Django issue - NoReverseMatch

I'm working on extending Horizon to include a custom app. In that app, I have a DataTable:

class WorkloadsTable(tables.DataTable):
    name = tables.Column("name", verbose_name=_("Name"))
    description = tables.Column("description", verbose_name=_("Description"))
    image = tables.Column("image", verbose_name=_("Image"))
    flavor = tables.Column("flavor", verbose_name=_("Flavor"))

    class Meta:
        name = "workloads_table"
        verbose_name = _("Workloads Table")
        table_actions = (CreateNewWorkload, DeleteWorkload)
        row_actions = (UpdateWorkload, DeleteWorkload)

which has a LinkAction:

class UpdateWorkload(tables.LinkAction):
    name = "update"
    verbose_name = _("Edit Workload")
    url = "horizon:mydashboard:workloads_panel:update"
    classes = ("ajax-modal",)
    icon = "pencil"

    def get_link_url(self, datum):
        base_url = super(UpdateWorkload, self).get_link_url(datum)
        workload_id = self.table.get_object_id(datum)
        reversed = urlresolvers.reverse(self.url, args=[workload_id])
        print reversed
        return urlresolvers.reverse(self.url, args=[workload_id])

This LinkAction points to a routce in my urls.py:

WORKLOADS = r'(?P<workload_id>[^/]+)/%s$'

urlpatterns = patterns('',
    url(r'^create/$', views.CreateView.as_view(), name='create'),
    url(WORKLOADS % 'update', views.UpdateView.as_view(), name='update'),
    url(r'^$', views.IndexView.as_view(), name='index'),
)

The issue is: When I enter the following url:

http://localhost:9000/mydashboard/workloads_panel/3/update

I get:  NoReverseMatch: Reverse for 'update' with arguments '()' and keyword arguments '{}' not found. 1 pattern(s) tried: [u'mydashboard/workloads_panel/(?P<workload_id>[^/]+)/update$']

Where am I going wrong?

Well now the answer is quite simple. There is no matching URL for this reverse call:

{% url 'horizon:mydashboard:workloads_panel:update' %}

The update named URL pattern requires a valid workload_id argument matching your regex [^/]+