From: Gavin Kistner <gavin@...>
Date: 2004-10-27T11:32:58+09:00
Subject: Re: Learning erb

On Oct 26, 2004, at 6:21 PM, James Edward Gray II wrote:
> "Insert the given Ruby code at this point in the generated program.  
> If it outputs anything, include the output in the result."
>
> It's the last line that's confusing me.  If I feed erb:
[...]
> % a = 99
> <%= a %> bottles of beer...
> 99 bottles of beer...
>
> % a = 99
> <% a %> bottles of beer...
>  bottles of beer...
>
> % a = 99
> <% print a %> bottles of beer...
> 99 bottles of beer...
[...]
> So, what the heck does "If it outputs anything, include the output in 
> the result." really mean?  I'm confused.

I'm not sure what your question is. Perhaps this final test will make 
the end result (if not the magic mechanism) clear:

a = 99
b = 12
puts ERB.new( "<%= print a; b %> bottles of beer" ).result( binding )
#=> 9912 bottles of beer

puts ERB.new( "<%= puts a; b %> bottles of beer" ).result( binding )
#=> 99
#=> 12 bottles of beer

a) Without the =, run the ruby code. Any strings output by print, puts, 
etc. replace the block.
b) With the =, as above, except that the return value of the block 
should have .to_s called on it and appended to any output.


Thanks for doing the work to document this, James!