[rset] Always complete attribute/relation caches in ResultSet.get_entity
RQL queries are often designed to fill up the ORM's caches when fetching
entities out of the result set. Until now, if an entry already existed
in the entity cache, ResultSet.get_entity would return it unchanged,
not using the new ResultSet's contents to update the attribute cache,
breaking expectations (if the attributes are needed, they'd then be
fetched later one at a time, one entity at a time), resulting in loads
of DB accesses.
So we change ResultSet.get_entity so that:
* if the entity is already cached and has been instantiated from the
same rset, it is returned as-is (to avoid loops)
* if the entity is not yet cached, it is instantiated
* if the entity is cached via another rset, its attribute/relation
caches are completed
Closes #9942503
3.20 (06/01/2015)
=================
New features
------------
* virtual relations: a new ComputedRelation class can be used in
schema.py; its `rule` attribute is an RQL snippet that defines the new
relation.
* computed attributes: an attribute can now be defined with a `formula`
argument (also an RQL snippet); it will be read-only, and updated
automatically.
Both of these features are described in `CWEP-002`_, and the updated
"Data model" chapter of the CubicWeb book.
* cubicweb-ctl plugins can use the ``cubicweb.utils.admincnx`` function
to get a Connection object from an instance name.
* new 'tornado' wsgi backend
* session cookies have the HttpOnly flag, so they're no longer exposed to
javascript
* rich text fields can be formatted as markdown
* the edit controller detects concurrent editions, and raises a ValidationError
if an entity was modified between form generation and submission
* cubicweb can use a postgresql "schema" (namespace) for its tables
* "cubicweb-ctl configure" can be used to set values of the admin user
credentials in the sources configuration file
* in debug mode, setting the _cwtracehtml parameter on a request allows tracing
where each bit of output is produced
.. _CWEP-002: http://hg.logilab.org/review/cwep/file/tip/CWEP-002.rst
API Changes
-----------
* ``ucsvreader()`` and ``ucsvreader_pb()`` from the ``dataimport`` module have
2 new keyword arguments ``delimiter`` and ``quotechar`` to replace the
``separator`` and ``quote`` arguments respectively. This makes the API match
that of Python's ``csv.reader()``. The old arguments are still supported
though deprecated.
* the migration environment's ``remove_cube`` function is now called ``drop_cube``.
* cubicweb.old.css is now cubicweb.css. The previous "new"
cubicweb.css, along with its cubicweb.reset.css companion, have been
removed.
* the jquery-treeview plugin was updated to its latest version
Deprecated Code Drops
----------------------
* most of 3.10 and 3.11 backward compat is gone; this includes:
- CtxComponent.box_action() and CtxComponent.build_link()
- cubicweb.devtools.htmlparser.XMLDemotingValidator
- various methods and properties on Entities, replaced by cw_edited
and cw_attr_cache
- 'commit_event' method on hooks, replaced by 'postcommit_event'
- server.hook.set_operation(), replaced by
Operation.get_instance(...).add_data()
- View.div_id(), View.div_class() and View.create_url()
- `*VComponent` classes
- in forms, Field.value() and Field.help() must take the form and
the field itself as arguments
- form.render() must get `w` as a named argument, and
renderer.render() must take `w` as first argument
- in breadcrumbs, the optional `recurs` argument must be a set, not
False
- cubicweb.web.views.idownloadable.{download_box,IDownloadableLineView}
- primary views no longer have `render_entity_summary` and `summary`
methods
- WFHistoryVComponent's `cell_call` method is replaced by
`render_body`
- cubicweb.dataimport.ObjectStore.add(), replaced by create_entity
- ManageView.{folders,display_folders}