capybara/virtualenv/lib/python2.7/site-packages/flask/helpers.py
def flash(message, category='message'):
    """Flashes a message to the next request.  In order to remove the
    flashed message from the session and to display it to the user,
    the template has to call :func:`get_flashed_messages`.

    .. versionchanged:: 0.3
       `category` parameter added.

    :param message: the message to be flashed.
    :param category: the category for the message.  The following values
                     are recommended: ``'message'`` for any kind of message,
                     ``'error'`` for errors, ``'info'`` for information
                     messages and ``'warning'`` for warnings.  However any
                     kind of string can be used as category.
    """
    # Original implementation:
    #
    #     session.setdefault('_flashes', []).append((category, message))
    #
    # This assumed that changes made to mutable structures in the session are
    # are always in sync with the sess on object, which is not true for session
    # implementations that use external storage for keeping their keys/values.
    flashes = session.get('_flashes', [])
    flashes.append((category, message))
    session['_flashes'] = flashes
    message_flashed.send(current_app._get_current_object(),
                         message=message, category=category)
def flash(message, category='message'):
    """Flashes a message to the next request.  In order to remove the
    flashed message from the session and to display it to the user,
    the template has to call :func:`get_flashed_messages`.

    .. versionchanged:: 0.3
       `category` parameter added.

    :param message: the message to be flashed.
    :param category: the category for the message.  The following values
                     are recommended: ``'message'`` for any kind of message,
                     ``'error'`` for errors, ``'info'`` for information
                     messages and ``'warning'`` for warnings.  However any
                     kind of string can be used as category.
    """
    # Original implementation:
    #
    #     session.setdefault('_flashes', []).append((category, message))
    #
    # This assumed that changes made to mutable structures in the session are
    # are always in sync with the sess on object, which is not true for session
    # implementations that use external storage for keeping their keys/values.
    flashes = session.get('_flashes', [])
    flashes.append((category, message))
    session['_flashes'] = flashes
    message_flashed.send(current_app._get_current_object(),
                         message=message, category=category)
Flashes a message to the next request.  In order to remove the
    flashed message from the session and to display it to the user,
    the template has to call :func:`get_flashed_messages`.

    .. versionchanged:: 0.3
       `category` parameter added.

    :param message: the message to be flashed.
    :param category: the category for the message.  The following values
                     are recommended: ``'message'`` for any kind of message,
                     ``'error'`` for errors, ``'info'`` for information
                     messages and ``'warning'`` for warnings.  However any
                     kind of string can be used as category.