Embed fixes and tests

panel/io/embed.py

@@ -73,20 +73,25 @@ def param_to_jslink(model, widget):
     Converts Param pane widget links into JS links if possible.
     """
     from ..viewable import Reactive
-    from ..widgets import LiteralInput
+    from ..widgets import Widget, LiteralInput
 
     param_pane = widget._param_pane
     pobj = param_pane.object
     pname = [k for k, v in param_pane._widgets.items() if v is widget]
     watchers = [w for w in get_watchers(widget) if w not in widget._callbacks
                 and w not in param_pane._callbacks]
 
+    tgt_links = [Watcher(*l[:-3]) for l in pobj._links]
+    tgt_watchers = [w for w in get_watchers(pobj) if w not in pobj._callbacks
+                    and w not in tgt_links and w not in param_pane._callbacks]
+
     for widget in param_pane._widgets.values():
         if isinstance(widget, LiteralInput):
             widget.serializer = 'json'
 
     if (not pname or not isinstance(pobj, Reactive) or watchers or
-        pname[0] not in pobj._linkable_params):
+        pname[0] not in pobj._linkable_params or
+        (not isinstance(pobj, Widget) and tgt_watchers)):
         return
     return link_to_jslink(model, widget, 'value', pobj, pname[0])
 
@@ -97,13 +102,10 @@ def link_to_jslink(model, source, src_spec, target, tgt_spec):
     declared forward and reverse JS transforms on the source and target.
     """
     ref = model.ref['id']
-    tgt_links = [Watcher(*l[:-3]) for l in target._links]
-    tgt_watchers = [w for w in get_watchers(target) if w not in target._callbacks
-                    and w not in tgt_links]
 
     if ((source._source_transforms.get(src_spec, False) is None) or
         (target._target_transforms.get(tgt_spec, False) is None) or
-        ref not in source._models or ref not in target._models or tgt_watchers):
+        ref not in source._models or ref not in target._models):
         # We cannot jslink if either source or target declare
         # that they apply Python transforms
         return
@@ -116,18 +118,24 @@ def link_to_jslink(model, source, src_spec, target, tgt_spec):
 
 
 def links_to_jslinks(model, widget):
+    from ..widgets import Widget
+
     src_links = [Watcher(*l[:-3]) for l in widget._links]
     if any(w not in widget._callbacks and w not in src_links for w in get_watchers(widget)):
         return
 
     links = []
     for link in widget._links:
-        if link.transformed:
+        target = link.target
+        tgt_watchers = [w for w in get_watchers(target) if w not in target._callbacks]
+        if link.transformed or (tgt_watchers and not isinstance(target, Widget)):
             return
+
         mappings = []
         for pname, tgt_spec in link.links.items():
             if Watcher(*link[:-3]) in widget._param_watchers[pname]['value']:
                 mappings.append((pname, tgt_spec))
+
         if mappings:
             links.append((link, mappings))
     jslinks = []
@@ -199,15 +207,12 @@ def embed_state(panel, model, doc, max_states=1000, max_opts=3,
             # Replace parameter links with JS links
             link = param_to_jslink(model, widget)
             if link is not None:
+                pobj = widget._param_pane.object
+                if isinstance(pobj, Widget):
+                    if not any(w not in pobj._callbacks and w not in widget._param_pane._callbacks
+                               for w in get_watchers(pobj)):
+                        ignore.append(pobj)
                 continue # Skip if we were able to attach JS link
-            pobj = widget._param_pane.object
-            if isinstance(pobj, Widget):
-                watchers = [w for w in get_watchers(pobj) if widget not in pobj._callbacks
-                            and widget not in widget._param_pane._callbacks]
-                if not watchers:
-                    # If underlying parameterized object is a widget
-                    # which has no other links ensure it is skipped later
-                    ignore.append(pobj) 
 
         if widget._links:
             jslinks = links_to_jslinks(model, widget)
@@ -242,7 +247,7 @@ def embed_state(panel, model, doc, max_states=1000, max_opts=3,
     add_to_doc(model, doc, True)
     doc._held_events = []
 
-    if not values:
+    if not widget_data:
         return
 
     restore = [w.value for w, _, _, _ in values]

panel/tests/test_io.py

@@ -13,11 +13,55 @@
 from panel.config import config
 from panel.io.embed import embed_state
 from panel.pane import Str
+from panel.param import Param
 from panel.widgets import Select, FloatSlider, Checkbox
 
 from .util import jb_available
 
 
+def test_embed_param_jslink(document, comm):
+    select = Select(options=['A', 'B', 'C'])
+    params = Param(select, parameters=['disabled']).layout
+    panel = Row(select, params)
+    with config.set(embed=True):
+        model = panel.get_root(document, comm)
+    embed_state(panel, model, document)
+    assert len(document.roots) == 1
+
+    ref = model.ref['id']
+    cbs = list(model.select({'type': CustomJS}))
+    assert len(cbs) == 2
+    cb1, cb2 = cbs
+    cb1, cb2 = (cb1, cb2) if select._models[ref][0] is cb1.args['target'] else (cb2, cb1)
+    assert cb1.code == """
+    value = source['active'];
+    value = value.indexOf(0) >= 0;
+    value = value;
+    try {
+      property = target.properties['disabled'];
+      if (property !== undefined) { property.validate(value); }
+    } catch(err) {
+      console.log('WARNING: Could not set disabled on target, raised error: ' + err);
+      return;
+    }
+    target['disabled'] = value;
+    """
+
+    assert cb2.code == """
+    value = source['disabled'];
+    value = value;
+    value = value ? [0] : [];
+    try {
+      property = target.properties['active'];
+      if (property !== undefined) { property.validate(value); }
+    } catch(err) {
+      console.log('WARNING: Could not set active on target, raised error: ' + err);
+      return;
+    }
+    target['active'] = value;
+    """
+
+
 def test_embed_select_str_link(document, comm):
     select = Select(options=['A', 'B', 'C'])
     string = Str()
@@ -42,6 +86,36 @@ def link(target, event):
         assert event['new'] == '<pre>%s</pre>' % k
 
 
+def test_embed_select_str_link_two_steps(document, comm):
+    select = Select(options=['A', 'B', 'C'])
+    string1 = Str()
+    select.link(string1, value='object')
+    string2 = Str()
+    string1.link(string2, object='object')
+    panel = Row(select, string1, string2)
+    with config.set(embed=True):
+        model = panel.get_root(document, comm)
+    embed_state(panel, model, document)
+    _, state = document.roots
+    assert set(state.state) == {'A', 'B', 'C'}
+    for k, v in state.state.items():
+        content = json.loads(v['content'])
+        assert 'events' in content
+        events = content['events']
+        assert len(events) == 2
+        event = events[0]
+        assert event['kind'] == 'ModelChanged'
+        assert event['attr'] == 'text'
+        assert event['model'] == model.children[1].ref
+        assert event['new'] == '<pre>%s</pre>' % k
+
+        event = events[1]
+        assert event['kind'] == 'ModelChanged'
+        assert event['attr'] == 'text'
+        assert event['model'] == model.children[2].ref
+        assert event['new'] == '<pre>%s</pre>' % k
+
+
 def test_embed_select_str_link_with_secondary_watch(document, comm):
     select = Select(options=['A', 'B', 'C'])
     string = Str()

panel/tests/test_reactive.py

@@ -3,7 +3,9 @@
 import param
 
 from bokeh.models import Div
-from panel.viewable import Reactive
+from panel.layout import Tabs, WidgetBox
+from panel.viewable import Layoutable, Reactive
+from panel.widgets import Checkbox, StaticText, TextInput
 
 
 def test_link():
@@ -76,3 +78,54 @@ class ReactiveLink(Reactive):
     assert isinstance(cb, partial)
     assert cb.args == (document, div.ref['id'])
     assert cb.func == obj._server_change
+
+
+def test_text_input_controls():
+    text_input = TextInput()
+
+    controls = text_input.controls()
+
+    assert isinstance(controls, Tabs)
+    assert len(controls) == 2
+    wb1, wb2 = controls
+    assert isinstance(wb1, WidgetBox)
+    assert len(wb1) == 4
+    name, disabled, value, placeholder = wb1
+
+    assert isinstance(name, StaticText)
+    assert isinstance(disabled, Checkbox)
+    assert isinstance(value, TextInput)
+    assert isinstance(placeholder, TextInput)
+
+    text_input.disabled = True
+    assert disabled.value
+
+    text_input.placeholder = "Test placeholder..."
+    assert placeholder.value == "Test placeholder..."
+
+    text_input.value = "New value"
+    assert value.value == "New value"
+
+    assert isinstance(wb2, WidgetBox)
+    assert len(wb2) == len(list(Layoutable.param)) + 1
+
+
+
+def test_text_input_controls_explicit():
+    text_input = TextInput()
+
+    controls = text_input.controls(['placeholder', 'disabled'])
+
+    assert isinstance(controls, WidgetBox)
+    assert len(controls) == 3
+    name, disabled, placeholder = controls
+
+    assert isinstance(name, StaticText)
+    assert isinstance(disabled, Checkbox)
+    assert isinstance(placeholder, TextInput)
+
+    text_input.disabled = True
+    assert disabled.value
+
+    text_input.placeholder = "Test placeholder..."
+    assert placeholder.value == "Test placeholder..."

panel/viewable.py

@@ -886,18 +886,17 @@ def controls(self, parameters=[], jslink=True):
         from .widgets import LiteralInput
 
         if parameters:
-            return Param(self.param, parameters=parameters, default_layout=WidgetBox,
-                         name='Controls').layout
-
-        if jslink:
+            linkable = parameters
+        elif jslink:
             linkable = self._linkable_params
         else:
             linkable = list(self.param)
+
         params = [p for p in linkable if p not in Layoutable.param]
         controls = Param(self.param, parameters=params, default_layout=WidgetBox,
                          name='Controls')
         layout_params = [p for p in linkable if p in Layoutable.param]
-        if 'name' not in layout_params and self._rename.get('name', False) is not None:
+        if 'name' not in layout_params and self._rename.get('name', False) is not None and not parameters:
             layout_params.insert(0, 'name')
         style = Param(self.param, parameters=layout_params, default_layout=WidgetBox,
                       name='Layout')
@@ -912,8 +911,11 @@ def controls(self, parameters=[], jslink=True):
                 widget.jslink(self, value=p, bidirectional=True)
                 if isinstance(widget, LiteralInput):
                     widget.serializer = 'json'
-        if params:
+
+        if params and layout_params:
             return Tabs(controls.layout[0], style.layout[0])
+        elif params:
+            return controls.layout[0]
         return style.layout[0]
 
     def link(self, target, callbacks=None, **links):