Re:Re: widget-create 'menu-choice

Re:Re: widget-create 'menu-choice

[Mortimer Cladwell]

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Your suggestion evaluates to:

((item "human") (item "rat") (item "mouse"))

which when inserted into a form results in the error:

widget-create: Invalid function: (item "human")

Evaluations that would work are:

'(item "human") '(item "rat") '(item "mouse")
OR 

(quote (item "human"))  (quote (item "rat")) (quote (item "mouse"))

Note that there are no enclosing parenthesis around the list.
Thanks
Mortimer-----------------------------------------------------------------

Mortimer Cladwell wrote: 
Hi,
>I would like to dynamically populate a dropdown widget from a database. the 'menu-choice widget looks like
>(widget-create 'menu-choice
>:tag "Select Host Species"
>:value "unknown"
>:notify (lambda (widget &rest ignore)
>(setq host-species (widget-value widget)))
>'(item "human")
>'(item "rat")
>'(item "mouse"))
>Suppose I can generate a list '( "human "rat" "mouse") from the database. How to create
>'(item "human")
>'(item "rat")
>'(item "mouse")
>on the fly? The closest I can come is
>(progn
>(setq var '( "human" "rat" "mouse"))
>(mapcar '(lambda (a) `'(item ,a)) var)
>) 

i.e.

(let ((var '("human" "rat" "mouse")))
  (mapcar (lambda (label) (list 'item label))
          var))

--
Kevin Rodgers
Denver, Colorado, USA


      

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Re: widget-create 'menu-choice

[Kevin Rodgers]

Mortimer Cladwell wrote:
> Your suggestion evaluates to:
>  
> ((item "human") (item "rat") (item "mouse"))
>  
> which when inserted into a form results in the error:
>  
> widget-create: Invalid function: (item "human")

Ah, I misread the widget-create arguments.  That function's doc string is
practically useless.

> Evaluations that would work are:
>  
> '(item "human") '(item "rat") '(item "mouse")
> OR
> 
> (quote (item "human"))  (quote (item "rat")) (quote (item "mouse"))
 >
> Note that there are no enclosing parenthesis around the list.

As Andreas points out, you need apply:

(defvar species '("human" "rat" "mouse"))

(apply 'widget-create
        'menu-choice
        :tag "Select Host Species"
        :value "unknown"
        :notify (lambda (widget &rest ignore)
		 (setq host-species (widget-value widget)))
        (mapcar (lambda (label) (list 'item label))
	       species))

-- 
Kevin Rodgers
Denver, Colorado, USA