Events

Infinite Ajax Scroll provides a wide range of events which we can use to hook into its functionality and customize where needed.

Working with events

You can bind and unbind to events with the on, once and off methods.

let ias = new InfiniteAjaxScroll('.container', options);

function handler(event) {
  console.log('New items have been appended', event);
}

ias.on('appended', handler);
ias.off('appended', handler);
ias.once('appended', handler);

Reference

ready

This event is triggered when the DOM is ready. Right after this event Infinite Ajax Scroll will bind (unless the bind option is set to false).

binded

This event is triggered when Infinite Ajax Scroll binds to the scroll and resize events of the scroll container. This mostly happens right after the DOM is ready, but this can be configured with the bind option.

unbinded

Triggered when Infinite Ajax Scroll removed its listeners from the scroll and resize events.

Infinite Ajax Scroll will only unbind when we call the unbind method.

scrolled

Triggered when the user scrolls inside the scroll container.

propertytypedescription

scroll.y

integer

Current vertical scroll position from the top of the page (can be negative)

scroll.x

integer

Current horizontal scroll position from the left of the page (can be negative)

scroll.deltaY

integer

Delta between current vertical scroll position and previous position

scroll.deltaX

integer

Delta between current horizontal scroll position and previous position

The delta values can be used to determine the scroll direction. A positive value means scrolling down (deltaY) or to the right (deltaX). A negative value means the opposite direction.

resized

Triggered when the user resizes the scroll container.

propertytypedescription

scroll

object

Object with x y coord of the current scroll position

hit

Triggered when the user has hit the scroll threshold for the next page due to scrolling or resizing.

propertytypedescription

distance

int

The distance to the scroll threshold in pixels

top

Introduced in Infinite Ajax Scroll 3.1.0

Triggered when the user has hit the top of the scroll area for the previous page due to scrolling or resizing.

propertytypedescription

distance

int

The distance to the scroll top in pixels

next

Triggered right after the hit event. Indicating that the next page will be loaded.

propertytypedescription

pageIndex

int

The page index of the next page (the page that is about to be loaded)

pageIndex is zero indexed. This means the index starts at 0 on the first page.

For example to notify the user about loading the next page, you can do:

ias.on('next', function(event) {
  // pageIndex is 0-indexed, so we add 1
  alert(`Page ${event.pageIndex+1} is loading...`);
});
ias.on('nexted', function(event) {
    alert(`Page ${event.pageIndex+1} is loaded and added to the page.`);
});

nexted

Trigger when loading and appending the next page is completed.

propertytypedescription

pageIndex

int

The page index of the next page (the page that is finished loading)

prev

Introduced in Infinite Ajax Scroll 3.1.0

Triggered right after the top event. Indicating that the previous page will be loaded.

propertytypedescription

pageIndex

int

The page index of the prev page (the page that is about to be loaded)

pageIndex is zero indexed. This means the index starts at 0 on the first page.

For example to notify the user about loading the previous page, you can do:

ias.on('prev', function(event) {
  // pageIndex is 0-indexed, so we add 1
  alert(`Page ${event.pageIndex+1} is loading...`);
});
ias.on('preved', function(event) {
    alert(`Page ${event.pageIndex+1} is loaded and prepended to the page.`);
});

preved

Introduced in Infinite Ajax Scroll 3.1.0

Trigger when loading and prepending the previous page is completed.

propertytypedescription

pageIndex

int

The page index of the next page (the page that is finished loading)

load

This event is triggered before the next page is requested from the server.

propertytypedefaultdescription

url

string

The url that is about to be requested

xhr

XMLHttpRequest

The configured XMLHttpRequest that is going to be used (see MDN)

method

string

"GET"

The request method to use, e.g. "GET", "POST", etc.

body

mixed

null

Body of the request in case of POST (see MDN)

nocache

boolean

false

Disables cache busting mechanism

responseType

string

"document"

The expected type of response, eg. "document", "json", etc. (also see responseType option)

headers

Object

{'X-Requested-With': 'XMLHttpRequest'}

Key-value object containing request headers

You can use this event to modify any of the above properties.

For example to disable the cache busting you can do:

ias.on('load', function(event) {
  event.nocache = true; // prevent IAS from adding a timestamp query param to the url
});

loaded

This event is triggered when the next page is requested from the server, right before the items will be appended.

propertytypedescription

items

array

Array of items that have loaded and will be appended. These items match the selector given in the next option

url

string

The url that is about to be requested

xhr

XMLHttpRequest

The configured XMLHttpRequest that is going to be used

error

This event is triggered when an error occurred while loading the next page.

propertytypedescription

url

string

The url that is about to be requested

method

string

The method used to fetch the url ("GET", "POST", etc)

xhr

XMLHttpRequest

The configured XMLHttpRequest that was used

append

This event is triggered before the items are about to be appended.

propertytypedescription

items

array

Array of items that will be appended

parent

Element

The element to which the items will be appended

appendFn

function

Function used to append items to the container

See src/append.js for the default append function.

appended

This event is triggered after the items have been appended.

propertytypedescription

items

array

Array of items that have been appended

parent

Element

The element to which the items have been appended

prepend

Introduced in Infinite Ajax Scroll 3.1.0

This event is triggered before the items are about to be prepended.

propertytypedescription

items

array

Array of items that will be prepended

parent

Element

The element to which the items will be prepended

prependFn

function

Function used to prepend items to the container

See src/prepend.js for the default prepend function.

prepended

Introduced in Infinite Ajax Scroll 3.1.0

This event is triggered after the items have been prepended.

propertytypedescription

items

array

Array of items that have been prepended

parent

Element

The element to which the items have been prepended

last

Triggered when the last page is appended.

ias.on('last', () => {
  console.log('User has reached the last page');
})

Read more on how we can inform the user about reaching the last page

first

Introduced in Infinite Ajax Scroll 3.1.0

Triggered when the last page is appended.

ias.on('first', () => {
  console.log('User has reached the first page');
})

page

Triggered when the user scrolls past a page break. The event provides information about the page in view.

propertytypedescription

pageIndex

int

The page index of the current page

url

string

Url of the page

title

string

Title of the page

sentinel

Element

Sentinel element. Element used to determine on which page the user is

pageIndex is zero-based. This means the index starts at 0 on the first page.

One use case for this event is to update the browser url and title:

ias.on('page', (event) => {
  // update the title
  document.title = event.title;

  // update the url
  let state = history.state;
  history.replaceState(state, event.title, event.url);
})

View this behaviour in a live demo

prefill

This event is triggered when Infinite Ajax Scroll starts prefill.

ias.on('prefill', () => {
  // do something before prefill starts
})

prefilled

This event is triggered when prefill is finished.

ias.on('prefilled', () => {
  // do something when prefill finished
})

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