Source code for panel.template.base

"""
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