Set web-mode engine per directory

Question

I'm hoping this is possible. I work in a variety of environments and languages. Right now it's mostly django and Node.js, but there have been others. What I would like to do is set the web-mode engine based on the project I am currently working on, and not the file extension. I know I could use .djhtml as the file extension, but that messes things up for others who aren't using Emacs because, for example, Pycharm doesn't know what to do with a .djhtml file. I would prefer to keep my .html if at all possible.

I am wondering if there is any way to set the web-mode engine based on the project I'm working in. I'd rather not have to put -*- engine: django -*- into each of my files either, if I can avoid it.

UPDATE:

I've tried adding the following to a .dir-locals.el file, but it doesn't seem to make a difference. I get prompted to allow the variable change, and the value of the variable web-mode-engines-alist has changed to (("django" . "\\.html\\'")), but django is not set as the template engine when I open a .html file.

((web-mode .
    ((web-mode-engines-alist .
          (("django" . "\\.html\\'"))))))

UPDATE 2

To clarify, I can set all .html files to open with the django engine by putting the following in my .spacemacs file:

(setq web-mode-engines-alist
      '(("django" . "\\.html\\'")))

That works just fine, but sets it globally, meaning I'll get the django engine in any .html file, regardless if it's a django project or another language.

SYSTEM INFORMATION

• Emacs: 25.2.1
• OS: Windows 10

I found this bug reported in web-mode (https://github.com/fxbois/web-mode/issues/799), but it's just referred to be asked as a question here.

Answer 1

Have you tried adding a web-mode-hook to check if you are in a projectile project? You would also have to check if the projectile project is a django one, but I am not that familiar with django.

(defun cesco/django ()
    (if (projectile-project-p)
        (if (file-exists-p (concat (projectile-project-root) "manage.py"))
            (web-mode-set-engine "django")
            (message "do not exists") ;; You can safely delet this line
            )
        )
    )
(add-hook 'web-mode-hook 'cesco/django)

Answer 2

I have found a solution thanks to this recipe: https://www.emacswiki.org/emacs/LocalVariables .

I set a custom variable in .dir-locals:

((nil . ((mik-web-mode-engine . "django")))
 (python-mode (pyvenv-activate . "../pyenv/api_bo"))
 (mhtml-mode . ((mik-web-mode-engine . "django")
                (mode . web))))

Then I read it from a hook defined in my init file:

;; web-mode
(defun my-web-mode-hook ()
  "Hooks for Web mode. Add a local hook which set the engine to the one specified by
   `mik-web-mode-engine` local variable."
  (add-hook
   'hack-local-variables-hook
   (lambda ()
     (if (boundp 'mik-web-mode-engine)
         (progn
           (message "web-mode-engine is %s" mik-web-mode-engine)
           (web-mode-set-engine mik-web-mode-engine))
       (progn
         (message "no web-mode-engine settled")
         (web-mode-set-engine "none"))))))
(add-hook 'web-mode-hook  'my-web-mode-hook nil nil)

Note that I switch from mhtml-mode (the default on my setup) to web-mode. If you have defined web-mode as the default for HTML you don't need that.