问题描述
以下是我的基本Web应用程序的代码:
> #lang racket
(需要web-server / servlet
web-server / servlet-env )
(define test())
(define(start request)
(define bindings(request-bindings request))
(cond
((exists-binding?`cb1 bindings)
(set!test'(1 2 3))
(printf〜a(test)has been set to'(1 (b)(
(head(title)My Blog))
(body
(h1正在建设中)
(form,`(input((namecb1)(typecheckbox))(valueCheckbox 1))
(p(input((typesubmit )(valueSubmit)))))))))
(serve / servlet start)
我希望能够提交而无需按提交,而是按下输入等键。是否有可能做到这一点?
Racket servlet生成发送给客户端的网页(以html格式)。
在客户端,网页显示在用户的浏览器中。当用户按下一个键时,浏览器需要处理它。让浏览器在按键上执行任何特殊操作的唯一方法是在JavaScript中使用写入处理程序。请注意,程序的Racket部分只能在服务器上运行。
请参阅
了解如何在JavaScript中执行此操作的更多信息。
I've been through the documentation for web-servers and can't find anything on it.
Here's my code for a basic web application:
#lang racket
(require web-server/servlet
web-server/servlet-env)
(define test '())
(define (start request)
(define bindings (request-bindings request))
(cond
((exists-binding? `cb1 bindings)
(set! test '(1 2 3))
(printf "~a" "(test) has been set to '(1 2 3)!")))
(response/xexpr
`(html
(head (title "My Blog"))
(body
(h1 "Under construction")
(form ,`(input ((name "cb1") (type "checkbox")) (value " Checkbox 1"))
(p (input ((type "submit") (value "Submit")))))))))
(serve/servlet start)
I want to be able to submit without having to press submit and instead by pressing a key such as enter. Is it possible to do this?
The Racket servlet produces a web page (in html) that is sent to the client.On the client the web page is shown in the user's browser. When the user press a key the browser needs to handle it. The only way to get the browser to do anything special on a key press is to use write a handler in JavaScript. Note that the Racket portion of your program only runs on the server.
In short: You need to write a small piece of JavaScript and embed it in the html page.
See How to submit form on keypress?for more information on how to do this in JavaScript.
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