Moved PDF logic into Post-Processor class

IPython/nbconvert/post_processors/__init__.py

@@ -0,0 +1,2 b''
+from .base import PostProcessorBase
+from .pdf import PDFPostProcessor

IPython/nbconvert/post_processors/base.py

@@ -0,0 +1,36 b''
+#!/usr/bin/env python
+"""
+Basic post processor
+"""
+#-----------------------------------------------------------------------------
+#Copyright (c) 2013, the IPython Development Team.
+#
+#Distributed under the terms of the Modified BSD License.
+#
+#The full license is in the file COPYING.txt, distributed with this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+from ..utils.base import NbConvertBase
+
+
+#-----------------------------------------------------------------------------
+# Classes
+#-----------------------------------------------------------------------------
+class PostProcessorBase(NbConvertBase):
+
+    def __call__(self, input):
+        """
+        See def call() ...
+        """
+        self.call(input)
+
+
+    def call(self, input):
+        """
+        Post-process output from a writer.
+        """
+        raise NotImplementedError('call')

IPython/nbconvert/__init__.py

@@ -3,4 +3,5 b''
 from .exporters import *
 import filters
 import transformers
+import post_processors
 import writers

IPython/nbconvert/nbconvertapp.py

@@ -30,7 +30,7 b' from IPython.utils.traitlets import ('
 from IPython.utils.importstring import import_item
 
 from .exporters.export import export_by_name, get_export_names, ExporterNameError
-from IPython.nbconvert import exporters, transformers, writers
+from IPython.nbconvert import exporters, transformers, writers, post_processors
 from .utils.base import NbConvertBase
 from .utils.exceptions import ConversionException
 
@@ -38,6 +38,19 b' from .utils.exceptions import ConversionException'
 #Classes and functions
 #-----------------------------------------------------------------------------
 
+class DottedOrNone(DottedObjectName):
+    """
+    A string holding a valid dotted object name in Python, such as A.b3._c
+    Also allows for None type."""
+    
+    default_value = u''
+
+    def validate(self, obj, value):
+        if value is not None and len(value) > 0:
+            return super(DottedOrNone, self).validate(obj, value)
+        else:
+            return value
+            
 nbconvert_aliases = {}
 nbconvert_aliases.update(base_aliases)
 nbconvert_aliases.update({
@@ -45,6 +58,7 b' nbconvert_aliases.update({'
     'template' : 'Exporter.template_file',
     'notebooks' : 'NbConvertApp.notebooks',
     'writer' : 'NbConvertApp.writer_class',
+    'post': 'NbConvertApp.post_processor_class'
 })
 
 nbconvert_flags = {}
@@ -53,11 +67,6 b' nbconvert_flags.update({'
     'stdout' : (
         {'NbConvertApp' : {'writer_class' : "StdoutWriter"}},
         "Write notebook output to stdout instead of files."
-        ),
-
-    'pdf' : (
-        {'NbConvertApp' : {'writer_class' : "PDFWriter"}},
-        "Compile notebook output to a PDF (requires `--to latex`)."
         )
 })
 
@@ -120,6 +129,7 b' class NbConvertApp(BaseIPythonApplication):'
         
         > ipython nbconvert --config mycfg.py
         """.format(get_export_names()))
+
     # Writer specific variables
     writer = Instance('IPython.nbconvert.writers.base.WriterBase',  
                       help="""Instance of the writer class used to write the 
@@ -138,6 +148,23 b' class NbConvertApp(BaseIPythonApplication):'
             new = self.writer_aliases[new]
         self.writer_factory = import_item(new)
 
+    # Post-processor specific variables
+    post_processor = Instance('IPython.nbconvert.post_processors.base.PostProcessorBase',  
+                      help="""Instance of the PostProcessor class used to write the 
+                      results of the conversion.""")
+
+    post_processor_class = DottedOrNone(config=True, 
+                                    help="""PostProcessor class used to write the 
+                                    results of the conversion""")
+    post_processor_aliases = {'PDF': 'IPython.nbconvert.post_processors.pdf.PDFPostProcessor'}
+    post_processor_factory = Type()
+
+    def _post_processor_class_changed(self, name, old, new):
+        if new in self.post_processor_aliases:
+            new = self.post_processor_aliases[new]
+        if new:
+            self.post_processor_factory = import_item(new)
+
 
     # Other configurable variables
     export_format = CaselessStrEnum(get_export_names(),
@@ -157,6 +184,8 b' class NbConvertApp(BaseIPythonApplication):'
         self.init_syspath()
         self.init_notebooks()
         self.init_writer()
+        self.init_post_processor()
+
 
 
     def init_syspath(self):
@@ -201,6 +230,15 b' class NbConvertApp(BaseIPythonApplication):'
         self._writer_class_changed(None, self.writer_class, self.writer_class)
         self.writer = self.writer_factory(parent=self)
 
+    def init_post_processor(self):
+        """
+        Initialize the post_processor (which is stateless)
+        """
+        self._post_processor_class_changed(None, self.post_processor_class, 
+            self.post_processor_class)
+        if self.post_processor_factory:
+            self.post_processor = self.post_processor_factory(parent=self)
+
     def start(self):
         """
         Ran after initialization completed
@@ -242,7 +280,11 b' class NbConvertApp(BaseIPythonApplication):'
                       file=sys.stderr)
                 self.exit(1)
             else:
-                self.writer.write(output, resources, notebook_name=notebook_name)
+                write_resultes = self.writer.write(output, resources, notebook_name=notebook_name)
+
+                #Post-process if post processor has been defined.
+                if hasattr(self, 'post_processor') and self.post_processor:
+                    self.post_processor(write_resultes)
                 conversion_success += 1
 
         # If nothing was converted successfully, help the user.

IPython/nbconvert/post_processors/pdf.py

@@ -17,14 +17,14 b' Contains writer for writing nbconvert output to PDF.'
 import subprocess
 import os
 
-from IPython.utils.traitlets import Integer, Unicode
+from IPython.utils.traitlets import Integer, Unicode, Bool
 
-from .files import FilesWriter
+from .base import PostProcessorBase
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
-class PDFWriter(FilesWriter):
+class PDFPostProcessor(PostProcessorBase):
     """Writer designed to write to PDF files"""
 
     iteration_count = Integer(3, config=True, help="""
@@ -34,14 +34,19 b' class PDFWriter(FilesWriter):'
     compiler = Unicode(u'pdflatex {0}', config=True, help="""
         Shell command used to compile PDF.""")
 
-    def write(self, output, resources, notebook_name=None, **kw):
+    verbose = Bool(False, config=True, help="""
+        Whether or not to display the output of the compile call.
+        """)
+
+    def call(self, input):
             """
             Consume and write Jinja output a PDF.  
             See files.py for more...
             """        
-            dest = super(PDFWriter, self).write(output, resources, 
-                notebook_name=notebook_name, **kw)
-            command = self.compiler.format(dest)
-
+            command = self.compiler.format(input)
             for index in range(self.iteration_count):
-                subprocess.Popen(command, shell=True, stdout=open(os.devnull, 'wb'))
+                if self.verbose:
+                    subprocess.Popen(command, shell=True)
+                else:
+                    with open(os.devnull, 'wb') as null:
+                        subprocess.Popen(command, shell=True, stdout=null)

IPython/nbconvert/tests/test_nbconvertapp.py

@@ -17,6 +17,7 b' import os'
 from .base import TestsBase
 
 from IPython.utils import py3compat
+from IPython.testing import decorators as dec
 
     
 #-----------------------------------------------------------------------------
@@ -80,6 +81,19 b' class TestNbConvertApp(TestsBase):'
             assert os.path.isfile('notebook2.py')
 
 
+    #@dec.skip_known_failure
+    def test_post_processor(self):
+        """
+        Do post processors work?
+        """
+        with self.create_temp_cwd(['notebook1.ipynb']):
+            assert not 'error' in self.call([IPYTHON, 'nbconvert', '--to="latex"', 
+                'notebook1', '--post="PDF"', 'PDFPostProcessor.verbose=True']).lower()
+            assert os.path.isfile('notebook1.tex')
+            print("\n\n\t" + "\n\t".join([f for f in os.listdir('.') if os.path.isfile(f)]) + "\n\n")
+            assert os.path.isfile('notebook1.pdf')
+
+
     def test_template(self):
         """
         Do export templates work?