Why is this code throwing an ActionView::TemplateError

I have some straight forward code that looks like the following in one of my erb templates:

if (<%= is_defined? foo %>) /* some j开发者_如何学Pythonavascript to do stuff with foo */

Is there a reason that code is throwing an ActionView::TemplateError exception saying `undefined local variable or methodfoo'? I thought is_defined?() should take care of that and not try to execute the code after utilizing foo if it isn't defined?

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it's because you not define the foo method or variable in your view. Define it. You not generate some javascript. You generate some ruby code.