bokeh.core.templates

Provide Jinja2 templates used by Bokeh to embed Bokeh documents and models in various ways.

AUTOLOAD_JS = <Template 'autoload_js.js'>

Renders JavaScript code for “autoloading”.

The code automatically and asynchronously loads BokehJS (if necessary) and then replaces the AUTOLOAD_TAG <script> tag that calls it with the rendered model.

Parameters
  • elementid (str) – the unique id for the script tag

  • js_urls (list) – URLs of JS files making up Bokeh library

  • css_urls (list) – CSS urls to inject

Template: autoload_js.js
(function(root) {
  function now() {
    return new Date();
  }

  const force = {{ force|default(False)|tojson }};

  if (typeof root._bokeh_onload_callbacks === "undefined" || force === true) {
    root._bokeh_onload_callbacks = [];
    root._bokeh_is_loading = undefined;
  }

  {% block register_mimetype %}
  {% endblock %}

  {% block autoload_init %}
    {%- if elementid -%}
    const element = document.getElementById({{ elementid|tojson }});
    if (element == null) {
      console.warn("Bokeh: autoload.js configured with elementid '{{ elementid }}' but no matching script tag was found.")
    }
    {%- endif %}
  {% endblock %}

  function run_callbacks() {
    try {
      root._bokeh_onload_callbacks.forEach(function(callback) {
        if (callback != null)
          callback();
      });
    } finally {
      delete root._bokeh_onload_callbacks
    }
    console.debug("Bokeh: all callbacks have finished");
  }

  function load_libs(css_urls, js_urls, callback) {
    if (css_urls == null) css_urls = [];
    if (js_urls == null) js_urls = [];

    root._bokeh_onload_callbacks.push(callback);
    if (root._bokeh_is_loading > 0) {
      console.debug("Bokeh: BokehJS is being loaded, scheduling callback at", now());
      return null;
    }
    if (js_urls == null || js_urls.length === 0) {
      run_callbacks();
      return null;
    }
    console.debug("Bokeh: BokehJS not loaded, scheduling load and callback at", now());
    root._bokeh_is_loading = css_urls.length + js_urls.length;

    function on_load() {
      root._bokeh_is_loading--;
      if (root._bokeh_is_loading === 0) {
        console.debug("Bokeh: all BokehJS libraries/stylesheets loaded");
        run_callbacks()
      }
    }

    function on_error(url) {
      console.error("failed to load " + url);
    }

    for (let i = 0; i < css_urls.length; i++) {
      const url = css_urls[i];
      const element = document.createElement("link");
      element.onload = on_load;
      element.onerror = on_error.bind(null, url);
      element.rel = "stylesheet";
      element.type = "text/css";
      element.href = url;
      console.debug("Bokeh: injecting link tag for BokehJS stylesheet: ", url);
      document.body.appendChild(element);
    }

    for (let i = 0; i < js_urls.length; i++) {
      const url = js_urls[i];
      const element = document.createElement('script');
      element.onload = on_load;
      element.onerror = on_error.bind(null, url);
      element.async = false;
      element.src = url;
      console.debug("Bokeh: injecting script tag for BokehJS library: ", url);
      document.head.appendChild(element);
    }
  };

  function inject_raw_css(css) {
    const element = document.createElement("style");
    element.appendChild(document.createTextNode(css));
    document.body.appendChild(element);
  }

  {% if bundle %}
  const js_urls = {{ bundle.js_urls|tojson }};
  const css_urls = {{ bundle.css_urls|tojson }};
  {% else %}
  const js_urls = {{ js_urls|tojson }};
  const css_urls = {{ css_urls|tojson }};
  {% endif %}

  const inline_js = [
    {%- for css in (bundle.css_raw if bundle else css_raw) %}
    function(Bokeh) {
      inject_raw_css({{ css|tojson }});
    },
    {%- endfor %}
    {%- for js in (bundle.js_raw if bundle else js_raw) %}
    function(Bokeh) {
      {{ js|indent(6) }}
    },
    {% endfor -%}
    function(Bokeh) {
    {% block inline_js %}
    {% endblock %}
    }
  ];

  function run_inline_js() {
    {% block run_inline_js %}
    for (let i = 0; i < inline_js.length; i++) {
      inline_js[i].call(root, root.Bokeh);
    }
    {% endblock %}
  }

  if (root._bokeh_is_loading === 0) {
    console.debug("Bokeh: BokehJS loaded, going straight to plotting");
    run_inline_js();
  } else {
    load_libs(css_urls, js_urls, function() {
      console.debug("Bokeh: BokehJS plotting callback run at", now());
      run_inline_js();
    });
  }
}(window));
AUTOLOAD_NB_JS = <Template 'autoload_nb_js.js'>
Template: autoload_nb_js.js
{% extends "autoload_js.js" %}

{% block register_mimetype %}

  {%- if register_mime -%}
  const JS_MIME_TYPE = 'application/javascript';
  const HTML_MIME_TYPE = 'text/html';
  const EXEC_MIME_TYPE = 'application/vnd.bokehjs_exec.v0+json';
  const CLASS_NAME = 'output_bokeh rendered_html';

  /**
   * Render data to the DOM node
   */
  function render(props, node) {
    const script = document.createElement("script");
    node.appendChild(script);
  }

  /**
   * Handle when an output is cleared or removed
   */
  function handleClearOutput(event, handle) {
    const cell = handle.cell;

    const id = cell.output_area._bokeh_element_id;
    const server_id = cell.output_area._bokeh_server_id;
    // Clean up Bokeh references
    if (id != null && id in Bokeh.index) {
      Bokeh.index[id].model.document.clear();
      delete Bokeh.index[id];
    }

    if (server_id !== undefined) {
      // Clean up Bokeh references
      const cmd_clean = "from bokeh.io.state import curstate; print(curstate().uuid_to_server['" + server_id + "'].get_sessions()[0].document.roots[0]._id)";
      cell.notebook.kernel.execute(cmd_clean, {
        iopub: {
          output: function(msg) {
            const id = msg.content.text.trim();
            if (id in Bokeh.index) {
              Bokeh.index[id].model.document.clear();
              delete Bokeh.index[id];
            }
          }
        }
      });
      // Destroy server and session
      const cmd_destroy = "import bokeh.io.notebook as ion; ion.destroy_server('" + server_id + "')";
      cell.notebook.kernel.execute(cmd_destroy);
    }
  }

  /**
   * Handle when a new output is added
   */
  function handleAddOutput(event, handle) {
    const output_area = handle.output_area;
    const output = handle.output;

    // limit handleAddOutput to display_data with EXEC_MIME_TYPE content only
    if ((output.output_type != "display_data") || (!Object.prototype.hasOwnProperty.call(output.data, EXEC_MIME_TYPE))) {
      return
    }

    const toinsert = output_area.element.find("." + CLASS_NAME.split(' ')[0]);

    if (output.metadata[EXEC_MIME_TYPE]["id"] !== undefined) {
      toinsert[toinsert.length - 1].firstChild.textContent = output.data[JS_MIME_TYPE];
      // store reference to embed id on output_area
      output_area._bokeh_element_id = output.metadata[EXEC_MIME_TYPE]["id"];
    }
    if (output.metadata[EXEC_MIME_TYPE]["server_id"] !== undefined) {
      const bk_div = document.createElement("div");
      bk_div.innerHTML = output.data[HTML_MIME_TYPE];
      const script_attrs = bk_div.children[0].attributes;
      for (let i = 0; i < script_attrs.length; i++) {
        toinsert[toinsert.length - 1].firstChild.setAttribute(script_attrs[i].name, script_attrs[i].value);
        toinsert[toinsert.length - 1].firstChild.textContent = bk_div.children[0].textContent
      }
      // store reference to server id on output_area
      output_area._bokeh_server_id = output.metadata[EXEC_MIME_TYPE]["server_id"];
    }
  }

  function register_renderer(events, OutputArea) {

    function append_mime(data, metadata, element) {
      // create a DOM node to render to
      const toinsert = this.create_output_subarea(
        metadata,
        CLASS_NAME,
        EXEC_MIME_TYPE
      );
      this.keyboard_manager.register_events(toinsert);
      // Render to node
      const props = {data: data, metadata: metadata[EXEC_MIME_TYPE]};
      render(props, toinsert[toinsert.length - 1]);
      element.append(toinsert);
      return toinsert
    }

    /* Handle when an output is cleared or removed */
    events.on('clear_output.CodeCell', handleClearOutput);
    events.on('delete.Cell', handleClearOutput);

    /* Handle when a new output is added */
    events.on('output_added.OutputArea', handleAddOutput);

    /**
     * Register the mime type and append_mime function with output_area
     */
    OutputArea.prototype.register_mime_type(EXEC_MIME_TYPE, append_mime, {
      /* Is output safe? */
      safe: true,
      /* Index of renderer in `output_area.display_order` */
      index: 0
    });
  }

  // register the mime type if in Jupyter Notebook environment and previously unregistered
  if (root.Jupyter !== undefined) {
    const events = require('base/js/events');
    const OutputArea = require('notebook/js/outputarea').OutputArea;

    if (OutputArea.prototype.mime_types().indexOf(EXEC_MIME_TYPE) == -1) {
      register_renderer(events, OutputArea);
    }
  }
  {%- endif -%}

{% endblock %}

{% block autoload_init %}
  if (typeof (root._bokeh_timeout) === "undefined" || force === true) {
    root._bokeh_timeout = Date.now() + {{ timeout|default(0)|tojson }};
    root._bokeh_failed_load = false;
  }

  const NB_LOAD_WARNING = {'data': {'text/html':
     "<div style='background-color: #fdd'>\n"+
     "<p>\n"+
     "BokehJS does not appear to have successfully loaded. If loading BokehJS from CDN, this \n"+
     "may be due to a slow or bad network connection. Possible fixes:\n"+
     "</p>\n"+
     "<ul>\n"+
     "<li>re-rerun `output_notebook()` to attempt to load from CDN again, or</li>\n"+
     "<li>use INLINE resources instead, as so:</li>\n"+
     "</ul>\n"+
     "<code>\n"+
     "from bokeh.resources import INLINE\n"+
     "output_notebook(resources=INLINE)\n"+
     "</code>\n"+
     "</div>"}};

  function display_loaded() {
    const el = document.getElementById({{ elementid|tojson }});
    if (el != null) {
      el.textContent = "BokehJS is loading...";
    }
    if (root.Bokeh !== undefined) {
      if (el != null) {
        el.textContent = "BokehJS " + root.Bokeh.version + " successfully loaded.";
      }
    } else if (Date.now() < root._bokeh_timeout) {
      setTimeout(display_loaded, 100)
    }
  }
{% endblock %}

{% block run_inline_js %}
    if (root.Bokeh !== undefined || force === true) {
      {{ super() }}
      {%- if elementid -%}
      if (force === true) {
        display_loaded();
      }
      {%- endif -%}
    } else if (Date.now() < root._bokeh_timeout) {
      setTimeout(run_inline_js, 100);
    } else if (!root._bokeh_failed_load) {
      console.log("Bokeh: BokehJS failed to load within specified timeout.");
      root._bokeh_failed_load = true;
    } else if (force !== true) {
      const cell = $(document.getElementById({{ elementid|tojson }})).parents('.cell').data().cell;
      cell.output_area.append_execute_result(NB_LOAD_WARNING)
    }
{% endblock %}
AUTOLOAD_REQUEST_TAG = <Template 'autoload_request_tag.html'>

Renders <script> tags that automatically load BokehJS (if necessary) and then renders a Bokeh model or document. The document may be specified as either an embedded doc ID or a server session ID. If a specific model ID is not specified, the entire document will be rendered.

Parameters
  • src_path (str) – path to AUTOLOAD script

  • elementid (str) – the a unique id for the script tag

  • modelid (str) – The Bokeh model id for the object to render (if missing, render the whole doc; if present, only render the one model)

  • docid (str) – The id of the embedded Bokeh document to render

  • headers (dict) – A dictionary of HTTP request headers to include in the request

Note

This script injects a <div> in place, so must be placed under <body>.

Template: autoload_request_tag.html
<script id="{{ elementid }}">
  (function() {
    const xhr = new XMLHttpRequest()
    xhr.responseType = 'blob';
    xhr.open('GET', "{{ src_path }}", true);
    {% for header, value in headers.items() %}
    xhr.setRequestHeader("{{ header }}", "{{ value }}")
    {% endfor %}
    xhr.onload = function (event) {
      const script = document.createElement('script');
      const src = URL.createObjectURL(event.target.response);
      script.src = src;
      document.body.appendChild(script);
    };
    xhr.send();
  })();
</script>
AUTOLOAD_TAG = <Template 'autoload_tag.html'>

Renders <script> tags that automatically load BokehJS (if necessary) and then renders a Bokeh model or document. The document may be specified as either an embedded doc ID or a server session ID. If a specific model ID is not specified, the entire document will be rendered.

Parameters
  • src_path (str) – path to AUTOLOAD script

  • elementid (str) – the a unique id for the script tag

  • modelid (str) – The Bokeh model id for the object to render (if missing, render the whole doc; if present, only render the one model)

  • docid (str) – The id of the embedded Bokeh document to render

Note

This script injects a <div> in place, so must be placed under <body>.

Template: autoload_tag.html
<script src="{{ src_path }}" id="{{ elementid }}"></script>
CSS_RESOURCES = <Template 'css_resources.html'>

Renders HTML that loads Bokeh CSS according to the configuration in a Resources object.

Parameters
  • css_files (list[str]) – a list of URIs for CSS files to include

  • css_raw (list[str]) – a list of raw CSS snippets to put between <style> tags

Template: css_resources.html
{% for file in css_files %}
    <link rel="stylesheet" href="{{ file }}" type="text/css" />
{% endfor %}
{% for css in css_raw %}
    <style>
        {{ css }}
    </style>
{% endfor %}
DOC_JS = <Template 'doc_js.js'>
Template: doc_js.js
{% extends "try_run.js" %}

{% block code_to_run %}
  const docs_json = {{ docs_json }};
  const render_items = {{ render_items }};
  root.Bokeh.embed.embed_items(docs_json, render_items{%- if app_path -%}, "{{ app_path }}" {%- endif -%}{%- if absolute_url -%}, "{{ absolute_url }}" {%- endif -%});
{% endblock %}
DOC_NB_JS = <Template 'doc_nb_js.js'>
Template: doc_nb_js.js
{% extends "try_run.js" %}

{% block code_to_run %}
  const docs_json = {{ docs_json }};
  const render_items = {{ render_items }};
  root.Bokeh.embed.embed_items_notebook(docs_json, render_items);
{% endblock %}
FILE = <Template 'file.html'>

Renders Bokeh models into a basic .html file.

Parameters
  • title (str) – value for <title> tags

  • plot_resources (str) – typically the output of RESOURCES

  • plot_script (str) – typically the output of PLOT_SCRIPT

Users can customize the file output by providing their own Jinja2 template that accepts these same parameters.

Template: file.html
{% from macros import embed %}
<!DOCTYPE html>
<html lang="en">
  {% block head %}
  <head>
  {% block inner_head %}
    <meta charset="utf-8">
    <title>{% block title %}{{ title | e if title else "Bokeh Plot" }}{% endblock %}</title>
  {%  block preamble -%}{%- endblock %}
  {%  block resources -%}
  {%   block css_resources -%}
    {{- bokeh_css if bokeh_css }}
  {%-  endblock css_resources %}
  {%   block js_resources -%}
    {{  bokeh_js if bokeh_js }}
  {%-  endblock js_resources %}
  {%  endblock resources %}
  {%  block postamble %}{% endblock %}
  {% endblock inner_head %}
  </head>
  {% endblock head%}
  {% block body %}
  <body>
  {%  block inner_body %}
  {%    block contents %}
  {%      for doc in docs %}
  {{        embed(doc) if doc.elementid }}
  {%-       for root in doc.roots %}
  {%          block root scoped %}
  {{            embed(root) }}
  {%          endblock %}
  {%        endfor %}
  {%      endfor %}
  {%    endblock contents %}
  {{ plot_script | indent(4) }}
  {%  endblock inner_body %}
  </body>
  {% endblock body%}
</html>
JS_RESOURCES = <Template 'js_resources.html'>

Renders HTML that loads BokehJS JavaScript code and CSS according to the configuration in a Resources object.

Parameters
  • hashes (dict[str, str]) – a map of filenames for to SRI hashes

  • js_files (list[str]) – a list of URIs for JS files to include

  • js_raw (list[str]) – a list of raw JS snippets to put between <style> tags

Template: js_resources.html
{% for file in js_files %}
    <script type="text/javascript" src="{{ file }}"></script>
{% endfor %}
{% for js in js_raw %}
    <script type="text/javascript">
        {{ js }}
    </script>
{% endfor %}
NOTEBOOK_LOAD = <Template 'notebook_load.html'>

Renders HTML for loading BokehJS JavaScript code and CSS into a Jupyter Notebook according to a Resources object.

Parameters
  • plot_resources (str) – typically the output of RESOURCES

  • verbose (bool) – whether to display verbose info about BokehJS configuration, etc

  • bokeh_version (str) – the current version of Bokeh

  • js_info (str) – information about the location, version, etc. of BokehJS code

  • css_info (str) – information about the location, version, etc. of BokehJS css

  • warnings (list[str]) – a list of warnings to display to user

Template: notebook_load.html
    <div class="bk-root">
        <a href="https://bokeh.org" target="_blank" class="bk-logo bk-logo-small bk-logo-notebook"></a>
        <span id="{{ element_id }}">Loading BokehJS ...</span>
    </div>
    {% if verbose %}
    <style>
        p.bokeh_notebook { margin-left: 24px; }
        table.bokeh_notebook {
            border: 1px solid #e7e7e7;
            margin: 5px;
            margin-left: 24px;
            width: 80%;
        }
        tr.bokeh_notebook {
            border: 1px solid #e7e7e7;
            background-color: #FFF;
        }
        th.bokeh_notebook {
            border: 1px solid #e7e7e7;
            background-color: #f8f8f8;
            text-align: center;
        }
        td.bokeh_notebook {
            border: 1px solid #e7e7e7;
            background-color: #d2d7ec;
            text-align: left;
        }
    </style>
    <p class="bokeh_notebook">Using Settings:</p>
    <table class="bokeh_notebook">
        <tr class="bokeh_notebook">
            <th class="bokeh_notebook">Bokeh</th>
            <th class="bokeh_notebook">version</th>
            <td class="bokeh_notebook">{{ bokeh_version }}</td>
        </tr>
        <tr class="bokeh_notebook">
            <th class="bokeh_notebook" rowspan="2">BokehJS</th>
            <th class="bokeh_notebook">js</th>
            <td class="bokeh_notebook">{{ js_info }}</td>
        </tr>
        <tr class="bokeh_notebook">
            <th class="bokeh_notebook">css</th>
            <td class="bokeh_notebook">{{ css_info }}</td>
        </tr>
    </table>
    {% endif %}
    {% for warning in warnings %}
    <p style="background-color: #f2d7dc;">{{ warning }}</p>
    {% endfor %}
PLOT_DIV = <Template 'plot_div.html'>

Renders a basic plot div, that can be used in conjunction with PLOT_JS.

Parameters

elementid (str) – a unique identifier for the <div> a PLOT_JS template should be configured with the same elementid

Template: plot_div.html
{% from macros import embed %}
{{ embed(doc) if doc.elementid }}
{% for root in doc.roots %}
  {{ embed(root) }}
{% endfor %}
ROOT_DIV = <Template 'root_div.html'>
Template: root_div.html
{% from macros import embed %}
{{ embed(root) }}
SCRIPT_TAG = <Template 'script_tag.html'>

Renders a <script> tag for raw JavaScript code.

Parameters

js_code (str) – raw JavaScript code to put in the tag.

Template: script_tag.html
<script type="{{ type }}"{% if id %} id="{{ id }}"{% endif %}>

{{ js_code }}
</script>