syntastic/syntax_checkers/eruby.vim

"============================================================================
"File:        eruby.vim
"Description: Syntax checking plugin for syntastic.vim
"Maintainer:  Martin Grenfell <martin.grenfell at gmail dot com>
"License:     This program is free software. It comes without any warranty,
"             to the extent permitted by applicable law. You can redistribute
"             it and/or modify it under the terms of the Do What The Fuck You
"             Want To Public License, Version 2, as published by Sam Hocevar.
"             See http://sam.zoy.org/wtfpl/COPYING for more details.
"
"============================================================================
if exists("loaded_eruby_syntax_checker")
    finish
endif
let loaded_eruby_syntax_checker = 1

"bail if the user doesnt have ruby or cat installed
if !executable("ruby") || !executable("cat")
    finish
endif

function! SyntaxCheckers_eruby_GetLocList()
    let makeprg='sed "s/<%=/<%/g" '. shellescape(expand("%")) . ' \| RUBYOPT= ruby -e "require \"erb\"; puts ERB.new(ARGF.read, nil, \"-\").src" \| RUBYOPT= ruby -c'
    let errorformat='%-GSyntax OK,%E-:%l: syntax error\, %m,%Z%p^,%W-:%l: warning: %m,%Z%p^,%-C%.%#'
    let loclist = SyntasticMake({ 'makeprg': makeprg, 'errorformat': errorformat })

    "the file name isnt in the output so stick in the buf num manually
    for i in loclist
        let i['bufnr'] = bufnr("")
    endfor

    return loclist
endfunction