Add Tabulator.on_click callback (#3245)

examples/reference/widgets/Tabulator.ipynb

@@ -82,6 +82,11 @@
     "* **``current_view``** (``DataFrame``): The current view of the table that is displayed, i.e. after sorting and filtering are applied\n",
     "* **``selected_dataframe``** (``DataFrame``): A DataFrame reflecting the currently selected rows.\n",
     "\n",
+    "##### Callbacks\n",
+    "\n",
+    "* **``on_click``**: Allows registering callbacks which are given `CellClickEvent` objects containing the `column`, `row` and `value` of the clicked cell.\n",
+    "* **``on_edit``**: Allows registering callbacks which are given `TableEditEvent` objects containing the `column`, `row`, `value` and `old` value.\n",
+    "\n",
     "___"
    ]
   },
@@ -559,6 +564,27 @@
     "pn.widgets.Tabulator(sel_df, selectable_rows=lambda df: list(range(0, len(df), 2)))"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "To trigger events based on an exact cell that was clicked you may also register an `on_click` callback which is called whenever a cell is clicked."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def click(event):\n",
+    "    print(f'Clicked cell in {event.column} column, row {event.row}')\n",
+    "\n",
+    "select_table.on_click(click) \n",
+    "# Optionally we can also limit the callback to a specific column\n",
+    "# select_table.on_click(click, column='A') "
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -1064,7 +1090,7 @@
    "source": [
     "## Buttons\n",
     "\n",
-    "If you want to trigger custom actions by clicking on a table cell you may declare a set of `buttons` that are rendered in columns after all the data columns. To respond to button clicks you can register a callback using the `on_button_click` method:"
+    "If you want to trigger custom actions by clicking on a table cell you may declare a set of `buttons` that are rendered in columns after all the data columns. To respond to button clicks you can register a callback using the general `on_click` method:"
    ]
   },
   {

panel/models/tabulator.py

@@ -42,9 +42,10 @@ class CellClickEvent(ModelEvent):
 
     event_name = 'cell-click'
 
-    def __init__(self, model, column, row):
+    def __init__(self, model, column, row, value=None):
         self.column = column
         self.row = row
+        self.value = value
         super().__init__(model=model)
 
 

panel/models/tabulator.ts

@@ -735,6 +735,10 @@ export class DataTabulatorView extends PanelHTMLBoxView {
           tab_column.headerFilterParams = tab_column.editorParams
         }
       }
+      tab_column.cellClick = (_: any, cell: any) => {
+	const index = cell._cell.row.data._index;
+	this.model.trigger_event(new CellClickEvent(column.field, index))
+      }
       if (config_columns == null)
         columns.push(tab_column)
     }

panel/widgets/tables.py

@@ -958,16 +958,14 @@ def _cleanup(self, root):
         super()._cleanup(root)
 
     def _process_event(self, event):
+        if self.pagination == 'remote':
+            nrows = self.page_size
+            event.row = (self.page-1)*nrows
+        if event.column not in self.buttons:
+            event.value = self._processed[event.column].iloc[event.row]
         if event.event_name == 'table-edit':
-            if self.pagination:
-                nrows = self.page_size
-                offset = (self.page-1)*nrows
-            else:
-                offset = 0
-            row = offset + event.row
             if self._old is not None:
-                event.old = self._old[event.column].iloc[row]
-            event.value = self._processed[event.column].iloc[row]
+                event.old = self._old[event.column].iloc[event.row]
             for cb in self._on_edit_callbacks:
                 cb(event)
         else:
@@ -1543,6 +1541,24 @@ def on_edit(self, callback):
         """
         self._on_edit_callbacks.append(callback)
 
+    def on_click(self, callback, column=None):
+        """
+        Register a callback to be executed when any cell is clicked.
+        The callback is given a CellClickEvent declaring the column
+        and row of the cell that was clicked.
+
+        Arguments
+        ---------
+        callback: (callable)
+            The callback to run on edit events.
+        column: (str)
+            Optional argument restricting the callback to a specific
+            column.
+        """
+        if column not in self._on_click_callbacks:
+            self._on_click_callbacks[column] = []
+        self._on_click_callbacks[column].append(callback)
+
     def on_button_click(self, callback, column=None):
         """
         Register a callback to be executed when a cell corresponding
@@ -1558,6 +1574,11 @@ def on_button_click(self, callback, column=None):
             Optional argument restricting the callback to a specific
             column.
         """
+        self.param.warning(
+            "DeprecationWarning: The on_button_click callbacks will be "
+            "removed before the 0.13.0 release, please use the generic "
+            "on_click callback instead."
+        )
         if column not in self._on_click_callbacks:
             self._on_click_callbacks[column] = []
         self._on_click_callbacks[column].append(callback)