[racket] formlets with radio button & checkbox example?

On Tue, Dec 27, 2011 at 2:20 PM, keydana at gmx.de <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?

Such radio groups have not yet been implemented, it should be
straight-forward to do so though. You could look at the code in

https://github.com/plt/racket/blob/master/collects/web-server/formlets/input.rkt

around multiselect-input for a way to do it.

Or you could just write some test cases for me and I'll do it.

>
> 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?

Ya, you're right, it gets thrown out. I'll fix that.

Jay

>
> 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
>



-- 
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