Fixed bokeh FuncTickFormater

.travis.yml

@@ -26,7 +26,7 @@ install:
   - conda info -a
   - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION scipy numpy freetype nose bokeh pandas jupyter ipython=4.2.0 param pyqt=4 matplotlib=1.5.1 xarray datashader
   - source activate test-environment
-  - conda install -c conda-forge  -c scitools iris sip=4.18 plotly
+  - conda install -c conda-forge  -c scitools iris sip=4.18 plotly flexx
   - if [[ "$TRAVIS_PYTHON_VERSION" == "3.4" ]]; then
       conda install python=3.4.3;
     fi

holoviews/plotting/bokeh/element.py

@@ -34,7 +34,7 @@
 from ..util import dynamic_update, get_sources
 from .plot import BokehPlot
 from .util import (mpl_to_bokeh, convert_datetime, update_plot,
-                   bokeh_version, mplcmap_to_palette)
+                   bokeh_version, mplcmap_to_palette, py2js_tickformatter)
 
 if bokeh_version >= '0.12':
     from bokeh.models import FuncTickFormatter
@@ -450,17 +450,9 @@ def _axis_properties(self, axis, key, plot, dimension,
             if formatter:
                 msg = ('%s dimension formatter could not be '
                        'converted to tick formatter. ' % dimension.name)
-                try:
-                    formatter = FuncTickFormatter.from_py_func(formatter)
-                except RuntimeError:
-                    self.warning(msg+'Ensure Flexx is installed '
-                                 '("conda install -c bokeh flexx" or '
-                                 '"pip install flexx")')
-                except Exception as e:
-                    error = 'Pyscript raised an error: {0}'.format(e)
-                    error = error.replace('%', '%%')
-                    self.warning(msg+error)
-                else:
+                jsfunc = py2js_tickformatter(formatter, msg)
+                if jsfunc:
+                    formatter = FuncTickFormatter(code=jsfunc)
                     axis_props['formatter'] = formatter
         return axis_props
 

holoviews/plotting/bokeh/util.py

@@ -1,4 +1,4 @@
-import itertools
+import itertools, inspect, re
 from distutils.version import LooseVersion
 from collections import defaultdict
 
@@ -10,6 +10,7 @@
 except ImportError:
     cm, colors = None, None
 
+import param
 import bokeh
 bokeh_version = LooseVersion(bokeh.__version__)
 from bokeh.core.enums import Palette
@@ -372,3 +373,31 @@ def pad_plots(plots, padding=0.85):
               for p, w in zip(row, ws)] for row, ws in zip(plots, widths)]
     total_width = np.max([np.sum(row) for row in widths])
     return plots, total_width
+
+
+def py2js_tickformatter(formatter, msg=''):
+    """
+    Uses flexx.pyscript to compile a python tick formatter to JS code
+    """
+    try:
+        from flexx.pyscript import py2js
+    except ImportError:
+        param.main.warning(msg+'Ensure Flexx is installed '
+                           '("conda install -c bokeh flexx" or '
+                           '"pip install flexx")')
+        return
+    try:
+        jscode = py2js(formatter, 'formatter')
+    except Exception as e:
+        error = 'Pyscript raised an error: {0}'.format(e)
+        error = error.replace('%', '%%')
+        param.main.warning(msg+error)
+        return
+
+    args = inspect.getargspec(formatter).args
+    arg_define = 'var %s = tick;' % args[0] if args else ''
+    return_js = 'return formatter();\n'
+    jsfunc = '\n'.join([arg_define, jscode, return_js])
+    match = re.search('(function \(.*\))', jsfunc )
+    return jsfunc[:match.start()] + 'function ()' + jsfunc[match.end():]
+

tests/testplotutils.py

@@ -0,0 +1,42 @@
+from unittest import SkipTest
+
+from holoviews.core.options import Store
+from holoviews.element.comparison import ComparisonTestCase
+
+try:
+    from holoviews.plotting.bokeh import util
+    bokeh_renderer = Store.renderers['bokeh']
+except:
+    bokeh_renderer = None
+
+
+class TestBokehUtils(ComparisonTestCase):
+
+    def setUp(self):
+        if not bokeh_renderer:
+            raise SkipTest("Bokeh required to test bokeh plot utils.")
+
+
+    def test_py2js_funcformatter_single_arg(self):
+        def test(x):  return '%s$' % x
+        jsfunc = util.py2js_tickformatter(test)
+        js_func = ('var x = tick;\nvar formatter;\nformatter = function () {\n'
+                   '    return "" + x + "$";\n};\n\nreturn formatter();\n')
+        self.assertEqual(jsfunc, js_func)
+
+
+    def test_py2js_funcformatter_two_args(self):
+        def test(x, pos):  return '%s$' % x
+        jsfunc = util.py2js_tickformatter(test)
+        js_func = ('var x = tick;\nvar formatter;\nformatter = function () {\n'
+                   '    return "" + x + "$";\n};\n\nreturn formatter();\n')
+        self.assertEqual(jsfunc, js_func)
+
+
+    def test_py2js_funcformatter_arg_and_kwarg(self):
+        def test(x, pos=None):  return '%s$' % x
+        jsfunc = util.py2js_tickformatter(test)
+        js_func = ('var x = tick;\nvar formatter;\nformatter = function () {\n'
+                   '    pos = (pos === undefined) ? null: pos;\n    return "" '
+                   '+ x + "$";\n};\n\nreturn formatter();\n')
+        self.assertEqual(jsfunc, js_func)