Adding better logic to the PDF postprocessor.

IPython/nbconvert/postprocessors/pdf.py

@@ -30,31 +30,101 b' class PDFPostProcessor(PostProcessorBase):'
         How many times pdflatex will be called.
         """)
 
-    command = List(["pdflatex", "{filename}"], config=True, help="""
+    pdflatex_command = List(["pdflatex", "{filename}"], config=True, help="""
         Shell command used to compile PDF.""")
 
+    bibtex_command = List(["bibtex", "{filename}"], config=True, help="""
+        Shell command used to run bibtex.""")
+
     verbose = Bool(False, config=True, help="""
         Whether or not to display the output of the compile call.
         """)
 
-    def postprocess(self, input):
-            """
-            Consume and write Jinja output a PDF.  
-            See files.py for more...
-            """        
-            command = [c.format(filename=input) for c in self.command]
-            self.log.info("Building PDF: %s", command)
-            with open(os.devnull, 'rb') as null:
-                stdout = subprocess.PIPE if not self.verbose else None
-                for index in range(self.iteration_count):
-                    p = subprocess.Popen(command, stdout=stdout, stdin=null)
-                    out, err = p.communicate()
-                    if p.returncode:
-                        if self.verbose:
-                            # verbose means I didn't capture stdout with PIPE,
-                            # so it's already been displayed and `out` is None.
-                            out = u''
-                        else:
-                            out = out.decode('utf-8', 'replace')
-                        self.log.critical(u"PDF conversion failed: %s\n%s", command, out)
-                        return
+    temp_file_exts = List(['.aux', '.bbl', '.blg', '.idx', '.log', '.out'], 
+        config=True, help="""
+        Filename extensions of temp files to remove after running
+        """)
+
+    def run_command(self, command_list, filename, count, log_function):
+        """Run pdflatex or bibtext count times.
+        
+        Parameters
+        ----------
+        command_list : list
+            A list of args to provide to Popen. Each element of this
+            list will be interpolated with the filename to convert.
+        filename : unicode
+            The name of the file to convert.
+        count : int
+            How many times to run the command.
+        
+        Returns
+        -------
+        continue : bool
+            A boolean indicating if the command was successful (True)
+            or failed (False).
+        """
+        command = [c.format(filename=filename) for c in command_list]
+        times = 'time' if count == 1 else 'times'
+        self.log.info("Running %s %i %s: %s", command_list[0], count, times, command)
+        with open(os.devnull, 'rb') as null:
+            stdout = subprocess.PIPE if not self.verbose else None
+            for index in range(count):
+                p = subprocess.Popen(command, stdout=stdout, stdin=null)
+                out, err = p.communicate()
+                if p.returncode:
+                    if self.verbose:
+                        # verbose means I didn't capture stdout with PIPE,
+                        # so it's already been displayed and `out` is None.
+                        out = u''
+                    else:
+                        out = out.decode('utf-8', 'replace')
+                    log_function(command, out)
+                    return False # failure
+        return True # success
+
+    def run_pdflatex(self, filename):
+        """Run pdflatex self.iteration_count times."""
+
+        def log_error(command, out):
+            self.log.critical(u"pdflatex failed: %s\n%s", command, out)
+
+        return self.run_command(self.pdflatex_command, filename, 
+            self.iteration_count, log_error)
+
+    def run_bibtex(self, filename):
+        """Run bibtex self.iteration_count times."""
+        filename = filename.rstrip('.tex')
+        
+        def log_error(command, out):
+            self.log.warn('bibtex had problems, most likely because there were no citations')
+            self.log.debug(u"bibtex output: %s\n%s", command, out)
+
+        return self.run_command(self.bibtex_command, filename, 1, log_error)
+
+    def clean_temp_files(self, filename):
+        """Remove temporary files created by pdflatex/bibtext."""
+        self.log.info("Removing temporary LaTeX files")
+        filename = filename.strip('.tex')
+        for ext in self.temp_file_exts:
+            try:
+                os.remove(filename+ext)
+            except OSError:
+                pass
+        
+    def postprocess(self, filename):
+        """Build a PDF by running pdflatex and bibtex"""
+        self.log.info("Building PDF")
+        cont = self.run_pdflatex(filename)
+        if cont:
+            cont = self.run_bibtex(filename)
+        else:
+            self.clean_temp_files(filename)
+            return
+        if cont:
+            cont = self.run_pdflatex(filename)
+        self.clean_temp_files(filename)
+        if os.path.isfile(filename.rstrip('.tex')+'.pdf'):
+            self.log.info('PDF successfully created')
+        return
+

IPython/nbconvert/postprocessors/tests/test_pdf.py

@@ -62,3 +62,7 b' class TestPDF(TestsBase):'
 
             # Check that the PDF was created.
             assert os.path.isfile('a.pdf')
+            
+            # Make sure that temp files are cleaned up
+            for ext in processor.temp_file_exts:
+                assert not os.path.isfile('a'+ext)