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"""Traits-aware tab completion.
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This module provides a custom tab-completer that intelligently hides the names
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that the enthought.traits library (http://code.enthought.com/traits)
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automatically adds to all objects that inherit from its base HasTraits class.
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To use this, put in your ~/.ipython/ipy_user_conf.py file:
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from ipy_traits_completer import activate
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activate([complete_threshold])
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The optional complete_threshold argument is the minimal length of text you need
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to type for tab-completion to list names that are automatically generated by
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traits. The default value is 3. Note that at runtime, you can change this
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value simply by doing:
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import ipy_traits_completer
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ipy_traits_completer.COMPLETE_THRESHOLD = 4
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The system works as follows. If t is an empty object that HasTraits, then
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(assuming the threshold is at the default value of 3):
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doesn't show anything at all, but:
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t.edit_traits t.editable_traits
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shows these two names that come from traits. This allows you to complete on
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the traits-specific names by typing at least 3 letters from them (or whatever
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you set your threshold to), but to otherwise not see them in normal completion.
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- This requires Python 2.4 to work (I use sets). I don't think anyone is
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using traits with 2.3 anyway, so that's OK.
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#############################################################################
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from enthought.traits import api as T
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from IPython.ipapi import TryNext, get as ipget
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from IPython.genutils import dir2
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from sets import Set as set
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#############################################################################
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# The completion threshold
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# This is currently implemented as a module global, since this sytem isn't
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# likely to be modified at runtime by multiple instances. If needed in the
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# future, we can always make it local to the completer as a function attribute.
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COMPLETE_THRESHOLD = 3
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# Set of names that Traits automatically adds to ANY traits-inheriting object.
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# These are the names we'll filter out.
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TRAIT_NAMES = set( dir2(T.HasTraits()) ) - set( dir2(object()) )
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#############################################################################
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def trait_completer(self,event):
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"""A custom IPython tab-completer that is traits-aware.
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It tries to hide the internal traits attributes, and reveal them only when
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it can reasonably guess that the user really is after one of them.
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#print '\nevent is:',event # dbg
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symbol_parts = event.symbol.split('.')
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base = '.'.join(symbol_parts[:-1])
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#print 'base:',base # dbg
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oinfo = self._ofind(base)
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if not oinfo['found']:
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# OK, we got the object. See if it's traits, else punt
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if not isinstance(obj,T.HasTraits):
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# it's a traits object, don't show the tr* attributes unless the completion
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# Now, filter out the attributes that start with the user's request
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attr_start = symbol_parts[-1]
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attrs = [a for a in attrs if a.startswith(attr_start)]
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# Let's also respect the user's readline_omit__names setting:
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omit__names = ipget().options.readline_omit__names
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attrs = [a for a in attrs if not a.startswith('__')]
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elif omit__names == 2:
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attrs = [a for a in attrs if not a.startswith('_')]
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#print '\nastart:<%r>' % attr_start # dbg
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if len(attr_start)<COMPLETE_THRESHOLD:
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attrs = list(set(attrs) - TRAIT_NAMES)
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# The base of the completion, so we can form the final results list
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tcomp = [bdot+a for a in attrs]
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#print 'tcomp:',tcomp
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def activate(complete_threshold = COMPLETE_THRESHOLD):
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"""Activate the Traits completer.
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complete_threshold : int
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The minimum number of letters that a user must type in order to
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activate completion of traits-private names."""
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if not (isinstance(complete_threshold,int) and
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complete_threshold>0):
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e='complete_threshold must be a positive integer, not %r' % \
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# Set the module global
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global COMPLETE_THRESHOLD
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COMPLETE_THRESHOLD = complete_threshold
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# Activate the traits aware completer
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ip.set_hook('complete_command', trait_completer, re_key = '.*')
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#############################################################################
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if __name__ == '__main__':
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# A sorted list of the names we'll filter out
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TNL = list(TRAIT_NAMES)
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# Make a few objects for testing
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class TClean(T.HasTraits): pass
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class Bunch(object): pass
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# A clean traits object
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# A nested object containing t
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# And a naked new-style object
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# A few simplistic tests
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# Reset the threshold to the default, in case the test is running inside an
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# instance of ipython that changed it
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import ipy_traits_completer
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ipy_traits_completer.COMPLETE_THRESHOLD = 3
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assert ip.complete('t.ed') ==[]
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# For some bizarre reason, these fail on the first time I run them, but not
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# afterwards. Traits does some really weird stuff at object instantiation
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ta = ip.complete('t.edi')
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assert ta == ['t.edit_traits', 't.editable_traits']
added
removed
IPython/Extensions/ipy_traits_completer.py
