On 11/8/11 12:37 PM, Axel Rauschmayer wrote:
What’s the use case?
I thought I gave a pretty reasonable one before, but just in case:
In YUI, it’s impossible to use this otherwise-useful pattern:
---------
var base_config = { width: "600px" };
…
var my_config = Object.create(base_config);
my_config.visible = false;
var widget = new Y.Widget(my_config);
---------
In the example above, YUI will not see the “width” property because
YUI rejects all inherited properties when it iterates through the
configuration hash.
Don’t forget that whenever you set a property, you only ever modify the
first object in the prototype chain.
Right…that’s why gave() walks the prototype chain unless it finds the
property *on* the object itself.
The “own property” debate mainly exists, because objects are (ab)used as
dictionaries. Then you don’t want inherited entries such as "toString".
I disagree. That’s actually the crux of what I’m getting at.
IMO, you actually do want “inherited entries”; what you don’t want are
specifically those things inherited from Object.prototype. Weeding out
*all* inherited properties assumes that there is no legitimate use case
for objects inheriting from other objects…which defeats the whole
purpose of stuff like Object.create().
-FG
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