Initial commit of updated ViewMagic with support for saving output

holoviews/ipython/display_hooks.py

@@ -52,6 +52,7 @@ def get_plot_size(size):
 def animate(anim, dpi, writer, mime_type, anim_kwargs, extra_args, tag):
     if extra_args != []:
         anim_kwargs = dict(anim_kwargs, extra_args=extra_args)
+    ViewMagic.save_anim(anim, mime_type, writer, dpi=dpi, **anim_kwargs)
 
     if not hasattr(anim, '_encoded_video'):
         with NamedTemporaryFile(suffix='.%s' % mime_type) as f:
@@ -106,6 +107,7 @@ def process_cell_magics(obj):
     "Hook into %%opts and %%channels magics to process displayed element"
     invalid_options = OptsMagic.process_view(obj)
     if invalid_options: return invalid_options
+    ViewMagic.register_object(obj)
 
 
 def render(plot):
@@ -152,6 +154,7 @@ def display_figure(fig, message=None, max_width='100%'):
         mpld3.plugins.connect(fig, mpld3.plugins.MousePosition(fontsize=14))
         html = "<center>" + mpld3.fig_to_html(fig) + "<center/>"
     else:
+        ViewMagic.save_fig(fig, figure_format, dpi=dpi)
         figdata = print_figure(fig, figure_format, dpi=dpi)
         if figure_format=='svg':
             mime_type = 'svg+xml'

holoviews/ipython/magics.py

@@ -1,6 +1,10 @@
+import string
 import time
+import os
+import sha
 try:
     from IPython.core.magic import Magics, magics_class, cell_magic, line_magic, line_cell_magic
+    from IPython.core.pylabtools import print_figure
 except:
     from unittest import SkipTest
     raise SkipTest("IPython extension requires IPython >= 0.13")
@@ -61,6 +65,7 @@ class ViewMagic(Magics):
     # Codec or system-dependent format options
     optional_formats = ['webm','h264', 'gif']
 
+    # Lists: strict options, Set: suggested options, Tuple: numeric bounds.
     allowed = {'backend'     : ['mpl','d3'],
                'fig'         : ['svg', 'png'],
                'holomap'     : inbuilt_formats,
@@ -70,7 +75,8 @@ class ViewMagic(Magics):
                'max_branches': (0, float('inf')),
                'size'        : (0, float('inf')),
                'dpi'         : (1, float('inf')),
-               'charwidth'   : (0, float('inf'))}
+               'charwidth'   : (0, float('inf')),
+               'filename'   : {None, '{type}-{group}-{label}'}}
 
     defaults = OrderedDict([('backend'     , 'mpl'),
                             ('fig'         , 'png'),
@@ -81,7 +87,8 @@ class ViewMagic(Magics):
                             ('max_branches', 2),
                             ('size'        , 100),
                             ('dpi'         , 72),
-                            ('charwidth'   , 80)])
+                            ('charwidth'   , 80),
+                            ('filename'    , None)])
 
     options = OrderedDict(defaults.items())
 
@@ -98,6 +105,9 @@ class ViewMagic(Magics):
         'scrubber': ('html', None, {'fps': 5}, None, None)
     }
 
+    _object_handle = None
+    _generate_SHA = False   # For testing. Whether to compute SHA as output
+    _SHA = None             # For testing purposes: the saved output SHA.
 
     def __init__(self, *args, **kwargs):
         super(ViewMagic, self).__init__(*args, **kwargs)
@@ -133,8 +143,9 @@ def _generate_docstring(cls):
                   % cls.defaults['dpi'])
         chars =  ("charwidth    : The max character width view magic options display (default %r)"
                   % cls.defaults['charwidth'])
-
-        descriptions = [backend, fig, holomap, widgets, fps, frames, branches, size, dpi, chars]
+        fname =  ("filename    : The filename of the saved output, if any (default %r)"
+                  % cls.defaults['filename'])
+        descriptions = [backend, fig, holomap, widgets, fps, frames, branches, size, dpi, chars, fname]
         return '\n'.join(intro + descriptions)
 
 
@@ -168,6 +179,20 @@ def _extract_keywords(self, line, items):
                 raise SyntaxError("Could not evaluate keyword: %s" % keyword)
         return items
 
+    @classmethod
+    def _filename_fields(cls, filename):
+        "Returns valid filename format fields otherwise raise exception"
+        if filename is None: return []
+        valid_fields = ['type', 'group', 'label']
+        try:
+            parse = list(string.Formatter().parse(filename))
+            fields = [f for f in zip(*parse)[1] if f is not None]
+        except:
+            raise SyntaxError("Could not parse filename string formatter")
+        if any(f not in valid_fields for f in fields):
+            raise ValueError("Valid formatters for the filename are: %s"
+                             % ','.join(valid_fields))
+        return fields
 
     def _validate(self, options):
         "Validation of edge cases and incompatible options"
@@ -184,6 +209,8 @@ def _validate(self, options):
             and options['widgets']!='embed'
             and options['fig']=='svg'):
             raise ValueError("SVG mode not supported by widgets unless in embed mode")
+
+        self._filename_fields(options['filename'])
         return options
 
 
@@ -194,7 +221,8 @@ def get_options(self, line, options):
             if keyword in items:
                 value = items[keyword]
                 allowed = self.allowed[keyword]
-                if isinstance(allowed, list) and value not in allowed:
+                if isinstance(allowed, set):  pass
+                elif isinstance(allowed, list) and value not in allowed:
                     raise ValueError("Value %r for key %r not one of %s"
                                      % (value, keyword, allowed))
                 elif isinstance(allowed, tuple):
@@ -268,6 +296,58 @@ def view(self, line, cell=None):
         if cell is not None:
             self.shell.run_cell(cell, store_history=STORE_HISTORY)
             ViewMagic.options = restore_copy
+        self._object_handle=None
+
+    @classmethod
+    def register_object(cls, obj):
+        cls._object_handle = obj
+
+
+    @classmethod
+    def _basename(cls, formatter):
+        info = {'group':getattr(cls._object_handle, 'group', 'group'),
+                'label':getattr(cls._object_handle, 'label', 'label'),
+                'type':cls._object_handle.__class__.__name__}
+        filtered = {k:v for k,v in info.items()
+                    if k in cls._filename_fields(formatter)}
+        return formatter.format(**filtered)
+
+    @classmethod
+    def _save_filename(cls, fmt):
+        if cls.options['filename'] is None: return None
+        name = cls._basename(cls.options['filename'])
+        filename = '%s.%s' % (name, fmt)
+        counter = 1
+        while os.path.isfile(filename):
+            basename = '%s-%d' % (name, counter)
+            filename = '%s.%s' % (basename, fmt)
+            counter += 1
+        return filename
+
+    @classmethod
+    def _digest(cls, data):
+        if cls._generate_SHA:
+            hashfn = sha.new()
+            hashfn.update(data)
+            cls._SHA  = hashfn.hexdigest()
+            return True
+        else:
+            return False
+
+    @classmethod
+    def save_fig(cls, fig, figure_format, dpi):
+        filename = cls._save_filename(figure_format)
+        if filename is None: return
+        figure_data = print_figure(fig, figure_format, dpi=dpi)
+        if cls._digest(figure_data): return
+        with open(filename, 'w') as f:
+            f.write(figure_data)
+
+    @classmethod
+    def save_anim(cls, anim, mime_type, writer, dpi, **anim_kwargs):
+        filename = cls._save_filename(mime_type)
+        if filename is None: return
+        anim.save(filename, writer=writer, dpi=dpi, **anim_kwargs)
 
 
 

holoviews/plotting/__init__.py

@@ -13,66 +13,6 @@
 from . import seaborn # pyflakes:ignore (API import)
 
 
-class PlotSaver(param.ParameterizedFunction):
-    """
-    Parameterized function for saving the plot of a ViewableElement object to
-    disk either as a static figure or as an animation. Keywords that
-    are not parameters are passed into the anim method of the
-    appropriate plot for animations and into matplotlib.figure.savefig
-    for static figures.
-    """
-
-    size = param.NumericTuple(default=(5, 5), doc="""
-      The matplotlib figure size in inches.""")
-
-    filename = param.String(default=None, allow_None=True, doc="""
-      This is the filename of the saved file. The output file type
-      will be inferred from the file extension.""")
-
-    anim_opts = param.Dict(
-        default={'.webm':({}, ['-vcodec', 'libvpx', '-b', '1000k']),
-                 '.mp4':({'codec':'libx264'}, ['-pix_fmt', 'yuv420p']),
-                 '.gif':({'fps':10}, [])}, doc="""
-        The arguments to matplotlib.animation.save for different
-        animation formats. The key is the file extension and the tuple
-        consists of the kwargs followed by a list of arguments for the
-        'extra_args' keyword argument.""" )
-
-
-    def __call__(self, view, **params):
-        anim_exts = ['.webm', '.mp4', 'gif']
-        image_exts = ['.png', '.jpg', '.svg']
-        writers = {'.mp4': 'ffmpeg', '.webm':'ffmpeg', '.gif':'imagemagick'}
-        supported_extensions = image_exts + anim_exts
-
-        self.p = param.ParamOverrides(self, params, allow_extra_keywords=True)
-        if self.p.filename is None:
-            raise Exception("Please supply a suitable filename.")
-
-        _, ext = os.path.splitext(self.p.filename)
-        if ext not in supported_extensions:
-            valid_exts = ', '.join(supported_extensions)
-            raise Exception("File of type %r not in %s" % (ext, valid_exts))
-        file_format = ext[1:]
-
-        plottype = Store.defaults[type(view)]
-        plotopts = Store.lookup_options(view, 'plot').options
-        plot = plottype(view, **dict(plotopts, size=self.p.size))
-
-        if len(plot) > 1 and ext in anim_exts:
-            anim_kwargs, extra_args = self.p.anim_opts[ext]
-            anim = plot.anim(**self.p.extra_keywords())
-            anim.save(self.p.filename, writer=writers[ext],
-                      **dict(anim_kwargs, extra_args=extra_args))
-        elif len(plot) > 1:
-            raise Exception("Invalid extension %r for animation." % ext)
-        elif ext in anim_exts:
-            raise Exception("Invalid extension %r for figure." % ext)
-        else:
-            plot().savefig(filename=self.p.filename, format=file_format,
-                           **self.p.extra_keywords())
-
-
 Store.register_plots()
 
 # Charts