doc/refactoring-the-css-with-uiprops.rst
author Christophe de Vienne <christophe@unlish.com>
Wed, 28 Jan 2015 14:03:00 +0100
changeset 10175 2659f8529a43
parent 10121 23af005426bf
permissions -rw-r--r--
[devtools] Make PostgresTestDataBaseHandler multi-use friendly Dont init the pgdb twice on the same datadir - If two test case with the same apphome use a Postgres configuration, the handler is initialised twice, so it has to check if the pgdb directory has already been initialized. - Work with the realpath of the pgdb In some cases, the self.config.apphome will resolve symbolic links, but not always. It can result in an attempt to start twice the pg server for the same directory, in the same test run... resulting in failure. Closes #4875827

=========================================
Refactoring the CSSs with UI properties
=========================================

Overview
=========

Managing styles progressively became difficult in CubicWeb. The
introduction of uiprops is an attempt to fix this problem.

The goal is to make it possible to use variables in our CSSs.

These variables are defined or computed in the uiprops.py python file
and inserted in the CSS using the Python string interpolation syntax.

A quick example, put in ``uiprops.py``::

  defaultBgColor = '#eee'

and in your css::

  body { background-color: %(defaultBgColor)s; }


The good practices are:

- define a variable in uiprops to avoid repetitions in the CSS
  (colors, borders, fonts, etc.)

- define a variable in uiprops when you need to compute values
  (compute a color palette, etc.)

The algorithm implemented in CubicWeb is the following:

- read uiprops file while walk up the chain of cube dependencies: if
  cube myblog depends on cube comment, the variables defined in myblog
  will have precedence over the ones in comment

- replace the %(varname)s in all the CSSs of all the cubes

Keep in mind that the browser will then interpret the CSSs and apply
the standard cascading mechanism.