src/mewa/slot-presentations.lisp

(in-package :it.bese.ucw)

(defun multiple-value-funcall->list (function &rest args)
  "The function to be called by m-v-bf"
		   (multiple-value-call #'list (apply function args)))

(defmacro multiple-value-bindf (vars form &body body)
  "Like M-V-B, only it works in actions. form must be a function call"
		   `(destructuring-bind ,vars
		     (multiple-value-funcall->list #',(car form) ,@(cdr form))
		     ,@body))

(defcomponent mewa-slot-presentation ()
  ((slot-name :accessor slot-name
	      :initarg :slot-name
	      :documentation
	      "The name of the slot being accessed")
   (fill-gaps-only-p :accessor fill-gaps-only-p
		     :initarg :fill-gaps-only-p
		     :initform nil
		     :documentation
		     "When nil, the instance is syncronised with the database.
When T, only the default value for primary keys and the joins are updated."))
  (:documentation "The superclass of all Mewa slot presentations"))

;;;; this has to be in the eval when i would think
(eval-when (:compile-toplevel :load-toplevel :execute)
  (defun generate-slot-presentation-definition-for-type (type)
    (let* ((u-name (intern (format nil "~A-SLOT-PRESENTATION" type)))
	   (sp-name (intern (format nil "MEWA-~A" u-name)))
	   (t-name (intern (format nil "MEWA-~A" type))))
      `(defslot-presentation ,sp-name (,u-name mewa-slot-presentation)
	()
	(:type-name ,t-name)))))

(defmacro define-base-mewa-presentations (&body types)
  "Define the mewa-slot-presentations by subclassing the base UCW ones"
    `(progn ,@(mapcar #'generate-slot-presentation-definition-for-type
		      types)))

;;;then actually define the base presentations :
(define-base-mewa-presentations
  boolean
  string
  number
  integer
  currency)


(defslot-presentation clsql-wall-time-slot-presentation (mewa-relation-slot-presentation)
       ()
       (:type-name clsql-sys:wall-time))

(defmethod presentation-slot-value ((slot clsql-wall-time-slot-presentation) instance)
  (let ((date (call-next-method)))
    (when date (multiple-value-bind (y m d) (clsql:time-ymd date)
      (format nil "~a/~a/~a" m d y)))))

(defmethod (setf presentation-slot-value) ((value string) (slot clsql-wall-time-slot-presentation) instance)
  (let ((new-time (clsql:parse-date-time (remove #\Space value)))
	(old-time (when (slot-boundp instance (slot-name slot))
		    (slot-value instance (slot-name slot)))))
    (unless (or (eql old-time new-time)
		(when (and new-time old-time)
		  (equal :equal (clsql:time-compare new-time old-time))))
    (setf (presentation-slot-value slot instance) new-time ))))

(defmethod label :around ((slot clsql-wall-time-slot-presentation))
  (concatenate 'string (call-next-method) "  (mm/dd/yyyy)"))

(defmethod present-slot ((slot clsql-wall-time-slot-presentation) instance)
  (let ((date (presentation-slot-value slot instance))
	(input-id (string (gensym))))
    (if (and date (not (editablep slot)))
	(<:span (<:as-html date)))
    (when (editablep slot)
      (<ucw:input :accessor (presentation-slot-value slot instance) :id input-id)
      (<:script :type "text/javascript"
		(<:as-is (format nil "
      Calendar.setup({
        inputField     :    \"~a\",
        ifFormat       :    \"%m/%d/%Y\",
      });" input-id))))))

(defslot-presentation  mewa-relation-slot-presentation (mewa-slot-presentation slot-presentation)
  ((foreign-instance :accessor foreign-instance)
   (linkedp :accessor linkedp :initarg :linkedp :initform t)
   (creator :accessor creator :initarg :creator :initform :editor))
  (:type-name relation))

(defaction search-records ((slot mewa-relation-slot-presentation) instance)
  (multiple-value-bindf (finstance foreign-slot-name)
      (meta-model:explode-foreign-key instance (slot-name slot))
    (let ((new-instance
            (call-component
             (parent slot)
             (make-instance (or (cadr (mewa:find-attribute finstance :presentation-search))
                                'mewa::mewa-presentation-search)
                            :search-presentation
                            (mewa:make-presentation finstance
                                                    :type :search-presentation)
                            :list-presentation
                            (mewa:make-presentation finstance
                                                    :type :listing)))))
      (setf (slot-value instance (slot-name slot)) (slot-value new-instance foreign-slot-name))
      (meta-model:sync-instance instance :fill-gaps-only-p (fill-gaps-only-p self)))))

(defaction create-record-on-foreign-key ((slot mewa-relation-slot-presentation) instance)
  (multiple-value-bindf (finstance foreign-slot-name)
      (meta-model:explode-foreign-key instance (slot-name slot))
    (let ((new-instance
           (call-component
            (parent slot)
            (mewa:make-presentation finstance :type (creator self)))))

      ;;;; TODO: this next bit is due to a bad design decision.
      ;;;; Components should always have (ok) return self, but somewhere
      ;;;; i've made in return (instance self) sometimes, and this
      ;;;; bahaviour is totatlly fucked.

     (when (typep new-instance 'mewa::mewa)
       (setf new-instance (instance new-instance)))

      ;;;; sorry about that, and now back t our regular program.

      (meta-model:sync-instance new-instance)
      (setf (slot-value instance (slot-name slot)) (slot-value new-instance foreign-slot-name))
      (meta-model:sync-instance instance :fill-gaps-only-p (fill-gaps-only-p self)))))


(defmethod present-relation ((slot mewa-relation-slot-presentation) instance)
 ;;;;(<:as-html (slot-name slot) "=> " (foreign-instance slot) " from " instance )
  (let* ((i (foreign-instance slot))
	 (pres (mewa::make-presentation
		i
		:type :one-line
		:initargs (list
			   :global-properties
			   (list :editablep nil :linkedp nil)))))
      (when (and (ucw::parent slot) (slot-boundp slot 'ucw::place))
	(setf (component.place pres) (component.place (ucw::parent slot))))
      (when i (<ucw:render-component :component pres))))


(defmethod present-slot ((slot mewa-relation-slot-presentation) instance)
  (present-relation slot instance))

(defslot-presentation foreign-key-slot-presentation (mewa-relation-slot-presentation)
  ()
  (:type-name foreign-key)
  (:default-initargs))

(defaction view-instance ((self component) instance &rest initargs)
  (call-component (parent self) (apply #'mewa:make-presentation instance initargs))
  ;; the viewed instance could have been changed/deleted, so we sync this instance
  (meta-model:sync-instance (instance (parent self))))


(defmethod present-slot :before ((slot foreign-key-slot-presentation) instance)
  ())


(defmethod  present-slot :around ((slot foreign-key-slot-presentation) instance)
  (setf (foreign-instance slot)
	(when (presentation-slot-value slot instance)
	  (meta-model:explode-foreign-key instance (slot-name slot))))
  (flet ((render () (when (foreign-instance slot)(call-next-method))))
    (if (slot-boundp slot 'place)
        (cond
          ((editablep slot)
           (render)
           (<ucw:submit :action  (search-records slot instance) :value "Search" :style "display:inline")
           (<ucw:submit :action  (create-record-on-foreign-key slot instance) :value "Add New" :style "display:inline"))
          ((linkedp slot)
           (<ucw:a :action (view-instance slot (foreign-instance slot))
                   (render)))
          (t
           (render)))
	;; presentation is used only for rendering
        (render))))

;;;; HAS MANY
(defslot-presentation has-many-slot-presentation (mewa-relation-slot-presentation)
  ((add-new-label :accessor add-new-label :initarg :add-new-label :initform "Add New"))
  (:type-name has-many))


(defaction add-to-has-many ((slot has-many-slot-presentation) instance)
  ;; if the instance is not stored we must make sure to mark it stored now!
  (unless (mewa::instance-is-stored-p instance)
    (setf (mewa::modifiedp (parent self)) t))
  ;; sync up the instance
  (mewa:ensure-instance-sync (parent slot))

  (multiple-value-bindf (class home foreign)
      (meta-model:explode-has-many instance (slot-name slot))
    (let ((new (make-instance class)))
      (setf (slot-value new foreign) (slot-value instance home))
      (meta-model:sync-instance new :fill-gaps-only-p (fill-gaps-only-p self))
      (call-component (parent slot) (mewa:make-presentation new :type (creator slot)))
      (meta-model:sync-instance instance))))

(defmethod present-slot ((slot has-many-slot-presentation) instance)
  (when (slot-boundp slot 'place)
    (<ucw:submit :action (add-to-has-many slot instance) :value (add-new-label slot)))
  (let ((i (get-foreign-instances slot instance)))

    (<:ul
     (dolist (s i)
       (let ((s s))
	 (setf (foreign-instance slot) s)
         (when (slot-boundp slot 'place)
           (<ucw:a :action (view-instance slot s :initargs `(:global-properties ,(list :linkedp t :editablep nil)))
		 (<:li   (setf (linkedp slot) nil)
			 (present-relation slot instance)))))))))


(defmethod get-foreign-instances ((slot has-many-slot-presentation) instance)
  (slot-value instance (slot-name slot)))

(defmethod presentation-slot-value ((slot has-many-slot-presentation) instance)
  (get-foreign-instances slot instance))

(defslot-presentation has-very-many-slot-presentation (has-many-slot-presentation)
  ((number-to-display :accessor number-to-display :initarg :number-to-display :initform 10)
   (current :accessor current :initform 0)
   (len :accessor len )
   (instances :accessor instances))

  (:type-name has-very-many))

(defmethod list-next ((slot has-very-many-slot-presentation))
  (setf (current slot) (incf (current slot) (number-to-display slot)))
  (when (< (len slot) (current slot))
    (setf (current slot) (- (number-to-display slot) (len slot)))))

(defmethod list-prev ((slot has-very-many-slot-presentation))
  (setf (current slot) (decf (current slot) (number-to-display slot)))
  (when  (> 0 (current slot))
    ;;what to do here is open to debate
    (setf (current slot) (- (len slot)(number-to-display slot)  ))))


(defmethod present-slot ((slot has-very-many-slot-presentation) instance)
  ;;(<:as-html "isance: " instance)
  (if (slot-boundp slot 'place)
      (progn
        (<ucw:a :action (list-prev slot) (<:as-html "<<"))
        (let ((self (parent slot)))
          (<ucw:a :action (call-component self (mewa:make-presentation (car (slot-value instance (slot-name slot))) :type :listing :initargs (list :instances (instances slot))))
	        (<:as-html  (label slot) (format nil " ~a-~a " (current slot) (+ (current slot) (number-to-display slot))))))
        (<ucw:a :action (list-next slot) (<:as-html ">>"))
        (call-next-method)
        (<:as-html "total :" (len slot)))
      (call-next-method)))

(defmethod get-foreign-instances :around ((slot has-very-many-slot-presentation) instance)
  (let ((f (call-next-method)))
    (setf (len slot) (length f))
    (setf (instances slot) f)
  (loop for cons on (nthcdr (current slot) f)
		   for i from 0 upto (number-to-display slot)
		   collect (car cons))))

(defslot-presentation has-a-slot-presentation (one-of-presentation)
  ((key :initarg :key :accessor key))
  (:type-name has-a))

(defmethod get-foreign-slot-value ((slot has-a-slot-presentation) (object t) (slot-name t))
  (slot-value object slot-name))

(defmethod present-slot ((slot has-a-slot-presentation) instance)
      (<:as-html (presentation-slot-value slot instance))
  (if (editablep slot)
      (<ucw:select :accessor (presentation-slot-value slot instance) :test #'equalp
        (when (allow-nil-p slot)
	  (<ucw:option :value nil (<:as-html (none-label slot))))
	(dolist (option (get-foreign-instances (presentation slot) instance))
	  (setf (instance (presentation slot)) option)
	  (<ucw:option :value (get-foreign-slot-value slot option (key slot)) (present (presentation slot)))))
      (if (presentation-slot-value slot instance)
	  (progn
	    (setf (instance (presentation slot)) (presentation-slot-value slot instance))
	    (present (presentation slot)))
	  (<:as-html "--"))))
Commit	Line	Data
	1	(in-package :it.bese.ucw)
	2
	3	(defun multiple-value-funcall->list (function &rest args)
	4	"The function to be called by m-v-bf"
	5	(multiple-value-call #'list (apply function args)))
	6
	7	(defmacro multiple-value-bindf (vars form &body body)
	8	"Like M-V-B, only it works in actions. form must be a function call"
	9	`(destructuring-bind ,vars
	10	(multiple-value-funcall->list #',(car form) ,@(cdr form))
	11	,@body))
	12
	13	(defcomponent mewa-slot-presentation ()
	14	((slot-name :accessor slot-name
	15	:initarg :slot-name
	16	:documentation
	17	"The name of the slot being accessed")
	18	(fill-gaps-only-p :accessor fill-gaps-only-p
	19	:initarg :fill-gaps-only-p
	20	:initform nil
	21	:documentation
	22	"When nil, the instance is syncronised with the database.
	23	When T, only the default value for primary keys and the joins are updated."))
	24	(:documentation "The superclass of all Mewa slot presentations"))
	25
	26	;;;; this has to be in the eval when i would think
	27	(eval-when (:compile-toplevel :load-toplevel :execute)
	28	(defun generate-slot-presentation-definition-for-type (type)
	29	(let* ((u-name (intern (format nil "~A-SLOT-PRESENTATION" type)))
	30	(sp-name (intern (format nil "MEWA-~A" u-name)))
	31	(t-name (intern (format nil "MEWA-~A" type))))
	32	`(defslot-presentation ,sp-name (,u-name mewa-slot-presentation)
	33	()
	34	(:type-name ,t-name)))))
	35
	36	(defmacro define-base-mewa-presentations (&body types)
	37	"Define the mewa-slot-presentations by subclassing the base UCW ones"
	38	`(progn ,@(mapcar #'generate-slot-presentation-definition-for-type
	39	types)))
	40
	41	;;;then actually define the base presentations :
	42	(define-base-mewa-presentations
	43	boolean
	44	string
	45	number
	46	integer
	47	currency)
	48
	49
	50	(defslot-presentation clsql-wall-time-slot-presentation (mewa-relation-slot-presentation)
	51	()
	52	(:type-name clsql-sys:wall-time))
	53
	54	(defmethod presentation-slot-value ((slot clsql-wall-time-slot-presentation) instance)
	55	(let ((date (call-next-method)))
	56	(when date (multiple-value-bind (y m d) (clsql:time-ymd date)
	57	(format nil "~a/~a/~a" m d y)))))
	58
	59	(defmethod (setf presentation-slot-value) ((value string) (slot clsql-wall-time-slot-presentation) instance)
	60	(let ((new-time (clsql:parse-date-time (remove #\Space value)))
	61	(old-time (when (slot-boundp instance (slot-name slot))
	62	(slot-value instance (slot-name slot)))))
	63	(unless (or (eql old-time new-time)
	64	(when (and new-time old-time)
	65	(equal :equal (clsql:time-compare new-time old-time))))
	66	(setf (presentation-slot-value slot instance) new-time ))))
	67
	68	(defmethod label :around ((slot clsql-wall-time-slot-presentation))
	69	(concatenate 'string (call-next-method) " (mm/dd/yyyy)"))
	70
	71	(defmethod present-slot ((slot clsql-wall-time-slot-presentation) instance)
	72	(let ((date (presentation-slot-value slot instance))
	73	(input-id (string (gensym))))
	74	(if (and date (not (editablep slot)))
	75	(<:span (<:as-html date)))
	76	(when (editablep slot)
	77	(<ucw:input :accessor (presentation-slot-value slot instance) :id input-id)
	78	(<:script :type "text/javascript"
	79	(<:as-is (format nil "
	80	Calendar.setup({
	81	inputField : \"~a\",
	82	ifFormat : \"%m/%d/%Y\",
	83	});" input-id))))))
	84
	85	(defslot-presentation mewa-relation-slot-presentation (mewa-slot-presentation slot-presentation)
	86	((foreign-instance :accessor foreign-instance)
	87	(linkedp :accessor linkedp :initarg :linkedp :initform t)
	88	(creator :accessor creator :initarg :creator :initform :editor))
	89	(:type-name relation))
	90
	91	(defaction search-records ((slot mewa-relation-slot-presentation) instance)
	92	(multiple-value-bindf (finstance foreign-slot-name)
	93	(meta-model:explode-foreign-key instance (slot-name slot))
	94	(let ((new-instance
	95	(call-component
	96	(parent slot)
	97	(make-instance (or (cadr (mewa:find-attribute finstance :presentation-search))
	98	'mewa::mewa-presentation-search)
	99	:search-presentation
	100	(mewa:make-presentation finstance
	101	:type :search-presentation)
	102	:list-presentation
	103	(mewa:make-presentation finstance
	104	:type :listing)))))
	105	(setf (slot-value instance (slot-name slot)) (slot-value new-instance foreign-slot-name))
	106	(meta-model:sync-instance instance :fill-gaps-only-p (fill-gaps-only-p self)))))
	107
	108	(defaction create-record-on-foreign-key ((slot mewa-relation-slot-presentation) instance)
	109	(multiple-value-bindf (finstance foreign-slot-name)
	110	(meta-model:explode-foreign-key instance (slot-name slot))
	111	(let ((new-instance
	112	(call-component
	113	(parent slot)
	114	(mewa:make-presentation finstance :type (creator self)))))
	115
	116	;;;; TODO: this next bit is due to a bad design decision.
	117	;;;; Components should always have (ok) return self, but somewhere
	118	;;;; i've made in return (instance self) sometimes, and this
	119	;;;; bahaviour is totatlly fucked.
	120
	121	(when (typep new-instance 'mewa::mewa)
	122	(setf new-instance (instance new-instance)))
	123
	124	;;;; sorry about that, and now back t our regular program.
	125
	126	(meta-model:sync-instance new-instance)
	127	(setf (slot-value instance (slot-name slot)) (slot-value new-instance foreign-slot-name))
	128	(meta-model:sync-instance instance :fill-gaps-only-p (fill-gaps-only-p self)))))
	129
	130
	131	(defmethod present-relation ((slot mewa-relation-slot-presentation) instance)
	132	;;;;(<:as-html (slot-name slot) "=> " (foreign-instance slot) " from " instance )
	133	(let* ((i (foreign-instance slot))
	134	(pres (mewa::make-presentation
	135	i
	136	:type :one-line
	137	:initargs (list
	138	:global-properties
	139	(list :editablep nil :linkedp nil)))))
	140	(when (and (ucw::parent slot) (slot-boundp slot 'ucw::place))
	141	(setf (component.place pres) (component.place (ucw::parent slot))))
	142	(when i (<ucw:render-component :component pres))))
	143
	144
	145
	146	(defmethod present-slot ((slot mewa-relation-slot-presentation) instance)
	147	(present-relation slot instance))
	148
	149	(defslot-presentation foreign-key-slot-presentation (mewa-relation-slot-presentation)
	150	()
	151	(:type-name foreign-key)
	152	(:default-initargs))
	153
	154	(defaction view-instance ((self component) instance &rest initargs)
	155	(call-component (parent self) (apply #'mewa:make-presentation instance initargs))
	156	;; the viewed instance could have been changed/deleted, so we sync this instance
	157	(meta-model:sync-instance (instance (parent self))))
	158
	159
	160
	161	(defmethod present-slot :before ((slot foreign-key-slot-presentation) instance)
	162	())
	163
	164
	165	(defmethod present-slot :around ((slot foreign-key-slot-presentation) instance)
	166	(setf (foreign-instance slot)
	167	(when (presentation-slot-value slot instance)
	168	(meta-model:explode-foreign-key instance (slot-name slot))))
	169	(flet ((render () (when (foreign-instance slot)(call-next-method))))
	170	(if (slot-boundp slot 'place)
	171	(cond
	172	((editablep slot)
	173	(render)
	174	(<ucw:submit :action (search-records slot instance) :value "Search" :style "display:inline")
	175	(<ucw:submit :action (create-record-on-foreign-key slot instance) :value "Add New" :style "display:inline"))
	176	((linkedp slot)
	177	(<ucw:a :action (view-instance slot (foreign-instance slot))
	178	(render)))
	179	(t
	180	(render)))
	181	;; presentation is used only for rendering
	182	(render))))
	183
	184	;;;; HAS MANY
	185	(defslot-presentation has-many-slot-presentation (mewa-relation-slot-presentation)
	186	((add-new-label :accessor add-new-label :initarg :add-new-label :initform "Add New"))
	187	(:type-name has-many))
	188
	189
	190	(defaction add-to-has-many ((slot has-many-slot-presentation) instance)
	191	;; if the instance is not stored we must make sure to mark it stored now!
	192	(unless (mewa::instance-is-stored-p instance)
	193	(setf (mewa::modifiedp (parent self)) t))
	194	;; sync up the instance
	195	(mewa:ensure-instance-sync (parent slot))
	196
	197	(multiple-value-bindf (class home foreign)
	198	(meta-model:explode-has-many instance (slot-name slot))
	199	(let ((new (make-instance class)))
	200	(setf (slot-value new foreign) (slot-value instance home))
	201	(meta-model:sync-instance new :fill-gaps-only-p (fill-gaps-only-p self))
	202	(call-component (parent slot) (mewa:make-presentation new :type (creator slot)))
	203	(meta-model:sync-instance instance))))
	204
	205	(defmethod present-slot ((slot has-many-slot-presentation) instance)
	206	(when (slot-boundp slot 'place)
	207	(<ucw:submit :action (add-to-has-many slot instance) :value (add-new-label slot)))
	208	(let ((i (get-foreign-instances slot instance)))
	209
	210	(<:ul
	211	(dolist (s i)
	212	(let ((s s))
	213	(setf (foreign-instance slot) s)
	214	(when (slot-boundp slot 'place)
	215	(<ucw:a :action (view-instance slot s :initargs `(:global-properties ,(list :linkedp t :editablep nil)))
	216	(<:li (setf (linkedp slot) nil)
	217	(present-relation slot instance)))))))))
	218
	219
	220	(defmethod get-foreign-instances ((slot has-many-slot-presentation) instance)
	221	(slot-value instance (slot-name slot)))
	222
	223	(defmethod presentation-slot-value ((slot has-many-slot-presentation) instance)
	224	(get-foreign-instances slot instance))
	225
	226	(defslot-presentation has-very-many-slot-presentation (has-many-slot-presentation)
	227	((number-to-display :accessor number-to-display :initarg :number-to-display :initform 10)
	228	(current :accessor current :initform 0)
	229	(len :accessor len )
	230	(instances :accessor instances))
	231
	232	(:type-name has-very-many))
	233
	234	(defmethod list-next ((slot has-very-many-slot-presentation))
	235	(setf (current slot) (incf (current slot) (number-to-display slot)))
	236	(when (< (len slot) (current slot))
	237	(setf (current slot) (- (number-to-display slot) (len slot)))))
	238
	239	(defmethod list-prev ((slot has-very-many-slot-presentation))
	240	(setf (current slot) (decf (current slot) (number-to-display slot)))
	241	(when (> 0 (current slot))
	242	;;what to do here is open to debate
	243	(setf (current slot) (- (len slot)(number-to-display slot) ))))
	244
	245
	246	(defmethod present-slot ((slot has-very-many-slot-presentation) instance)
	247	;;(<:as-html "isance: " instance)
	248	(if (slot-boundp slot 'place)
	249	(progn
	250	(<ucw:a :action (list-prev slot) (<:as-html "<<"))
	251	(let ((self (parent slot)))
	252	(<ucw:a :action (call-component self (mewa:make-presentation (car (slot-value instance (slot-name slot))) :type :listing :initargs (list :instances (instances slot))))
	253	(<:as-html (label slot) (format nil " ~a-~a " (current slot) (+ (current slot) (number-to-display slot))))))
	254	(<ucw:a :action (list-next slot) (<:as-html ">>"))
	255	(call-next-method)
	256	(<:as-html "total :" (len slot)))
	257	(call-next-method)))
	258
	259	(defmethod get-foreign-instances :around ((slot has-very-many-slot-presentation) instance)
	260	(let ((f (call-next-method)))
	261	(setf (len slot) (length f))
	262	(setf (instances slot) f)
	263	(loop for cons on (nthcdr (current slot) f)
	264	for i from 0 upto (number-to-display slot)
	265	collect (car cons))))
	266
	267	(defslot-presentation has-a-slot-presentation (one-of-presentation)
	268	((key :initarg :key :accessor key))
	269	(:type-name has-a))
	270
	271	(defmethod get-foreign-slot-value ((slot has-a-slot-presentation) (object t) (slot-name t))
	272	(slot-value object slot-name))
	273
	274	(defmethod present-slot ((slot has-a-slot-presentation) instance)
	275	(<:as-html (presentation-slot-value slot instance))
	276	(if (editablep slot)
	277	(<ucw:select :accessor (presentation-slot-value slot instance) :test #'equalp
	278	(when (allow-nil-p slot)
	279	(<ucw:option :value nil (<:as-html (none-label slot))))
	280	(dolist (option (get-foreign-instances (presentation slot) instance))
	281	(setf (instance (presentation slot)) option)
	282	(<ucw:option :value (get-foreign-slot-value slot option (key slot)) (present (presentation slot)))))
	283	(if (presentation-slot-value slot instance)
	284	(progn
	285	(setf (instance (presentation slot)) (presentation-slot-value slot instance))
	286	(present (presentation slot)))
	287	(<:as-html "--"))))