Horizon themes are now configurable at a user level, through the use
of cookies. The themes that can be set are configurable at a
deployment level through settings.py. Horizon can be configured to
run with multiple themes, and allow users to choose which themes
they wish to run.
Django Compressor:
In order to support dynamic themes, each theme configuration must
be pre-compiled through the Django compressor. By making use of its
built in COMPRESS_OFFLINE_CONTEXT, we now return a generator to
create each of the theme's necessary offline contexts.
Templates:
Horizon themes allowed template overrides via their 'templates'
subfolder. In order to maintain this parity, a custom theme template
loader was created. It is run before the other loads, and simply
looks for a Django template in the current theme (cookie driven)
before diverting to the previous template loaders.
Static Files:
Horizon themes allowed static overrides of the images in
'dashboard/img' folder. A template tag, 'themable_asset' was created
to maintain this parity. Any asset that is wished to be made themable,
given that it is located in Horizon's 'static/dashboard' folder, can
now be made ot be themable. By making this a template tag, this
gives the developers more granular control over what branders can
customize.
Angular and Plugins:
By far, the trickiest part of this task, Angular and Plugins are
dynamic in the files that they 'discover'. SCSS is not flexible in
this manner at ALL. SCSS disallows the importation of a variable
name. To get around this, themes.scss was created as a Django
template. This template is the top level import file for all styles
within Horizon, and therefore, allows ALL the scss files to share a
common namespace and thus, can use shared variables as well as extend
shared styles.
Other:
This change is fundamental, in that it changes the method by which
Horizon ingests its SCSS files. Many problems existing in the
previous implementation, in an effort to make Horizon flexible, its
SCSS was made very inflexible. This patch corrects those problems.
Change-Id: Ic48b4b5c1d1a41f1e01a8d52784c9d38d192c8f1
Implements: blueprint horizon-dynamic-theme
Closes-Bug: #1480427
c9de52d6bb