How to create self-populating “smart” forms in Drupal 8 with Form API

Hello! Many years ago (2015 to be exact), we published an article on how to create self-populating dropdown forms using the Drupal 7 Webform API. Now that the year is 2019 and Drupal 8 has been “Released” for quite some time now, with 8.7.1 as of May 2019, we thought it might be a good idea to update the strategy to do the same or similar action in Drupal 8. What are we trying to do anyways? Well we want a way for people to interact with a Webform in an interactive way. This means we want subsequent dropdown selections to be populated by previous choices. This logic doesn’t have to be restricted to dropdowns, it can be input  boxes, checkboxes or radio buttons. Anything, really. In the example above, you can see “Beverage” is chosen for “Industries”. The “Products” dropdown underneath has the options that you see  populated based […]

Create self-populating ajax drop-down forms in Drupal with the Form API

Hello! At risk of making the title of this post a mouth full, I thought I’d share some of our experience with interacting with Drupal’s Form API (Specficially Drupal 7.x). There is a lot of documentation on different ways you can interact with the Form API to accomplish a wide range of tasks from collecting information, processing information or building complex search queries. The latter is where we ventured in our most recent work interacting with Drupal’s Form API. We worked on a project where the requirement was to build a drop-down based filtration system where content category choices in the drop-down boxes would auto populate dependent taxonomies based on the relationship of the taxonomies , content fields and content in general. After choosing all the drop-down boxes, the end-user would then be able to click a “Go” button to build a list of results that apply the selected filters. […]