Walter's patch for ipapi.py & hooks.py: TryNext exception can now

have arguments that alter the values passed for the second hook
(and thus enable using hooks as filters)

IPython/hooks.py

@@ -1,189 +1,191 b''
 """hooks for IPython.
 
 In Python, it is possible to overwrite any method of any object if you really
 want to.  But IPython exposes a few 'hooks', methods which are _designed_ to
 be overwritten by users for customization purposes.  This module defines the
 default versions of all such hooks, which get used by IPython if not
 overridden by the user.
 
 hooks are simple functions, but they should be declared with 'self' as their
 first argument, because when activated they are registered into IPython as
 instance methods.  The self argument will be the IPython running instance
 itself, so hooks have full access to the entire IPython object.
 
 If you wish to define a new hook and activate it, you need to put the
 necessary code into a python file which can be either imported or execfile()'d
 from within your ipythonrc configuration.
 
 For example, suppose that you have a module called 'myiphooks' in your
 PYTHONPATH, which contains the following definition:
 
 import os
 import IPython.ipapi
 ip = IPython.ipapi.get()
 
 def calljed(self,filename, linenum):
     "My editor hook calls the jed editor directly."
     print "Calling my own editor, jed ..."
     os.system('jed +%d %s' % (linenum,filename))
 
 ip.set_hook('editor', calljed)
 
 You can then enable the functionality by doing 'import myiphooks'
 somewhere in your configuration files or ipython command line.
 
-$Id: hooks.py 1214 2006-03-16 17:22:15Z vivainio $"""
+$Id: hooks.py 1274 2006-04-26 14:01:37Z vivainio $"""
 
 #*****************************************************************************
 #       Copyright (C) 2005 Fernando Perez. <[e-mail]>
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #*****************************************************************************
 
 from IPython import Release
 from IPython import ipapi
 __author__  = '%s <%s>' % Release.authors['Fernando']
 __license__ = Release.license
 __version__ = Release.version
 
 import os,bisect
 from genutils import Term
 from pprint import pformat
 
 # List here all the default hooks.  For now it's just the editor functions
 # but over time we'll move here all the public API for user-accessible things.
 __all__ = ['editor', 'fix_error_editor', 'result_display',
            'input_prefilter', 'shutdown_hook', 'late_startup_hook']
 
 def editor(self,filename, linenum=None):
     """Open the default editor at the given filename and linenumber.
 
     This is IPython's default editor hook, you can use it as an example to
     write your own modified one.  To set your own editor function as the
     new editor hook, call ip.set_hook('editor',yourfunc)."""
 
     # IPython configures a default editor at startup by reading $EDITOR from
     # the environment, and falling back on vi (unix) or notepad (win32).
     editor = self.rc.editor
     
     # marker for at which line to open the file (for existing objects)
     if linenum is None or editor=='notepad':
         linemark = ''
     else:
         linemark = '+%d' % linenum
     
     # Enclose in quotes if necessary and legal
     if ' ' in editor and os.path.isfile(editor) and editor[0] != '"':
         editor = '"%s"' % editor
         
     # Call the actual editor
     os.system('%s %s %s' % (editor,linemark,filename))
 
 import tempfile
 def fix_error_editor(self,filename,linenum,column,msg):
     """Open the editor at the given filename, linenumber, column and 
     show an error message. This is used for correcting syntax errors.
     The current implementation only has special support for the VIM editor,
     and falls back on the 'editor' hook if VIM is not used.
 
     Call ip.set_hook('fix_error_editor',youfunc) to use your own function,
     """
     def vim_quickfix_file():
         t = tempfile.NamedTemporaryFile()
         t.write('%s:%d:%d:%s\n' % (filename,linenum,column,msg))
         t.flush()
         return t
     if os.path.basename(self.rc.editor) != 'vim':
         self.hooks.editor(filename,linenum)
         return
     t = vim_quickfix_file()
     try:
         os.system('vim --cmd "set errorformat=%f:%l:%c:%m" -q ' + t.name)
     finally:
         t.close()
 
 
 class CommandChainDispatcher:
     """ Dispatch calls to a chain of commands until some func can handle it
     
     Usage: instantiate, execute "add" to add commands (with optional
     priority), execute normally via f() calling mechanism.
     
     """
     def __init__(self,commands=None):
         if commands is None:
             self.chain = []
         else:
             self.chain = commands
             
             
     def __call__(self,*args, **kw):
         """ Command chain is called just like normal func. 
         
         This will call all funcs in chain with the same args as were given to this
         function, and return the result of first func that didn't raise
         TryNext """
         
         for prio,cmd in self.chain:
             #print "prio",prio,"cmd",cmd #dbg
             try:
                 ret = cmd(*args, **kw)
                 return ret
-            except ipapi.TryNext:
-                pass
+            except ipapi.TryNext, exc:
+                if exc.args or exc.kwargs:
+                    args = exc.args
+                    kw = exc.kwargs
                 
     def __str__(self):
         return str(self.chain)
     
     def add(self, func, priority=0):
         """ Add a func to the cmd chain with given priority """
         bisect.insort(self.chain,(priority,func))
 
 def result_display(self,arg):
     """ Default display hook.
     
     Called for displaying the result to the user.
     """
     
     if self.rc.pprint:
         out = pformat(arg)
         if '\n' in out:
             # So that multi-line strings line up with the left column of
             # the screen, instead of having the output prompt mess up
             # their first line.                
             Term.cout.write('\n')
         print >>Term.cout, out
     else:
         print >>Term.cout, arg
     # the default display hook doesn't manipulate the value to put in history    
     return None 
 
 def input_prefilter(self,line):     
     """ Default input prefilter
     
     This returns the line as unchanged, so that the interpreter
     knows that nothing was done and proceeds with "classic" prefiltering
     (%magics, !shell commands etc.). 
     
     Note that leading whitespace is not passed to this hook. Prefilter
     can't alter indentation.
     
     """
     #print "attempt to rewrite",line #dbg
     return line
 
 def shutdown_hook(self):
     """ default shutdown hook
     
     Typically, shotdown hooks should raise TryNext so all shutdown ops are done
     """
     
     #print "default shutdown hook ok" # dbg
     return
 
 def late_startup_hook(self):
     """ Executed after ipython has been constructed and configured 
     
     """
     #print "default startup hook ok" # dbg

IPython/ipapi.py

@@ -1,197 +1,203 b''
 ''' IPython customization API
 
 Your one-stop module for configuring & extending ipython
 
 The API will probably break when ipython 1.0 is released, but so 
 will the other configuration method (rc files).
 
 All names prefixed by underscores are for internal use, not part 
 of the public api.
 
 Below is an example that you can just put to a module and import from ipython. 
 
 A good practice is to install the config script below as e.g. 
 
 ~/.ipython/my_private_conf.py
 
 And do 
 
 import_mod my_private_conf 
 
 in ~/.ipython/ipythonrc
 
 That way the module is imported at startup and you can have all your
 personal configuration (as opposed to boilerplate ipythonrc-PROFILENAME 
 stuff) in there. 
 
 -----------------------------------------------
 import IPython.ipapi as ip
 
 def ankka_f(self, arg):
     print "Ankka",self,"says uppercase:",arg.upper()
 
 ip.expose_magic("ankka",ankka_f)
 
 ip.magic('alias sayhi echo "Testing, hi ok"')
 ip.magic('alias helloworld echo "Hello world"')
 ip.system('pwd')
 
 ip.ex('import re')
 ip.ex("""
 def funcci(a,b):
     print a+b
 print funcci(3,4)
 """)
 ip.ex("funcci(348,9)")
 
 def jed_editor(self,filename, linenum=None):
     print "Calling my own editor, jed ... via hook!"
     import os
     if linenum is None: linenum = 0
     os.system('jed +%d %s' % (linenum, filename))
     print "exiting jed"
 
 ip.set_hook('editor',jed_editor)
 
 o = ip.options()
 o.autocall = 2  # FULL autocall mode
 
 print "done!"
     
 '''
  
  
 class TryNext(Exception):
     """ Try next hook exception.
      
      Raise this in your hook function to indicate that the next
      hook handler should be used to handle the operation.
+     If you pass arguments to the constructor those arguments will be
+     used by the next hook instead of the original ones.
     """
- 
-   
+
+    def __init__(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+
 # contains the most recently instantiated IPApi
 _recent = None
 
 def get():
     """ Get an IPApi object, or None if not running under ipython
 
     Running this should be the first thing you do when writing
     extensions that can be imported as normal modules. You can then 
     direct all the configuration operations against the returned 
     object.
 
     """
 
     return _recent
 
  
  
 class IPApi:
     """ The actual API class for configuring IPython 
     
     You should do all of the IPython configuration by getting 
     an IPApi object with IPython.ipapi.get() and using the provided
     methods.
     
     """
     def __init__(self,ip):
         
         self.magic = ip.ipmagic
         
         self.system = ip.ipsystem
         
         self.set_hook = ip.set_hook
         
         self.set_custom_exc = ip.set_custom_exc
         
         self.IP = ip
         global _recent
         _recent = self
 
         
     
     def options(self):
         """ All configurable variables """
         return self.IP.rc
     
     def user_ns(self):
         return self.IP.user_ns
     
     def expose_magic(self,magicname, func):
         ''' Expose own function as magic function for ipython 
     
         def foo_impl(self,parameter_s=''):
             """My very own magic!. (Use docstrings, IPython reads them)."""
             print 'Magic function. Passed parameter is between < >: <'+parameter_s+'>'
             print 'The self object is:',self
     
         ipapi.expose_magic("foo",foo_impl)
         '''
                 
         import new
         im = new.instancemethod(func,self.IP, self.IP.__class__)
         setattr(self.IP, "magic_" + magicname, im)
     
     
     def ex(self,cmd):
         """ Execute a normal python statement in user namespace """
         exec cmd in self.user_ns()
     
     def ev(self,expr):
         """ Evaluate python expression expr in user namespace 
         
         Returns the result of evaluation"""
         return eval(expr,self.user_ns())
     
     def meta(self):
         """ Get a session-specific data store
         
         Object returned by this method can be used to store
         data that should persist through the ipython session.
         """
         return self.IP.meta
     
     def getdb(self):
         """ Return a handle to persistent dict-like database
         
         Return a PickleShareDB object.
         """
         return self.IP.db
     def runlines(self,lines):
         """ Run the specified lines in interpreter, honoring ipython directives.
         
         This allows %magic and !shell escape notations.
         
         Takes either all lines in one string or list of lines.
         """
         if isinstance(lines,basestring):
             self.IP.runlines(lines)
         else:
             self.IP.runlines('\n'.join(lines))
 
 
 def launch_new_instance(user_ns = None):
     """ Create and start a new ipython instance.
     
     This can be called even without having an already initialized 
     ipython session running.
     
     This is also used as the egg entry point for the 'ipython' script.
     
     """
     ses = create_session(user_ns)
     ses.mainloop()
 
 
 def create_session(user_ns = None):    
     """ Creates, but does not launch an IPython session.
     
     Later on you can call obj.mainloop() on the returned object.
     
     This should *not* be run when a session exists already.
     
     """
     if user_ns is not None: 
         user_ns["__name__"] = user_ns.get("__name__",'ipy_session')
     import IPython
     return IPython.Shell.start(user_ns = user_ns)
  No newline at end of file