Re: intercept settable_event

[hz <hz@...>]

just a little inconvenient when used with: 

for k, v in pairs(obj) do … end

the keys in the realobj will be ignored. It's a known issue:

Why don't pairs() and ipairs() obey an __index metamethod

http://lua-users.org/lists/lua-l/2007-09/msg00374.html

/hz

在 2017年1月17日，下午8:46，hz <hz@fiosoftware.com> 写道：

Thanks. 

had implemented as this:

--

setmetatable(obj, {

__newindex = function (tab, k, v)

print('setting: ' .. k .. ' -> ' .. tostring(v))

rawset(tab, k, v)

end

})

which will only trigger the first setting for a new key:

self.data['foo'] = 'bar'

self.data['foo'] = 'next-bar’

—

any way, nice solution, thanks.

在 2017年1月17日，下午8:06，云风 Cloud Wu <cloudwu@gmail.com> 写道：

hz <hz@fiosoftware.com>于2017年1月18日周三 上午11:45写道：

is there a way to intercept the settable_event?

want to implement kind of getter/setter observer for a table (similar to the KVO in Cocoa). Is there a way to do this in pure lua?

local realobj = {}

local obj = setmetatable({}, { 

  __index = realobj, 

  __newindex = function(self, k, v)

    -- it's settable event for obj

    realobj[k]=v

 end,

})