Diverse aanpassingen ivm foutgedrag.

racket-webview.rkt

@@ -729,7 +729,11 @@
     'oke))
 
 (define/contract (webview-bind! wv selector event no-prevent-default)
-  (-> wv-win? (or/c symbol? string?) (or/c symbol? list-of-symbol?) boolean? list?)
+  (-> wv-win?
+      (or/c symbol? string?)
+      (or/c symbol? list-of-symbol?)
+      boolean?
+      (or/c #f list?))
   (let* ((sel (if (symbol? selector)
                   (format "#~a" selector)
                   selector))
@@ -909,7 +913,12 @@
 (wvv webview-value/number number? string->number)
 (wvv webview-value/symbol symbol? string->symbol)
 (wvv webview-value/color rgba? hex->rgba)
-(wvv webview-value/boolean boolean? (λ (e) (if (string=? e "true") #t #f)))
+(wvv webview-value/boolean
+     boolean?
+     (λ (e)
+       (if (boolean? e)
+           e
+           (string-ci=? e "true"))))
 
 
 (define/contract (webview-add-class! wv id-or-selector class)

wv-window.rkt

@@ -384,7 +384,9 @@
 
     (define/public (bind! selector events callback . no-prevent-default)
       (let* ((npd   (if (null? no-prevent-default) #f (car no-prevent-default)))
-             (items (webview-bind! wv selector events npd))
+             (items (or (webview-bind!
+                         wv selector events npd)
+                        '()))
              (events* (if (symbol? events) (list events) events))
              )
         ;(dbg-webview "No-prevent-default = ~a" npd)