gruntjs - Taking a variable value at runtime in Grunt-Concat task -

i have implemented below grunt configuration concating 2 css files single css file(common_tfn_bsa.min.css ) in jsp file.

<!-- build:css ./assets/css/common_tfn_bsa.min.css -->   <link href="./${theme}/css/style.css" rel="stylesheet">   <link href="./${theme}/css/component.css" rel="stylesheet">   <!-- endbuild --> 

but while running grunt task above code generated :

    concat:    { generated:     { files:         [ { dest: '.tmp\\concat\\assets\\css\\common_bom.min.css',            src:             [ '.\\app\\${theme}\\css\\style.css',               '.\\app\\${theme}\\css\\component.css' ] }         ]     }     } 

what need ,the value of ${theme} in generated file can pick css files correct location concat.

try this:

<!-- build:css(./<%= theme %>) ./assets/css/common_tfn_bsa.min.css -->   <link href="/css/style.css" rel="stylesheet">   <link href="/css/component.css" rel="stylesheet"> <!-- endbuild -->