Improve Markdown handling

examples/reference/panes/Markdown.ipynb

@@ -21,6 +21,8 @@
     "\n",
     "For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).\n",
     "\n",
+    "* **``dedent``** (bool): Whether to dedent common whitespace across all lines.\n",
+    "* **``extensions``** (list): A list of [Python-Markdown extensions](https://python-markdown.github.io/extensions/) to use.\n",
     "* **``object``** (str or object): A string containing Markdown, or an object with a ``_repr_markdown_`` method\n",
     "* **``style``** (dict): Dictionary specifying CSS styles\n",
     "\n",
@@ -49,25 +51,13 @@
     "##### H5\n",
     "###### H6\n",
     "\n",
-    "<br>\n",
-    "\n",
     "### Emphasis\n",
     "\n",
-    "Emphasis, aka italics, with *asterisks* or _underscores_.\n",
+    "Emphasis, aka italics, with **asterisks** or _underscores_.\n",
     "\n",
     "Strong emphasis, aka bold, with **asterisks** or __underscores__.\n",
     "\n",
-    "Combined emphasis with **asterisks and _underscores_**.\n",
-    "\n",
-    "Strikethrough uses two tildes. ~~Scratch this.~~\n",
-    "\n",
-    "<br>\n",
-    "\n",
-    "### Task list\n",
-    "\n",
-    "- [x] Write the press release\n",
-    "- [ ] Update the website\n",
-    "- [ ] Contact the media\n",
+    "Combined emphasis with ** asterisks and _underscores_ **.\n",
     "\n",
     "<br>\n",
     "\n",
@@ -90,10 +80,16 @@
     "}\n",
     "```\n",
     "\n",
+    "### Nested list\n",
+    "\n",
+    "1. First list item\n",
+    "    - First nested list item\n",
+    "        - Second nested list item\n",
+    "\n",
     "[This is a link to panel web portal](https://panel.pyviz.org/)\n",
-    "\"\"\")\n",
     "\n",
-    "\n"
+    "------------\n",
+    "\"\"\", width=500)"
    ]
   },
   {
@@ -203,5 +199,5 @@
   }
  },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }

panel/_styles/markdown.css

@@ -0,0 +1,81 @@
+.codehilite .hll { background-color: #ffffcc }
+.codehilite  { background: #f8f8f8; }
+.codehilite .c { color: #408080; font-style: italic } /* Comment */
+.codehilite .err { border: 1px solid #FF0000 } /* Error */
+.codehilite .k { color: #008000; font-weight: bold } /* Keyword */
+.codehilite .o { color: #666666 } /* Operator */
+.codehilite .ch { color: #408080; font-style: italic } /* Comment.Hashbang */
+.codehilite .cm { color: #408080; font-style: italic } /* Comment.Multiline */
+.codehilite .cp { color: #BC7A00 } /* Comment.Preproc */
+.codehilite .cpf { color: #408080; font-style: italic } /* Comment.PreprocFile */
+.codehilite .c1 { color: #408080; font-style: italic } /* Comment.Single */
+.codehilite .cs { color: #408080; font-style: italic } /* Comment.Special */
+.codehilite .gd { color: #A00000 } /* Generic.Deleted */
+.codehilite .ge { font-style: italic } /* Generic.Emph */
+.codehilite .gr { color: #FF0000 } /* Generic.Error */
+.codehilite .gh { color: #000080; font-weight: bold } /* Generic.Heading */
+.codehilite .gi { color: #00A000 } /* Generic.Inserted */
+.codehilite .go { color: #888888 } /* Generic.Output */
+.codehilite .gp { color: #000080; font-weight: bold } /* Generic.Prompt */
+.codehilite .gs { font-weight: bold } /* Generic.Strong */
+.codehilite .gu { color: #800080; font-weight: bold } /* Generic.Subheading */
+.codehilite .gt { color: #0044DD } /* Generic.Traceback */
+.codehilite .kc { color: #008000; font-weight: bold } /* Keyword.Constant */
+.codehilite .kd { color: #008000; font-weight: bold } /* Keyword.Declaration */
+.codehilite .kn { color: #008000; font-weight: bold } /* Keyword.Namespace */
+.codehilite .kp { color: #008000 } /* Keyword.Pseudo */
+.codehilite .kr { color: #008000; font-weight: bold } /* Keyword.Reserved */
+.codehilite .kt { color: #B00040 } /* Keyword.Type */
+.codehilite .m { color: #666666 } /* Literal.Number */
+.codehilite .s { color: #BA2121 } /* Literal.String */
+.codehilite .na { color: #7D9029 } /* Name.Attribute */
+.codehilite .nb { color: #008000 } /* Name.Builtin */
+.codehilite .nc { color: #0000FF; font-weight: bold } /* Name.Class */
+.codehilite .no { color: #880000 } /* Name.Constant */
+.codehilite .nd { color: #AA22FF } /* Name.Decorator */
+.codehilite .ni { color: #999999; font-weight: bold } /* Name.Entity */
+.codehilite .ne { color: #D2413A; font-weight: bold } /* Name.Exception */
+.codehilite .nf { color: #0000FF } /* Name.Function */
+.codehilite .nl { color: #A0A000 } /* Name.Label */
+.codehilite .nn { color: #0000FF; font-weight: bold } /* Name.Namespace */
+.codehilite .nt { color: #008000; font-weight: bold } /* Name.Tag */
+.codehilite .nv { color: #19177C } /* Name.Variable */
+.codehilite .ow { color: #AA22FF; font-weight: bold } /* Operator.Word */
+.codehilite .w { color: #bbbbbb } /* Text.Whitespace */
+.codehilite .mb { color: #666666 } /* Literal.Number.Bin */
+.codehilite .mf { color: #666666 } /* Literal.Number.Float */
+.codehilite .mh { color: #666666 } /* Literal.Number.Hex */
+.codehilite .mi { color: #666666 } /* Literal.Number.Integer */
+.codehilite .mo { color: #666666 } /* Literal.Number.Oct */
+.codehilite .sa { color: #BA2121 } /* Literal.String.Affix */
+.codehilite .sb { color: #BA2121 } /* Literal.String.Backtick */
+.codehilite .sc { color: #BA2121 } /* Literal.String.Char */
+.codehilite .dl { color: #BA2121 } /* Literal.String.Delimiter */
+.codehilite .sd { color: #BA2121; font-style: italic } /* Literal.String.Doc */
+.codehilite .s2 { color: #BA2121 } /* Literal.String.Double */
+.codehilite .se { color: #BB6622; font-weight: bold } /* Literal.String.Escape */
+.codehilite .sh { color: #BA2121 } /* Literal.String.Heredoc */
+.codehilite .si { color: #BB6688; font-weight: bold } /* Literal.String.Interpol */
+.codehilite .sx { color: #008000 } /* Literal.String.Other */
+.codehilite .sr { color: #BB6688 } /* Literal.String.Regex */
+.codehilite .s1 { color: #BA2121 } /* Literal.String.Single */
+.codehilite .ss { color: #19177C } /* Literal.String.Symbol */
+.codehilite .bp { color: #008000 } /* Name.Builtin.Pseudo */
+.codehilite .fm { color: #0000FF } /* Name.Function.Magic */
+.codehilite .vc { color: #19177C } /* Name.Variable.Class */
+.codehilite .vg { color: #19177C } /* Name.Variable.Global */
+.codehilite .vi { color: #19177C } /* Name.Variable.Instance */
+.codehilite .vm { color: #19177C } /* Name.Variable.Magic */
+.codehilite .il { color: #666666 } /* Literal.Number.Integer.Long */
+
+.markdown h1 { margin-block-start: 0.34em }
+.markdown h2 { margin-block-start: 0.42em }
+.markdown h3 { margin-block-start: 0.5em }
+.markdown h4 { margin-block-start: 0.67em }
+.markdown h5 { margin-block-start: 0.84em }
+.markdown h6 { margin-block-start: 1.17em }
+.markdown ul { padding-inline-start: 2em }
+.markdown ol { padding-inline-start: 2em }
+.markdown strong { font-weight: 600 }
+.markdown a { color: -webkit-link }
+.markdown a { color: -moz-hyperlinkText }

panel/pane/markup.py

@@ -4,6 +4,8 @@
 """
 from __future__ import absolute_import, division, unicode_literals
 
+import textwrap
+
 try:
     from html import escape
 except:
@@ -263,9 +265,18 @@ class Markdown(DivPaneBase):
     standard string, therefore it has to be invoked explicitly.
     """
 
+    dedent = param.Boolean(default=True, doc="""
+        Whether to dedent common whitespace across all lines.""")
+
+    extensions = param.List(default=[
+        "extra", "smarty", "codehilite"], doc="""
+        Markdown extension to apply when transforming markup.""")
+
     # Priority depends on the data type
     priority = None
 
+    _rerender_params = ['object', 'dedent', 'extensions']
+
     @classmethod
     def applies(cls, obj):
         if hasattr(obj, '_repr_markdown_'):
@@ -282,8 +293,11 @@ def _get_properties(self):
             data = ''
         elif not isinstance(data, string_types):
             data = data._repr_markdown_()
+        if self.dedent:
+            data = textwrap.dedent(data)
         properties = super(Markdown, self)._get_properties()
         properties['style'] = properties.get('style', {})
-        extensions = ['markdown.extensions.extra', 'markdown.extensions.smarty']
-        html = markdown.markdown(data, extensions=extensions, output_format='html5')
-        return dict(properties, text=html)
+        css_classes = properties.pop('css_classes', []) + ['markdown']
+        html = markdown.markdown(data, extensions=self.extensions,
+                                 output_format='html5')
+        return dict(properties, text=html, css_classes=css_classes)

panel/tests/pane/test_base.py

@@ -21,14 +21,20 @@ def test_pane_repr(document, comm):
 
 @pytest.mark.parametrize('pane', all_panes)
 def test_pane_layout_properties(pane, document, comm):
-    p = pane()
+    try:
+        p = pane()
+    except ImportError:
+        pytest.skip("Dependent library could not be imported.")
     model = p.get_root(document, comm)
     check_layoutable_properties(p, model)
 
 
 @pytest.mark.parametrize('pane', all_panes)
 def test_pane_clone(pane):
-    p = pane()
+    try:
+        p = pane()
+    except ImportError:
+        pytest.skip("Dependent library could not be imported.")
     clone = p.clone()
 
     assert ([(k, v) for k, v in sorted(p.param.get_param_values()) if k != 'name'] ==

panel/tests/pane/test_markup.py

@@ -61,6 +61,33 @@ def test_markdown_pane(document, comm):
     pane._cleanup(model)
     assert pane._models == {}
 
+def test_markdown_pane_dedent(document, comm):
+    pane = Pane("    ABC")
+
+    # Create pane
+    model = pane.get_root(document, comm=comm)
+    assert pane._models[model.ref['id']][0] is model
+    assert model.text.endswith("<p>ABC</p>")
+
+    pane.dedent = False
+    assert model.text.endswith('<div class="codehilite"><pre><span></span><span class="err">ABC</span>\n</pre></div>')
+
+
+def test_markdown_pane_extensions(document, comm):
+    pane = Pane("""
+    ```python
+    None
+    ```
+    """)
+
+    # Create pane
+    model = pane.get_root(document, comm=comm)
+    assert pane._models[model.ref['id']][0] is model
+    assert model.text.endswith('<div class="codehilite"><pre><span></span><span class="kc">None</span>\n</pre></div>')
+
+    pane.extensions = ["extra", "smarty"]
+    assert model.text.endswith('<pre><code class="python">None\n</code></pre>')
+
 
 def test_html_pane(document, comm):
     pane = HTML("<h1>Test</h1>")

panel/util.py

@@ -130,7 +130,15 @@ def param_reprs(parameterized, skip=None):
     cls = type(parameterized).__name__
     param_reprs = []
     for p, v in sorted(parameterized.get_param_values()):
-        if v is parameterized.param[p].default: continue
+        default = parameterized.param[p].default
+        equal = v is default
+        if not equal:
+            try:
+                equal = bool(v==default)
+            except:
+                equal = False
+
+        if equal: continue
         elif v is None: continue
         elif isinstance(v, string_types) and v == '': continue
         elif isinstance(v, list) and v == []: continue