18 """abstract action classes for CubicWeb web client"""

    18 """abstract action classes for CubicWeb web client

    19 

    20 Actions are typically displayed in an action box, but can also be used

    21 in other parts of the interface (the user menu, the footer, etc.). The

    22 'order', 'category' and 'title' class attributes control how the action will

    23 be displayed. The 'submenu' attribute is only used for actions in the

    24 action box.

    25 

    26 The most important method from a developper point of view in the

    27 :meth:'Action.url' method, which returns a URL on which the navigation

    28 should directed to perform the action.  There are two common ways of

    29 writing that method:

    30 

    31 * do nothing special and simply return a URL to the current rset with

    32   a special view (with `self._cw.build_url(...)` for instance)

    33 

    34 * define an inner function `callback_func(req, *args)` which will do

    35   the work and call it through `self._cw.user_callback(callback_func,

    36   args, msg)`: this method will return a URL which calls the inner

    37   function, and displays the message in the web interface when the

    38   callback has completed (and report any exception occuring in the

    39   callback too)

    40 

    41 Many examples of the first approach are available in :mod:`cubicweb.web.views.actions`.

    42 

    43 Here is an example of the second approach:

    44 

    45 .. sourcecode:: python

    46 

    47  from cubicweb.web import action

    48  class SomeAction(action.Action):

    49      __regid__ = 'mycube_some_action'

    50      title = _(some action)

    51      __select__ = action.Action.__select__ & is_instance('TargetEntity')

    52  

    53      def url(self):

    54          if self.cw_row is None:

    55              eids = [row[0] for row in self.cw_rset]

    56          else:

    57              eids = (self.cw_rset[self.cw_row][self.cw_col or 0],)

    58          def do_action(req, eids):

    59              for eid in eids:

    60                  entity = req.entity_from_eid(eid, 'TargetEntity')

    61                  entity.perform_action()

    62          msg = self._cw._('some_action performed')

    63          return self._cw.user_callback(do_action, (eids,), msg)

    64 

    65 """