Rails core - Oct 2011 - ActionView::OutputBuffer - append= and << are not QUITE identical

Not sure if this is the right place for this, but it''s certainly to do
with core Rails and only of interest to pretty hard-core framework hackers...

Anyways, the issue I ran into was that aliasing a method (<<) to a setter
(append=) doesn''t quite work the way you''d expect. For
instance:

x = ActionView::OutputBuffer.new(''something'')
result1 = (x << '' else '') # => ''something
else''
result2 = (x.append= (''entirely'')) # =>
''entirely''

In the second example, the return value from the call is the value that was
passed in (Ruby''s standard behavior for assignments in general). The
return value of append= is silently dropped on the floor.

Note that this will never be observed by users of the built-in ERB template
parser, since it automatically grabs @output_buffer in the Erubis postamble.

--Matt Jones

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On Monday, 10 October 2011 at 9:12 AM, Matt Jones wrote:
> Not sure if this is the right place for this, but it''s certainly
to do with core Rails and only of interest to pretty hard-core framework
hackers...
> 
> Anyways, the issue I ran into was that aliasing a method (<<) to a
setter (append=) doesn''t quite work the way you''d expect. For
instance:
> 
> x = ActionView::OutputBuffer.new(''something'')
> result1 = (x << '' else '') # =>
''something else''
> result2 = (x.append= (''entirely'')) # =>
''entirely''
> 
Unless I''m mistaken, which is often the case, this difference was
actually deliberately introduced to allow the backwards compatible support for
<%= foo do %> and <% foo do %>. 
> In the second example, the return value from the call is the value that was
passed in (Ruby''s standard behavior for assignments in general). The
return value of append= is silently dropped on the floor.
> 
> Note that this will never be observed by users of the built-in ERB template
parser, since it automatically grabs @output_buffer in the Erubis postamble.
> 
> --Matt Jones
> 
> -- 
> You received this message because you are subscribed to the Google Groups
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 -- 
Cheers,

Koz

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