--- a/doc/book/en/annexes/faq.rst Fri Oct 22 14:36:39 2010 +0200
+++ b/doc/book/en/annexes/faq.rst Fri Oct 22 14:54:24 2010 +0200
@@ -1,7 +1,7 @@
.. -*- coding: utf-8 -*-
-Frequently Asked Questions
-==========================
+Frequently Asked Questions (FAQ)
+================================
[XXX 'copy answer from forum' means reusing text from
http://groups.google.com/group/google-appengine/browse_frm/thread/c9476925f5f66ec6
@@ -73,7 +73,7 @@
Why is the RQL query language looking similar to X ?
------------------------------------------------------
+----------------------------------------------------
It may remind you of SQL but it is higher level than SQL, more like
SPARQL. Except that SPARQL did not exist when we started the project.
@@ -97,13 +97,57 @@
Which ajax library is CubicWeb using ?
--------------------------------------
-CubicWeb uses jQuery and provides a few helpers on top of
-that. Additionally, some jQuery plugins are provided (some are
-provided in specific cubes).
+CubicWeb uses jQuery_ and provides a few helpers on top of that. Additionally,
+some jQuery plugins are provided (some are provided in specific cubes).
+
+.. _jQuery: http://jquery.com
+
Development
```````````
+How to change the instance logo ?
+---------------------------------
+
+There are two ways of changing the logo.
+
+1. The easiest way to use a different logo is to replace the existing
+ ``logo.png`` in ``myapp/data`` by your prefered icon and refresh.
+ By default all instance will look for a ``logo.png`` to be
+ rendered in the logo section.
+
+ .. image:: ../images/lax-book_06-main-template-logo_en.png
+
+2. In your cube directory, you can specify which file to use for the logo.
+ This is configurable in ``mycube/uiprops.py``: ::
+
+ LOGO = data('mylogo.gif')
+
+ ``mylogo.gif`` is in ``mycube/data`` directory.
+
+How to create an anonymous user ?
+---------------------------------
+
+This allows to browse the site without being authenticated. In the
+``all-in-one.conf`` file of your instance, define the anonymous user
+as follows ::
+
+ # login of the CubicWeb user account to use for anonymous user (if you want to
+ # allow anonymous)
+ anonymous-user=anon
+
+ # password of the CubicWeb user account matching login
+ anonymous-password=anon
+
+You also must ensure that this `anon` user is a registered user of
+the DB backend. If not, you can create through the administation
+interface of your instance by adding a user with in the group `guests`.
+
+.. note::
+ While creating a new instance, you can decide to allow access
+ to anonymous user, which will automatically execute what is
+ decribed above.
+
How to load data from a script ?
--------------------------------
@@ -117,42 +161,29 @@
cnx = dbapi.connect(database='instance-id', user='admin', password='admin')
cur = cnx.cursor()
- for name in ('Personal', 'Professional', 'Computers'):
- cur.execute('INSERT Blog B: B name %s', name)
+ for name in (u'Personal', u'Professional', u'Computers'):
+ cur.execute('INSERT Tag T: T name %(n)s', {'n': name})
cnx.commit()
+Wether your instance as pyro activated or not, you can still acheive this by
+using cubicweb-ctl shell scripts.
How to format an entity date attribute ?
----------------------------------------
-If your schema has an attribute of type Date or Datetime, you might
-want to format it. First, you should define your preferred format using
-the site configuration panel ``http://appurl/view?vid=systempropertiesform``
-and then set ``ui.date`` and/or ``ui.datetime``.
-Then in the view code, use:
+If your schema has an attribute of type `Date` or `Datetime`, you usually want to
+format it when displaying it. First, you should define your preferred format
+using the site configuration panel
+``http://appurl/view?vid=systempropertiesform`` and then set ``ui.date`` and/or
+``ui.datetime``. Then in the view code, use:
.. sourcecode:: python
- self.format_date(entity.date_attribute)
-
-What is the CubicWeb datatype corresponding to GAE datastore's UserProperty ?
------------------------------------------------------------------------------
+ entity.printable_value(date_attribute)
-If you take a look at your instance schema and
-click on "display detailed view of metadata" you will see that there
-is a Euser entity in there. That's the one that is modeling users. The
-thing that corresponds to a UserProperty is a relationship between
-your entity and the Euser entity. As in:
-
-.. sourcecode:: python
-
- class TodoItem(EntityType):
- text = String()
- todo_by = SubjectRelation('Euser')
-
-[XXX check that cw handle users better by mapping Google Accounts to local Euser
-entities automatically]
-
+which will always return a string whatever the attribute's type (so it's
+recommended also for other attribute types). By default it expects to generate
+HTML, so it deals with rich text formating, xml escaping...
How do I translate an msg id defined (and translated) in another cube ?
-----------------------------------------------------------------------
@@ -160,46 +191,6 @@
You should put these translations in the `i18n/static-messages.pot`
file of your own cube.
-
-What is `Error while publishing rest text ...` ?
-------------------------------------------------
-
-While modifying the description of an entity, you get an error message in
-the instance `Error while publishing ...` for Rest text and plain text.
-The server returns a traceback like as follows ::
-
- 2008-10-06 15:05:08 - (cubicweb.rest) ERROR: error while publishing ReST text
- Traceback (most recent call last):
- File "/home/user/src/blogdemo/cubicweb/common/rest.py", line 217, in rest_publish
- File "/usr/lib/python2.5/codecs.py", line 817, in open
- file = __builtin__.open(filename, mode, buffering)
- TypeError: __init__() takes at most 3 arguments (4 given)
-
-This can be fixed by applying the patch described in :
-http://code.google.com/p/googleappengine/issues/detail?id=48
-
-What are hooks used for ?
--------------------------
-
-Hooks are executed around (actually before or after) events. The
-most common events are data creation, update and deletion. They
-permit additional constraint checking (those not expressible at the
-schema level), pre and post computations depending on data
-movements.
-
-As such, they are a vital part of the framework.
-
-Other kinds of hooks, called Operations, are available
-for execution just before commit.
-
-When should you define an HTML template rather than define a graphical component ?
-----------------------------------------------------------------------------------
-
-An HTML template cannot contain code, hence it is only about static
-content. A component is made of code and operations that apply on a
-well defined context (request, result set). It enables much more
-dynamic views.
-
How to update a database after a schema modification ?
------------------------------------------------------
@@ -212,51 +203,76 @@
* add a relation: ``add_relation_definition('SubjRelation', 'MyRelation', 'ObjRelation')``.
+I get `NoSelectableObject` exceptions, how do I debug selectors ?
+-----------------------------------------------------------------
-How to create an anonymous user ?
----------------------------------
+You just need to put the appropriate context manager around view/component
+selection. One standard place for components is in cubicweb/vregistry.py:
+
+.. sourcecode:: python
-This allows to bypass authentication for your site. In the
-``all-in-one.conf`` file of your instance, define the anonymous user
-as follows ::
+ def possible_objects(self, *args, **kwargs):
+ """return an iterator on possible objects in this registry for the given
+ context
+ """
+ from cubicweb.selectors import traced_selection
+ with traced_selection():
+ for appobjects in self.itervalues():
+ try:
+ yield self._select_best(appobjects, *args, **kwargs)
+ except NoSelectableObject:
+ continue
- # login of the CubicWeb user account to use for anonymous user (if you want to
- # allow anonymous)
- anonymous-user=anon
+Don't forget the 'from __future__ import with_statement' at the module
+top-level if you're using python 2.5.
+
+This will yield additional WARNINGs, like this::
+
+ 2009-01-09 16:43:52 - (cubicweb.selectors) WARNING: selector one_line_rset returned 0 for <class 'cubicweb.web.views.basecomponents.WFHistoryVComponent'>
- # password of the CubicWeb user account matching login
- anonymous-password=anon
+For views, you can put this context in `cubicweb/web/views/basecontrollers.py` in
+the `ViewController`:
+
+.. sourcecode:: python
-You also must ensure that this `anon` user is a registered user of
-the DB backend. If not, you can create through the administation
-interface of your instance by adding a user with the role `guests`.
-This could be the admin account (for development
-purposes, of course).
+ def _select_view_and_rset(self, rset):
+ ...
+ try:
+ from cubicweb.selectors import traced_selection
+ with traced_selection():
+ view = self._cw.vreg['views'].select(vid, req, rset=rset)
+ except ObjectNotFound:
+ self.warning("the view %s could not be found", vid)
+ req.set_message(req._("The view %s could not be found") % vid)
+ vid = vid_from_rset(req, rset, self._cw.vreg.schema)
+ view = self._cw.vreg['views'].select(vid, req, rset=rset)
+ ...
-.. note::
- While creating a new instance, you can decide to allow access
- to anonymous user, which will automatically execute what is
- decribed above.
+I get "database is locked" when executing tests
+-----------------------------------------------
+
+If you have "database is locked" as error when you are executing security tests,
+it is usually because commit or rollback are missing before login() calls.
+
+You can also use a context manager, to avoid such errors, as described
+here: :ref:`securitytest`.
-How to change the instance logo ?
-------------------------------------
+What are hooks used for ?
+-------------------------
-There are two ways of changing the logo.
+Hooks are executed around (actually before or after) events. The most common
+events are data creation, update and deletion. They permit additional constraint
+checking (those not expressible at the schema level), pre and post computations
+depending on data movements.
-1. The easiest way to use a different logo is to replace the existing
- ``logo.png`` in ``myapp/data`` by your prefered icon and refresh.
- By default all instance will look for a ``logo.png`` to be
- rendered in the logo section.
-
- .. image:: ../images/lax-book_06-main-template-logo_en.png
+As such, they are a vital part of the framework.
-2. In your cube directory, you can specify which file to use for the logo.
- This is configurable in ``mycube/data/external_resources``: ::
+Other kinds of hooks, called Operations, are available
+for execution just before commit.
- LOGO = DATADIR/path/to/mylogo.gif
+For more information, read :ref:`hooks` section.
- where DATADIR is ``mycube/data``.
Configuration
`````````````
@@ -264,31 +280,7 @@
How to configure a LDAP source ?
--------------------------------
-Your instance's sources are defined in ``/etc/cubicweb.d/myapp/sources``.
-Configuring an LDAP source is about declaring that source in your
-instance configuration file such as: ::
-
- [ldapuser]
- adapter=ldapuser
- # ldap host
- host=myhost
- # base DN to lookup for usres
- user-base-dn=ou=People,dc=mydomain,dc=fr
- # user search scope
- user-scope=ONELEVEL
- # classes of user
- user-classes=top,posixAccount
- # attribute used as login on authentication
- user-login-attr=uid
- # name of a group in which ldap users will be by default
- user-default-group=users
- # map from ldap user attributes to cubicweb attributes
- user-attrs-map=gecos:email,uid:login
-
-Any change applied to configuration file requires to restart your
-instance.
-
-You can find additional information in the section :ref:`LDAP`.
+See :ref:`LDAP`.
How to import LDAP users in |cubicweb| ?
----------------------------------------
@@ -350,34 +342,6 @@
cnx.close()
-I get NoSelectableObject exceptions, how do I debug selectors ?
----------------------------------------------------------------
-
-You just need to put the appropriate context manager around view/component
-selection (one standard place in in vreg.py):
-
-.. sourcecode:: python
-
- def possible_objects(self, registry, *args, **kwargs):
- """return an iterator on possible objects in a registry for this result set
-
- actions returned are classes, not instances
- """
- from cubicweb.selectors import traced_selection
- with traced_selection():
- for vobjects in self.registry(registry).values():
- try:
- yield self.select(vobjects, *args, **kwargs)
- except NoSelectableObject:
- continue
-
-Don't forget the 'from __future__ import with_statement' at the module
-top-level.
-
-This will yield additional WARNINGs, like this::
-
- 2009-01-09 16:43:52 - (cubicweb.selectors) WARNING: selector one_line_rset returned 0 for <class 'cubicweb.web.views.basecomponents.WFHistoryVComponent'>
-
Security
````````
@@ -410,7 +374,7 @@
Be careful, the encryption algorithm is different on Windows and on
Unix. You cannot therefore use a hash generated on Unix to fill in a
-Windows database, nor the other way round.
+Windows database, nor the other way round.
You can prefer use a migration script similar to this shell invocation instead::
@@ -434,7 +398,8 @@
remove {'PR': 'Project', 'C': 'CWUser'} from solutions since your_user has no read access to cost
-This is because you have to put your user in the "users" group. The user has to be in both groups.
+This is because you have to put your user in the "users" group. The user has to
+be in both groups.
How is security implemented ?
------------------------------
@@ -491,9 +456,7 @@
Is it possible to bypass security from the UI (web front) part ?
----------------------------------------------------------------
-No.
-
-Only Hooks/Operations can do that.
+No. Only Hooks/Operations can do that.
Can PostgreSQL and CubicWeb authentication work with kerberos ?
----------------------------------------------------------------