# Passing variables to a required file

**URL:** <https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785>\
**Category:** Ruby\
**Created:** [July 30, 2007, 10:19pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785 "2007-07-30T22:19:50Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 30, 2007, 10:19pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/1 "2007-07-30T22:19:50Z")

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I want to pass about 10 variables to a "require"d file. My understanding  
is that I need to use global variables. Is this correct?

I’m reluctant to change all the variables to global for fear of messing  
up the methods in the script. I can of course define new global  
variables equal to the local variable. Seems inelegant.

I guess my best option is to rework the require’d file as a method, but  
my script is getting long and keeping the file separate makes sense,  
particularly since it is creating the GUI, so is different from the  
script function if I understand the MVC philosophy.

Is there a better way? FWIW I’m "require’ing a modified example.rb file  
that is included in the Pashua app for creating a simple GUI for OS X.  
[http://www.bluem.net/downloads/pashua\_en/](http://www.bluem.net/downloads/pashua_en/)

Thanks for info

PS The example file as a

Config = \<\<EOS

EOS

I can’t find EOS in Ruby on Rails or PickAxe, so maybe I’m missing  
something in how it’s used.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 30, 2007, 10:52pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/2 "2007-07-30T22:52:57Z")

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12 34 wrote:

> script function if I understand the MVC philosophy.
> 
> Is there a better way? FWIW I’m "require’ing a modified example.rb file  
> that is included in the Pashua app for creating a simple GUI for OS X.  
> [http://www.bluem.net/downloads/pashua\_en/](http://www.bluem.net/downloads/pashua_en/)  
> Change your code. It’ll be easier to do it now than to unpick  
> everything later.

What you want (probably) is to wrap your code in the require’d file into  
a class that you can instantiate with the relevant parameters in your  
main script.

> something in how it’s used.  
> It’s a heredoc marker. It’s just another way of creating a multiline  
> string. The critical bit is the “\<\<EOS” start marker - after “\<\<” you  
> can put any identifier, and a string will be created from the content  
> between that line and the first occurrence of that marker on its own  
> later in the file.

HTH

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 30, 2007, 11:07pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/3 "2007-07-30T23:07:58Z")

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2007/7/30, 12 34 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> I want to pass about 10 variables to a "require"d file. My understanding  
> is that I need to use global variables. Is this correct?

I’d do the same as Alex and put the Config constant in a class(or any  
other way to pass the parameters, I am quite new to Ruby and don’t  
know of something better yet)

> 

Check Chapter 5 “Strings” in the Pickaxe, it is called _here document_  
there.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 30, 2007, 11:26pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/4 "2007-07-30T23:26:30Z")

</div>

Alex Y. wrote:

> 12 34 wrote:
> 
> > Is there a better way? FWIW I’m "require’ing a modified example.rb file  
> > that is included in the Pashua app for creating a simple GUI for OS X.  
> > [http://www.bluem.net/downloads/pashua\_en/](http://www.bluem.net/downloads/pashua_en/)  
> > Change your code. It’ll be easier to do it now than to unpick  
> > everything later.
> 
> What you want (probably) is to wrap your code in the require’d file into  
> a class that you can instantiate with the relevant parameters in your  
> main script.

OK. For now that’s the best solution for me, but later I will look at  
putting in a separate file.

> > something in how it’s used.  
> > It’s a heredoc marker. It’s just another way of creating a multiline  
> > string. The critical bit is the “\<\<EOS” start marker - after “\<\<” you  
> > can put any identifier, and a string will be created from the content  
> > between that line and the first occurrence of that marker on its own  
> > later in the file.

Thank you Alex and Thomas, now I see that a long string is being  
prepared to send to the Perl script or something like that. And I’m  
trying to get my Ruby variable in that string. They syntax in the string  
didn’t quite look like Ruby, missing quotes and things.

So EOS presumably means something like End of String and is commonly  
used but has no special meaning to Ruby. Confusing also to me that the  
word in front of \<\<EOS was “Config” which could be just a descriptive  
name or word with a special meaning.

> HTH

I think this will get me over the hump of using a file to prepare a  
string to send to some kind of Perl script (it’s really an OS X app) to  
make a GUI. At the moment I was trying to recover the return from  
calling the “require.” That problem will probably go away if I make it  
class or method.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 30, 2007, 11:44pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/5 "2007-07-30T23:44:03Z")

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12 34 wrote:

> > main script.
> 
> OK. For now that’s the best solution for me, but later I will look at  
> putting in a separate file.  
> Well, the class definition can still be in the external file - that’s  
> actually what I meant. You can do something like this:

main.rb:

require ‘ui\_code’

UICode.new(all, your, parameters).run

ui\_code.rb:

class UICode  
def initialize(use, meaningful, parameter, names)  
@use = use  
@meaningful = meaningful  
# etc…  
end

def run  
#your current code goes here, referring to instance variables  
rather  
# than globals  
end  
end

That’s a fairly typical arrangement, in fact.

> didn’t quite look like Ruby, missing quotes and things.
> 
> So EOS presumably means something like End of String and is commonly  
> used but has no special meaning to Ruby. Confusing also to me that the  
> word in front of \<\<EOS was “Config” which could be just a descriptive  
> name or word with a special meaning.  
> Nope, it’s just a variable name. Except that here it’s a little weird -  
> because it’s capitalised, it’s a constant. Not sure if that’s relevant,  
> but don’t worry about the specific name “Config” being anything special.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 31, 2007, 1:14am UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/6 "2007-07-31T01:14:29Z")

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Alex Y. wrote:

> 12 34 wrote:
> 
> > > main script.
> > 
> > OK. For now that’s the best solution for me, but later I will look at  
> > putting in a separate file.  
> > Well, the class definition can still be in the external file - that’s  
> > actually what I meant. You can do something like this:
> 
> main.rb:
> 
> require ‘ui\_code’
> 
> UICode.new(all, your, parameters).run
> 
> ui\_code.rb:
> 
> class UICode  
> def initialize(use, meaningful, parameter, names)  
> @use = use  
> @meaningful = meaningful  
> # etc…  
> end
> 
> def run  
> #your current code goes here, referring to instance variables  
> rather  
> # than globals  
> end  
> end
> 
> That’s a fairly typical arrangement, in fact.

Thank you for clarifying this. Since it’s a one shot thing I’ve been  
using defs and not classes. But maybe that makes a difference. I need to  
reread my books to get clearer on this.

> > didn’t quite look like Ruby, missing quotes and things.
> > 
> > So EOS presumably means something like End of String and is commonly  
> > used but has no special meaning to Ruby. Confusing also to me that the  
> > word in front of \<\<EOS was “Config” which could be just a descriptive  
> > name or word with a special meaning.  
> > Nope, it’s just a variable name. Except that here it’s a little weird -  
> > because it’s capitalised, it’s a constant. Not sure if that’s relevant,  
> > but don’t worry about the specific name “Config” being anything special.

Turns out to matter a lot. Broken with EOS, works with eos. Although did  
worked when in a separate file. I had moved it into my main script. I  
came back to the thread to repost about an error I was getting at the  
\<\<EOS. So that’s fixed.

Thanks for your comments.

---

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 31, 2007, 1:29am UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/7 "2007-07-31T01:29:37Z")

</div>

12 34 wrote:

> > > So EOS presumably means something like End of String and is commonly  
> > > used but has no special meaning to Ruby. Confusing also to me that the  
> > > word in front of \<\<EOS was “Config” which could be just a descriptive  
> > > name or word with a special meaning.  
> > > Nope, it’s just a variable name. Except that here it’s a little weird -  
> > > because it’s capitalised, it’s a constant. Not sure if that’s relevant,  
> > > but don’t worry about the specific name “Config” being anything special.
> 
> Turns out to matter a lot. Broken with EOS, works with eos. Although did  
> worked when in a separate file. I had moved it into my main script. I  
> came back to the thread to repost about an error I was getting at the  
> \<\<EOS. So that’s fixed.

Sorry, my response above is incorrect. I made the change from EOS to  
eos in the stand alone file and ran that file in TextMate. When I use it  
as a require or integrated in my main script I get the following error  
(changed from eos to end\_of\_string).

dynamic constant assignment  
Config = \<\<end\_of\_string

Maybe I’d better go back to the separate file and start over again.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 31, 2007, 9:55pm UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/8 "2007-07-31T21:55:15Z")

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Robert K. wrote:

> 2007/7/30, 12 34 :
> 
> > EOS
> 
> I’d suggest to refactor your code so you have multiple classes and can  
> instantiate them with appropriate parameters. Storing code in a long  
> string is a bad option if the code is known at compile time which  
> seems to be the case here.
> 
> Kind regards
> 
> robert

This is getting over my head, but the code that is a string will be  
changed on running the script. I’ll be putting in variable via  
#{variable}. As I understand it this string is sent to a Mac application  
that puts up a GUI window and then returns the options (text, filenames,  
etc) entered in a hash. I’m using the initial #{variable} to put in  
default selections in the GUI. They could be written in the original  
script, but I’d rather keep them in the main script. And I envision  
transitioning to other GUI’s if this one doesn’t work out or I learn  
Rails or who know what?

If I should still do as you say, let me know and I’ll study some more.  
As I may have said earlier, I’ve only used defs (and I use them  
liberally for what I think is the usual reason to keep the code easier  
to read). Although I’ve worked through some tutorials and Ruby on Rails  
stuff, I haven’t quite got my head around classes and instantiation. My  
script / app will be run each time I download photos and set them up for  
transfer to my photo program (Aperture). I’m not saving any of the  
information except defaults which at the moment I’m hard wiring into the  
code, but may set up a YAML to save the last selections which then  
become the defaults. I’ve also set myself the task of (re)reading  
PickAxe on my vacation which starts next week.

Thank you for your comments.

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**Author:** ![mtnbiker](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ad7895/32.png) [@mtnbiker](https://www.ruby-forum.com/u/mtnbiker)\
**Post date:** [July 31, 2007, 10:32am UTC](https://www.ruby-forum.com/t/passing-variables-to-a-required-file/110785/9 "2007-07-31T10:32:02Z")

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2007/7/30, 12 34 [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> script function if I understand the MVC philosophy.
> 
> EOS
> 
> I can’t find EOS in Ruby on Rails or PickAxe, so maybe I’m missing  
> something in how it’s used.

I’d suggest to refactor your code so you have multiple classes and can  
instantiate them with appropriate parameters. Storing code in a long  
string is a bad option if the code is known at compile time which  
seems to be the case here.

Kind regards

robert