The comparison between Angular and Rails I base on broader characteristics than those embodied in language or framework features. One of those characteristics, a primary one in fact, is that of convention over configuration; Angular, like Rails, defines specific conventions, which only an expert can safely bypass, and to which non-experts must adhere on pain of having a very bad time.
> there are at least 20 books on angularjs that are easy to read to understand the framework properly
A prototypical example of the sort of wizard comment about which I spoke earlier.
> The big issue[, ]in my opinion[, ]is that one needs to know how [J]avascript works in order to understand how directives work.
True of any framework, though; if you don't understand the language in which it is built, you are certainly going to be at sea in trying to use it. Angular isn't special in this regard.
(Also, some notes on English orthographic conventions, for the benefit of someone who may not yet be familiar with them: First, medial and terminal punctuation, such as commas and periods, is invariably followed by a space, as exemplified in this comment. Second, abbreviations such as "isn't" and "doesn't" take an apostrophe before the final 't'. Hope this helps!)
> there are at least 20 books on angularjs that are easy to read to understand the framework properly
A prototypical example of the sort of wizard comment about which I spoke earlier.
> The big issue[, ]in my opinion[, ]is that one needs to know how [J]avascript works in order to understand how directives work.
True of any framework, though; if you don't understand the language in which it is built, you are certainly going to be at sea in trying to use it. Angular isn't special in this regard.
(Also, some notes on English orthographic conventions, for the benefit of someone who may not yet be familiar with them: First, medial and terminal punctuation, such as commas and periods, is invariably followed by a space, as exemplified in this comment. Second, abbreviations such as "isn't" and "doesn't" take an apostrophe before the final 't'. Hope this helps!)