Added default 'detect time from' time boundary in case there are no time intervals defined.

* If none of the following search parameters (dt_from, dt_to, st_from, st_to) is present in the URL, provide default dt_from (last 7 days) to reduce amount of processed events.
* User still has the ability to perform unbound search by submitting empty form.

(Redmine issue: #4609)

lib/hawat/blueprints/events/__init__.py

@@ -51,7 +51,7 @@ BLUEPRINT_NAME = 'events'
 def _get_search_form(request_args = None):
     choices = hawat.events.get_event_form_choices()
 
-    return SimpleEventSearchForm(
+    form = SimpleEventSearchForm(
         request_args,
         meta = {'csrf': False},
         choices_source_types    = choices['source_types'],
@@ -66,6 +66,12 @@ def _get_search_form(request_args = None):
         choices_inspection_errs = choices['inspection_errs'],
     )
 
+    # In case no time bounds were set adjust them manually.
+    if request_args and not ('dt_from' in request_args or 'dt_to' in request_args or 'st_from' in request_args or 'st_to' in request_args):
+        form.dt_from.process_data(hawat.forms.default_dt_with_delta())
+
+    return form
+
 
 class AbstractSearchView(PsycopgMixin, BaseSearchView):  # pylint: disable=locally-disabled,abstract-method
     """

lib/hawat/blueprints/timeline/__init__.py

@@ -50,7 +50,7 @@ BLUEPRINT_NAME = 'timeline'
 def _get_search_form(request_args = None):
     choices = hawat.events.get_event_form_choices()
 
-    return SimpleTimelineSearchForm(
+    form = SimpleTimelineSearchForm(
         request_args,
         meta = {'csrf': False},
         choices_source_types    = choices['source_types'],
@@ -65,6 +65,12 @@ def _get_search_form(request_args = None):
         choices_inspection_errs = choices['inspection_errs'],
     )
 
+    # In case no time bounds were set adjust them manually.
+    if request_args and not ('dt_from' in request_args or 'dt_to' in request_args or 'st_from' in request_args or 'st_to' in request_args):
+        form.dt_from.process_data(hawat.forms.default_dt_with_delta())
+
+    return form
+
 
 class AbstractSearchView(PsycopgMixin, BaseSearchView):  # pylint: disable=locally-disabled,abstract-method
     """