Page objects
============

Model each website page as a :class:`wabot.Page` subclass with a
class-level ``elements`` map; drive them through one
:class:`wabot.Browser`.

.. code-block:: python

   class Inventory(wabot.Page):
       elements = {
           "search":  ("el",       ("id", "search-box")),
           "region":  ("select",   ("id", "region")),
           "instock": ("checkbox", ("id", "in-stock-only")),
           "rows":    ("els",      ("css selector", "table#items tr")),
       }

Element types
-------------

============  =======================================  =====================
Type key      Returned wrapper                         Main methods
============  =======================================  =====================
``el``        :class:`wabot.TextField`                 get_value / set_value
``select``    :class:`wabot.SelectField`               set_value(value|text)
``checkbox``  :class:`wabot.CheckField`                 get/set_checked
``els``       list of raw WebElements                  (selenium API)
a class       your :class:`wabot.PageObject` subclass  whatever you define
============  =======================================  =====================

Missing elements come back as a falsy :class:`wabot.NullField`, so guard
with ``if el:`` instead of try/except.

Inheritance
-----------

Element lookup walks the MRO: subclasses inherit the parent map and can
override individual keys — useful for sites with shared page chrome.

Verification and delegation
---------------------------

``Browser.set_page(PageClass)`` refuses the switch if the page's
``verify()`` returns False. Once set, unknown attributes on the Browser
delegate to the current page: ``bot.log_in(...)`` calls
``bot.page.log_in(...)``. After any trapped failure the Browser refuses
further actions until ``bot.reset()``.