From 5dc754fb832bbbd1c890922015d390fa4ce72961 2008-07-20 20:04:22
From: Gael Varoquaux <gael.varoquaux@normalesup.org>
Date: 2008-07-20 20:04:22
Subject: [PATCH] Add forgotten file.

---

diff --git a/IPython/frontend/prefilterfrontend.py b/IPython/frontend/prefilterfrontend.py
new file mode 100644
index 0000000..62a21f8
--- /dev/null
+++ b/IPython/frontend/prefilterfrontend.py
@@ -0,0 +1,143 @@
+"""
+Frontend class that uses IPython0 to prefilter the inputs.
+
+Using the IPython0 mechanism gives us access to the magics.
+"""
+__docformat__ = "restructuredtext en"
+
+#-------------------------------------------------------------------------------
+#  Copyright (C) 2008  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-------------------------------------------------------------------------------
+
+#-------------------------------------------------------------------------------
+# Imports
+#-------------------------------------------------------------------------------
+import sys
+
+from linefrontendbase import LineFrontEndBase, common_prefix
+
+from IPython.ipmaker import make_IPython
+from IPython.ipapi import IPApi
+from IPython.kernel.core.sync_output_trap import SyncOutputTrap
+
+from IPython.genutils import Term
+
+#-------------------------------------------------------------------------------
+# Utility functions (temporary, should be moved out of here)
+#-------------------------------------------------------------------------------
+import os
+def xterm_system(command):
+    """ Run a command in a separate console window.
+    """
+    os.system("""
+    xterm -title "%s" -e \'/bin/sh -c "%s ; 
+    printf \\"\\\\n\\"; 
+    printf \\"press a key to close\\" ; 
+    printf \\"\x1b]0;%s (finished -- press a key to close)\x07\\" ;
+    read foo;"\'
+    """  % (command, command, command) )
+
+#-------------------------------------------------------------------------------
+# Frontend class using ipython0 to do the prefiltering. 
+#-------------------------------------------------------------------------------
+class PrefilterFrontEnd(LineFrontEndBase):
+    
+    def __init__(self, *args, **kwargs):
+        LineFrontEndBase.__init__(self, *args, **kwargs)
+        # Instanciate an IPython0 interpreter to be able to use the
+        # prefiltering.
+        self.ipython0 = make_IPython()
+        # Set the pager:
+        self.ipython0.set_hook('show_in_pager', 
+                    lambda s, string: self.write("\n"+string))
+        self.ipython0.write = self.write
+        self._ip = _ip = IPApi(self.ipython0)
+        # XXX: Hack: mix the two namespaces
+        self.shell.user_ns = self.ipython0.user_ns
+        self.shell.user_global_ns = self.ipython0.user_global_ns
+        # Make sure the raw system call doesn't get called, as we don't
+        # have a stdin accessible.
+        self._ip.system = xterm_system
+        # Redefine a serie of magics to avoid os.system:
+        # FIXME: I am redefining way too much magics.
+        for alias_name, (_, alias_value) in \
+                    _ip.IP.shell.alias_table.iteritems():
+            magic = lambda s : _ip.magic('sx %s %s' % (alias_value, s))
+            setattr(_ip.IP, 'magic_%s' % alias_name, magic)
+        # FIXME: I should create a real file-like object dedicated to this
+        # terminal
+        Term.cout.flush = lambda : None
+        Term.cout.getvalue = lambda : ''
+        Term.cerr.flush = lambda : None
+        Term.cerr.getvalue = lambda : ''
+        self.shell.output_trap = SyncOutputTrap(write_out=self.write,
+                                                write_err=self.write)
+
+
+    
+    def prefilter_input(self, input_string):
+        """ Using IPython0 to prefilter the commands.
+        """
+        input_string = LineFrontEndBase.prefilter_input(self, input_string)
+        filtered_lines = []
+        # The IPython0 prefilters sometime produce output. We need to
+        # capture it.
+        self.capture_output()
+        self.last_result = dict(number=self.prompt_number)
+        try:
+            for line in input_string.split('\n'):
+                filtered_lines.append(self.ipython0.prefilter(line, False))
+        except:
+            # XXX: probably not the right thing to do.
+            self.ipython0.showsyntaxerror()
+            self.after_execute()
+        finally:
+            self.release_output()
+
+        filtered_string = '\n'.join(filtered_lines)
+        return filtered_string
+
+
+    def show_traceback(self):
+        self.capture_output()
+        self.ipython0.showtraceback()
+        self.release_output()
+
+
+    def capture_output(self):
+        """ Capture all the output mechanism we can think of.
+        """
+        self.__old_cout_write = Term.cout.write
+        self.__old_err_write = Term.cerr.write
+        Term.cout.write = self.write
+        Term.cerr.write = self.write
+        self.__old_stdout = sys.stdout
+        self.__old_stderr= sys.stderr
+        sys.stdout = Term.cout
+        sys.stderr = Term.cerr
+        # FIXME: I still need to provide the writelines method
+
+    def release_output(self):
+        """ Release all the different captures we have made,
+            and flush the buffers.
+        """
+        Term.cout.write = self.__old_cout_write
+        Term.cerr.write = self.__old_err_write
+        sys.stdout = self.__old_stdout
+        sys.stderr = self.__old_stderr
+
+
+    def complete(self, line):
+        word = line.split('\n')[-1].split(' ')[-1]
+        completions = self.ipython0.complete(word)
+        key = lambda x: x.replace('_', '')
+        completions.sort(key=key)
+        if completions:
+            prefix = common_prefix(completions) 
+            line = line[:-len(word)] + prefix
+        return line, completions 
+ 
+