doc/refactoring-the-css-with-uiprops.rst
author Rémi Cardona <remi.cardona@logilab.fr>
Wed, 11 Mar 2015 15:17:25 +0100
changeset 10224 996cf2c0ec99
parent 5492 da983679fab5
child 10121 23af005426bf
permissions -rw-r--r--
[config] Lowercase the FQDN we get from the OS (closes #5040345) Browsers convert the host name part of URLs to lowercase. This has the unfortunate effect of triggering various CORS error messages in CubicWeb (because the Origin: header will contain lowercase letters). As per RFC 4343, host name comparison should be case-insensitive. So let's put it in lowercase when we grab it from the host system. If admins put uppercase letters in "host" or "base-url" in their all-in-one.conf, then it's their fault.

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