published on %s in category %s
' % \ - 11. (entity.publish_date.strftime('%Y-%m-%d'), entity.category)) - 12. self.w(u'%s
' % entity.text) - -The above source code defines a new primary view (`line 03`) for -``BlogEntry`` (`line 05`). - -Since views are applied to resultsets and resulsets can be tables of -data, it is needed to recover the entity from its (row,col) -coordinates (`line 08`). We will get to this in more detail later. - -The view has a ``self.w()`` method that is used to output data. Here `lines -09-12` output HTML tags and values of the entity's attributes. - -When displaying same blog entry as before, you will notice that the -page is now looking much nicer. - -.. 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 :: - - 01. class BlogPrimaryView(baseviews.PrimaryView): - 02. - 03. accepts = ('Blog',) - 04. - 05. def cell_call(self, row, col): - 06. entity = self.entity(row, col) - 07. self.w(u'%s
' % entity.description) - 09. rset = self.req.execute('Any E WHERE E entry_of B, B eid "%s"' % entity.eid) - 10. self.wview('primary', rset) - -In the above source code, `lines 01-08` are similar to the previous -view we defined. - -At `line 09`, a simple request in made to build a resultset 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 infer that such entities have to be of the -``BlogEntry`` kind and retrieves them. - -The request returns a selection of data called a resultset. At -`line 10` the view 'primary' is applied to this resultset to output -HTML. - -**This is to be compared to interfaces and protocols in object-oriented -languages. Applying a given view to all the entities of a resultset only -requires the availability, for each entity of this resultset, of a -view with that name that can accepts the entity.** - -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 - -**Before we move forward, remember that the selection/view principle is -at the core of `CubicWeb`. Everywhere in the engine, data is requested -using the RQL language, then HTML/XML/text/PNG is output by applying a -view to the resultset returned by the query. That is where most of the -flexibility comes from.** - -[WRITE ME] - -* implementing interfaces, calendar for blog entries -* show that a calendar view can export data to ical - -We will implement the cubicwweb.interfaces.ICalendarable interfaces on -entities.BloEntry and apply the OneMonthCalendar and iCalendar views -to resultsets like "Any E WHERE E is BlogEntry" - -* create view "blogentry table" with title, publish_date, category - -We will show that by default the view that displays -"Any E,D,C WHERE E publish_date D, E category C" is the table view. -Of course, the same can be obtained by calling -self.wview('table',rset) - -* in view blog, select blogentries and apply view "blogentry table" -* demo ajax by filtering blogentry table on category - -we did the same with 'primary', but with tables we can turn on filters -and show that ajax comes for free. -[FILLME] - - -Templates ---------- - -*Templates* are specific view that does not depend on a result set. The basic -class `Template` (`cubicweb.common.view`) is derived from the class `View`. - -To build a HTML page, a *main template* is used. In general, the template of -identifier `main` is the one (it is not used in case an error is raised or for -the login form by example). This template uses other templates in addition -to the views which depends on the content to generate the HTML page to return. - -A *template* is responsible for: - -1. executing RQL query of data to render if necessarry -2. identifying the view to use to render data if it is not specified -3. composing the HTML page to return - - -The default main template (`cubicweb.web.views.basetemplates.TheMainTemplate`) ------------------------------------------------------------------------------- - -The default main template build the page based on the following pattern: - -.. image:: images/main_template_layout.png - -The rectangle containing `view.dispathc()` represents the area where the content -view has to be displayed. The others represents sub-templates called to complete -the page. A default implementation of those is provided in -`cubicweb.views.basetemplates`. You can, of course, overload those sub-templates -to implement your own customization of the HTML page. - -We can also control certain aspects of the main template thanks to the following -forms parameters: - -* `__notemplate`, if present (whatever the value assigned), only the content view - is returned -* `__force_display`, if present and its value is not null, no navigation - whatever the number of entities to display -* `__method`, if the result set to render contains only one entity and this - parameter is set, it refers to a method to call on the entity by passing it - the dictionnary of the forms parameters, before going the classic way (through - step 1 and 2 described juste above) - -.. include:: 05-01-views-stdlib.en.txt - - -XML views, binaries... ----------------------- -For the views generating other formats that HTML (an image generated dynamically -by example), and which can not usually be included in the HTML page generated -by the main template (see above), you have to: - -* set the atribute `templatable` of the class to `False` -* set, through the attribute `content_type` of the class, the MIME type generated - by the view to `application/octet-stream` - -For the views dedicated to binary content creation (an image dynamically generated -by example), we have to set the attribute `binary` of the class to `True` (which -implies that `templateable == False`, so that the attribute `w` of the view could be -replaced by a binary flow instead of unicode). - -(X)HTML tricks to apply ------------------------ - -Some web browser (Firefox by example) are not happy with empty `