[massive store] Use a slave specific table for relation insertion in the massive store
* attribute a random id to the store
* add a column containing this id in the cwmassive_initialized table
* separate generic `master_init` which create the cwmassive_initialized table
from rtype specific initialization which must be done in each slave now
* delay removal of table indexes to `finish`
* get back relations from each table on `finish`
Similar work still has to be done for entities insertion - which will allow more
cleanup to the constraints handling which is still rough for now.
Related to #15538303
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Refactoring the CSSs with UI properties
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Overview
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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.