Add set_next_input method to ZMQInteractiveShell, so that %recall can put code at the next prompt.

IPython/frontend/qt/console/ipython_widget.py

@@ -1,496 +1,496 b''
 """ A FrontendWidget that emulates the interface of the console IPython and
     supports the additional functionality provided by the IPython kernel.
 """
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 # Standard library imports
 from collections import namedtuple
 import os.path
 import re
 from subprocess import Popen
 import sys
 from textwrap import dedent
 
 # System library imports
 from IPython.external.qt import QtCore, QtGui
 
 # Local imports
 from IPython.core.inputsplitter import IPythonInputSplitter, \
     transform_ipy_prompt
 from IPython.core.usage import default_gui_banner
 from IPython.utils.traitlets import Bool, Str, Unicode
 from frontend_widget import FrontendWidget
 from styles import (default_light_style_sheet,  default_light_syntax_style,
                     default_dark_style_sheet, default_dark_syntax_style,
                     default_bw_style_sheet, default_bw_syntax_style)
 
 #-----------------------------------------------------------------------------
 # Constants
 #-----------------------------------------------------------------------------
 
 # Default strings to build and display input and output prompts (and separators
 # in between)
 default_in_prompt = 'In [<span class="in-prompt-number">%i</span>]: '
 default_out_prompt = 'Out[<span class="out-prompt-number">%i</span>]: '
 default_input_sep = '\n'
 default_output_sep = ''
 default_output_sep2 = ''
 
 # Base path for most payload sources.
 zmq_shell_source = 'IPython.zmq.zmqshell.ZMQInteractiveShell'
 
 #-----------------------------------------------------------------------------
 # IPythonWidget class
 #-----------------------------------------------------------------------------
 
 class IPythonWidget(FrontendWidget):
     """ A FrontendWidget for an IPython kernel.
     """
 
     # If set, the 'custom_edit_requested(str, int)' signal will be emitted when
     # an editor is needed for a file. This overrides 'editor' and 'editor_line'
     # settings.
     custom_edit = Bool(False)
     custom_edit_requested = QtCore.Signal(object, object)
 
     # A command for invoking a system text editor. If the string contains a
     # {filename} format specifier, it will be used. Otherwise, the filename will
     # be appended to the end the command.
     editor = Unicode('default', config=True)
 
     # The editor command to use when a specific line number is requested. The
     # string should contain two format specifiers: {line} and {filename}. If
     # this parameter is not specified, the line number option to the %edit magic
     # will be ignored.
     editor_line = Unicode(config=True)
 
     # A CSS stylesheet. The stylesheet can contain classes for:
     #     1. Qt: QPlainTextEdit, QFrame, QWidget, etc
     #     2. Pygments: .c, .k, .o, etc (see PygmentsHighlighter)
     #     3. IPython: .error, .in-prompt, .out-prompt, etc
     style_sheet = Unicode(config=True)
     
     # If not empty, use this Pygments style for syntax highlighting. Otherwise,
     # the style sheet is queried for Pygments style information.
     syntax_style = Str(config=True)
 
     # Prompts.
     in_prompt = Str(default_in_prompt, config=True)
     out_prompt = Str(default_out_prompt, config=True)
     input_sep = Str(default_input_sep, config=True)
     output_sep = Str(default_output_sep, config=True)
     output_sep2 = Str(default_output_sep2, config=True)
 
     # FrontendWidget protected class variables.
     _input_splitter_class = IPythonInputSplitter
 
     # IPythonWidget protected class variables.
     _PromptBlock = namedtuple('_PromptBlock', ['block', 'length', 'number'])
     _payload_source_edit = zmq_shell_source + '.edit_magic'
     _payload_source_exit = zmq_shell_source + '.ask_exit'
-    _payload_source_loadpy = zmq_shell_source + '.magic_loadpy'
+    _payload_source_next_input = zmq_shell_source + '.set_next_input'
     _payload_source_page = 'IPython.zmq.page.page'
 
     #---------------------------------------------------------------------------
     # 'object' interface
     #---------------------------------------------------------------------------
     
     def __init__(self, *args, **kw):
         super(IPythonWidget, self).__init__(*args, **kw)
 
         # IPythonWidget protected variables.
         self._code_to_load = None
         self._payload_handlers = { 
             self._payload_source_edit : self._handle_payload_edit,
             self._payload_source_exit : self._handle_payload_exit,
             self._payload_source_page : self._handle_payload_page,
-            self._payload_source_loadpy : self._handle_payload_loadpy }
+            self._payload_source_next_input : self._handle_payload_next_input }
         self._previous_prompt_obj = None
         self._keep_kernel_on_exit = None
 
         # Initialize widget styling.
         if self.style_sheet:
             self._style_sheet_changed()
             self._syntax_style_changed()
         else:
             self.set_default_style()
 
     #---------------------------------------------------------------------------
     # 'BaseFrontendMixin' abstract interface
     #---------------------------------------------------------------------------
 
     def _handle_complete_reply(self, rep):
         """ Reimplemented to support IPython's improved completion machinery.
         """
         cursor = self._get_cursor()
         info = self._request_info.get('complete')
         if info and info.id == rep['parent_header']['msg_id'] and \
                 info.pos == cursor.position():
             matches = rep['content']['matches']
             text = rep['content']['matched_text']
             offset = len(text)
 
             # Clean up matches with period and path separators if the matched
             # text has not been transformed. This is done by truncating all
             # but the last component and then suitably decreasing the offset
             # between the current cursor position and the start of completion.
             if len(matches) > 1 and matches[0][:offset] == text:
                 parts = re.split(r'[./\\]', text) 
                 sep_count = len(parts) - 1
                 if sep_count:
                     chop_length = sum(map(len, parts[:sep_count])) + sep_count
                     matches = [ match[chop_length:] for match in matches ]
                     offset -= chop_length
 
             # Move the cursor to the start of the match and complete.
             cursor.movePosition(QtGui.QTextCursor.Left, n=offset)
             self._complete_with_items(cursor, matches)
 
     def _handle_execute_reply(self, msg):
         """ Reimplemented to support prompt requests.
         """
         info = self._request_info.get('execute')
         if info and info.id == msg['parent_header']['msg_id']:
             if info.kind == 'prompt':
                 number = msg['content']['execution_count'] + 1
                 self._show_interpreter_prompt(number)
             else:
                 super(IPythonWidget, self)._handle_execute_reply(msg)
 
     def _handle_history_reply(self, msg):
         """ Implemented to handle history tail replies, which are only supported
             by the IPython kernel.
         """
         history_items = msg['content']['history']
         items = [ line.rstrip() for _, _, line in history_items ]
         self._set_history(items)
 
     def _handle_pyout(self, msg):
         """ Reimplemented for IPython-style "display hook".
         """
         if not self._hidden and self._is_from_this_session(msg):
             content = msg['content']
             prompt_number = content['execution_count']
             data = content['data']
             if data.has_key('text/html'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 html = data['text/html']
                 self._append_plain_text('\n')
                 self._append_html(html + self.output_sep2)
             elif data.has_key('text/plain'):
                 self._append_plain_text(self.output_sep)
                 self._append_html(self._make_out_prompt(prompt_number))
                 text = data['text/plain']
                 self._append_plain_text(text + self.output_sep2)
 
     def _handle_display_data(self, msg):
         """ The base handler for the ``display_data`` message.
         """
         # For now, we don't display data from other frontends, but we 
         # eventually will as this allows all frontends to monitor the display
         # data. But we need to figure out how to handle this in the GUI.
         if not self._hidden and self._is_from_this_session(msg):
             source = msg['content']['source']
             data = msg['content']['data']
             metadata = msg['content']['metadata']
             # In the regular IPythonWidget, we simply print the plain text
             # representation.
             if data.has_key('text/html'):
                 html = data['text/html']
                 self._append_html(html)
             elif data.has_key('text/plain'):
                 text = data['text/plain']
                 self._append_plain_text(text)
             # This newline seems to be needed for text and html output.
             self._append_plain_text(u'\n')
 
     def _started_channels(self):
         """ Reimplemented to make a history request.
         """
         super(IPythonWidget, self)._started_channels()
         self.kernel_manager.xreq_channel.history(hist_access_type='tail', n=1000)
 
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' public interface
     #---------------------------------------------------------------------------
 
     def copy(self):
         """ Copy the currently selected text to the clipboard, removing prompts
             if possible.
         """
         text = self._control.textCursor().selection().toPlainText()
         if text:
             lines = map(transform_ipy_prompt, text.splitlines())
             text = '\n'.join(lines)
             QtGui.QApplication.clipboard().setText(text)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' public interface
     #---------------------------------------------------------------------------
 
     def execute_file(self, path, hidden=False):
         """ Reimplemented to use the 'run' magic.
         """
         # Use forward slashes on Windows to avoid escaping each separator.
         if sys.platform == 'win32':
             path = os.path.normpath(path).replace('\\', '/')
 
         self.execute('%%run %s' % path, hidden=hidden)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _complete(self):
         """ Reimplemented to support IPython's improved completion machinery.
         """
         # We let the kernel split the input line, so we *always* send an empty
         # text field. Readline-based frontends do get a real text field which
         # they can use.
         text = ''
         
         # Send the completion request to the kernel
         msg_id = self.kernel_manager.xreq_channel.complete(
             text,                                    # text
             self._get_input_buffer_cursor_line(),    # line
             self._get_input_buffer_cursor_column(),  # cursor_pos
             self.input_buffer)                       # block 
         pos = self._get_cursor().position()
         info = self._CompletionRequest(msg_id, pos)
         self._request_info['complete'] = info
 
     def _get_banner(self):
         """ Reimplemented to return IPython's default banner.
         """
         return default_gui_banner
 
     def _process_execute_error(self, msg):
         """ Reimplemented for IPython-style traceback formatting.
         """
         content = msg['content']
         traceback = '\n'.join(content['traceback']) + '\n'
         if False:
             # FIXME: For now, tracebacks come as plain text, so we can't use
             # the html renderer yet.  Once we refactor ultratb to produce
             # properly styled tracebacks, this branch should be the default
             traceback = traceback.replace(' ', '&nbsp;')
             traceback = traceback.replace('\n', '<br/>')
 
             ename = content['ename']
             ename_styled = '<span class="error">%s</span>' % ename
             traceback = traceback.replace(ename, ename_styled)
 
             self._append_html(traceback)
         else:
             # This is the fallback for now, using plain text with ansi escapes
             self._append_plain_text(traceback)    
 
     def _process_execute_payload(self, item):
         """ Reimplemented to dispatch payloads to handler methods.
         """
         handler = self._payload_handlers.get(item['source'])
         if handler is None:
             # We have no handler for this type of payload, simply ignore it
             return False
         else:
             handler(item)
             return True
         
     def _show_interpreter_prompt(self, number=None):
         """ Reimplemented for IPython-style prompts.
         """
         # If a number was not specified, make a prompt number request.
         if number is None:
             msg_id = self.kernel_manager.xreq_channel.execute('', silent=True)
             info = self._ExecutionRequest(msg_id, 'prompt')
             self._request_info['execute'] = info
             return
 
         # Show a new prompt and save information about it so that it can be
         # updated later if the prompt number turns out to be wrong.
         self._prompt_sep = self.input_sep
         self._show_prompt(self._make_in_prompt(number), html=True)
         block = self._control.document().lastBlock()
         length = len(self._prompt)
         self._previous_prompt_obj = self._PromptBlock(block, length, number)
 
         # Update continuation prompt to reflect (possibly) new prompt length.
         self._set_continuation_prompt(
             self._make_continuation_prompt(self._prompt), html=True)
 
         # Load code from the %loadpy magic, if necessary.
         if self._code_to_load is not None:
             self.input_buffer = dedent(self._code_to_load.rstrip())
             self._code_to_load = None
 
     def _show_interpreter_prompt_for_reply(self, msg):
         """ Reimplemented for IPython-style prompts.
         """
         # Update the old prompt number if necessary.
         content = msg['content']
         previous_prompt_number = content['execution_count']
         if self._previous_prompt_obj and \
                 self._previous_prompt_obj.number != previous_prompt_number:
             block = self._previous_prompt_obj.block
 
             # Make sure the prompt block has not been erased.
             if block.isValid() and block.text():
 
                 # Remove the old prompt and insert a new prompt.
                 cursor = QtGui.QTextCursor(block)
                 cursor.movePosition(QtGui.QTextCursor.Right,
                                     QtGui.QTextCursor.KeepAnchor, 
                                     self._previous_prompt_obj.length)
                 prompt = self._make_in_prompt(previous_prompt_number)
                 self._prompt = self._insert_html_fetching_plain_text(
                     cursor, prompt)
 
                 # When the HTML is inserted, Qt blows away the syntax
                 # highlighting for the line, so we need to rehighlight it.
                 self._highlighter.rehighlightBlock(cursor.block())
 
             self._previous_prompt_obj = None
 
         # Show a new prompt with the kernel's estimated prompt number.
         self._show_interpreter_prompt(previous_prompt_number + 1)
 
     #---------------------------------------------------------------------------
     # 'IPythonWidget' interface
     #---------------------------------------------------------------------------
 
     def set_default_style(self, colors='lightbg'):
         """ Sets the widget style to the class defaults.
 
         Parameters:
         -----------
         colors : str, optional (default lightbg)
             Whether to use the default IPython light background or dark
             background or B&W style.
         """
         colors = colors.lower()
         if colors=='lightbg':
             self.style_sheet = default_light_style_sheet
             self.syntax_style = default_light_syntax_style
         elif colors=='linux':
             self.style_sheet = default_dark_style_sheet
             self.syntax_style = default_dark_syntax_style
         elif colors=='nocolor':
             self.style_sheet = default_bw_style_sheet
             self.syntax_style = default_bw_syntax_style
         else:
             raise KeyError("No such color scheme: %s"%colors)
 
     #---------------------------------------------------------------------------
     # 'IPythonWidget' protected interface
     #---------------------------------------------------------------------------
 
     def _edit(self, filename, line=None):
         """ Opens a Python script for editing.
 
         Parameters:
         -----------
         filename : str
             A path to a local system file.
 
         line : int, optional
             A line of interest in the file.
         """
         if self.custom_edit:
             self.custom_edit_requested.emit(filename, line)
         elif self.editor == 'default':
             self._append_plain_text('No default editor available.\n')
         else:
             try:
                 filename = '"%s"' % filename
                 if line and self.editor_line:
                     command = self.editor_line.format(filename=filename,
                                                       line=line)
                 else:
                     try:
                         command = self.editor.format()
                     except KeyError:
                         command = self.editor.format(filename=filename)
                     else:
                         command += ' ' + filename
             except KeyError:
                 self._append_plain_text('Invalid editor command.\n')
             else:
                 try:
                     Popen(command, shell=True)
                 except OSError:
                     msg = 'Opening editor with command "%s" failed.\n'
                     self._append_plain_text(msg % command)
 
     def _make_in_prompt(self, number):
         """ Given a prompt number, returns an HTML In prompt.
         """
         body = self.in_prompt % number
         return '<span class="in-prompt">%s</span>' % body
 
     def _make_continuation_prompt(self, prompt):
         """ Given a plain text version of an In prompt, returns an HTML
             continuation prompt.
         """
         end_chars = '...: '
         space_count = len(prompt.lstrip('\n')) - len(end_chars)
         body = '&nbsp;' * space_count + end_chars
         return '<span class="in-prompt">%s</span>' % body
         
     def _make_out_prompt(self, number):
         """ Given a prompt number, returns an HTML Out prompt.
         """
         body = self.out_prompt % number
         return '<span class="out-prompt">%s</span>' % body
 
     #------ Payload handlers --------------------------------------------------
 
     # Payload handlers with a generic interface: each takes the opaque payload
     # dict, unpacks it and calls the underlying functions with the necessary
     # arguments.
 
     def _handle_payload_edit(self, item):
         self._edit(item['filename'], item['line_number'])
 
     def _handle_payload_exit(self, item):
         self._keep_kernel_on_exit = item['keepkernel']
         self.exit_requested.emit()
 
-    def _handle_payload_loadpy(self, item):
-        # Simple save the text of the .py file for later. The text is written
-        # to the buffer when _prompt_started_hook is called.
+    def _handle_payload_next_input(self, item):
+        # Simply store the text for now. It is written to the buffer when
+        # _show_interpreter_prompt is called.
         self._code_to_load = item['text']
 
     def _handle_payload_page(self, item):
         # Since the plain text widget supports only a very small subset of HTML
         # and we have no control over the HTML source, we only page HTML
         # payloads in the rich text widget.
         if item['html'] and self.kind == 'rich':
             self._page(item['html'], html=True)
         else:
             self._page(item['text'], html=False)
 
     #------ Trait change handlers --------------------------------------------
 
     def _style_sheet_changed(self):
         """ Set the style sheets of the underlying widgets.
         """
         self.setStyleSheet(self.style_sheet)
         self._control.document().setDefaultStyleSheet(self.style_sheet)
         if self._page_control:
             self._page_control.document().setDefaultStyleSheet(self.style_sheet)
 
         bg_color = self._control.palette().window().color()
         self._ansi_processor.set_background_color(bg_color)
 
     def _syntax_style_changed(self):
         """ Set the style for the syntax highlighter.
         """
         if self.syntax_style:
             self._highlighter.set_style(self.syntax_style)
         else:
             self._highlighter.set_style_sheet(self.style_sheet)
 

IPython/zmq/zmqshell.py

@@ -1,601 +1,606 b''
 """A ZMQ-based subclass of InteractiveShell.
 
 This code is meant to ease the refactoring of the base InteractiveShell into
 something with a cleaner architecture for 2-process use, without actually
 breaking InteractiveShell itself.  So we're doing something a bit ugly, where
 we subclass and override what we want to fix.  Once this is working well, we
 can go back to the base class and refactor the code for a cleaner inheritance
 implementation that doesn't rely on so much monkeypatching.
 
 But this lets us maintain a fully working IPython as we develop the new
 machinery.  This should thus be thought of as scaffolding.
 """
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 from __future__ import print_function
 
 # Stdlib
 import inspect
 import os
 
 # Our own
 from IPython.core.interactiveshell import (
     InteractiveShell, InteractiveShellABC
 )
 from IPython.core import page
 from IPython.core.autocall import ZMQExitAutocall
 from IPython.core.displayhook import DisplayHook
 from IPython.core.displaypub import DisplayPublisher
 from IPython.core.macro import Macro
 from IPython.core.payloadpage import install_payload_page
 from IPython.utils import io
 from IPython.utils.path import get_py_filename
 from IPython.utils.traitlets import Instance, Type, Dict
 from IPython.utils.warn import warn
 from IPython.zmq.session import extract_header
 from session import Session
 
 #-----------------------------------------------------------------------------
 # Globals and side-effects
 #-----------------------------------------------------------------------------
 
 # Install the payload version of page.
 install_payload_page()
 
 #-----------------------------------------------------------------------------
 # Functions and classes
 #-----------------------------------------------------------------------------
 
 class ZMQDisplayHook(DisplayHook):
     """A displayhook subclass that publishes data using ZeroMQ."""
 
     session = Instance(Session)
     pub_socket = Instance('zmq.Socket')
     parent_header = Dict({})
 
     def set_parent(self, parent):
         """Set the parent for outbound messages."""
         self.parent_header = extract_header(parent)
 
     def start_displayhook(self):
         self.msg = self.session.msg(u'pyout', {}, parent=self.parent_header)
 
     def write_output_prompt(self):
         """Write the output prompt."""
         if self.do_full_cache:
             self.msg['content']['execution_count'] = self.prompt_count
 
     def write_format_data(self, format_dict):
         self.msg['content']['data'] = format_dict
 
     def finish_displayhook(self):
         """Finish up all displayhook activities."""
         self.session.send(self.pub_socket, self.msg)
         self.msg = None
 
 
 class ZMQDisplayPublisher(DisplayPublisher):
     """A display publisher that publishes data using a ZeroMQ PUB socket."""
 
     session = Instance(Session)
     pub_socket = Instance('zmq.Socket')
     parent_header = Dict({})
 
     def set_parent(self, parent):
         """Set the parent for outbound messages."""
         self.parent_header = extract_header(parent)
 
     def publish(self, source, data, metadata=None):
         if metadata is None:
             metadata = {}
         self._validate_data(source, data, metadata)
         content = {}
         content['source'] = source
         content['data'] = data
         content['metadata'] = metadata
         self.session.send(
             self.pub_socket, u'display_data', content,
             parent=self.parent_header
         )
 
 
 class ZMQInteractiveShell(InteractiveShell):
     """A subclass of InteractiveShell for ZMQ."""
 
     displayhook_class = Type(ZMQDisplayHook)
     display_pub_class = Type(ZMQDisplayPublisher)
     
     exiter = Instance(ZMQExitAutocall)
     def _exiter_default(self):
         return ZMQExitAutocall(self)
 
     keepkernel_on_exit = None
 
     def init_environment(self):
         """Configure the user's environment.
 
         """
         env = os.environ
         # These two ensure 'ls' produces nice coloring on BSD-derived systems
         env['TERM'] = 'xterm-color'
         env['CLICOLOR'] = '1'
         # Since normal pagers don't work at all (over pexpect we don't have
         # single-key control of the subprocess), try to disable paging in
         # subprocesses as much as possible.
         env['PAGER'] = 'cat'
         env['GIT_PAGER'] = 'cat'
 
     def auto_rewrite_input(self, cmd):
         """Called to show the auto-rewritten input for autocall and friends.
 
         FIXME: this payload is currently not correctly processed by the
         frontend.
         """
         new = self.displayhook.prompt1.auto_rewrite() + cmd
         payload = dict(
             source='IPython.zmq.zmqshell.ZMQInteractiveShell.auto_rewrite_input',
             transformed_input=new,
             )
         self.payload_manager.write_payload(payload)
         
     def ask_exit(self):
         """Engage the exit actions."""
         payload = dict(
             source='IPython.zmq.zmqshell.ZMQInteractiveShell.ask_exit',
             exit=True,
             keepkernel=self.keepkernel_on_exit,
             )
         self.payload_manager.write_payload(payload)
 
     def _showtraceback(self, etype, evalue, stb):
 
         exc_content = {
             u'traceback' : stb,
             u'ename' : unicode(etype.__name__),
             u'evalue' : unicode(evalue)
         }
 
         dh = self.displayhook
         # Send exception info over pub socket for other clients than the caller
         # to pick up
         exc_msg = dh.session.send(dh.pub_socket, u'pyerr', exc_content, dh.parent_header)
 
         # FIXME - Hack: store exception info in shell object.  Right now, the
         # caller is reading this info after the fact, we need to fix this logic
         # to remove this hack.  Even uglier, we need to store the error status
         # here, because in the main loop, the logic that sets it is being
         # skipped because runlines swallows the exceptions.
         exc_content[u'status'] = u'error'
         self._reply_content = exc_content
         # /FIXME
         
         return exc_content
 
     #------------------------------------------------------------------------
     # Magic overrides
     #------------------------------------------------------------------------
     # Once the base class stops inheriting from magic, this code needs to be
     # moved into a separate machinery as well.  For now, at least isolate here
     # the magics which this class needs to implement differently from the base
     # class, or that are unique to it.
 
     def magic_doctest_mode(self,parameter_s=''):
         """Toggle doctest mode on and off.
 
         This mode is intended to make IPython behave as much as possible like a
         plain Python shell, from the perspective of how its prompts, exceptions
         and output look.  This makes it easy to copy and paste parts of a
         session into doctests.  It does so by:
 
         - Changing the prompts to the classic ``>>>`` ones.
         - Changing the exception reporting mode to 'Plain'.
         - Disabling pretty-printing of output.
 
         Note that IPython also supports the pasting of code snippets that have
         leading '>>>' and '...' prompts in them.  This means that you can paste
         doctests from files or docstrings (even if they have leading
         whitespace), and the code will execute correctly.  You can then use
         '%history -t' to see the translated history; this will give you the
         input after removal of all the leading prompts and whitespace, which
         can be pasted back into an editor.
 
         With these features, you can switch into this mode easily whenever you
         need to do testing and changes to doctests, without having to leave
         your existing IPython session.
         """
 
         from IPython.utils.ipstruct import Struct
 
         # Shorthands
         shell = self.shell
         disp_formatter = self.shell.display_formatter
         ptformatter = disp_formatter.formatters['text/plain']
         # dstore is a data store kept in the instance metadata bag to track any
         # changes we make, so we can undo them later.
         dstore = shell.meta.setdefault('doctest_mode', Struct())
         save_dstore = dstore.setdefault
 
         # save a few values we'll need to recover later
         mode = save_dstore('mode', False)
         save_dstore('rc_pprint', ptformatter.pprint)
         save_dstore('rc_plain_text_only',disp_formatter.plain_text_only)
         save_dstore('xmode', shell.InteractiveTB.mode)
         
         if mode == False:
             # turn on
             ptformatter.pprint = False
             disp_formatter.plain_text_only = True
             shell.magic_xmode('Plain')
         else:
             # turn off
             ptformatter.pprint = dstore.rc_pprint
             disp_formatter.plain_text_only = dstore.rc_plain_text_only
             shell.magic_xmode(dstore.xmode)
 
         # Store new mode and inform on console
         dstore.mode = bool(1-int(mode))
         mode_label = ['OFF','ON'][dstore.mode]
         print('Doctest mode is:', mode_label)
         
         # Send the payload back so that clients can modify their prompt display
         payload = dict(
             source='IPython.zmq.zmqshell.ZMQInteractiveShell.magic_doctest_mode',
             mode=dstore.mode)
         self.payload_manager.write_payload(payload)
 
     def magic_edit(self,parameter_s='',last_call=['','']):
         """Bring up an editor and execute the resulting code.
 
         Usage:
           %edit [options] [args]
 
         %edit runs IPython's editor hook.  The default version of this hook is
         set to call the __IPYTHON__.rc.editor command.  This is read from your
         environment variable $EDITOR.  If this isn't found, it will default to
         vi under Linux/Unix and to notepad under Windows.  See the end of this
         docstring for how to change the editor hook.
 
         You can also set the value of this editor via the command line option
         '-editor' or in your ipythonrc file. This is useful if you wish to use
         specifically for IPython an editor different from your typical default
         (and for Windows users who typically don't set environment variables).
 
         This command allows you to conveniently edit multi-line code right in
         your IPython session.
         
         If called without arguments, %edit opens up an empty editor with a
         temporary file and will execute the contents of this file when you
         close it (don't forget to save it!).
 
 
         Options:
 
         -n <number>: open the editor at a specified line number.  By default,
         the IPython editor hook uses the unix syntax 'editor +N filename', but
         you can configure this by providing your own modified hook if your
         favorite editor supports line-number specifications with a different
         syntax.
         
         -p: this will call the editor with the same data as the previous time
         it was used, regardless of how long ago (in your current session) it
         was.
 
         -r: use 'raw' input.  This option only applies to input taken from the
         user's history.  By default, the 'processed' history is used, so that
         magics are loaded in their transformed version to valid Python.  If
         this option is given, the raw input as typed as the command line is
         used instead.  When you exit the editor, it will be executed by
         IPython's own processor.
         
         -x: do not execute the edited code immediately upon exit. This is
         mainly useful if you are editing programs which need to be called with
         command line arguments, which you can then do using %run.
 
 
         Arguments:
 
         If arguments are given, the following possibilites exist:
 
         - The arguments are numbers or pairs of colon-separated numbers (like
         1 4:8 9). These are interpreted as lines of previous input to be
         loaded into the editor. The syntax is the same of the %macro command.
 
         - If the argument doesn't start with a number, it is evaluated as a
         variable and its contents loaded into the editor. You can thus edit
         any string which contains python code (including the result of
         previous edits).
 
         - If the argument is the name of an object (other than a string),
         IPython will try to locate the file where it was defined and open the
         editor at the point where it is defined. You can use `%edit function`
         to load an editor exactly at the point where 'function' is defined,
         edit it and have the file be executed automatically.
 
         If the object is a macro (see %macro for details), this opens up your
         specified editor with a temporary file containing the macro's data.
         Upon exit, the macro is reloaded with the contents of the file.
 
         Note: opening at an exact line is only supported under Unix, and some
         editors (like kedit and gedit up to Gnome 2.8) do not understand the
         '+NUMBER' parameter necessary for this feature. Good editors like
         (X)Emacs, vi, jed, pico and joe all do.
 
         - If the argument is not found as a variable, IPython will look for a
         file with that name (adding .py if necessary) and load it into the
         editor. It will execute its contents with execfile() when you exit,
         loading any code in the file into your interactive namespace.
 
         After executing your code, %edit will return as output the code you
         typed in the editor (except when it was an existing file). This way
         you can reload the code in further invocations of %edit as a variable,
         via _<NUMBER> or Out[<NUMBER>], where <NUMBER> is the prompt number of
         the output.
 
         Note that %edit is also available through the alias %ed.
 
         This is an example of creating a simple function inside the editor and
         then modifying it. First, start up the editor:
 
         In [1]: ed
         Editing... done. Executing edited code...
         Out[1]: 'def foo():n    print "foo() was defined in an editing session"n'
 
         We can then call the function foo():
         
         In [2]: foo()
         foo() was defined in an editing session
 
         Now we edit foo.  IPython automatically loads the editor with the
         (temporary) file where foo() was previously defined:
         
         In [3]: ed foo
         Editing... done. Executing edited code...
 
         And if we call foo() again we get the modified version:
         
         In [4]: foo()
         foo() has now been changed!
 
         Here is an example of how to edit a code snippet successive
         times. First we call the editor:
 
         In [5]: ed
         Editing... done. Executing edited code...
         hello
         Out[5]: "print 'hello'n"
 
         Now we call it again with the previous output (stored in _):
 
         In [6]: ed _
         Editing... done. Executing edited code...
         hello world
         Out[6]: "print 'hello world'n"
 
         Now we call it with the output #8 (stored in _8, also as Out[8]):
 
         In [7]: ed _8
         Editing... done. Executing edited code...
         hello again
         Out[7]: "print 'hello again'n"
 
 
         Changing the default editor hook:
 
         If you wish to write your own editor hook, you can put it in a
         configuration file which you load at startup time.  The default hook
         is defined in the IPython.core.hooks module, and you can use that as a
         starting example for further modifications.  That file also has
         general instructions on how to set a new hook for use once you've
         defined it."""
         
         # FIXME: This function has become a convoluted mess.  It needs a
         # ground-up rewrite with clean, simple logic.
 
         def make_filename(arg):
             "Make a filename from the given args"
             try:
                 filename = get_py_filename(arg)
             except IOError:
                 if args.endswith('.py'):
                     filename = arg
                 else:
                     filename = None
             return filename
 
         # custom exceptions
         class DataIsObject(Exception): pass
 
         opts,args = self.parse_options(parameter_s,'prn:')
         # Set a few locals from the options for convenience:
         opts_p = opts.has_key('p')
         opts_r = opts.has_key('r')
         
         # Default line number value
         lineno = opts.get('n',None)
         if lineno is not None:
             try:
                 lineno = int(lineno)
             except:
                 warn("The -n argument must be an integer.")
                 return
 
         if opts_p:
             args = '_%s' % last_call[0]
             if not self.shell.user_ns.has_key(args):
                 args = last_call[1]
             
         # use last_call to remember the state of the previous call, but don't
         # let it be clobbered by successive '-p' calls.
         try:
             last_call[0] = self.shell.displayhook.prompt_count
             if not opts_p:
                 last_call[1] = parameter_s
         except:
             pass
 
         # by default this is done with temp files, except when the given
         # arg is a filename
         use_temp = True
 
         data = ''
         if args[0].isdigit():
             # Mode where user specifies ranges of lines, like in %macro.
             # This means that you can't edit files whose names begin with
             # numbers this way. Tough.
             ranges = args.split()
             data = ''.join(self.extract_input_slices(ranges,opts_r))
         elif args.endswith('.py'):
             filename = make_filename(args)
             use_temp = False
         elif args:
             try:
                 # Load the parameter given as a variable. If not a string,
                 # process it as an object instead (below)
 
                 #print '*** args',args,'type',type(args)  # dbg
                 data = eval(args, self.shell.user_ns)
                 if not isinstance(data, basestring):
                     raise DataIsObject
 
             except (NameError,SyntaxError):
                 # given argument is not a variable, try as a filename
                 filename = make_filename(args)
                 if filename is None:
                     warn("Argument given (%s) can't be found as a variable "
                          "or as a filename." % args)
                     return
                 use_temp = False
                 
             except DataIsObject:
                 # macros have a special edit function
                 if isinstance(data, Macro):
                     self._edit_macro(args,data)
                     return
                                 
                 # For objects, try to edit the file where they are defined
                 try:
                     filename = inspect.getabsfile(data)
                     if 'fakemodule' in filename.lower() and inspect.isclass(data):                     
                         # class created by %edit? Try to find source
                         # by looking for method definitions instead, the
                         # __module__ in those classes is FakeModule.
                         attrs = [getattr(data, aname) for aname in dir(data)]
                         for attr in attrs:
                             if not inspect.ismethod(attr):
                                 continue
                             filename = inspect.getabsfile(attr)
                             if filename and 'fakemodule' not in filename.lower():
                                 # change the attribute to be the edit target instead
                                 data = attr 
                                 break
                     
                     datafile = 1
                 except TypeError:
                     filename = make_filename(args)
                     datafile = 1
                     warn('Could not find file where `%s` is defined.\n'
                          'Opening a file named `%s`' % (args,filename))
                 # Now, make sure we can actually read the source (if it was in
                 # a temp file it's gone by now).
                 if datafile:
                     try:
                         if lineno is None:
                             lineno = inspect.getsourcelines(data)[1]
                     except IOError:
                         filename = make_filename(args)
                         if filename is None:
                             warn('The file `%s` where `%s` was defined cannot '
                                  'be read.' % (filename,data))
                             return
                 use_temp = False
 
         if use_temp:
             filename = self.shell.mktempfile(data)
             print('IPython will make a temporary file named:', filename)
 
         # Make sure we send to the client an absolute path, in case the working
         # directory of client and kernel don't match
         filename = os.path.abspath(filename)
 
         payload = {
             'source' : 'IPython.zmq.zmqshell.ZMQInteractiveShell.edit_magic',
             'filename' : filename,
             'line_number' : lineno
         }
         self.payload_manager.write_payload(payload)
 
     def magic_gui(self, *args, **kwargs):
         raise NotImplementedError(
             'GUI support must be enabled in command line options.')
 
     def magic_pylab(self, *args, **kwargs):
         raise NotImplementedError(
             'pylab support must be enabled in command line options.')
 
     # A few magics that are adapted to the specifics of using pexpect and a
     # remote terminal
 
     def magic_clear(self, arg_s):
         """Clear the terminal."""
         if os.name == 'posix':
             self.shell.system("clear")
         else:
             self.shell.system("cls")
 
     if os.name == 'nt':
         # This is the usual name in windows
         magic_cls = magic_clear
 
     # Terminal pagers won't work over pexpect, but we do have our own pager
     
     def magic_less(self, arg_s):
         """Show a file through the pager.
 
         Files ending in .py are syntax-highlighted."""
         cont = open(arg_s).read()
         if arg_s.endswith('.py'):
             cont = self.shell.pycolorize(cont)
         page.page(cont)
 
     magic_more = magic_less
 
     # Man calls a pager, so we also need to redefine it
     if os.name == 'posix':
         def magic_man(self, arg_s):
             """Find the man page for the given command and display in pager."""
             page.page(self.shell.getoutput('man %s | col -b' % arg_s,
                                            split=False))
 
     # FIXME: this is specific to the GUI, so we should let the gui app load
     # magics at startup that are only for the gui.  Once the gui app has proper
     # profile and configuration management, we can have it initialize a kernel
     # with a special config file that provides these.
     def magic_guiref(self, arg_s):
         """Show a basic reference about the GUI console."""
         from IPython.core.usage import gui_reference
         page.page(gui_reference, auto_html=True)
 
     def magic_loadpy(self, arg_s):
         """Load a .py python script into the GUI console.
 
         This magic command can either take a local filename or a url::
 
         %loadpy myscript.py
         %loadpy http://www.example.com/myscript.py
         """
         if not arg_s.endswith('.py'):
             raise ValueError('%%load only works with .py files: %s' % arg_s)
         if arg_s.startswith('http'):
             import urllib2
             response = urllib2.urlopen(arg_s)
             content = response.read()
         else:
             content = open(arg_s).read()
+        self.set_next_input(content)
+    
+    def set_next_input(self, text):
+        """Send the specified text to the frontend to be presented at the next
+        input cell."""
         payload = dict(
-            source='IPython.zmq.zmqshell.ZMQInteractiveShell.magic_loadpy', 
-            text=content
+            source='IPython.zmq.zmqshell.ZMQInteractiveShell.set_next_input', 
+            text=text
         )
         self.payload_manager.write_payload(payload)
 
 InteractiveShellABC.register(ZMQInteractiveShell)