htmx 4.0 is under construction — migration guide

hx-boost

Convert links and forms to AJAX

The hx-boost attribute allows you to “boost” normal anchors and form tags to use AJAX instead. This has the nice fallback that, if the user does not have javascript enabled, the site will continue to work.

Syntax

<div hx-boost="true">
  <a href="/page1">Go To Page 1</a>
</div>

For anchor tags, clicking on the anchor will issue a GET request to the url specified in the href and will push the url so that a history entry is created. The target is the <body> tag, and the innerHTML swap strategy is used by default. All of these can be modified by using the appropriate attributes, except the click trigger.

For forms the request will be converted into a GET or POST, based on the method in the method attribute and will be triggered by a submit. Again, the target will be the body of the page, and the innerHTML swap will be used. The url will not be pushed, however, and no history entry will be created. (You can use the hx-push-url attribute if you want the url to be pushed.)

Here is an example of some boosted links:

<div hx-boost="true">
  <a href="/page1">Go To Page 1</a>
  <a href="/page2">Go To Page 2</a>
</div>

These links will issue an ajax GET request to the respective URLs and replace the body’s inner content with it.

Here is an example of a boosted form:

<form hx-boost="true" action="/example" method="post">
    <input name="email" type="email" placeholder="Enter email...">
    <button>Submit</button>
</form>

This form will issue an ajax POST to the given URL and replace the body’s inner content with it.

Notes

  • Only links that are to the same domain and that are not local anchors will be boosted
  • All requests are done via AJAX, so keep that in mind when doing things like redirects
  • To find out if the request results from a boosted anchor or form, look for HX-Boosted in the request header
  • Selectively disable boost on child elements with hx-boost="false"
  • Disable the replacement of elements via boost, and their children, with hx-preserve="true"