"""
Templates allow multiple Panel objects to be embedded into custom HTML
documents.
"""
from __future__ import annotations
import os
import sys
import uuid
from collections import OrderedDict
from functools import partial
from pathlib import PurePath
from typing import TYPE_CHECKING, Any, Dict, IO, List, Optional
import param
from bokeh.document.document import Document as _Document
from bokeh.io import curdoc as _curdoc
from bokeh.settings import settings as _settings
from pyviz_comms import JupyterCommManager as _JupyterCommManager
from ..config import _base_config, config, panel_extension
from ..io.model import add_to_doc
from ..io.notifications import NotificationArea
from ..io.notebook import render_template
from ..io.resources import (
CDN_DIST, LOCAL_DIST, BUNDLE_DIR, _env, component_resource_path,
resolve_custom_path
)
from ..io.save import save
from ..io.state import state
from ..layout import Column, ListLike, GridSpec
from ..models.comm_manager import CommManager
from ..pane import panel as _panel, HTML, Str, HoloViews
from ..pane.image import ImageBase
from ..reactive import ReactiveHTML
from ..util import isurl, url_path
from ..viewable import ServableMixin, Viewable
from ..widgets import Button
from ..widgets.indicators import BooleanIndicator, LoadingSpinner
from .theme import THEMES, DefaultTheme, Theme
if TYPE_CHECKING:
from bokeh.document import Document
from bokeh.model import Model
from bokeh.server.contexts import BokehSessionContext
from jinja2 import Template as _Template
from pyviz_comms import Comm
from ..io.location import Location
_server_info: str = (
'<b>Running server:</b> <a target="_blank" href="https://localhost:{port}">'
'https://localhost:{port}</a>'
)
FAVICON_URL: str = "/static/extensions/panel/icons/favicon.ico"
[docs]class BaseTemplate(param.Parameterized, ServableMixin):
location = param.Boolean(default=False, doc="""
Whether to add a Location component to this Template.
Note if this is set to true, the Jinja2 template must
either insert all available roots or explicitly embed
the location root with : {{ embed(roots.location) }}.""")
# Dictionary of property overrides by bokeh Model type
_modifiers = {}
__abstract = True
def __init__(
self, template: Optional[str | _Template] = None, items=None,
nb_template: Optional[str | _Template] = None, **params
):
super().__init__(**params)
if isinstance(template, str):
self._code = template
template = _env.from_string(template)
else:
self._code = None
self.template = template
if isinstance(nb_template, str):
nb_template = _env.from_string(nb_template)
self.nb_template = nb_template or template
self._render_items = OrderedDict()
self._render_variables = {}
self._documents = []
self._server = None
self._layout = self._build_layout()
def _build_layout(self) -> Column:
str_repr = Str(repr(self))
server_info = HTML('')
button = Button(name='Launch server')
def launch(event):
if self._server:
button.name = 'Launch server'
server_info.object = ''
self._server.stop()
self._server = None
else:
button.name = 'Stop server'
self._server = self._get_server(start=True, show=True)
server_info.object = _server_info.format(port=self._server.port)
button.param.watch(launch, 'clicks')
return Column(str_repr, server_info, button)
def __repr__(self) -> str:
cls = type(self).__name__
spacer = '\n '
objs = ['[%s] %s' % (name, obj[0].__repr__(1))
for name, obj in self._render_items.items()
if not name.startswith('_')]
template = '{cls}{spacer}{objs}'
return template.format(
cls=cls, objs=('%s' % spacer).join(objs), spacer=spacer)
@classmethod
def _apply_hooks(cls, viewable: Viewable, root: Model) -> None:
ref = root.ref['id']
for o in viewable.select():
cls._apply_modifiers(o, ref)
@classmethod
def _apply_modifiers(cls, viewable: Viewable, mref: str) -> None:
if mref not in viewable._models:
return
model, _ = viewable._models[mref]
modifiers = cls._modifiers.get(type(viewable), {})
child_modifiers = modifiers.get('children', {})
if child_modifiers:
for child in viewable:
child_params = {
k: v for k, v in child_modifiers.items()
if getattr(child, k) == child.param[k].default
}
child.param.set_param(**child_params)
child_props = child._process_param_change(child_params)
child._models[mref][0].update(**child_props)
params = {
k: v for k, v in modifiers.items() if k != 'children' and
getattr(viewable, k) == viewable.param[k].default
}
viewable.param.update(**params)
props = viewable._process_param_change(params)
model.update(**props)
def _apply_root(self, name: str, viewable: Viewable, tags: List[str]) -> None:
pass
def _server_destroy(self, session_context: BokehSessionContext):
doc = session_context._document
self._documents.remove(doc)
def _init_doc(
self, doc: Optional[Document] = None, comm: Optional[Comm] = None,
title: Optional[str] = None, notebook: bool = False,
location: bool | Location=True
):
doc = doc or _curdoc()
self._documents.append(doc)
if location and self.location:
self._add_location(doc, location)
doc.on_session_destroyed(state._destroy_session)
doc.on_session_destroyed(self._server_destroy)
if title or doc.title == 'Bokeh Application':
title = title or 'Panel Application'
doc.title = title
# Initialize fake root. This is needed to ensure preprocessors
# which assume that all models are owned by a single root can
# link objects across multiple roots in a template.
col = Column()
preprocess_root = col.get_root(doc, comm)
col._hooks.append(self._apply_hooks)
ref = preprocess_root.ref['id']
objs, models = [], []
for name, (obj, tags) in self._render_items.items():
if self._apply_hooks not in obj._hooks:
obj._hooks.append(self._apply_hooks)
# We skip preprocessing on the individual roots
model = obj.get_root(doc, comm, preprocess=False)
mref = model.ref['id']
doc.on_session_destroyed(obj._server_destroy)
for sub in obj.select(Viewable):
submodel = sub._models.get(mref)
if submodel is None:
continue
sub._models[ref] = submodel
if isinstance(sub, HoloViews) and mref in sub._plots:
sub._plots[ref] = sub._plots.get(mref)
obj._documents[doc] = model
model.name = name
model.tags = tags
self._apply_root(name, model, tags)
add_to_doc(model, doc, hold=bool(comm))
objs.append(obj)
models.append(model)
# Here we ensure that the preprocessor is run across all roots
# and set up session cleanup hooks for the fake root.
state._fake_roots.append(ref) # Ensure no update is run
state._views[ref] = (col, preprocess_root, doc, comm)
col.objects = objs
preprocess_root.children[:] = models
col._preprocess(preprocess_root)
col._documents[doc] = preprocess_root
doc.on_session_destroyed(col._server_destroy)
if notebook:
doc.template = self.nb_template
else:
doc.template = self.template
doc._template_variables.update(self._render_variables)
return doc
def _repr_mimebundle_(self, include=None, exclude=None) -> Dict[str, str]:
loaded = panel_extension._loaded
if not loaded and 'holoviews' in sys.modules:
import holoviews as hv
loaded = hv.extension._loaded
if not loaded:
param.main.param.warning(
'Displaying Panel objects in the notebook requires '
'the panel extension to be loaded. Ensure you run '
'pn.extension() before displaying objects in the '
'notebook.'
)
return None
try:
assert get_ipython().kernel is not None # noqa
state._comm_manager = _JupyterCommManager
except Exception:
pass
from IPython.display import display
doc = _Document()
comm = state._comm_manager.get_server_comm()
self._init_doc(doc, comm, notebook=True)
ref = doc.roots[0].ref['id']
manager = CommManager(
comm_id=comm.id, plot_id=ref, name='comm_manager'
)
client_comm = state._comm_manager.get_client_comm(
on_msg=partial(self._on_msg, ref, manager),
on_error=partial(self._on_error, ref),
on_stdout=partial(self._on_stdout, ref)
)
manager.client_comm_id = client_comm.id
doc.add_root(manager)
if config.console_output != 'disable':
handle = display(display_id=uuid.uuid4().hex)
state._handles[ref] = (handle, [])
return render_template(doc, comm, manager)
#----------------------------------------------------------------
# Public API
#----------------------------------------------------------------
[docs] def save(
self, filename: str | os.PathLike | IO, title: Optional[str] = None,
resources=None, embed: bool = False, max_states: int = 1000,
max_opts: int = 3, embed_json: bool = False, json_prefix: str='',
save_path: str='./', load_path: Optional[str] = None
) -> None:
"""
Saves Panel objects to file.
Arguments
---------
filename: string or file-like object
Filename to save the plot to
title: string
Optional title for the plot
resources: bokeh resources
One of the valid bokeh.resources (e.g. CDN or INLINE)
embed: bool
Whether the state space should be embedded in the saved file.
max_states: int
The maximum number of states to embed
max_opts: int
The maximum number of states for a single widget
embed_json: boolean (default=True)
Whether to export the data to json files
json_prefix: str (default='')
Prefix for the auto-generated json directory
save_path: str (default='./')
The path to save json files to
load_path: str (default=None)
The path or URL the json files will be loaded from.
"""
if embed:
raise ValueError("Embedding is not yet supported on Template.")
return save(self, filename, title, resources, self.template,
self._render_variables, embed, max_states, max_opts,
embed_json, json_prefix, save_path, load_path)
[docs] def server_doc(
self, doc: Optional[Document] = None, title: str = None,
location: bool | Location = True
) -> Document:
"""
Returns a servable bokeh Document with the panel attached
Arguments
---------
doc : bokeh.Document (optional)
The Bokeh Document to attach the panel to as a root,
defaults to bokeh.io.curdoc()
title : str
A string title to give the Document
location : boolean or panel.io.location.Location
Whether to create a Location component to observe and
set the URL location.
Returns
-------
doc : bokeh.Document
The Bokeh document the panel was attached to
"""
return self._init_doc(doc, title=title, location=location)
[docs] def select(self, selector=None):
"""
Iterates over the Template and any potential children in the
applying the Selector.
Arguments
---------
selector: type or callable or None
The selector allows selecting a subset of Viewables by
declaring a type or callable function to filter by.
Returns
-------
viewables: list(Viewable)
"""
objects = []
for obj, _ in self._render_items.values():
objects += obj.select(selector)
return objects
[docs]class TemplateActions(ReactiveHTML):
"""
A component added to templates that allows triggering events such
as opening and closing a modal.
"""
open_modal = param.Integer(default=0)
close_modal = param.Integer(default=0)
margin = param.Integer(default=0)
_template = ""
_scripts = {
'open_modal': ["document.getElementById('pn-Modal').style.display = 'block'"],
'close_modal': ["document.getElementById('pn-Modal').style.display = 'none'"],
}
[docs]class BasicTemplate(BaseTemplate):
"""
BasicTemplate provides a baseclass for templates with a basic
organization including a header, sidebar and main area. Unlike the
more generic Template class these default templates make it easy
for a user to generate an application with a polished look and
feel without having to write any Jinja2 template themselves.
"""
config = param.ClassSelector(default=_base_config(), class_=_base_config,
constant=True, doc="""
Configuration object declaring custom CSS and JS files to load
specifically for this template.""")
busy_indicator = param.ClassSelector(default=LoadingSpinner(width=20, height=20),
class_=BooleanIndicator, constant=True, doc="""
Visual indicator of application busy state.""")
header = param.ClassSelector(class_=ListLike, constant=True, doc="""
A list-like container which populates the header bar.""")
main = param.ClassSelector(class_=ListLike, constant=True, doc="""
A list-like container which populates the main area.""")
main_max_width = param.String(default="", doc="""
The maximum width of the main area. For example '800px' or '80%'.
If the string is '' (default) no max width is set.""")
sidebar = param.ClassSelector(class_=ListLike, constant=True, doc="""
A list-like container which populates the sidebar.""")
sidebar_width = param.Integer(330, doc="""
The width of the sidebar in pixels. Default is 330.""")
modal = param.ClassSelector(class_=ListLike, constant=True, doc="""
A list-like container which populates the modal""")
notifications = param.ClassSelector(class_=NotificationArea, constant=True, doc="""
The NotificationArea instance attached to this template.
Automatically added if config.notifications is set, but may
also be provided explicitly.""")
logo = param.String(doc="""
URI of logo to add to the header (if local file, logo is
base64 encoded as URI). Default is '', i.e. not shown.""")
favicon = param.String(default=FAVICON_URL, doc="""
URI of favicon to add to the document head (if local file, favicon is
base64 encoded as URI).""")
title = param.String(default="Panel Application", doc="""
A title to show in the header. Also added to the document head
meta settings and as the browser tab title.""")
site = param.String(default="", doc="""
Name of the site. Will be shown in the header and link to the
'site_url'. Default is '', i.e. not shown.""")
site_url = param.String(default="/", doc="""
Url of the site and logo. Default is '/'.""")
meta_description = param.String(doc="""
A meta description to add to the document head for search
engine optimization. For example 'P.A. Nelson'.""")
meta_keywords = param.String(doc="""
Meta keywords to add to the document head for search engine
optimization.""")
meta_author = param.String(doc="""
A meta author to add to the the document head for search
engine optimization. For example 'P.A. Nelson'.""")
meta_refresh = param.String(doc="""
A meta refresh rate to add to the document head. For example
'30' will instruct the browser to refresh every 30
seconds. Default is '', i.e. no automatic refresh.""")
meta_viewport = param.String(doc="""
A meta viewport to add to the header.""")
base_url = param.String(doc="""
Specifies the base URL for all relative URLs in a
page. Default is '', i.e. not the domain.""")
base_target = param.ObjectSelector(default="_self",
objects=["_blank", "_self", "_parent", "_top"], doc="""
Specifies the base Target for all relative URLs in a page.""")
header_background = param.String(doc="""
Optional header background color override.""")
header_color = param.String(doc="""
Optional header text color override.""")
theme = param.ClassSelector(class_=Theme, default=DefaultTheme,
constant=True, is_instance=False, instantiate=False)
location = param.Boolean(default=True, readonly=True)
_actions = param.ClassSelector(default=TemplateActions(), class_=TemplateActions)
#############
# Resources #
#############
# Resource locations for bundled resources
_CDN: str = CDN_DIST
_LOCAL: str = LOCAL_DIST
# pathlib.Path pointing to local CSS file(s)
_css: str | None = None
# pathlib.Path pointing to local JS file(s)
_js: str | None = None
# pathlib.Path pointing to local Jinja2 template
_template = None
# External resources
_resources: Dict[str, Dict[str, str]] = {'css': {}, 'js': {}, 'js_modules': {}, 'tarball': {}}
_modifiers = {}
__abstract = True
def __init__(self, **params):
template = self._template.read_text()
if 'header' not in params:
params['header'] = ListLike()
else:
params['header'] = self._get_params(params['header'], self.param.header.class_)
if 'main' not in params:
params['main'] = ListLike()
else:
params['main'] = self._get_params(params['main'], self.param.main.class_)
if 'sidebar' not in params:
params['sidebar'] = ListLike()
else:
params['sidebar'] = self._get_params(params['sidebar'], self.param.sidebar.class_)
if 'modal' not in params:
params['modal'] = ListLike()
else:
params['modal'] = self._get_params(params['modal'], self.param.modal.class_)
if 'theme' in params and isinstance(params['theme'], str):
params['theme'] = THEMES[params['theme']]
if 'favicon' in params and isinstance(params['favicon'], PurePath):
params['favicon'] = str(params['favicon'])
if 'notifications' not in params and config.notifications:
params['notifications'] = state.notifications if state.curdoc else NotificationArea()
super().__init__(template=template, **params)
self._js_area = HTML(margin=0, width=0, height=0)
if 'embed(roots.js_area)' in template:
self._render_items['js_area'] = (self._js_area, [])
if 'embed(roots.actions)' in template:
self._render_items['actions'] = (self._actions, [])
if 'embed(roots.notifications)' in template and self.notifications:
self._render_items['notifications'] = (self.notifications, [])
self._render_variables['notifications'] = True
self._update_busy()
self.main.param.watch(self._update_render_items, ['objects'])
self.modal.param.watch(self._update_render_items, ['objects'])
self.sidebar.param.watch(self._update_render_items, ['objects'])
self.header.param.watch(self._update_render_items, ['objects'])
self.main.param.trigger('objects')
self.sidebar.param.trigger('objects')
self.header.param.trigger('objects')
self.modal.param.trigger('objects')
def _init_doc(
self, doc: Optional[Document] = None, comm: Optional['Comm'] = None,
title: Optional[str]=None, notebook: bool = False, location: bool | Location = True
) -> Document:
title = self.title if self.title != self.param.title.default else title
if self.busy_indicator:
state.sync_busy(self.busy_indicator)
self._update_vars()
doc = super()._init_doc(doc, comm, title, notebook, location)
if self.notifications:
state._notifications[doc] = self.notifications
if self.theme:
theme = self._get_theme()
if theme and theme.bokeh_theme:
doc.theme = theme.bokeh_theme
return doc
def _apply_hooks(self, viewable: Viewable, root: Model):
super()._apply_hooks(viewable, root)
theme = self._get_theme()
if theme and theme.bokeh_theme and root.document:
root.document.theme = theme.bokeh_theme
def _get_theme(self) -> Theme:
for cls in type(self).__mro__:
try:
return self.theme.find_theme(cls)()
except Exception:
pass
def _template_resources(self) -> Dict[str, Dict[str, str] | List[str]]:
clsname = type(self).__name__
name = clsname.lower()
if _settings.resources(default="server") == 'server':
if state.rel_path:
dist_path = f'{state.rel_path}/{self._LOCAL}'
else:
dist_path = self._LOCAL
else:
dist_path = self._CDN
# External resources
css_files, js_files, js_modules = {}, {}, {}
resource_types = {'css': css_files, 'js': js_files, 'js_modules': js_modules}
for resource_type, files in self._resources.items():
if resource_type not in resource_types:
continue
resource_files = resource_types[resource_type]
for rname, resource in files.items():
resource_path = url_path(resource)
if rname in self._resources.get('tarball', {}):
resource_path += '/index.mjs'
else:
resource_path += '.mjs'
if (BUNDLE_DIR / rname / resource_path.replace('/', os.path.sep)).is_file():
resource_files[rname] = dist_path + f'bundled/{resource_type}/{resource_path}'
elif isurl(resource):
resource_files[rname] = resource
elif resolve_custom_path(self, resource):
resource_files[rname] = component_resource_path(
self, f'_resources/{resource_type}', resource
)
for name, js in self.config.js_files.items():
if not '//' in js and state.rel_path:
js = f'{state.rel_path}/{js}'
js_files[name] = js
for name, js in self.config.js_modules.items():
if not '//' in js and state.rel_path:
js = f'{state.rel_path}/{js}'
js_modules[name] = js
resource_types['extra_css'] = extra_css = []
for css in list(self.config.css_files):
if not '//' in css and state.rel_path:
css = f'{state.rel_path}/{css}'
extra_css.append(css)
resource_types['raw_css'] = list(self.config.raw_css)
# CSS files
base_css = self._css
if not isinstance(base_css, list):
base_css = [base_css] if base_css else []
for css in base_css:
tmpl_name = name
for cls in type(self).__mro__[1:-5]:
tmpl_css = cls._css if isinstance(cls._css, list) else [cls._css]
if css in tmpl_css:
tmpl_name = cls.__name__.lower()
css_file = os.path.basename(css)
if (BUNDLE_DIR / tmpl_name / css_file).is_file():
css_files[f'base_{css_file}'] = dist_path + f'bundled/{tmpl_name}/{css_file}'
elif isurl(css):
css_files[f'base_{css_file}'] = css
elif resolve_custom_path(self, css):
css_files[f'base_{css_file}' ] = component_resource_path(self, '_css', css)
# JS files
base_js = self._js
if not isinstance(base_js, list):
base_js = [base_js] if base_js else []
for js in base_js:
tmpl_name = name
for cls in type(self).__mro__[1:-5]:
tmpl_js = cls._js if isinstance(cls._js, list) else [cls._js]
if js in tmpl_js:
tmpl_name = cls.__name__.lower()
js_name = os.path.basename(js)
if (BUNDLE_DIR / tmpl_name / js_name).is_file():
js_files[f'base_{js_name}'] = dist_path + f'bundled/{tmpl_name}/{js_name}'
elif isurl(js):
js_files[f'base_{js_name}'] = js
elif resolve_custom_path(self, js):
js_files[f'base_{js_name}'] = component_resource_path(self, '_js', js)
theme = self._get_theme()
if not theme:
return resource_types
if theme.base_css:
basename = os.path.basename(theme.base_css)
owner = type(theme).param.base_css.owner
owner_name = owner.__name__.lower()
if (BUNDLE_DIR / owner_name / basename).is_file():
css_files['theme_base'] = dist_path + f'bundled/{owner_name}/{basename}'
elif isurl(theme.base_css):
css_files['theme_base'] = theme.base_css
elif resolve_custom_path(theme, theme.base_css):
css_files['theme_base'] = component_resource_path(owner, 'base_css', theme.base_css)
if theme.css:
basename = os.path.basename(theme.css)
if (BUNDLE_DIR / name / basename).is_file():
css_files['theme'] = dist_path + f'bundled/{name}/{basename}'
elif isurl(theme.css):
css_files['theme'] = theme.css
elif resolve_custom_path(theme, theme.css):
css_files['theme'] = component_resource_path(theme, 'css', theme.css)
return resource_types
def _update_vars(self, *args) -> None:
self._render_variables['app_title'] = self.title
self._render_variables['meta_name'] = self.title
self._render_variables['site_title'] = self.site
self._render_variables['site_url'] = self.site_url
self._render_variables['meta_description'] = self.meta_description
self._render_variables['meta_keywords'] = self.meta_keywords
self._render_variables['meta_author'] = self.meta_author
self._render_variables['meta_refresh'] = self.meta_refresh
self._render_variables['meta_viewport'] = self.meta_viewport
self._render_variables['base_url'] = self.base_url
self._render_variables['base_target'] = self.base_target
if os.path.isfile(self.logo):
img = _panel(self.logo)
if not isinstance(img, ImageBase):
raise ValueError(f"Could not determine file type of logo: {self.logo}.")
logo = img._b64()
else:
logo = self.logo
if os.path.isfile(self.favicon):
img = _panel(self.favicon)
if not isinstance(img, ImageBase):
raise ValueError(f"Could not determine file type of favicon: {self.favicon}.")
favicon = img._b64()
else:
if _settings.resources(default='server') == 'cdn' and self.favicon == FAVICON_URL:
favicon = CDN_DIST+"icons/favicon.ico"
else:
favicon = self.favicon
self._render_variables['template_resources'] = self._template_resources()
self._render_variables['app_logo'] = logo
self._render_variables['app_favicon'] = favicon
self._render_variables['app_favicon_type'] = self._get_favicon_type(self.favicon)
self._render_variables['header_background'] = self.header_background
self._render_variables['header_color'] = self.header_color
self._render_variables['main_max_width'] = self.main_max_width
self._render_variables['sidebar_width'] = self.sidebar_width
def _update_busy(self) -> None:
if self.busy_indicator:
self._render_items['busy_indicator'] = (self.busy_indicator, [])
elif 'busy_indicator' in self._render_items:
del self._render_items['busy_indicator']
self._render_variables['busy'] = self.busy_indicator is not None
def _update_render_items(self, event: param.parameterized.Event) -> None:
if event.obj is self and event.name == 'busy_indicator':
return self._update_busy()
if event.obj is self.main:
tag = 'main'
elif event.obj is self.sidebar:
tag = 'nav'
elif event.obj is self.header:
tag = 'header'
elif event.obj is self.modal:
tag = 'modal'
old = event.old if isinstance(event.old, list) else list(event.old.values())
for obj in old:
ref = str(id(obj))
if ref in self._render_items:
del self._render_items[ref]
new = event.new if isinstance(event.new, list) else event.new.values()
theme = self._get_theme()
bk_theme = theme.bokeh_theme
for o in new:
if o not in old:
for hvpane in o.select(HoloViews):
if bk_theme:
hvpane.theme = bk_theme
labels = {}
for obj in new:
ref = str(id(obj))
if obj.name.startswith(type(obj).__name__):
labels[ref] = 'Content'
else:
labels[ref] = obj.name
self._render_items[ref] = (obj, [tag])
tags = [tags for _, tags in self._render_items.values()]
self._render_variables['nav'] = any('nav' in ts for ts in tags)
self._render_variables['header'] = any('header' in ts for ts in tags)
self._render_variables['root_labels'] = labels
def _server_destroy(self, session_context: BokehSessionContext):
super()._server_destroy(session_context)
if not self._documents and self.busy_indicator in state._indicators:
state._indicators.remove(self.busy_indicator)
[docs] def open_modal(self) -> None:
"""
Opens the modal area
"""
self._actions.open_modal += 1
[docs] def close_modal(self) -> None:
"""
Closes the modal area
"""
self._actions.close_modal += 1
@staticmethod
def _get_favicon_type(favicon) -> str:
if not favicon:
return ""
elif favicon.endswith(".png"):
return "image/png"
elif favicon.endswith("jpg"):
return "image/jpg"
elif favicon.endswith("gif"):
return "image/gif"
elif favicon.endswith("svg"):
return "image/svg"
elif favicon.endswith("ico"):
return "image/x-icon"
else:
raise ValueError("favicon type not supported.")
@staticmethod
def _get_params(value, class_):
if isinstance(value, class_):
return value
if isinstance(value, tuple):
value = [*value]
elif not isinstance(value, list):
value = [value]
# Important to fx. convert @param.depends functions
value = [_panel(item) for item in value]
if class_ is ListLike:
return ListLike(objects=value)
if class_ is GridSpec:
grid = GridSpec(ncols=12, mode='override')
for index, item in enumerate(value):
grid[index, :]=item
return grid
return value
[docs]class Template(BaseTemplate):
"""
A Template is a high-level component to render multiple Panel
objects into a single HTML document defined through a Jinja2
template. The Template object is given a Jinja2 template and then
allows populating this template by adding Panel objects, which are
given unique names. These unique names may then be referenced in
the template to insert the rendered Panel object at a specific
location. For instance, given a Jinja2 template that defines roots
A and B like this:
<div> {{ embed(roots.A) }} </div>
<div> {{ embed(roots.B) }} </div>
We can then populate the template by adding panel 'A' and 'B' to
the Template object:
template.add_panel('A', pn.panel('A'))
template.add_panel('B', pn.panel('B'))
Once a template has been fully populated it can be rendered using
the same API as other Panel objects. Note that all roots that have
been declared using the {{ embed(roots.A) }} syntax in the Jinja2
template must be defined when rendered.
Since embedding complex CSS frameworks inside a notebook can have
undesirable side-effects and a notebook does not afford the same
amount of screen space a Template may given separate template
and nb_template objects. This allows for different layouts when
served as a standalone server and when used in the notebook.
"""
def __init__(
self, template: str | _Template = None, nb_template: str | _Template = None,
items: Optional[Dict[str, Any]] = None, **params
):
super().__init__(template=template, nb_template=nb_template, items=items, **params)
items = {} if items is None else items
for name, item in items.items():
self.add_panel(name, item)
#----------------------------------------------------------------
# Public API
#----------------------------------------------------------------
[docs] def add_panel(self, name: str, panel: Viewable, tags: List[str] = []) -> None:
"""
Add panels to the Template, which may then be referenced by
the given name using the jinja2 embed macro.
Arguments
---------
name : str
The name to refer to the panel by in the template
panel : panel.Viewable
A Panel component to embed in the template.
"""
if name in self._render_items:
raise ValueError('The name %s has already been used for '
'another panel. Ensure each panel '
'has a unique name by which it can be '
'referenced in the template.' % name)
self._render_items[name] = (_panel(panel), tags)
self._layout[0].object = repr(self)
[docs] def add_variable(self, name: str, value: Any) -> None:
"""
Add parameters to the template, which may then be referenced
by the given name in the Jinja2 template.
Arguments
---------
name : str
The name to refer to the panel by in the template
value : object
Any valid Jinja2 variable type.
"""
if name in self._render_variables:
raise ValueError('The name %s has already been used for '
'another variable. Ensure each variable '
'has a unique name by which it can be '
'referenced in the template.' % name)
self._render_variables[name] = value