doc/refactoring-the-css-with-uiprops.rst
author Julien Cristau <julien.cristau@logilab.fr>
Thu, 23 Feb 2012 19:05:36 +0100
branchstable
changeset 8261 d4d9c88d4a5f
parent 5492 da983679fab5
child 10121 23af005426bf
permissions -rw-r--r--
[devtools] make a copy of the xvfb-run script so we can kill it properly Since changeset a3d3bdd46463 we don't run firefox directly but through a wrapper script. This meant that on stopping the test, we would kill that wrapper script but leave the Xvfb server and firefox processes running. So make a local copy of xvfb-run, and make it kill Xvfb when it goes down, not just when its client exits.

=========================================
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.

FAQ
====

- How do I keep the old style?

  Put ``STYLESHEET = [data('cubicweb.old.css')]`` in your uiprops.py
  file and think about something else.

- What are the changes in cubicweb.css?

  Version 3.9.0 of cubicweb changed the following in the default html
  markup and css:

  ===============  ==================================
   old              new
  ===============  ==================================
   .navcol          #navColumnLeft, #navColumnRight
   #contentcol      #contentColumn
   .footer          #footer
   .logo	    #logo
   .simpleMessage   .loginMessage
   .appMsg	    (styles are removed from css)
   .searchMessage   (styles are removed from css)
  ===============  ==================================

  Introduction of the new cubicweb.reset.css based on Eric Meyer's
  reset css.

  Lots of margin, padding, etc.