[autoform] Use fieldclass from kwargs in guess_field for non-final relations
This follows up on af969080e7e6 in which a "fieldclass" kwarg has been
added in EntityFieldsForm.field_by_name() before calling guess_field().
In this changeset, this value was only used for final relation but the
way non-final relation actually also changed since we also use
guess_field from these relation (previously, the field class specified
through uicfg was instantiated directly in
EntityFieldsForm.field_by_name()). So in the non-final case in
guess_field() we simply try to retrieve "fieldclass" from kwargs and
fall back to RelationField.
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Refactoring the CSSs with UI properties
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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.