From: sto.mar@...
Date: 2012-10-31T02:25:53+09:00
Subject: Re: Erb syntax - unknown syntax

Am 30.10.2012 13:10, schrieb Georgy Daniel:
> I don't think it is associated with the if condition, here there is
> another instance of the '!'
>
> <%!
>     require 'cgi'
>    require 'json'
>          .....................
>          .....................
> %>
>
> Also here is the if condition block
>
> <%! if filmstrip_image_path.blank? %>
>     <div id="main-page">
>        <img src="resources/image.jpg" alt="My Image"></img>
>        <img id="main-page-text" src="resources/image.png"></img>
>     </div>
> <%! end  %>

And this code works? Are you really using the standard erb?
For me (ruby 1.9.3p194), the following template gives a syntax error

<%! if true %>
   true
<%! end %>

Because this is interpreted as

   ! if true
     ...
   ! end

where the first '!' is possible but completely useless here,
and the second '!' is syntactically wrong.

The fact that <%! has no special meaning but is treated
like <% and the boolean `!' can be seen here:

   require 'erb'
   template = <<EOF
   <%! false && (text = 'true!!!') %>
   <%= text %>
   EOF
   puts ERB.new(template).result

outputs `true!!!', because the ruby code is taken to be

   !false && (text = 'true!!!')

and the assignment of `true!!!' to the variable takes place.
The same with <%! true && ... %> gives no output, as expected.

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