Add support for showing the current user's events

Add support kwargs to the SourceColumn class. Improve the
event widgets, views and tests.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/events/html_widgets.py

@@ -0,0 +1,82 @@
+from __future__ import unicode_literals
+
+from django.apps import apps
+from django.template import Context, Template
+from django.urls import reverse
+from django.utils.encoding import force_text
+from django.utils.safestring import mark_safe
+from django.utils.translation import ugettext_lazy as _
+
+from .classes import EventType
+
+
+class ObjectLinkWidget(object):
+    template_string = '<a href="{{ url }}">{{ object_type }}{{ label }}</a>'
+
+    def __init__(self):
+        self.template = Template(template_string=self.template_string)
+
+    def render(self, name=None, value=None):
+        label = ''
+        object_type = ''
+        url = None
+
+        if value:
+            label = force_text(value)
+            object_type = '{}: '.format(value._meta.verbose_name)
+            try:
+                url = value.get_absolute_url()
+            except AttributeError:
+                url = None
+
+        return self.template.render(
+            context=Context(
+                {'label': label, 'object_type': object_type, 'url': url or '#'}
+            )
+        )
+
+
+def widget_event_actor_link(context, attribute=None):
+    entry = context['object']
+
+    ContentType = apps.get_model(
+        app_label='contenttypes', model_name='ContentType'
+    )
+
+    if attribute:
+        entry = getattr(entry, attribute)
+
+    if entry.actor == entry.target:
+        label = _('System')
+        url = None
+    else:
+        label = entry.actor
+        content_type = ContentType.objects.get_for_model(model=entry.actor)
+
+        url = reverse(
+            viewname='events:events_for_object', kwargs={
+                'app_label': content_type.app_label, 'model': content_type.model,
+                'object_id': entry.actor.pk
+            }
+        )
+
+    if url:
+        return Template(
+            template_string='<a href="{{ url }}">{{ label }}</a>'
+        ).render(context=Context({'label': entry.actor, 'url': url}))
+    else:
+        return label
+
+
+def widget_event_type_link(context, attribute=None):
+    entry = context['object']
+
+    if attribute:
+        entry = getattr(entry, attribute)
+
+    return mark_safe(
+        '<a href="%(url)s">%(label)s</a>' % {
+            'url': reverse(viewname='events:events_by_verb', kwargs={'verb': entry.verb}),
+            'label': EventType.get(name=entry.verb)
+        }
+    )