StrippedTextLine field
======================

The StrippedTextLine field strips the leading and trailing text from the
set value.

    >>> from lp.services.fields import StrippedTextLine

    >>> non_required_field = StrippedTextLine(
    ...     __name__='field', title=u'Title',  required=False)

    >>> class Thing:
    ...     def __init__(self, field):
    ...         self.field = field
    >>> thing = Thing('abc')

    >>> non_required_field.set(thing, '   egf   ')
    >>> non_required_field.get(thing)
    'egf'

None is an accepted field value.

    >>> non_required_field.set(thing, None)
    >>> print non_required_field.get(thing)
    None


StrippedTextLine Widget
-----------------------

This custom widget is used to strip leading and trailing whitespaces.

  >>> from canonical.launchpad.webapp.servers import LaunchpadTestRequest
  >>> from lp.app.widgets.textwidgets import StrippedTextWidget
  >>> from lp.bugs.interfaces.bugtracker import IRemoteBug

We pass a string with leading and trailing whitespaces to the widget

  >>> field = IRemoteBug['remotebug']
  >>> request = LaunchpadTestRequest(
  ...     form={'field.remotebug':'    123456    '})
  >>> widget = StrippedTextWidget(field, request)

And check that the leading and trailing whitespaces were correctly stripped.

  >>> widget.getInputValue()
  u'123456'

If only whitespace is provided, the widget acts like no input was
provided.

  >>> non_required_field.missing_value is None
  True
  >>> request = LaunchpadTestRequest(form={'field.field':'    \n    '})
  >>> widget = StrippedTextWidget(non_required_field, request)
  >>> widget.getInputValue() is None
  True

  >>> required_field = StrippedTextLine(
  ...     __name__='field', title=u'Title',  required=True)
  >>> request = LaunchpadTestRequest(form={'field.field':'    \n    '})
  >>> widget = StrippedTextWidget(required_field, request)
  >>> widget.getInputValue()
  Traceback (most recent call last):
  ...
  WidgetInputError: ('field', u'Title', RequiredMissing())