`hx-include`

The hx-include attribute allows you to include additional element values in an AJAX request. The value of this attribute can be:

A CSS query selector of the elements to include.
this which will include the descendants of the element.
closest <CSS selector> which will find the closest ancestor element or itself, that matches the given CSS selector (e.g. closest tr will target the closest table row to the element).
find <CSS selector> which will find the first child descendant element that matches the given CSS selector.
next <CSS selector> which will scan the DOM forward for the first element that matches the given CSS selector. (e.g. next .error will target the closest following sibling element with error class)
previous <CSS selector> which will scan the DOM backwards for the first element that matches the given CSS selector. (e.g previous .error will target the closest previous sibling with error class)

Here is an example that includes a separate input value:

<div>
    <button hx-post="/register" hx-include="[name='email']">
        Register!
    </button>
    Enter email: <input name="email" type="email"/>
</div>

This is a little contrived as you would typically enclose both of these elements in a form and submit the value automatically, but it demonstrates the concept.

Note that if you include a non-input element, all input elements enclosed in that element will be included.

Notes

hx-include is inherited and can be placed on a parent element
While hx-include is inherited, it is evaluated from the element triggering the request. It is easy to get confused when working with the extended selectors such as find and closest.
```
<div hx-include="find input">
    <button hx-post="/register">
        Register!
    </button>
    Enter email: <input name="email" type="email"/>
</div>
```
In the above example, when clicking on the button, the find input selector is resolved from the button itself, which does not return any element here, since the button doesn’t have any input child, thus in this case, raises an error.
A standard CSS selector resolves to document.querySelectorAll and will include multiple elements, while the extended selectors such as find or next only return a single element at most to include