[Bese-devel] Re: Small form patch

[Vladimir Sekissov]

Good day,

> Meanwhile I wonder how I can pass arguments to the constraints. 
> I got two scenarios: 
>     I'd like the user to type in a password, and repeat it and then check
>     that they match. So I'd like a :equal-to 'password, but I haven't 
>     figured out how to pass an argument to the constraint function.
> 
>     Another scenario is that I want a :unique 'table 'column check that
>     looks up in my database. Again, I need to pass arguments to the 
>     function.

There are two ways probably.

- from constraint function:

(defun my-passwd-constraint (value-first element)
   (let* ((form (parent element))
         ;; we don't know the order of elements in the form
         ;; get value directly
         (value-second (read-client-value (password-second form))))
      (unless (equal value-second value-first)
        (signal-ie-constraint-violation ...))))

- from form/composite VALIDATE-VALUE method:

(defmethod validate-value :after ((f my-form) slot-alist &key &allow-other-keys)
  (when (not (equal (cdr (assoc 'password slot-alist))
                         (cdr (assoc 'password-second slot-alist))))
     (report-error f 'password "Don't mutch")
     (push 'password (invalid-slots f))))


The second case is probably relevant to the first.

Best Regards,
Vladimir Sekissov