4 XXX the view controller, other controllers

     4 Overview

     5 ++++++++

     6 

     7 Controllers are responsible for taking action upon user requests

     8 (loosely following the terminology of the MVC meta pattern).

     9 

    10 The following controllers are provided out-of-the box in CubicWeb. We

    11 list them by category.

    12 

    13 Browsing:

    14 

    15 * the View controller (web/views/basecontrollers.py) is associated

    16   with most browsing actions within a CubicWeb application: it always

    17   instantiates a `main template` and lets the ResultSet/Views dispatch

    18   system build up the whole content; it handles ObjectNotFound and

    19   NoSelectableObject errors that may bubble up to its entry point, in

    20   an end-user-friendly way (but other programming errors will slip

    21   through)

    22 

    23 * the JSon controller (web/views/basecontrollers.py) provides services

    24   for Ajax calls, typically using JSON as a serialization format for

    25   input, and sometimes using either JSON or XML for output; 

    26 

    27 * the Login/Logout controllers (web/views/basecontrollers.py) make

    28   effective user login or logout requests

    29 

    30 Edition:

    31 

    32 * the Edit controller (web/views/editcontroller.py) handles CRUD

    33   operations in response to a form being submitted; it works in close

    34   association with the Forms, to which it delegates some of the work

    35 

    36 * the Form validator controller (web/views/basecontrollers.py)

    37   provides form validation from Ajax context, using the Edit

    38   controller, to implement the classic form handling loop (user edits,

    39   hits 'submit/apply', validation occurs server-side by way of the

    40   Form validator controller, and the UI is decorated with failure

    41   information, either global or per-field , until it is valid)

    42 

    43 Other:

    44 

    45 * the SendMail controller (web/views/basecontrollers.py) is reponsible

    46   for outgoing email notifications

    47 

    48 * the MailBugReport controller (web/views/basecontrollers.py) allows

    49   to quickly have a `repotbug` feature in one's application

    50 

    51 Registration

    52 ++++++++++++

    53 

    54 All controllers (should) live in the 'controllers' namespace within

    55 the global registry.

    56 

    57 API

    58 +++

    59 

    60 Most API details should be resolved by source code inspection, as the

    61 various controllers have differing goals.

    62 

    63 `web/controller.py` contains the top-level abstract Controller class and

    64 its (NotImplemented) entry point `publish(rset=None)` method.

    65 

    66 A handful of helpers are also provided there:

    67 

    68 * process_rql builds a result set from an rql query typically issued

    69   from the browser (and available through _cw.form['rql'])

    70 

    71 * validate_cache will force cache validation handling with respect to

    72   the HTTP Cache directives (that were typically originally issued

    73   from a previous server -> client response); concrete Controller

    74   implementations dealing with HTTP (thus, for instance, not the

    75   SendMail controller) may very well call this in their publication

    76   process.

    77 

    78 

    79