Javascript not autocompleting with Yasnippet and Auto-complete

Question

I really want to use emacs as a Javascript IDE. I have followed all the directions I can, includings Yasnippets and Autocomplete, but I still have some issues.

If you look at the differences, in Jedi the auto-completion and pop-up window appears almost right away in Python files. In my javascript, the only words that appear for autocorrect are those that previously appear (and they are not in a drop-down window) not even function (see attached).

I have loaded external libraries and it looks like everything works, does any body have advice here?

Here is my .emacs

;; js2 mode                                                                                                                                                                     
(add-hook 'js-mode-hook 'js2-minor-mode)                                                                                                                                        
(add-hook 'js-mode-hook 'ac-js2-mode)                                                                                                                                           
(setq js2-highlight-level 3)                                                                                                                                                    
(add-to-list 'auto-mode-alist (cons (rx ".js" eos) 'js2-mode))                                                                                                                  
(add-to-list 'auto-mode-alist '("\\.json$" . js2-mode)) 

;; yasnippit                                                                                                                                                                    
;; load before auto complete                                                                                                                                                    
(require 'yasnippet)                                                                                                                                                            
(setq yas-snippet-dirs                                                                                                                                                          
      '("~/.emacs.d/snippets/javascript-mode"                                                                                                                                   
        "~/.emacs.d/snippets/js-yasnippets"                                                                                                                                     
      ))                                                                                                                                                                        
(yas-global-mode 1)                                                                                                                                                             


;; autocomplete mode                                                                                                                                                            
(require 'auto-complete-config)                                                                                                                                                 
(add-to-list 'ac-dictionary-directories "~/.emacs.d/ac-dict")                                                                                                                   
(add-to-list 'ac-sources 'ac-source-yasnippet)                                                                                                                                  
(ac-config-default)                                                                                                                                                             
(ac-set-trigger-key "TAB")                                                                                                                                                      
(ac-set-trigger-key "<tab>")                                                                                                                                                    

;; use spaces instead of tabs                                                                                                                                                   
(setq-default indent-tabs-mode nil) 

Answer 1

That is because jedi is a Python library that statically analyzes Python code to suggest completion candidates. Installing the jedi.el package enabled its abilities for auto-complete-mode and extended them beyond the suggestion of already used words and predefined ones.

If you wish to have the same experience with Javascript, you will either need to find a similiarly powerful backend like tern.js and install an Emacs package for it or alternatively could check whether your major mode supports completion suggestions (by hitting M-TAB after typing a word partially) and enable these in auto-complete-mode with the ac-capf package.