Ruby-从控制器传递字符串以查看空格

Question

I am attempting to send a string variable from the controller to the view using an instance variable. The issue is that when the view is rendered the string variable that is sent is stripped of all spaces that were in the original string. Is there some special property of ruby strings or how rails handles them that I'm missing?

Ruby 2.0.0p481 (2014-05-08 revision 45883) [x86_64-linux]
Rails 4.0.5

Controller

def stringsub
  forminput = params['mystring']
  spaceinput = String.new(forminput)
  puts "Displaying @formstring from controller: " + @formstring
  @formstring = spaceinput
end

View

<!--HTML page view -->
<p><%= @formstring %></p>

Rails Terminal

Started POST "/pages/stringsub" for 127.0.0.1 at 2014-12-04 19:34:26 -0500
Processing by PagesController#stringsub as HTML
Parameters: {"mystring"=>"this should have spaces"}
Displaying @formstring from controller: this should have spaces
Rendered pages/stringsub.html.erb within layouts/application (1.4ms)
Completed 200 OK in 6ms (Views: 4.7ms | ActiveRecord: 0.0ms)

Rendered HTML

<!--HTML page view -->
<p>thisshouldhavespaces</p>

(note the spaces were removed in the final HTML)

Is there a way to preserve the spaces in the original string that is sent?

Edit:

The issue was a method created by a group member of this project whose method had the original string passed to it as a parameter and it used .gsub to remove spaces from the parameter sent to it.

Method that broke it

def groupmethod(start)
    sub = start.split(" ")
    count = (start.length - start.gsub!(/\s+/, "").length + 1) * 0.4

Ironically I was actually able to fix it by creating a new variable out of it with String.new and passing that to the method instead

Undamaged instance variable

forminput = params['mystring']
@formstring = forminput
testvariable = String.new(forminput)
groupmethod(testvariable)

Is there a better or more correct way of passing variables to ruby methods and use them separately without affecting the variable you passed to the method?

Answer 1

Your stringsub method can be simplified. Let's say you have a new action in your UsersController (simplified version):

def new
  set_str
end

private

def set_str
  @str = params['str']
  puts "@str: #{@str}"
end

The instance variable @str should be available to your view. Make sure the instance variable giving you trouble isn't being modified elsewhere in your application. Single spaces will be preserved, but if you want to preserve all whitespace you could style your element with .your-class { white-space: pre; } .your-class { white-space: pre; }

As an aside (in your original method), I don't see how the puts line outputs anything for @forminput when (apparently) it gets initialized at the very end.