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__setattr__ is not clean and easy readable piece of code. That's why I
dive into decorators and create a <b>notify_property</b>:<br>
<pre>class notify_property(property):
def __init__(self, getter):
def newgetter(slf):
#return None when the property does not exist yet
try:
return getter(slf)
except AttributeError:
return None
super(notify_property, self).__init__(newgetter)
def setter(self, setter):
def newsetter(slf, newvalue):
# do not change value if the new value is the same
# trigger PropertyChanged event when value changes
oldvalue = self.fget(slf)
if oldvalue != newvalue:
setter(slf, newvalue)
slf.OnPropertyChanged(setter.__name__)
return property(
fget=self.fget,
fset=newsetter,
fdel=self.fdel,
doc=self.__doc__)
</pre>
The usage is the same as for @property - see details on my blog:<br>
<a
href="http://gui-at.blogspot.com/2009/11/inotifypropertychanged-in-ironpython.html">http://gui-at.blogspot.com/2009/11/inotifypropertychanged-in-ironpython.html</a><br>
<br>
Unfortunately, this does not work in Silverlight - probably because
such properties are not CLR fields. I'd like to find a way to make it
work in Silverlight too.<br>
<br>
--<br>
-- Lukáš<br>
<br>
<br>
Curt Hagenlocher wrote:
<blockquote
cite="mid:d2155e360911061414x2b7afa83q2fda5d816a137bb6@mail.gmail.com"
type="cite">
<div>Why don't you think that __setattr__ is a good approach? The
alternative (as shown in the linked Japanese-language blog) is to
implement setters for the properties you care about and to manually
trigger the event.<br>
</div>
<div class="gmail_quote">2009/11/6 Lukas Cenovsky <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:cenovsky@bakalari.cz">cenovsky@bakalari.cz</a>></span><br>
<blockquote
style="border-left: 1px solid rgb(204, 204, 204); margin: 0px 0px 0px 0.8ex; padding-left: 1ex;"
class="gmail_quote">Hi all,<br>
I was looking for WPF data binding in IronPython and I have found nice
Japanese blog about it:<br>
<a moz-do-not-send="true"
href="http://palepoli.skr.jp/wp/2009/06/28/wpf-listview-databinding-for-ironpython/"
target="_blank">http://palepoli.skr.jp/wp/2009/06/28/wpf-listview-databinding-for-ironpython/</a><br>
<br>
It links to <a moz-do-not-send="true"
href="http://sdlsdk.codeplex.com/Thread/View.aspx?ThreadId=30322"
target="_blank">http://sdlsdk.codeplex.com/Thread/View.aspx?ThreadId=30322</a>
that should have more information about how to implement
INotifyPropertyChanged in IronPython which I am also interested in.
Unfortunately this page is no more available. Does the guideline exist
somewhere else? Thanks.<br>
<br>
PS: I know about <a moz-do-not-send="true"
href="http://lists.ironpython.com/pipermail/users-ironpython.com/2009-August/010938.html"
target="_blank">http://lists.ironpython.com/pipermail/users-ironpython.com/2009-August/010938.html</a>
but I don't think using __setattr__ is good approach. Also implementing
the PropertyChanged event is different on the blog.<br>
<font color="#888888"><br>
--<br>
-- Lukáš<br>
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</font></blockquote>
</div>
<br>
<pre wrap="">
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</pre>
</blockquote>
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