--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/book/devweb/views/primary.rst Thu Jan 08 22:11:06 2015 +0100
@@ -0,0 +1,276 @@
+.. _primary_view:
+
+The Primary View
+-----------------
+
+By default, *CubicWeb* provides a view that fits every available
+entity type. This is the first view you might be interested in
+modifying. It is also one of the richest and most complex.
+
+It is automatically selected on a one line result set containing an
+entity.
+
+It lives in the :mod:`cubicweb.web.views.primary` module.
+
+The *primary* view is supposed to render a maximum of informations about the
+entity.
+
+.. _primary_view_layout:
+
+Layout
+``````
+
+The primary view has the following layout.
+
+.. image:: ../../images/primaryview_template.png
+
+.. _primary_view_configuration:
+
+Primary view configuration
+``````````````````````````
+
+If you want to customize the primary view of an entity, overriding the primary
+view class may not be necessary. For simple adjustments (attributes or relations
+display locations and styles), a much simpler way is to use uicfg.
+
+Attributes/relations display location
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In the primary view, there are three sections where attributes and
+relations can be displayed (represented in pink in the image above):
+
+* 'attributes'
+* 'relations'
+* 'sideboxes'
+
+**Attributes** can only be displayed in the attributes section (default
+ behavior). They can also be hidden. By default, attributes of type `Password`
+ and `Bytes` are hidden.
+
+For instance, to hide the ``title`` attribute of the ``Blog`` entity:
+
+.. sourcecode:: python
+
+ from cubicweb.web.views import uicfg
+ uicfg.primaryview_section.tag_attribute(('Blog', 'title'), 'hidden')
+
+**Relations** can be either displayed in one of the three sections or hidden.
+
+For relations, there are two methods:
+
+* ``tag_object_of`` for modifying the primary view of the object
+* ``tag_subject_of`` for modifying the primary view of the subject
+
+These two methods take two arguments:
+
+* a triplet ``(subject, relation_name, object)``, where subject or object can be replaced with ``'*'``
+* the section name or ``hidden``
+
+.. sourcecode:: python
+
+ pv_section = uicfg.primaryview_section
+ # hide every relation `entry_of` in the `Blog` primary view
+ pv_section.tag_object_of(('*', 'entry_of', 'Blog'), 'hidden')
+
+ # display `entry_of` relations in the `relations`
+ # section in the `BlogEntry` primary view
+ pv_section.tag_subject_of(('BlogEntry', 'entry_of', '*'), 'relations')
+
+
+Display content
+^^^^^^^^^^^^^^^
+
+You can use ``primaryview_display_ctrl`` to customize the display of attributes
+or relations. Values of ``primaryview_display_ctrl`` are dictionaries.
+
+
+Common keys for attributes and relations are:
+
+* ``vid``: specifies the regid of the view for displaying the attribute or the relation.
+
+ If ``vid`` is not specified, the default value depends on the section:
+ * ``attributes`` section: 'reledit' view
+ * ``relations`` section: 'autolimited' view
+ * ``sideboxes`` section: 'sidebox' view
+
+* ``order``: int used to control order within a section. When not specified,
+ automatically set according to order in which tags are added.
+
+* ``label``: label for the relations section or side box
+
+* ``showlabel``: boolean telling whether the label is displayed
+
+.. sourcecode:: python
+
+ # let us remind the schema of a blog entry
+ class BlogEntry(EntityType):
+ title = String(required=True, fulltextindexed=True, maxsize=256)
+ publish_date = Date(default='TODAY')
+ content = String(required=True, fulltextindexed=True)
+ entry_of = SubjectRelation('Blog', cardinality='?*')
+
+ # now, we want to show attributes
+ # with an order different from that in the schema definition
+ view_ctrl = uicfg.primaryview_display_ctrl
+ for index, attr in enumerate('title', 'content', 'publish_date'):
+ view_ctrl.tag_attribute(('BlogEntry', attr), {'order': index})
+
+By default, relations displayed in the 'relations' section are being displayed by
+the 'autolimited' view. This view will use comma separated values, or list view
+and/or limit your rset if there is too much items in it (and generate the "view
+all" link in this case).
+
+You can control this view by setting the following values in the
+`primaryview_display_ctrl` relation tag:
+
+* `limit`, maximum number of entities to display. The value of the
+ 'navigation.related-limit' cwproperty is used by default (which is 8 by default).
+ If None, no limit.
+
+* `use_list_limit`, number of entities until which they should be display as a list
+ (eg using the 'list' view). Below that limit, the 'csv' view is used. If None,
+ display using 'csv' anyway.
+
+* `subvid`, the subview identifier (eg view that should be used of each item in the
+ list)
+
+Notice you can also use the `filter` key to set up a callback taking the related
+result set as argument and returning it filtered, to do some arbitrary filtering
+that can't be done using rql for instance.
+
+
+.. sourcecode:: python
+
+ pv_section = uicfg.primaryview_section
+ # in `CWUser` primary view, display `created_by`
+ # relations in relations section
+ pv_section.tag_object_of(('*', 'created_by', 'CWUser'), 'relations')
+
+ # display this relation as a list, sets the label,
+ # limit the number of results and filters on comments
+ def filter_comment(rset):
+ return rset.filtered_rset(lambda x: x.e_schema == 'Comment')
+ pv_ctrl = uicfg.primaryview_display_ctrl
+ pv_ctrl.tag_object_of(('*', 'created_by', 'CWUser'),
+ {'vid': 'list', 'label': _('latest comment(s):'),
+ 'limit': True,
+ 'filter': filter_comment})
+
+.. warning:: with the ``primaryview_display_ctrl`` rtag, the subject or the
+ object of the relation is ignored for respectively ``tag_object_of`` or
+ ``tag_subject_of``. To avoid warnings during execution, they should be set to
+ ``'*'``.
+
+
+.. automodule:: cubicweb.web.views.primary
+
+
+Example of customization and creation
+`````````````````````````````````````
+
+We'll show you now an example of a ``primary`` view and how to customize it.
+
+If you want to change the way a ``BlogEntry`` is displayed, just
+override the method ``cell_call()`` of the view ``primary`` in
+``BlogDemo/views.py``.
+
+.. sourcecode:: python
+
+ from cubicweb.predicates import is_instance
+ from cubicweb.web.views.primary import Primaryview
+
+ class BlogEntryPrimaryView(PrimaryView):
+ __select__ = PrimaryView.__select__ & is_instance('BlogEntry')
+
+ def render_entity_attributes(self, entity):
+ self.w(u'<p>published on %s</p>' %
+ entity.publish_date.strftime('%Y-%m-%d'))
+ super(BlogEntryPrimaryView, self).render_entity_attributes(entity)
+
+
+The above source code defines a new primary view for
+``BlogEntry``. The `__reid__` class attribute is not repeated there since it
+is inherited through the `primary.PrimaryView` class.
+
+The selector for this view chains the selector of the inherited class
+with its own specific criterion.
+
+The view method ``self.w()`` is used to output data. Here `lines
+08-09` output HTML for the publication date of the entry.
+
+.. image:: ../../images/lax-book_09-new-view-blogentry_en.png
+ :alt: blog entries now look much nicer
+
+Let us now improve the primary view of a blog
+
+.. sourcecode:: python
+
+ from logilab.mtconverter import xml_escape
+ from cubicweb.predicates import is_instance, one_line_rset
+ from cubicweb.web.views.primary import Primaryview
+
+ class BlogPrimaryView(PrimaryView):
+ __regid__ = 'primary'
+ __select__ = PrimaryView.__select__ & is_instance('Blog')
+ rql = 'Any BE ORDERBY D DESC WHERE BE entry_of B, BE publish_date D, B eid %(b)s'
+
+ def render_entity_relations(self, entity):
+ rset = self._cw.execute(self.rql, {'b' : entity.eid})
+ for entry in rset.entities():
+ self.w(u'<p>%s</p>' % entry.view('inblogcontext'))
+
+ class BlogEntryInBlogView(EntityView):
+ __regid__ = 'inblogcontext'
+ __select__ = is_instance('BlogEntry')
+
+ def cell_call(self, row, col):
+ entity = self.cw_rset.get_entity(row, col)
+ self.w(u'<a href="%s" title="%s">%s</a>' %
+ entity.absolute_url(),
+ xml_escape(entity.content[:50]),
+ xml_escape(entity.description))
+
+This happens in two places. First we override the
+render_entity_relations method of a Blog's primary view. Here we want
+to display our blog entries in a custom way.
+
+At `line 10`, a simple request is made to build a result set with all
+the entities linked to the current ``Blog`` entity by the relationship
+``entry_of``. The part of the framework handling the request knows
+about the schema and infers that such entities have to be of the
+``BlogEntry`` kind and retrieves them (in the prescribed publish_date
+order).
+
+The request returns a selection of data called a result set. Result
+set objects have an .entities() method returning a generator on
+requested entities (going transparently through the `ORM` layer).
+
+At `line 13` the view 'inblogcontext' is applied to each blog entry to
+output HTML. (Note that the 'inblogcontext' view is not defined
+whatsoever in *CubicWeb*. You are absolutely free to define whole view
+families.) We juste arrange to wrap each blogentry output in a 'p'
+html element.
+
+Next, we define the 'inblogcontext' view. This is NOT a primary view,
+with its well-defined sections (title, metadata, attribtues,
+relations/boxes). All a basic view has to define is cell_call.
+
+Since views are applied to result sets which can be tables of data, we
+have to recover the entity from its (row,col)-coordinates (`line
+20`). Then we can spit some HTML.
+
+.. warning::
+
+ Be careful: all strings manipulated in *CubicWeb* are actually
+ unicode strings. While web browsers are usually tolerant to
+ incoherent encodings they are being served, we should not abuse
+ it. Hence we have to properly escape our data. The xml_escape()
+ function has to be used to safely fill (X)HTML elements from Python
+ unicode strings.
+
+Assuming we added entries to the blog titled `MyLife`, displaying it
+now allows to read its description and all its entries.
+
+.. image:: ../../images/lax-book_10-blog-with-two-entries_en.png
+ :alt: a blog and all its entries
+