The “Click and Edit” (also reledit) View

The principal way to update data through the Web UI is through the modify action on entities, which brings a full form. This is described in the HTML form construction chapter.

There is however another way to perform piecewise edition of entities and relations, using a specific reledit (for relation edition) view from the cubicweb.web.views.reledit module.

This is typically applied from the default Primary View (see The Primary View) on the attributes and relation section. It makes small editions more convenient.

Of course, this can be used customely in any other view. Here come some explanation about its capabilities and instructions on the way to use it.

Using reledit

Let’s start again with a simple example:

class Company(EntityType):
     name = String(required=True, unique=True)
     boss = SubjectRelation('Person', cardinality='1*')
     status = SubjectRelation('File', cardinality='?*', composite='subject')

In some view code we might want to show these attributes/relations and allow the user to edit each of them in turn without having to leave the current page. We would write code as below:

company.view('reledit', rtype='name', default_value='<name>') # editable name attribute
company.view('reledit', rtype='boss') # editable boss relation
company.view('reledit', rtype='status') # editable attribute-like relation

If one wanted to edit the company from a boss’s point of view, one would have to indicate the proper relation’s role. By default the role is subject.

person.view('reledit', rtype='boss', role='object')

Each of these will provide with a different editing widget. The name attribute will obviously get a text input field. The boss relation will be edited through a selection box, allowing to pick another Person as boss. The status relation, given that it defines Company as a composite entity with one file inside, will provide additional actions

  • to add a File when there is one
  • to delete the File (if the cardinality allows it)

Moreover, editing the relation or using the add action leads to an embedded edition/creation form allowing edition of the target entity (which is File in our example) instead of merely allowing to choose amongst existing files.

The reledit_ctrl rtag

The behaviour of reledited attributes/relations can be finely controlled using the reledit_ctrl rtag, defined in cubicweb.web.views.uicfg.

This rtag provides four control variables:

  • default_value: alternative default value
    The default value is what is shown when there is no value.
  • reload: boolean, eid (to reload to) or function taking subject
    and returning bool/eid This is useful when editing a relation (or attribute) that impacts the url or another parts of the current displayed page. Defaults to false.
  • rvid: alternative view id (as str) for relation or composite
    edition Default is ‘incontext’ or ‘csv’ depending on the cardinality. They can also be statically changed by subclassing ClickAndEditFormView and redefining _one_rvid (resp. _many_rvid).
  • edit_target: ‘rtype’ (to edit the relation) or ‘related’ (to
    edit the related entity) This controls whether to edit the relation or the target entity of the relation. Currently only one-to-one relations support target entity edition. By default, the ‘related’ option is taken whenever the relation is composite and one-to-one.

Let’s see how to use these controls.

from logilab.mtconverter import xml_escape
from cubicweb.web.views.uicfg import reledit_ctrl
reledit_ctrl.tag_attribute(('Company', 'name'),
                           {'reload': lambda x:x.eid,
                            'default_value': xml_escape(u'<logilab tastes better>')})
reledit_ctrl.tag_object_of(('*', 'boss', 'Person'), {'edit_target': 'related'})

The default_value needs to be an xml escaped unicode string.

The edit_target tag on the boss relation being set to related will ensure edition of the Person entity instead (using a standard automatic form) of the association of Company and Person.

Finally, the reload key accepts either a boolean, an eid or a unicode string representing a url. If an eid is provided, it will be internally transformed into a url. The eid/url case helps when one needs to reload and the current url is inappropriate. A common case is edition of a key attribute, which is part of the current url. If one user changed the Company’s name from lozilab to logilab, reloading on http://myapp/company/lozilab would fail. Providing the entity’s eid, then, forces to reload on something like http://myapp/company/42, which always work.

Disable reledit

By default, reledit is available on attributes and relations displayed in the ‘attribute’ section of the default primary view. If you want to disable it for some attribute or relation, you have use uicfg:

from cubicweb.web.views.uicfg import primaryview_display_ctrl as _pvdc
_pvdc.tag_attribute(('Company', 'name'), {'vid': 'incontext'})

To deactivate it everywhere it’s used automatically, you may use the code snippet below somewhere in your cube’s views:

from cubicweb.web.views import reledit

class DeactivatedAutoClickAndEditFormView(reledit.AutoClickAndEditFormView):
    def _should_edit_attribute(self, rschema):
        return False

    def _should_edit_attribute(self, rschema, role):
        return False

def registration_callback(vreg):
    vreg.register_and_replace(DeactivatedAutoClickAndEditFormView,
                              reledit.AutoClickAndEditFormView)