From: Serg Koren <skoren@...>
Date: 2008-02-14T08:40:10+09:00
Subject: Re: HTML form action calling a Ruby def?

Um I dont want to call the server. I know I can call the server and  
handle it via cgi.   I want to capture the input and process it  
locally on the web page client PRIOR to a server side send..  Sort of  
like javascript.  I dont think its doable.  I was hoping for magic.   
Oh well.


Thx anyway.

Sent from my iPhone

On Feb 13, 2008, at 6:18 PM, Jim Clark <diegoslice@gmail.com> wrote:

> Serg Koren wrote:
>> Hi,
>> Does anyone have a solution to calling a Ruby method when someone  
>> clicks on the Submit button of an HTML form (without Rails)?  And  
>> an ancillary question, is there a way to catch the form input into  
>> Ruby variables?  My understanding is that the action element needs  
>> to invoke the server side logic which is a bother if you want to  
>> get form input and pre-process it.
>>
>> Thanks!
>>
> You can use Ruby exactly as you would use other languages such as  
> Perl to do this. For instance, place your Ruby script in the cgi-bin  
> directory, set up the web server to know that .rb or .cgi maps to  
> ruby (differs depending on OS and web server), and then write your  
> script. Set the post method of the form to be the URL of your  
> script. Use the Ruby CGI library (http://www.ruby-doc.org/stdlib/libdoc/cgi/rdoc/index.html 
> ) that handles a lot of the details for you.
>
> This section I pasted below is from the CGI docs regarding form  
> inputs and Ruby variables. From this it should be clear that passing  
> form parameters into Ruby variables is trivial.
>
> -Jim
>
>
>     Parameters
>
> The method params() returns a hash of all parameters in the request  
> as name/value-list pairs, where the value-list is an Array of one or  
> more values. The CGI <http://www.ruby-doc.org/stdlib/libdoc/cgi/rdoc/classes/CGI.html 
> > object itself also behaves as a hash of parameter names to values,  
> but only returns a single value (as a String) for each parameter name.
>
> For instance, suppose the request contains the parameter  
> "favourite_colours" with the multiple values "blue" and "green". The  
> following behaviour would occur:
>
> cgi.params["favourite_colours"]  # => ["blue", "green"]
> cgi["favourite_colours"]         # => "blue"
>
> If a parameter does not exist, the former method will return an  
> empty array, the latter an empty string. The simplest way to test  
> for existence of a parameter is by the has_key? method.
>
>
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