Re: Including gems in a bundle with Rawr (Jruby)

Eric Christopherson wrote:
> 
> OK. I was able to get it to load Barby, but I had to add
> 'lib/ruby/barby/lib' to my $LOAD_PATH. I don't understand the purpose
> of unpacking the gem into lib/ruby specifically, when it could reside
> anywhere within the hierarchy.

Wherever you want to place it, you have to be sure that the load path 
includes it. The rawr build_config has lib/ruby by default, I believe. 
(You need to indicate what local paths to set for $: in your code, but 
also what folders should be packaged up by rawr, and how they should be 
structured in any resulting jar file.)

Technically, you can set this up as you like, but it's far easier to use 
and to explain using some rawr conventions then saying, abstractly, you 
can set up your sub-dirs and load path almost any way you like. 
Because, as it happens, you have to be careful, since (as the page 
explains) code inside gems sometimes makes assumptions about it's parent 
directories and such.

For example, I had trouble using the 'builder' code.  It came down to 
there being 2 builder.rb files.  One would load the other.  But if $: is 
not set up correctly, then the wrong one may be found first, with 
annoying results.  (And I'm pretty sure I wrote an earlier version of 
the page under discussion precisely because of these issues.)

> 
>> If you have code that is attempting to load a gem instead of trying to load
>> files out of your bundled app then something is likely wrong.
>>
>> (Note that the example code on that help page never makes use of rubygems.
>>  Only plain old 'require'.)
>>
>> Some gems contain code that makes a call to "require 'rubygems'". (There was
>> a previous thread on ruby-talk about how inane this is.)
> 
> Yes, and I see now that prawn (which I also need) does just that. :(

GREG!  on noes ...  :)

> 
>> I usually hate to tell people "don't do that" when they ask how do do
>> something, but trying to use rubygems from inside an app packaged up with
>> rawr is just asking for trouble.  One of the purposes of rawr is create
>> self-sufficient apps.
> 
> That's what I want to do: make a program (that uses some gems) and
> package them all together so they don't need to be installed
> separately. I must be misunderstanding the intention of the page we're
> discussing; I thought it was about doing that.

The page is setting up unpacked gem files in an app.  (The larger 
premise of rawr is that the app has a main file, with all other required 
files being included in subdirectories or jars, all bundled up in such a 
way that Java can execute it. )

rawr can build installers for your app that makes sure all the related 
files get put in place.

But you have to unbundle any gems used by your code. And at that point, 
you should thinking of them as gems, and simply as libs that live in a 
subdirectory of your application folder.

-- 
James Britt

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