Actually Observer method worked pretty well, I used fontDidSave observer. Thanks Fredrik.

Thanks, that did it! :)

Thanks Fredrik, Another feature that I would love is ordering the glyphs manually by dragging them in the glyphs window. I like the glyphs organized when I work with the font, and during the font development I add some glyphs and ordering them manually is not easy. One question, Is there any data in the UFO file format that defines the glyph index of every glyph and make the glyph order sustainable? because adding and deleting glyphs changes the whole order of the glyphs.

thanks

I don’t know the difference! But in fontlab when I open a font, in the kern feature I can see that LTR kerning is interpreted like this:
pos uni0631 uni0628 -225;
But RTL kerning is interpreted like this:
pos uni0631 uni0628 < -225 0 -225 0>;
So I suppose RTL kerning should be implemented with adjustments applied to position of the glyph too, maybe I’m wrong; I’m not a pro. (see AFDKO OpenType Feature File Specification)
About the kerning in RoboFont, I think there is a malfunction in the “Right to left” Option in the kerning panel. Here is what I do:
I open a font which already has RTL kerning, Robofont interprets kerning correctly. I open the kerning panel and click on a class pair, the kerning shows up but order of glyphs is incorrect, I turn the “Right to Left” option on; Nothing Happens! I turn it off, now order of glyphs becomes right, even so the kerning has been implemented in RTL order.

Oh thanks Jens, I was starting to think that my arguments were so stupid, so nobody wants to answer me!
Yes, This is the case every time I’m implementing Kerning in Farsi/Arabic fonts. I always have to rely on external python scripts to generate the RTL kerning (except in the Glyphs app that handles it natively and brilliantly intuitive). I really wished that an app could do this without any inconvenient scripting. I can write simple tools but I would rather to concentrate more on design than writing programs. When I saw Robofont 1.4 enhancements and the feature list, I thought finally we have it in Robofont, bummer!