Support serialization of binary types on ReactiveHTML (#2400)

panel/models/reactive_html.py

@@ -7,7 +7,7 @@
 import bokeh.core.properties as bp
 import param as pm
 
-from bokeh.models import HTMLBox, LayoutDOM
+from bokeh.models import ColumnDataSource, HTMLBox, LayoutDOM
 from bokeh.model import DataModel
 from bokeh.events import ModelEvent
 
@@ -141,10 +141,15 @@ def find_attrs(html):
 
 
 PARAM_MAPPING = {
+    pm.Array: lambda p, kwargs: bp.Array(**kwargs),
     pm.Boolean: lambda p, kwargs: bp.Bool(**kwargs),
     pm.CalendarDate: lambda p, kwargs: bp.Date(**kwargs),
     pm.CalendarDateRange: lambda p, kwargs: bp.Tuple(bp.Date, bp.Date, **kwargs),
     pm.Color: lambda p, kwargs: bp.Color(**kwargs),
+    pm.DataFrame: lambda p, kwargs: (
+        bp.ColumnData(bp.Any, bp.Seq(bp.Any), **kwargs),
+        [(bp.PandasDataFrame, lambda x: ColumnDataSource._data_from_df(x))]
+    ),
     pm.DateRange: lambda p, kwargs: bp.Tuple(bp.Datetime, bp.Datetime, **kwargs),
     pm.Date: lambda p, kwargs: bp.Datetime(**kwargs),
     pm.Dict: lambda p, kwargs: bp.Dict(bp.String, bp.Any, **kwargs),
@@ -175,11 +180,15 @@ def construct_data_model(parameterized, name=None, ignore=[], types={}):
         nullable = getattr(p, 'allow_None', False)
         kwargs = {'default': p.default, 'help': p.doc}
         if prop is None:
-            properties[pname] = bp.Any(**kwargs)
-        elif nullable:
-            properties[pname] = bp.Nullable(prop(p, {}), **kwargs)
+            bk_prop, accepts = bp.Any(**kwargs), []
         else:
-            properties[pname] = prop(p, kwargs)
+            bkp = prop(p, {} if nullable else kwargs)
+            bk_prop, accepts = bkp if isinstance(bkp, tuple) else (bkp, [])
+            if nullable:
+                bk_prop = bp.Nullable(bk_prop, **kwargs)
+        for bkp, convert in accepts:
+            bk_prop = bk_prop.accepts(bkp, convert)
+        properties[pname] = bk_prop
     name = name or parameterized.name
     return type(name, (DataModel,), properties)