[racket] Strange behavior of web application , or may be not

There's also send/back, which sends a single response.

Jay

2011/6/27 Veer <diggerrrrr at gmail.com>:
> This is  really crazy , I wrote large program , and was getting
> the same behavior and whole day I tried to figure why and why me?
> Of course I forgot that response/xexpr does not
> send the response back to client.
> So view function becomes :
>
> (define (view request)
>    (send/suspend/dispatch
>     (lambda (make-url)
>       (response/xexpr
>        `(html)))))
>
> Thanks
>
>
>
> On Mon, Jun 27, 2011 at 7:47 PM, Jay McCarthy <jay.mccarthy at gmail.com> wrote:
>> This is not strange.
>>
>> When you click "Create Something", the continuation is []
>>
>> When you click "Start Again", the continuation is
>>
>> (begin [] (error 'oops ...) (recur))
>>
>> When you click "View", the value
>>
>> (response/xexpr
>>     `(html))
>>
>> gets returned to the continuation, so you get an error, because begin
>> ignores the value and drops through to the error.
>>
>> Jay
>>
>> 2011/6/27 Veer <diggerrrrr at gmail.com>:
>>> Hello,
>>>
>>> When I run this web application (given below) , I get strange behavior
>>>  , don't know if
>>> this is correct behavior or not.
>>>
>>> Follow/click the link in sequence :
>>> 1. Create Something
>>> 2. Start again
>>> 3. View
>>>
>>> So , when I click "view" I get exception instead of blank page.
>>>
>>> code :
>>> #lang web-server/insta
>>> (define (start request)
>>>  (do-1 request))
>>>
>>> (define (do-1 request)
>>>  (define (resp make-url)
>>>    (response/xexpr
>>>     `(html
>>>       (body (a ((href ,(make-url view))) "View")
>>>             (br)
>>>             (a ((href ,(make-url create-something))) "Create something")))))
>>>
>>>  (define (create-something request)
>>>    (recur))
>>>
>>>  (define (view request)
>>>    (response/xexpr
>>>     `(html)))
>>>
>>>  (send/suspend/dispatch resp))
>>>
>>>
>>> (define (recur)
>>>  (do-something)
>>>  (error 'oops "WHY ARE WE HERE?")
>>>  (recur))
>>>
>>> (define (do-something)
>>>  (define (resp make-url)
>>>    (response/xexpr
>>>     `(html
>>>       (body (a ((href ,(make-url start))) "Start again")))))
>>>  (send/suspend/dispatch resp))
>>>
>>>
>>> Thanks
>>> _________________________________________________
>>>  For list-related administrative tasks:
>>>  http://lists.racket-lang.org/listinfo/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