Restore accessible autocomplete component

[andysellick]

What

Restores the accessible autocomplete component, with changes.

This uses the accessible autocomplete code to progressively enhance a select element. This is based on the accessible autocomplete component that existed briefly in the gem until we didn't need it anymore, but with some changes, specifically:

• we don't currently need tracking
• tracking might be needed in the future so this includes a custom onConfirm function (a custom onConfirm was originally included because we needed to externally control the component in finder-frontend)
• the autocomplete onConfirm seems to have a bug where it fires when the autocomplete is blurred, but passes undefined even if something has been correctly entered in the autocomplete. An event listener has been added to the component to compensate for this
• all of the stuff to do with multiple selections has been removed, because we don't need that and it was really experimental
• tests have been updated

Why

We're exploring using this component in a travel smart answer and it's currently the most suitable thing available.

Visual Changes

[andysellick]

I'm creating this with reservations - there's something of a disconnect between the autocomplete and the hidden select, in that it's possible to choose a valid option then edit it such that what the user thinks they've entered is different from what will actually be submitted in the hidden select.

The use of the autocomplete with a hidden select was chosen to make the non-JS version slightly more helpful for users than an empty input but I'm strongly considering changing this component to use a normal input and a datalist.

[alex-ju]

Before reviewing the code, if it's only needed in one application (be that smart-answers), shall we add it there instead (so we can iterate it quicker if needed)?

Update: as discussed, the component is used by other applications (content-data-admin and content-publisher) in different forms, so there may be scope in having it in the library. Note the content-publisher implementation uses a fork of the accessible-autocomplete.

[andysellick]

Thanks for the information @alex-ju. content-data-admin uses the autocomplete component from the gem (a really old gem when that was still a component) and I have some concerns about the autocomplete component in content-publisher - the code looks quite complicated (it has multiple configuration options including enhancing a standard input and a hidden select and having a multiple select option, which is more than I need) and there doesn't seem to be a test file.

I'm still trying to decide how to proceed. I think my options are:

1. port the autocomplete from content-publisher (although I might need to write a test file)
2. write an autocomplete in smart-answers that only does what I need i.e. enhances a regular input and datalist
3. write that 'simple' autocomplete here in the gem, then iterate it based on the content-publisher one with the aim of future consolidation

[alex-ju]

I'm sharing some thoughts on this, but you are closer to the problem than I am.

Thanks for the information @alex-ju. content-data-admin uses the autocomplete component from the gem (a really old gem when that was still a component) and I have some concerns about the autocomplete component in content-publisher - the code looks quite complicated (it has multiple configuration options including enhancing a standard input and a hidden select and having a multiple select option, which is more than I need) and there doesn't seem to be a test file.

I'm still trying to decide how to proceed. I think my options are:

1. port the autocomplete from content-publisher (although I might need to write a test file)

The autocomplete code itself has unit tests in the main repo, hence in content-publisher we only made sure the different types of initialisations required in different areas of the project were captured in feature tests.

2. write an autocomplete in smart-answers that only does what I need i.e. enhances a regular input and datalist

This approach has the advantage of being able to test and iterate quickly without needing to release a new version of the component. It can also be retired with much ease.

3. write that 'simple' autocomplete here in the gem, then iterate it based on the content-publisher one with the aim of future consolidation

The work to converge/consolidate may fall between the cracks (as none the C19 or the Publishing team may be willing to take the time to do it).

[andysellick]

@alex-ju I've created a new component in smart-answers based on this code and the code in content-publisher, see alphagov/smart-answers#5694