[ui] Refactor business views for easier overriding

By clearling separating value retrieval / text generation from its injection in
the HTML layout, things are clearer and easier to override.

views/archiveunit.py

@@ -149,16 +149,11 @@ class TitleBusinessValueEntityView(BusinessValueLinkEntityView):
     element.
     """
     __select__ = BusinessValueLinkEntityView.__select__ & is_instance('SEDAContent')
+    no_value_msg = _('<no title specified>')
 
-    def entity_call(self, entity):
+    def entity_value(self, entity):
         seda_title = entity.related('seda_title', role='object').one()
-        title = seda_title.printable_value('title') or None
-        if title:
-            self.w(u'<span class="value">')
-            self.wvalue(entity, title)
-            self.w(u'</span>')
-        else:
-            self.wvalue(entity, self._cw._('<no title specified>'))
+        return seda_title.printable_value('title') or None
 
 
 class ArchiveUnitManagementTab(tabs.PrimaryTab):

views/viewlib.py

@@ -22,6 +22,8 @@ from cubicweb.web.views import tabs
 
 from cubes.seda.views import add_subobjects_button
 
+_ = unicode
+
 
 class XSDMetaEntityView(EntityView):
     __regid__ = 'seda.xsdmeta'
@@ -101,29 +103,34 @@ class BusinessValueEntityView(EntityView):
     entity's class
     """
     __regid__ = 'seda.business'
+    no_value_msg = _('<no value specified>')
 
     def entity_call(self, entity):
-        if entity.value_attr:
-            value = entity.printable_value(entity.value_attr)
-        else:
-            value = None
+        value = self.entity_value(entity)
         if value:
             self.w(u'<span class="value">')
-            self.wvalue(entity, value)
+            self.w(value)
             self.w(u'</span>')
         else:
-            self.wdata(self._cw._('<no value specified>'))
+            self.wdata(self._cw._(self.no_value_msg))
 
-    def wvalue(self, entity, value):
-        self.w(value)
+    def entity_value(self, entity):
+        if entity.value_attr:
+            value = entity.printable_value(entity.value_attr)
+        else:
+            value = None
+        return value
 
 
 class BusinessValueLinkEntityView(BusinessValueEntityView):
     """Similar to seda.business but value is enclosed in a link if specified"""
     __regid__ = 'seda.business.link'
 
-    def wvalue(self, entity, value):
-        self.w(tags.a(value, href=entity.absolute_url()))
+    def entity_value(self, entity):
+        value = super(BusinessValueLinkEntityView, self).entity_value(entity)
+        if value:
+            value = tags.a(value, href=entity.absolute_url())
+        return value
 
 
 class LinkMetaEntityView(EntityView):