HTML form action calling a Ruby def?

[Serg Koren]

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!

 

[Phlip]

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.

You are asking how to respond to a POST message with CGI. That's the primitive
layer under websites, and it typically packs parameters into ENV environmental
variables.

But why not Rails - you just need like 2 or 3 lines for that...

 

[Jim Clark]

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.

 

[Serg Koren]

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

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.