Predefined tag checkboxes with ActsAsTaggableOn

Last week, I designed an interface that lets a user optionally select from a set of predefined values. Since time for implementation was short, I tried to adapt my design to use as much off-the-shelf Rails functionality as possible, i.e. no custom JavaScript or React components (for now).

Since these predefined values were quite like tags, I chose ActsAsTaggableOn to provide the model- and controller-level functionality. But the ActsAsTaggableOn documentation prefers to skirt the matter of user interface, with but one paltry example.

In my case, I wanted to:

• predefine the list of available values
• show a checkbox for each available value
• store the selected choices as ActsAsTaggableOn dictates
• not hard-code the values in my view

A colleague recently used a form helper that stuck with me—collection_check_boxes, which renders a set of check boxes when provided a collection of options—though its documentation, too, left something to be desired, especially since I had a simple array of values and not the collection of models used in the published examples.

So, with some experimentation, here’s how I wired it all together: