Enable directory uploads with FileInput

examples/reference/widgets/FileInput.ipynb

@@ -26,6 +26,7 @@
     "##### Core\n",
     "\n",
     "* **``accept``** (str):  A list of file input filters that restrict what files the user can pick from\n",
+    "* **``directory``** (str): If directories is upload instead of files\n",
     "* **``filename``** (str/list): The filename(s) of the uploaded file(s)\n",
     "* **``mime_type``** (str/list): The mime type(s) of the uploaded file(s)\n",
     "* **``multiple``** (boolean): Whether to allow uploading multiple files\n",
@@ -113,7 +114,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "To allow uploading multiple files we can also set `multiple=True`:"
+    "To allow uploading multiple files we can also set `multiple=True` or if you want to upload a whole directory `directory=True`:"
    ]
   },
   {
@@ -131,7 +132,18 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "When uploading one or more files the `filename`, `mime_type` and `value` parameters will now be lists. "
+    "When uploading one or more files the `filename`, `mime_type` and `value` parameters will now be lists. \n",
+    "\n",
+    "You can also clear the file input with the `.clear()` method."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "file_input.clear()"
    ]
   },
   {

panel/custom.py

@@ -7,7 +7,6 @@
 import textwrap
 
 from collections import defaultdict
-from functools import partial
 from typing import (
     TYPE_CHECKING, Any, Callable, ClassVar, Literal, Mapping, Optional,
 )
@@ -18,7 +17,6 @@
 
 from .config import config
 from .io.datamodel import construct_data_model
-from .io.notebook import push
 from .io.state import state
 from .models import (
     AnyWidgetComponent as _BkAnyWidgetComponent,
@@ -406,15 +404,4 @@ def send(self, msg: dict):
         ---------
         msg: dict
         """
-        for ref, (model, _) in self._models.items():
-            if ref not in state._views or ref in state._fake_roots:
-                continue
-            event = ESMEvent(model=model, data=msg)
-            viewable, root, doc, comm = state._views[ref]
-            if comm or state._unblocked(doc) or not doc.session_context:
-                doc.callbacks.send_event(event)
-                if comm and 'embedded' not in root.tags:
-                    push(doc, comm)
-            else:
-                cb = partial(doc.callbacks.send_event, event)
-                doc.add_next_tick_callback(cb)
+        self._send_event(ESMEvent, data=msg)

panel/reactive.py

@@ -59,7 +59,7 @@
 
     from bokeh.document import Document
     from bokeh.events import Event
-    from bokeh.model import Model
+    from bokeh.model import Model, ModelEvent
     from bokeh.models.sources import DataDict, Patches
     from pyviz_comms import Comm
 
@@ -874,6 +874,33 @@ def jslink(
         return Link(self, target, properties=links, code=code, args=args,
                     bidirectional=bidirectional)
 
+    def _send_event(self, Event: ModelEvent, **event_kwargs):
+        """
+        Send an event to the frontend
+
+        Arguments
+        ----------
+        Event: Bokeh.Event
+            The event to send to the frontend
+        event_kwargs: dict
+            Additional keyword arguments to pass to the event
+            This will create the following event:
+            Event(model=model, **event_kwargs)
+
+        """
+        for ref, (model, _) in self._models.items():
+            if ref not in state._views or ref in state._fake_roots:
+                continue
+            event = Event(model=model, **event_kwargs)
+            _viewable, root, doc, comm = state._views[ref]
+            if comm or state._unblocked(doc) or not doc.session_context:
+                doc.callbacks.send_event(event)
+                if comm and 'embedded' not in root.tags:
+                    push(doc, comm)
+            else:
+                cb = partial(doc.callbacks.send_event, event)
+                doc.add_next_tick_callback(cb)
+
 
 TData = Union['pd.DataFrame', 'DataDict']
 

panel/widgets/input.py

@@ -24,6 +24,7 @@
     PasswordInput as _BkPasswordInput, Spinner as _BkSpinner,
     Switch as _BkSwitch,
 )
+from bokeh.models.widgets.inputs import ClearInput
 from pyviz_comms import JupyterComm
 
 from ..config import config
@@ -203,6 +204,20 @@ class FileInput(Widget):
         An HTML string describing the function of this component
         rendered as a tooltip icon.""")
 
+    directory = param.Boolean(default=False, doc="""
+        Whether to allow selection of directories instead of files.
+        The filename will be relative paths to the uploaded directory.
+
+        .. note::
+            When a directory is uploaded it will give add a confirmation pop up.
+            The confirmation pop up cannot be disabled, as this is a security feature
+            in the browser.
+
+        .. note::
+            The `accept` parameter only works with file extension.
+            When using `accept` with `directory`, the number of files
+            reported will be the total amount of files, not the filtered.""")
+
     filename = param.ClassSelector(
         default=None, class_=(str, list), is_instance=True, doc="""
         Name of the uploaded file(s).""")
@@ -246,9 +261,13 @@ def _process_property_change(self, msg):
         msg = super()._process_property_change(msg)
         if 'value' in msg:
             if isinstance(msg['value'], str):
-                msg['value'] = b64decode(msg['value'])
+                msg['value'] = b64decode(msg['value']) if msg['value'] else None
             else:
                 msg['value'] = [b64decode(content) for content in msg['value']]
+        if 'filename' in msg and len(msg['filename']) == 0:
+            msg['filename'] = None
+        if 'mime_type' in msg and len(msg['mime_type']) == 0:
+            msg['mime_type'] = None
         return msg
 
     def save(self, filename):
@@ -285,6 +304,12 @@ def save(self, filename):
             else:
                 fn.write(val)
 
+    def clear(self):
+        """
+        Clear the file(s) in the FileInput widget
+        """
+        self._send_event(ClearInput)
+
 
 class FileDropper(Widget):
     """