Improve checkbox click handling support for grids

i.e. let custom use define click handlers

tailbone/grids/core.py

@@ -73,7 +73,8 @@ class Grid(object):
                  joiners={}, filterable=False, filters={}, use_byte_string_filters=False,
                  sortable=False, sorters={}, default_sortkey=None, default_sortdir='asc',
                  pageable=False, default_pagesize=20, default_page=1,
-                 checkboxes=False, checked=None, main_actions=[], more_actions=[], delete_speedbump=False,
+                 checkboxes=False, checked=None, check_handler=None, check_all_handler=None,
+                 main_actions=[], more_actions=[], delete_speedbump=False,
                  ajax_data_url=None,
                  **kwargs):
 
@@ -124,6 +125,9 @@ class Grid(object):
         self.checked = checked
         if self.checked is None:
             self.checked = lambda item: False
+        self.check_handler = check_handler
+        self.check_all_handler = check_all_handler
+
         self.main_actions = main_actions or []
         self.more_actions = more_actions or []
         self.delete_speedbump = delete_speedbump
@@ -1155,6 +1159,7 @@ class Grid(object):
         raw_data = self.make_visible_data()
         data = []
         status_map = {}
+        checked = []
 
         # iterate over data rows
         for i in range(len(raw_data)):
@@ -1197,6 +1202,11 @@ class Grid(object):
                 if status:
                     status_map[i] = status
 
+            # set checked flag if applicable
+            if self.checkboxes:
+                if self.checked(rowobj):
+                    checked.append(i)
+
             data.append(row)
 
         results = {
@@ -1204,6 +1214,13 @@ class Grid(object):
             'row_status_map': status_map,
         }
 
+        if self.checkboxes:
+            results['checked_rows'] = checked
+            # TODO: this seems a bit hacky, but is required for now to
+            # initialize things on the client side...
+            results['checked_rows_code'] = '[{}]'.format(
+                ', '.join(['TailboneGridCurrentData[{}]'.format(i) for i in checked]))
+
         if self.pageable and self.pager is not None:
             results['total_items'] = self.pager.item_count
             results['per_page'] = self.pager.items_per_page