Text Processing with Ruby

Passing Data to Templates

We’ve skirted around one of the more complex areas of ERB: how to access variables from within our templates. We’ve seen that, by default, our templates are evaluated as though they were top-level Ruby code, allowing them access to variables in that scope. But in practice, that’s unworkable. We don’t want to create variables in the top-level scope if we can help it.

We need to be able to control the scope that our templates are evaluated in. We do this by passing a binding to ERB when our template is compiled. This binding holds information about the variables currently in scope. (These bindings aren’t a feature of ERB; they’re a concept within Ruby itself.)

It’s much easier to illustrate this with an example. So, ...