Checking if in list causes per-element queries

[thisisjamessmith]

Question

In your docs for checking if an item is in the list, you have this:

{% for entry in craft.entries.section('news').all() %}
    {% if list.getItem(entry) %}
        <a href="{{ list.removeItemUrl(entry) }}">Remove from List</a>
    {% else %}
        <a href="{{ list.addItemUrl(entry) }}">Add to List</a>
    {% endif %}
{% endfor %}

However list.getItem(entry) appears to cause a per-element DB query, resulting in many extra queries on long listing pages. I was going to look into solving this with some simple Twig arrays loaded upfront, but before I do that I wanted to check I wasn't missing something or making a mistake/omission in my implementation. Can we eager load this information in getUserList() or something?

Additional context

No response

[engram-design]

So while we do eager-load things with list->getItems(), this function doesn't use that, purely because you can pass in additional query params as a second argument.

I'll give this some extra thought for when you supply additional params, as I might have to make that a breaking change to just filter the eager-loaded items (with your provided params) rather than element query params. But this is going to disrupt anyone doing non-equality checks in params.

But - for everyone else that just wants to check an element "normally", I think we certainly should be using the eager-loaded items, and filter just that.

Updated for the next release. To get this early, run composer require verbb/wishlist:"dev-craft-5 as 3.0.3".