Working with templates and UI#
The pages of the JupyterHub application are generated from Jinja templates. These allow the header, for example, to be defined once and incorporated into all pages. By providing your own template(s), you can have complete control over JupyterHub’s appearance.
Custom Templates#
JupyterHub will look for custom templates in all paths included in the
JupyterHub.template_paths configuration option, falling back on these
default templates
if no custom template(s) with specified name(s) are found. This fallback
behavior is new in version 0.9; previous versions searched only the paths
explicitly included in template_paths. You may override as many
or as few templates as you desire.
Extending Templates#
Jinja provides a mechanism to extend templates.
A base template can define block(s) within itself that child templates can fill up or
supply content to. The
JupyterHub default templates
make extensive use of blocks, thus allowing you to customize parts of the
interface easily.
In general, a child template can extend a base template, page.html, by beginning with:
{% extends "page.html" %}
This works, unless you are trying to extend the default template for the same
file name. Starting in version 0.9, you may refer to the base file with a
templates/ prefix. Thus, if you are writing a custom page.html, start the
file with this block:
{% extends "templates/page.html" %}
By defining blocks with the same name as in the base template, child templates
can replace those sections with custom content. The content from the base
template can be included in the child template with the {{ super() }} directive.
Example#
To add an additional message to the spawn-pending page, below the existing
text about the server starting up, place the content below in a file named
spawn_pending.html. This directory must also be included in the
JupyterHub.template_paths configuration option.
{% extends "templates/spawn_pending.html" %} {% block message %} {{ super() }}
<p>Patience is a virtue.</p>
{% endblock %}
Page Announcements#
To add announcements to be displayed on a page, you have two options:
Use configuration variables
Announcement Configuration Variables#
If you set the configuration variable JupyterHub.template_vars = {'announcement': 'some_text'}, the given some_text will be placed on
the top of all pages. The more specific variables
announcement_login, announcement_spawn, announcement_home, and
announcement_logout are more specific and only show on their
respective pages (overriding the global announcement variable).
Note that changing these variables requires a restart, unlike direct
template extension.
Alternatively, you can get the same effect by extending templates, which allows you
to update the messages without restarting. Set
c.JupyterHub.template_paths as mentioned above, and then create a
template (for example, login.html) with:
{% extends "templates/login.html" %} {% set announcement = 'some message' %}
Extending page.html puts the message on all pages, but note that
extending page.html takes precedence over an extension of a specific
page (unlike the variable-based approach above).