The Bug Watch Widget
====================

There's a custom widget used to link a bug watch to a bug task. It's a
simple RadioWidget with some modifications.

First we need to bind a BugWatch field to a bug task. Let's bind it to
the Debian task in bug 1

    >>> login('test@canonical.com')

    >>> from lp.bugs.interfaces.bug import IBugSet, IBugTask
    >>> bug_one = getUtility(IBugSet).get(1)
    >>> bugwatch_field = IBugTask['bugwatch']
    >>> debian_task = bug_one.bugtasks[2]
    >>> debian_task.bugtargetname
    u'mozilla-firefox (Debian)'

    >>> bugwatch_field = bugwatch_field.bind(debian_task)

Now we can create a widget using a test request:

    >>> from canonical.launchpad.webapp.servers import LaunchpadTestRequest
    >>> from lp.bugs.browser.widgets.bugtask import BugTaskBugWatchWidget
    >>> request = LaunchpadTestRequest()
    >>> bugwatch_widget = BugTaskBugWatchWidget(
    ...     bugwatch_field, bugwatch_field.vocabulary, request)

We can assume that RadioWidget works probably, so let's look at what we
changed; renderItems(). It renders all the items of the widget, with
the one representing the value passed to the method as selected. It
also renders an option for creating a new bug watch. Let's
define a helper function to make it easier to see what's going on.

    >>> from BeautifulSoup import BeautifulSoup
    >>> def print_item(item):
    ...     soup = BeautifulSoup(item)
    ...     input_td, label_td = soup('td')
    ...     if input_td.input.get('checked'):
    ...         selected = 'SELECTED'
    ...     else:
    ...         selected = 'NOT SELECTED'
    ...     print "%s: %s" % (selected, label_td.label)

Now if we pass None to renderItems(), the first radio button will be
selected.

    >>> for item in bugwatch_widget.renderItems(None):
    ...     print_item(item)
    SELECTED: <label...> None, the status of the bug is updated manually...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#123543</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#2000</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#42</a>...
    NOT SELECTED: <label...> Debian Bug tracker <a...>#304014</a>...
    NOT SELECTED: <label...>
    <div>URL: <input...></div>
    </label>

If we pass a bug watch to renderItems(), the corresponding radio button
will be selected.

    >>> mozilla_bugwatch = bug_one.watches[0]
    >>> mozilla_bugwatch.title
    u'The Mozilla.org Bug Tracker #123543'

    >>> for item in bugwatch_widget.renderItems(mozilla_bugwatch):
    ...     print_item(item)
    NOT SELECTED: <label...> None, the status of the bug is updated manuall...
    SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#123543</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#2000</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#42</a>...
    NOT SELECTED: <label...> Debian Bug tracker <a...>#304014</a>...
    NOT SELECTED: <label...>
    <div>URL: <input...></div>
    </label>

If we pass _new_bugwatch_value to renderItems(), the corresponding radio
button will be selected.

    >>> new_bugwatch_value = bugwatch_widget._new_bugwatch_value
    >>> for item in bugwatch_widget.renderItems(new_bugwatch_value):
    ...     print_item(item)
    NOT SELECTED: <label...> None, the status of the bug is updated manuall...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#123543</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#2000</a>...
    NOT SELECTED: <label...> The Mozilla.org Bug Tracker <a...>#42</a>...
    NOT SELECTED: <label...> Debian Bug tracker <a...>#304014</a>...
    SELECTED: <label...>
    <div>URL: <input...></div>
    </label>

Now let's use the widget to actually create a new bug watch. First
let's take a look at which bug watches are currently associated with
the bug.

    >>> for bug_watch in bug_one.watches:
    ...     print "%s: #%s" % (
    ...         bug_watch.bugtracker.title, bug_watch.remotebug)
    The Mozilla.org Bug Tracker: #123543
    The Mozilla.org Bug Tracker: #2000
    The Mozilla.org Bug Tracker: #42
    Debian Bug tracker: #304014

Now let's create a new bug watch, pointing at bug #84 in the Gnome tracker.

    >>> NEW = BugTaskBugWatchWidget._new_bugwatch_value
    >>> request = LaunchpadTestRequest(form={
    ...     'field.bugwatch': NEW, 'field.url': (
    ...         u'http://bugzilla.gnome.org/bugs/show_bug.cgi?id=84')})
    >>> bugwatch_widget = BugTaskBugWatchWidget(
    ...     bugwatch_field, bugwatch_field.vocabulary, request)
    >>> bugwatch = bugwatch_widget.getInputValue()
    >>> bugwatch.bugtracker.title
    u'GnomeGBug GTracker'

    >>> bugwatch.remotebug
    u'84'

    >>> for bug_watch in bug_one.watches:
    ...     print "%s: #%s" % (
    ...         bug_watch.bugtracker.title, bug_watch.remotebug)
    The Mozilla.org Bug Tracker: #123543
    The Mozilla.org Bug Tracker: #2000
    The Mozilla.org Bug Tracker: #42
    GnomeGBug GTracker: #84
    Debian Bug tracker: #304014

If we try to create a bug watch that already exists, the existing bug
watch is being returned, and no new bug watch is created.

    >>> request = LaunchpadTestRequest(form={
    ...     'field.bugwatch': NEW, 'field.url': (
    ...         u'http://bugzilla.gnome.org/bugs/show_bug.cgi?id=84')})
    >>> bugwatch_widget = BugTaskBugWatchWidget(
    ...     bugwatch_field, bugwatch_field.vocabulary, request)
    >>> bugwatch = bugwatch_widget.getInputValue()
    >>> bugwatch.bugtracker.title
    u'GnomeGBug GTracker'
    >>> bugwatch.remotebug
    u'84'

    >>> for bug_watch in bug_one.watches:
    ...     print "%s: #%s" % (
    ...         bug_watch.bugtracker.title, bug_watch.remotebug)
    The Mozilla.org Bug Tracker: #123543
    The Mozilla.org Bug Tracker: #2000
    The Mozilla.org Bug Tracker: #42
    GnomeGBug GTracker: #84
    Debian Bug tracker: #304014


If we enter a URL that doesn't match an existing bug tracker,
a WidgetInputError is being raised.

    >>> request = LaunchpadTestRequest(form={
    ...     'field.bugwatch': NEW,
    ...     'field.url': 'http://not.a.bug.tracker/'})
    >>> bugwatch_widget = BugTaskBugWatchWidget(
    ...     bugwatch_field, bugwatch_field.vocabulary, request)

    >>> bugwatch = bugwatch_widget.getInputValue()
    Traceback (most recent call last):
    ...
    WidgetInputError:...

In order to make the widget not raise on error on 'NEW', which is not
part of the vocabulary, we've overridden _toFieldValue(), so that when
it's passed 'NEW', it will return the newly created bug watch.

    >>> request = LaunchpadTestRequest(form={
    ...     'field.bugwatch': NEW, 'field.url': (
    ...         'http://bugzilla.gnome.org/bugs/show_bug.cgi?id=177')})
    >>> bugwatch_widget = BugTaskBugWatchWidget(
    ...     bugwatch_field, bugwatch_field.vocabulary, request)
    >>> bugwatch = bugwatch_widget._toFieldValue(NEW)