Htmx provides an extensive events system that can be used to modify and enhance behavior. Events are listed below.
htmx:abort
This event is different than other events: htmx does not trigger it, but rather listens for it.
If you send an htmx:abort
event to an element making a request, it will abort the request:
<button id="request-button" hx-post="/example">Issue Request</button>
<button onclick="htmx.trigger('#request-button', 'htmx:abort')">Cancel Request</button>
htmx:afterOnLoad
This event is triggered after an AJAX onload
has finished. Note that this does not mean that the content
has been swapped or settled yet, only that the request has finished.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:afterProcessNode
This event is triggered after htmx has initialized a DOM node. It can be useful for extensions to build additional features onto a node.
detail.elt
- the element that dispatched the requesthtmx:afterRequest
This event is triggered after an AJAX request has finished either in the case of a successful request (although
one that may have returned a remote error code such as a 404
) or in a network error situation. This event
can be paired with htmx:beforeRequest
to wrap behavior around a request cycle.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requestdetail.successful
- true if the response has a 20x status code or is marked detail.isError = false
in the
htmx:beforeSwap
event, else falsedetail.failed
- true if the response does not have a 20x status code or is marked detail.isError = true
in the
htmx:beforeSwap
event, else falsehtmx:afterSettle
This event is triggered after the DOM has settled.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:afterSwap
This event is triggered after new content has been swapped into the DOM.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:beforeOnLoad
This event is triggered before any response processing occurs. If the event is cancelled, no swap will occur.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:beforeProcessNode
This event is triggered before htmx initializes a DOM node and has processed all of its hx-
attributes. This gives extensions and other external code the ability to modify the contents of a DOM node before it is processed.
detail.elt
- the element that dispatched the requesthtmx:beforeRequest
This event is triggered before an AJAX request is issued. If the event is cancelled, no request will occur.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:beforeSend
This event is triggered right before a request is sent. You may not cancel the request with this event.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:beforeSwap
This event is triggered before any new content has been swapped into the DOM. If the event is cancelled, no swap will occur.
You can modify the default swap behavior by modifying the shouldSwap
and target
properties of the event detail. See
the documentation on configuring swapping for more details.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.requestConfig
- the configuration of the AJAX requestdetail.shouldSwap
- if the content will be swapped (defaults to false
for non-200 response codes)detail.target
- the target of the swaphtmx:beforeTransition
This event is triggered before a View Transition wrapped swap occurs. If the event is cancelled, the View Transition will not occur and the normal swapping logic will happen instead.
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.requestConfig
- the configuration of the AJAX requestdetail.shouldSwap
- if the content will be swapped (defaults to false
for non-200 response codes)detail.target
- the target of the swaphtmx:configRequest
This event is triggered after htmx has collected parameters for inclusion in the request. It can be used to include or update the parameters that htmx will send:
document.body.addEventListener('htmx:configRequest', function(evt) {
evt.detail.parameters['auth_token'] = getAuthToken(); // add a new parameter into the mix
});
Note that if an input value appears more than once the value in the parameters
object will be an array, rather
than a single value.
detail.parameters
- the parameters that will be submitted in the requestdetail.unfilteredParameters
- the parameters that were found before filtering by hx-select
detail.headers
- the request headersdetail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.verb
- the HTTP verb in usehtmx:confirm
This event is triggered immediately after a trigger occurs on an element. It allows you to cancel (or delay) issuing
the AJAX request. If you call preventDefault()
on the event, it will not issue the given request. The detail
object contains a function, evt.detail.issueRequest()
, that can be used to issue the actual AJAX request at a
later point. Combining these two features allows you to create an asynchronous confirmation dialog.
Here is an example using sweet alert:
document.body.addEventListener('htmx:confirm', function(evt) {
evt.preventDefault();
swal({
title: "Are you sure?",
text: "Are you sure you are sure?",
icon: "warning",
buttons: true,
dangerMode: true,
}).then((confirmed) => {
if (confirmed) {
evt.detail.issueRequest();
}
});
});
{target: target, elt: elt, path: path, verb: verb, triggeringEvent: event, etc: etc, issueRequest: issueRequest}
detail.elt
- the element in questiondetail.etc
- additional request information (mostly unused)detail.issueRequest
- a no argument function that can be invoked to issue the request (should be paired with evt.preventDefault()
!)detail.path
- the path of the requestdetail.target
- the target of the requestdetail.triggeringEvent
- the original event that triggered this requestdetail.verb
- the verb of the request (e.g. GET
)htmx:historyCacheError
This event is triggered when an attempt to save the cache to localStorage
fails
detail.cause
- the Exception
that was thrown when attempting to save history to localStorage
htmx:historyCacheMiss
This event is triggered when a cache miss occurs when restoring history
detail.xhr
- the XMLHttpRequest
that will retrieve the remote content for restorationdetail.path
- the path and query of the page being restoredhtmx:historyCacheMissError
This event is triggered when a cache miss occurs and a response has been retrieved from the server
for the content to restore, but the response is an error (e.g. 404
)
detail.xhr
- the XMLHttpRequest
detail.path
- the path and query of the page being restoredhtmx:historyCacheMissLoad
This event is triggered when a cache miss occurs and a response has been retrieved successfully from the server for the content to restore
detail.xhr
- the XMLHttpRequest
detail.path
- the path and query of the page being restoredhtmx:historyRestore
This event is triggered when htmx handles a history restoration action
detail.path
- the path and query of the page being restoredhtmx:beforeHistorySave
This event is triggered when htmx handles a history restoration action
detail.path
- the path and query of the page being restoreddetail.historyElt
- the history element being restored intodetail.config
- the config that will be passed to the EventSource
constructorhtmx:load
This event is triggered when a new node is loaded into the DOM by htmx.
detail.elt
- the newly added elementhtmx:noSSESourceError
This event is triggered when an element refers to an SSE event in its trigger, but no parent SSE source has been defined
detail.elt
- the element with the bad SSE triggerhtmx:oobAfterSwap
This event is triggered as part of an out of band swap and behaves identically to an after swap event
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:oobBeforeSwap
This event is triggered as part of an out of band swap and behaves identically to a before swap event
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.requestConfig
- the configuration of the AJAX requestdetail.shouldSwap
- if the content will be swapped (defaults to false
for non-200 response codes)detail.target
- the target of the swaphtmx:oobErrorNoTarget
This event is triggered when an out of band swap does not have a corresponding element in the DOM to switch with.
detail.content
- the element with the bad oob id
htmx:onLoadError
This event is triggered when an error occurs during the load
handling of an AJAX call
detail.xhr
- the XMLHttpRequest
detail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.exception
- the exception that occurreddetail.requestConfig
- the configuration of the AJAX requesthtmx:prompt
This event is triggered after a prompt has been shown to the user with the hx-prompt
attribute. If this event is cancelled, the AJAX request will not occur.
detail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.prompt
- the user response to the prompthtmx:pushedIntoHistory
This event is triggered after a URL has been pushed into history.
detail.path
- the path and query of the URL that has been pushed into historyhtmx:responseError
This event is triggered when an HTTP error response occurs
detail.xhr
- the XMLHttpRequest
detail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:sendError
This event is triggered when a network error prevents an HTTP request from occurring
detail.xhr
- the XMLHttpRequest
detail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:sseError
This event is triggered when an error occurs with an SSE source
detail.elt
- the element with the bad SSE sourcedetail.error
- the errordetail.source
- the SSE sourcehtmx:swapError
This event is triggered when an error occurs during the swap phase
detail.xhr
- the XMLHttpRequest
detail.elt
- the element that triggered the requestdetail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:targetError
This event is triggered when a bad selector is used for a hx-target
attribute (e.g. an
element ID without a preceding #
)
detail.elt
- the element that triggered the requestdetail.target
- the bad CSS selectorhtmx:timeout
This event is triggered when a request timeout occurs. This wraps the typical timeout
event of XMLHttpRequest.
Timeout time can be set using htmx.config.timeout
or per element using hx-request
detail.elt
- the element that dispatched the requestdetail.xhr
- the XMLHttpRequest
detail.target
- the target of the requestdetail.requestConfig
- the configuration of the AJAX requesthtmx:trigger
This event is triggered whenever an AJAX request would be, even if no AJAX request is specified. It
is primarily intended to allow hx-trigger
to execute client-side scripts; AJAX requests have more
granular events available, like htmx:beforeRequest
or htmx:afterRequest
.
detail.elt
- the element that triggered the requesthtmx:validation:validate
This event is triggered before an element is validated. It can be used with the elt.setCustomValidity()
method
to implement custom validation rules.
<form hx-post="/test">
<input _="on htmx:validation:validate
if my.value != 'foo'
call me.setCustomValidity('Please enter the value foo')
else
call me.setCustomValidity('')"
name="example">
</form>
detail.elt
- the element that triggered the requesthtmx:validation:failed
This event is triggered when an element fails validation.
detail.elt
- the element that triggered the requestdetail.message
- the validation error messagedetail.validity
- the validity object, which contains properties specifying how validation failedhtmx:validation:halted
This event is triggered when a request is halted due to validation errors.
detail.elt
- the element that triggered the requestdetail.errors
- an array of error objects with the invalid elements and errors associated with themhtmx:xhr:abort
This event is triggered when an ajax request aborts
detail.elt
- the element that triggered the requesthtmx:xhr:loadstart
This event is triggered when an ajax request starts
detail.elt
- the element that triggered the requesthtmx:xhr:loadend
This event is triggered when an ajax request finishes
detail.elt
- the element that triggered the requesthtmx:xhr:progress
This event is triggered periodically when an ajax request that supports progress is in flight
detail.elt
- the element that triggered the request