa
try:
# PyScript Next Worker now patches js.document by default
from pyscript import RUNNING_IN_WORKER as _IN_PYSCRIPT_WORKER
if _IN_PYSCRIPT_WORKER:
from pyscript import window
js.window = window
except Exception:
_IN_PYSCRIPT_WORKER = False
_IN_WORKER = False
except Exception:
try:
# Initial version of PyScript Next Worker support did not patch js.document
from pyscript import RUNNING_IN_WORKER as _IN_PYSCRIPT_WORKER
if _IN_PYSCRIPT_WORKER:
from pyscript import document, window
js.document = document
js.window = window
_IN_WORKER = False
except Exception:
_IN_PYSCRIPT_WORKER = False
_IN_WORKER = True
# Ensure we don't try to load MPL WASM backend in worker
if _IN_WORKER:
os.environ['MPLBACKEND'] = 'agg'
try:
import pyodide_http
pyodide_http.patch_all()
except Exception:
pyodide_http = None
try:
# Patch fsspec with synchronous http support
import fsspec.implementations.http_sync # noqa
except Exception:
pass
#---------------------------------------------------------------------
# Private API
#---------------------------------------------------------------------
# Make bokeh sampledata available in pyolite kernel
if 'pyolite' in sys.modules and os.path.exists('/drive/assets/sampledata'):
def _sampledata_dir(create=None):
return '/drive/assets/sampledata'
bokeh.util.sampledata.external_data_dir = _sampledata_dir
if pyodide_http is None:
import pandas
def _read_file(*args, **kwargs):
if args and isurl(args[0]):
args = (pyodide.http.open_url(args[0]),)+args[1:]
elif isurl(kwargs.get('filepath_or_buffer')):
kwargs['filepath_or_buffer'] = pyodide.http.open_url(kwargs['filepath_or_buffer'])
return args, kwargs
# Patch pandas.read_csv
_read_csv_original = pandas.read_csv
@functools.wraps(pandas.read_csv)
def _read_csv(*args, **kwargs):
args, kwargs = _read_file(*args, **kwargs)
return _read_csv_original(*args, **kwargs)
pandas.read_csv = _read_csv
# Patch pandas.read_json
_read_json_original = pandas.read_json
@functools.wraps(pandas.read_json)
def _read_json(*args, **kwargs):
args, kwargs = _read_file(*args, **kwargs)
return _read_json_original(*args, **kwargs)
pandas.read_json = _read_json
_tasks = set()
def async_execute(func: Any):
event_loop = asyncio.get_running_loop()
if event_loop.is_running():
task = asyncio.create_task(func())
_tasks.add(task)
task.add_done_callback(_tasks.discard)
else:
event_loop.run_until_complete(func())
return
param.parameterized.async_executor = async_execute
def _doc_json(doc: Document, root_els=None) -> tuple[str, str, str]:
"""
Serializes a Bokeh Document into JSON representations of the entire
Document, the individual render_items and the ids of DOM nodes to
render each item into.
Arguments
---------
doc: bokeh.document.Document
The Bokeh document to serialize to JSON.
root_els:
A list of DOM nodes to render each root of the Document into.
Returns
-------
docs_json: str
render_items: str
root_ids: str
"""
docs_json, render_items = standalone_docs_json_and_render_items(
doc.roots, suppress_callback_warning=True
)
render_items_json = [item.to_json() for item in render_items]
root_ids = [m.id for m in doc.roots]
if root_els:
root_data = sorted([(el.getAttribute('data-root-id'), el.id) for el in root_els])
render_items_json[0].update({
'roots': {model_id: elid for (_, elid), model_id in zip(root_data, root_ids)},
'root_ids': root_ids
})
return json.dumps(docs_json), json.dumps(render_items_json), json.dumps(root_ids)
def _model_json(model: Model, target: str) -> tuple[Document, str]:
"""
Renders a Bokeh Model to JSON representation given a particular
DOM target and returns the Document and the serialized JSON string.
Arguments
---------
model: bokeh.model.Model
The bokeh model to render.
target: str
The id of the DOM node to render to.
Returns
-------
document: Document
The bokeh Document containing the rendered Bokeh Model.
model_json: str
The serialized JSON representation of the Bokeh Model.
"""
doc = Document()
doc.hold()
model.server_doc(doc=doc)
model = doc.roots[0]
docs_json, _ = standalone_docs_json_and_render_items(
[model], suppress_callback_warning=True
)
doc_json = list(docs_json.values())[0]
return doc, json.dumps(dict(
target_id = target,
root_id = model.ref['id'],
doc = doc_json,
version = __version__,
))
def _serialize_buffers(obj, buffers={}):
"""
Recursively iterates over a JSON patch and converts Buffer objects
to a reference or base64 serialized representation.
Arguments
---------
obj: dict
Dictionary containing events to patch the JS Document with.
buffers: dict
Binary array buffers.
Returns
--------
Serialization safe version of the original object.
"""
if isinstance(obj, dict):
return {
key: _serialize_buffers(o, buffers=buffers) for key, o in obj.items()
}
elif isinstance(obj, list):
return [
_serialize_buffers(o, buffers=buffers) for o in obj
]
elif isinstance(obj, tuple):
return tuple(
_serialize_buffers(o, buffers=buffers) for o in obj
)
elif isinstance(obj, Buffer):
if obj.id in buffers: # TODO: and len(obj.data) > _threshold:
return obj.ref
else:
return obj.to_base64()
return obj
def _process_document_events(doc: Document, events: list[Any]):
serializer = Serializer(references=doc.models.synced_references)
patch_json = PatchJson(events=serializer.encode(events))
doc.models.flush_synced()
buffer_map = {}
for buffer in serializer.buffers:
buffer_map[buffer.id] = pyodide.ffi.to_js(buffer.to_bytes()).buffer
patch_json = _serialize_buffers(patch_json, buffers=buffer_map)
return patch_json, buffer_map
# JS function to convert undefined -> null (workaround for https://github.com/pyodide/pyodide/issues/3968)
_dict_converter = pyodide.code.run_js("""
((entries) => {
for (let entry of entries) {
if (entry[1] === undefined) {
entry[1] = null;
}
}
return Object.fromEntries(entries);
})
""")
_current_buffers = []
_patching = False
def _bytes_converter(value, converter, other):
if not hasattr(value, 'buffer'):
return value
value = dict(value.object_entries())
uid = uuid.uuid4().hex
_current_buffers.append(
Buffer(id=uid, data=value['buffer'].to_bytes())
)
return {'id': uid}
def _convert_json_patch(json_patch):
try:
patch = json_patch.to_py(default_converter=_bytes_converter)
serialized = Serialized(content=patch, buffers=list(_current_buffers))
finally:
_current_buffers.clear()
return serialized
def _link_docs(pydoc: Document, jsdoc: Any) -> None:
"""
Links Python and JS documents in Pyodide ensuring that messages
are passed between them.
Arguments
---------
pydoc: bokeh.document.Document
The Python Bokeh Document instance to sync.
jsdoc: Javascript Document
The Javascript Bokeh Document instance to sync.
"""
def jssync(event):
setter_id = getattr(event, 'setter_id', None)
if (setter_id is not None and setter_id == 'python') or _patching:
return
json_patch = jsdoc.create_json_patch(pyodide.ffi.to_js([event]))
patch = _convert_json_patch(json_patch)
pydoc.apply_json_patch(patch, setter='js')
jsdoc.on_change(pyodide.ffi.create_proxy(jssync), pyodide.ffi.to_js(False))
def pysync(event):
global _patching
setter = getattr(event, 'setter', None)
if setter is not None and setter == 'js':
return
json_patch, buffer_map = _process_document_events(pydoc, [event])
json_patch = pyodide.ffi.to_js(json_patch, dict_converter=_dict_converter)
buffer_map = pyodide.ffi.to_js(buffer_map)
_patching = True
try:
jsdoc.apply_json_patch(json_patch, buffer_map)
finally:
_patching = False
pydoc.on_change(pysync)
try:
pydoc.unhold()
pydoc.callbacks.trigger_event(DocumentReady())
except Exception as e:
print(f'Error raised while processing Document events: {e}') # noqa: T201
def _link_docs_worker(doc: Document, dispatch_fn: Any, msg_id: str | None = None, setter: str | None = None):
"""
Links the Python document to a dispatch_fn which can be used to
sync messages between a WebWorker and the main thread in the
browser.
Arguments
---------
doc: bokeh.document.Document
The document to dispatch messages from.
dispatch_fn: JS function
The Javascript function to dispatch messages to.
setter: str
Setter ID used for suppressing events.
msg_id: str | None
An optional message ID to pass through to the dispatch_fn.
"""
def pysync(event):
if setter is not None and getattr(event, 'setter', None) == setter:
return
json_patch, buffer_map = _process_document_events(doc, [event])
json_patch = pyodide.ffi.to_js(json_patch, dict_converter=_dict_converter)
buffers = js.Map.new(pyodide.ffi.to_js(buffer_map))
dispatch_fn(json_patch, buffers, msg_id)
doc.on_change(pysync)
doc.unhold()
doc.callbacks.trigger_event(DocumentReady())
async def _link_model(ref: str, doc: Document) -> None:
"""
Links a rendered Bokeh model on the frontend to a Python Document
in Python.
Arguments
---------
ref: str
The ID of the rendered bokeh Model
doc: bokeh.document.Document
The bokeh Document to sync the rendered Model with.
"""
rendered = js.window.Bokeh.index.object_keys()
if ref not in rendered:
await asyncio.sleep(0.1)
await _link_model(ref, doc)
return
views = js.window.Bokeh.index.object_values()
view = views[rendered.indexOf(ref)]
_link_docs(doc, view.model.document)
def _get_pyscript_target():
if '__main__' in sys.modules and hasattr(sys.modules['__main__'], 'get_current_display_target'):
# pyscript >= 2022.10.01
return sys.modules['__main__'].get_current_display_target()
elif hasattr(sys.stdout, '_out'):
# pyscript <= 2022.09.01
return sys.stdout._out # type: ignore
elif not _IN_WORKER:
raise ValueError("Could not determine target node to write to.")
#---------------------------------------------------------------------
# Public API
#---------------------------------------------------------------------
def fetch_binary(url):
if not _IN_WORKER:
raise RuntimeError("Cannot make synchronous binary request in main thread.")
xhr = XMLHttpRequest.new()
xhr.responseType = "arraybuffer"
xhr.open('get', url, False)
xhr.send()
return io.BytesIO(xhr.response.to_py().tobytes())
def render_script(obj: Any, target: str) -> str:
"""
Generates a script to render the supplied object to the target.
Arguments
---------
obj: Viewable
Object to render into the DOM node
target: str
Target ID of the DOM node to render the object into.
"""
from js import document
from ..pane import panel as as_panel
doc = Document()
as_panel(obj).server_doc(doc, location=False)
docs_json, [render_item,] = standalone_docs_json_and_render_items(
doc.roots, suppress_callback_warning=True
)
for root in doc.roots:
render_item.roots._roots[root] = target
document.getElementById(target).classList.add('bk-root')
script = script_for_render_items(docs_json, [render_item])
task = asyncio.create_task(_link_model(doc.roots[0].ref['id'], doc))
_tasks.add(task)
task.add_done_callback(_tasks.discard)
return wrap_in_script_tag(script)
def serve(*args, **kwargs):
"""
Stub to replace Tornado based serve function.
"""
raise RuntimeError('Cannot serve application in pyodide context.')
def init_doc() -> None:
"""
Creates a Document mocking a server context for embedded Pyodide apps.
"""
bk_settings.simple_ids.set_value(False)
doc = Document()
set_curdoc(doc)
doc.hold()
doc._session_context = lambda: MockSessionContext(document=doc)
state.curdoc = doc
async def show(obj: Any, target: str) -> None:
"""
Renders the object into a DOM node specified by the target.
Arguments
---------
obj: Viewable
Object to render into the DOM node
target: str
Target ID of the DOM node to render the object into.
"""
from js import console
console.log('panel.io.pyodide.show is deprecated in favor of panel.io.pyodide.write')
await write(target, obj)
async def write(target: str, obj: Any) -> None:
"""
Renders the object into a DOM node specified by the target.
Arguments
---------
target: str
Target ID of the DOM node to render the object into.
obj: Viewable
Object to render into the DOM node
"""
from ..pane import panel as as_panel
obj = as_panel(obj)
pydoc, model_json = _model_json(obj, target)
views = await js.window.Bokeh.embed.embed_item(JSON.parse(model_json))
jsdoc = list(views.roots)[0].model.document
_link_docs(pydoc, jsdoc)
pydoc.unhold()
def hide_loader() -> None:
"""
Hides the global loading spinner.
"""
from js import document
body = document.getElementsByTagName('body')[0]
body.classList.remove(LOADING_INDICATOR_CSS_CLASS, f'pn-{config.loading_spinner}')
def sync_location():
"""
Syncs the JS window.location with the Panel Location component.
"""
if not state.location:
return
try:
loc_string = JSON.stringify(js.window.location)
except Exception:
return
loc_data = json.loads(loc_string)
with edit_readonly(state.location):
state.location.param.update({
k: v for k, v in loc_data.items() if k in state.location.param
})
async def write_doc(doc: Document | None = None) -> tuple[str, str, str]:
"""
Renders the contents of the Document into an existing template.
Note that this assumes that the HTML file this function runs in
was itself generated from the code being run. This function may
be used in the main browser thread or from within a WebWorker.
If invoked by a WebWorker the JSON return values can be sent
to the main thread for rendering.
Arguments
---------
doc: Document
The document to render to JSON.
Returns
-------
docs_json: str
render_items: str
root_ids: str
"""
pydoc: Document = doc or state.curdoc
if pydoc in state._templates and pydoc not in state._templates[pydoc]._documents:
template = state._templates[pydoc]
template.server_doc(title=template.title, location=True, doc=pydoc)
# Test whether we have access to DOM
try:
root_els = js.document.querySelectorAll('[data-root-id]')
for el in root_els:
el.innerHTML = ''
except Exception:
root_els = None
docs_json, render_items, root_ids = _doc_json(pydoc, root_els)
pydoc._session_context = None
# If we have DOM access render and sync the document
if root_els is not None:
views = await js.window.Bokeh.embed.embed_items(JSON.parse(docs_json), JSON.parse(render_items))
jsdoc = list(views[0].roots)[0].model.document
_link_docs(pydoc, jsdoc)
sync_location()
hide_loader()
return docs_json, render_items, root_ids
def pyrender(
code: str,
stdout_callback: Callable[[str], None] | None,
stderr_callback: Callable[[str], None] | None,
target: str
):
"""
Executes Python code and returns a MIME representation of the
return value.
Arguments
---------
code: str
Python code to execute
stdout_callback: Callable[[str, str], None] | None
Callback executed with output written to stdout.
stderr_callback: Callable[[str, str], None] | None
Callback executed with output written to stderr.
target: str
The ID of the DOM node to write the output into.
Returns
-------
Returns an JS Map containing the content, mime_type, stdout and stderr.
"""
from ..pane import HoloViews, Interactive, panel as as_panel
from ..param import ReactiveExpr
from ..viewable import Viewable, Viewer
PANES = (HoloViews, Interactive, ReactiveExpr)
kwargs = {}
if stdout_callback:
kwargs['stdout'] = WriteCallbackStream(stdout_callback)
if stderr_callback:
kwargs['stderr'] = WriteCallbackStream(stderr_callback)
out = exec_with_return(code, **kwargs)
ret = {}
if isinstance(out, (Model, Viewable, Viewer)) or any(pane.applies(out) for pane in PANES):
doc, model_json = _model_json(as_panel(out), target)
state.cache[target] = doc
ret['content'], ret['mime_type'] = model_json, 'application/bokeh'
elif out is not None:
ret['content'], ret['mime_type'] = format_mime(out)
return pyodide.ffi.to_js(ret)