Crafting Rails 4 Applications, 2nd Edition

Playing with the Template-Handler API

For an object to be compliant with the handler API, it needs to respond to the call method. This method receives as an argument an instance of ActionView::Template, which we introduced in ​Writing the Code​, and should return a string containing valid Ruby code. The Ruby code the handler returns is then compiled into a method, so rendering a template is as simple as invoking this compiled method.

Before diving into our Markdown + ERB handler, let’s create a few template handlers to get acquainted with the API.

Ruby Template Handler

Our first template handler simply allows arbitrary Ruby code as a template. This means the following template is valid:

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