[racket] formlets with radio button & checkbox example?

Sigrid,

Here's something that worked for me:

(define (radio-group values name)
   (make-input*
    (lambda (n)
      `(div
        ,@(for/list ((value values))
            (list 'div
                  (list 'input
                        (list
                         (list 'name name)
                         (list 'type "radio")
                         (list 'value (bytes->string/utf-8 value))))
                  (bytes->string/utf-8 value)))))))


(define radio-button-formlet
   (formlet
    (div
         ,{(default #"default" (radio-group (list #"Chocolate" 
#"Vanilla" #"Strawberry") "flavor")) . => . ci} )
    (list ci)))

Hope this helps,

Shad

On 12/27/2011 3:20 PM, keydana at gmx.de wrote:

> Jay,
>
> many thanks for the answer, that already helps a lot!
>
> Just one thing - the generated html does not have a "value" attribute, but instead uses a different "name" for every radio button - how can I get the radio buttons identified as a group by the browser, such that only one button can be selected?
>
> In fact, looking at the generated html as well as the input given to formlet-process, I do not see where the "value" passed to the radio constructor is used?
>
> Thanks again,
> Sigrid
>
>
>
>
>
> Am 26.12.2011 um 22:28 schrieb Jay McCarthy:
>
>> Here is a short example:
>>
>> #lang racket
>> (require racket/promise
>>          web-server/http/request-structs
>>          web-server/formlets
>>          net/url)
>>
>> (define some-formlet
>>   (formlet
>>    (div "Checked Radio"
>>         ,{(default #"default" (radio #"checked-radio" #t)) . =>  . cr}
>>         "Not-Checked Radio"
>>         ,{(default #"default" (radio #"unchecked-radio" #f)) . =>  . ncr}
>>         "Checked Checkbox"
>>         ,{(default #"default" (checkbox #"checked-checkbox" #t)) . =>  . cc}
>>         "Not-Checked Checkbox"
>>         ,{(default #"default" (checkbox #"uncheck-checkbox" #f)) . =>  . ncc})
>>    (list cr ncr cc ncc)))
>>
>> (formlet-display some-formlet)
>>
>> (define (show-example bs)
>>   (formlet-process some-formlet
>>                    (request #"GET"
>>                             (string->url "http://localhost")
>>                             empty
>>                             (delay bs)
>>                             #f
>>                             "host"
>>                             8943
>>                             "client")))
>>
>> (show-example empty)
>> (show-example (list (binding:form #"input_0" #"true")))
>> (show-example (list (binding:form #"input_0" #"true")
>>                     (binding:form #"input_1" #"false")))
>> (show-example (list (binding:form #"input_0" #"true")
>>                     (binding:form #"input_1" #"false")
>>                     (binding:form #"input_2" #"true")
>>                     (binding:form #"input_3" #"false")))
>>
>> It would be good to create a higher-level formlet that rendered to a
>> checkbox or radio button that would return a boolean or a selection,
>> like the select formlets do.
>>
>> Jay
>>
>> On Mon, Dec 26, 2011 at 12:02 PM, keydana at gmx.de<keydana at gmx.de>  wrote:
>>> Hi,
>>>
>>> it's me again, and whereas I don't know how dumb I am I sure might have been a bit lazy :-;
>>>
>>> Unfortunately, even after taking a bit more time, I don't know how it works. Lastly, I've been trying this, which displayed fine:
>>>
>>> (define f-choose-db
>>>   (let ((o (radio #"orcl" #t))
>>>         (r (radio #"rndba" #f)))
>>>     (formlet
>>>      (div "orcl" ,(o . =>  . orcl)
>>>           "rndba" ,(r . =>  . rndba))
>>>      (values orcl rndba))))
>>>
>>> But when I use formlet-process to extract the result (just clicking submit, leaving the checked box checked), I get the values #<binding:form>  and #f... (and see input_0=on in the browser).
>>>
>>> Also I was trying to add a binding name to the radio function calls themselves, e.g. (radio #"xx" #f . =>  . myname), but this throws a syntax error.
>>>
>>> Could anyone offer a hint what I'm doing wrong here?
>>>
>>> (BTW this list has the most helpful people&  inspiring content of all mailing lists I know of , and I'm not writing this in order to get a nice answer :-) )
>>>
>>> Ciao
>>> Sigrid
>>>
>>>
>>> ____________________
>>>   Racket Users list:
>>>   http://lists.racket-lang.org/users
>>
>>
>> --
>> Jay McCarthy<jay at cs.byu.edu>
>> Assistant Professor / Brigham Young University
>> http://faculty.cs.byu.edu/~jay
>>
>> "The glory of God is Intelligence" - D&C 93
>
> ____________________
>    Racket Users list:
>    http://lists.racket-lang.org/users
>