How To Add A Scroll To The Top Of The Page Link On The Jetpack Infinite Scroll Footer (WordPress Jetpack Plugin)

Customizing Jetpack’s Infinite Scroll Footer To Scroll The Top Of The Page

As stated in a previous post about removing the credits from the Infinite Scroll footer, as of November 10th, we use the new Jetpack 2.0 Infinite Scroll feature and give our website visitors the option to scroll to the top of the page via a simple text link with an arrow (↑)  opposed to using the preset alternative attribute assigned to the WordPress website title on the bottom left corner (clicking Botcrawl.com will scroll to the top of the page by default).

On a side note, we have also chosen the option to track each Infinite Scroll post load as a page view in Google Analytics. Meaning, each new set of posts loaded via Infinite Scroll will be recorded as a page view in Google Analytics, but for some cases this also means if customizing your Infinite Scroll footer to scroll to the top of the page, when someone loads a new set of posts and then clicks the scroll to the top option, they will only scroll to the top of the page that is technically loaded.

(If someone loads a new load of posts and clicks top they will redirect to the top of page 2, not the beginning of the posts)

How To Track Each Infinite Scroll Post Load As A Page View In Google Analytics

1. Access your WordPress dashboard and select Settings > Reading.

2. Locate the Track each Infinite Scroll post load as a page view in Google Analytics option on the page and check the radio box. Save changes.

How To Give The Infinite Scroll Footer A Top Of The Page Link/Option

This will give your visitors the option to scroll to the top of the page via a link on the bottom right of the Infinite Scroll footer.

1. Access your WordPress dashboard and select Plugins > Editor.

2. In the Select plugin to edit drop down menu, highlight Jetpack by WordPress.com and click the Select button.

3. Locate the jetpack/modules/infinite-scroll/infinity.php file and find the code below on lines 812 – 814.

$credits = '<a href="http://wordpress.org/" rel="generator">Proudly powered by WordPress</a> ';
 $credits .= sprintf( __( 'Theme: %1$s.', 'jetpack' ), function_exists( 'wp_get_theme' ) ? wp_get_theme()->Name : get_current_theme() );
 $credits = apply_filters( 'infinite_scroll_credit', $credits );

4. Switch the code above with the new code below. Also note, you can customize the code below however you wish.

$credits = '<a href="#" rel="generator">Top ↑</a> ';
$credits = apply_filters( 'infinite_scroll_credit', $credits );

Your Infinite Scroll footer should now have no credits and will give your WordPress website visitors an option to scroll back to the top of the page.

Custom jetpack/modules/infinite-scroll/infinity.php File

Here’s what the the entire custom jetpack/modules/infinite-scroll/infinity.php file should look like if you wish to use our example.

1. Copy and paste the entirety of the php below (unless this file has been previously customized) into the jetpack/modules/infinite-scroll/infinity.php file.

<?php
/*
Plugin Name: The Neverending Home Page.
Plugin URI: http://automattic.com/
Description: Adds infinite scrolling support to the front-end blog post view for themes, pulling the next set of posts automatically into view when the reader approaches the bottom of the page.
Version: 1.1
Author: Automattic
Author URI: http://automattic.com/
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
*/

/**
* Class: The_Neverending_Home_Page relies on add_theme_support, expects specific
* styling from each theme; including fixed footer.
*/
class The_Neverending_Home_Page {
/**
*
*/
function __construct() {
add_filter( 'pre_get_posts', array( $this, 'posts_per_page_query' ) );

add_action( 'admin_init', array( $this, 'settings_api_init' ) );
add_action( 'template_redirect', array( $this, 'action_template_redirect' ) );
add_action( 'template_redirect', array( $this, 'ajax_response' ) );
add_action( 'custom_ajax_infinite_scroll', array( $this, 'query' ) );
add_action( 'the_post', array( $this, 'preserve_more_tag' ) );
add_action( 'get_footer', array( $this, 'footer' ) );

// Parse IS settings from theme
self::get_settings();
}

/**
* Initialize our static variables
*/
static $the_time = null;
static $settings = null; // Don't access directly, instead use self::get_settings().

static $option_name_enabled = 'infinite_scroll';

/**
* Parse IS settings provided by theme
*
* @uses get_theme_support, infinite_scroll_has_footer_widgets, sanitize_title, add_action, get_option, wp_parse_args, is_active_sidebar
* @return object
*/
static function get_settings() {
if ( is_null( self::$settings ) ) {
$css_pattern = '#[^A-Z\d\-_]#i';

$settings = $defaults = array(
'type' => 'scroll', // scroll | click
'requested_type' => 'scroll', // store the original type for use when logic overrides it
'footer_widgets' => false, // true | false | sidebar_id | array of sidebar_ids -- last two are checked with is_active_sidebar
'container' => 'content', // container html id
'wrapper' => true, // true | false | html class
'render' => false, // optional function, otherwise the `content` template part will be used
'footer' => true, // boolean to enable or disable the infinite footer | string to provide an html id to derive footer width from
'posts_per_page' => false // int | false to set based on IS type
);

// Validate settings passed through add_theme_support()
$_settings = get_theme_support( 'infinite-scroll' );

if ( is_array( $_settings ) ) {
// Preferred implementation, where theme provides an array of options
if ( isset( $_settings[0] ) && is_array( $_settings[0] ) ) {
foreach ( $_settings[0] as $key => $value ) {
switch ( $key ) {
case 'type' :
if ( in_array( $value, array( 'scroll', 'click' ) ) )
$settings[ $key ] = $settings['requested_type'] = $value;

break;

case 'footer_widgets' :
if ( is_string( $value ) )
$settings[ $key ] = sanitize_title( $value );
elseif ( is_array( $value ) )
$settings[ $key ] = array_map( 'sanitize_title', $value );
elseif ( is_bool( $value ) )
$settings[ $key ] = $value;

break;

case 'container' :
case 'wrapper' :
if ( 'wrapper' == $key && is_bool( $value ) ) {
$settings[ $key ] = $value;
}
else {
$value = preg_replace( $css_pattern, '', $value );

if ( ! empty( $value ) )
$settings[ $key ] = $value;
}

break;

case 'render' :
if ( false !== $value && is_callable( $value ) ) {
$settings[ $key ] = $value;

add_action( 'infinite_scroll_render', $value );
}

break;

case 'footer' :
if ( is_bool( $value ) ) {
$settings[ $key ] = $value;
}
elseif ( is_string( $value ) ) {
$value = preg_replace( $css_pattern, '', $value );

if ( ! empty( $value ) )
$settings[ $key ] = $value;
}

break;

case 'posts_per_page' :
if ( is_numeric( $value ) )
$settings[ $key ] = (int) $value;

break;

default:
continue;

break;
}
}
}
// Checks below are for backwards compatibility
elseif ( is_string( $_settings[0] ) ) {
// Container to append new posts to
$settings['container'] = preg_replace( $css_pattern, '', $_settings[0] );

// Wrap IS elements?
if ( isset( $_settings[1] ) )
$settings['wrapper'] = (bool) $_settings[1];
}
}

// Always ensure all values are present in the final array
$settings = wp_parse_args( $settings, $defaults );

// Check if a legacy `infinite_scroll_has_footer_widgets()` function is defined and override the footer_widgets parameter's value.
// Otherwise, if a widget area ID or array of IDs was provided in the footer_widgets parameter, check if any contains any widgets.
// It is safe to use `is_active_sidebar()` before the sidebar is registered as this function doesn't check for a sidebar's existence when determining if it contains any widgets.
if ( function_exists( 'infinite_scroll_has_footer_widgets' ) ) {
$settings['footer_widgets'] = (bool) infinite_scroll_has_footer_widgets();
}
elseif ( is_array( $settings['footer_widgets'] ) ) {
$sidebar_ids = $settings['footer_widgets'];
$settings['footer_widgets'] = false;

foreach ( $sidebar_ids as $sidebar_id ) {
if ( is_active_sidebar( $sidebar_id ) ) {
$settings['footer_widgets'] = true;
break;
}
}

unset( $sidebar_ids );
unset( $sidebar_id );
}
elseif ( is_string( $settings['footer_widgets'] ) ) {
$settings['footer_widgets'] = (bool) is_active_sidebar( $settings['footer_widgets'] );
}

// For complex logic, let themes filter the `footer_widgets` parameter.
$settings['footer_widgets'] = apply_filters( 'infinite_scroll_has_footer_widgets', $settings['footer_widgets'] );

// Finally, after all of the sidebar checks and filtering, ensure that a boolean value is present, otherwise set to default of `false`.
if ( ! is_bool( $settings['footer_widgets'] ) )
$settings['footer_widgets'] = false;

// Ensure that IS is enabled and no footer widgets exist if the IS type isn't already "click".
if ( 'click' != $settings['type'] ) {
// Check the setting status
$disabled = '' === get_option( self::$option_name_enabled ) ? true : false;

// Footer content or Reading option check
if ( $settings['footer_widgets'] || $disabled )
$settings['type'] = 'click';
}

// Backwards compatibility for posts_per_page setting
if ( false === $settings['posts_per_page'] )
$settings['posts_per_page'] = 'click' == $settings['type'] ? (int) get_option( 'posts_per_page' ) : 7;

// Store final settings in a class static to avoid reparsing
self::$settings = apply_filters( 'infinite_scroll_settings', $settings );
}

return (object) self::$settings;
}

/**
* Has infinite scroll been triggered?
*/
static function got_infinity() {
return isset( $_GET[ 'infinity' ] );
}

/**
* The more tag will be ignored by default if the blog page isn't our homepage.
* Let's force the $more global to false.
*/
function preserve_more_tag( $array ) {
global $more;

if ( self::got_infinity() )
$more = 0; //0 = show content up to the more tag. Add more link.

return $array;
}

/**
* Add a checkbox field to Settings > Reading
* for enabling infinite scroll.
*
* Only show if the current theme supports infinity.
*
* @uses current_theme_supports, add_settings_field, __, register_setting
* @action admin_init
* @return null
*/
function settings_api_init() {
if ( ! current_theme_supports( 'infinite-scroll' ) )
return;

// Add the setting field [infinite_scroll] and place it in Settings > Reading
add_settings_field( self::$option_name_enabled, '<span id="infinite-scroll-options">' . __( 'To infinity and beyond', 'jetpack' ) . '</span>', array( $this, 'infinite_setting_html' ), 'reading' );
register_setting( 'reading', self::$option_name_enabled, 'esc_attr' );
}

/**
* HTML code to display a checkbox true/false option
* for the infinite_scroll setting.
*/
function infinite_setting_html() {
$notice = '<em>' . __( "We've disabled this option for you since you have footer widgets in Appearance &rarr; Widgets, or because your theme does not support infinite scroll.", 'jetpack' ) . '</em>';

// If the blog has footer widgets, show a notice instead of the checkbox
if ( self::get_settings()->footer_widgets || 'click' == self::get_settings()->requested_type ) {
echo '<label>' . $notice . '</label>';
} else {
echo '<label><input name="infinite_scroll" type="checkbox" value="1" ' . checked( 1, '' !== get_option( self::$option_name_enabled ), false ) . ' /> ' . __( 'Scroll Infinitely', 'jetpack' ) . '</br><small>' . sprintf( __( '(Shows %s posts on each load)', 'jetpack' ), number_format_i18n( self::get_settings()->posts_per_page ) ) . '</small>' . '</label>';
}
}

/**
* Does the legwork to determine whether the feature is enabled.
*
* @uses current_theme_supports, self::archive_supports_infinity, self::get_settings, self::set_last_post_time, add_filter, wp_enqueue_script, plugins_url, wp_enqueue_style, add_action
* @action template_redirect
* @return null
*/
function action_template_redirect() {
// Check that we support infinite scroll, and are on the home page.
if ( ! current_theme_supports( 'infinite-scroll' ) || ! self::archive_supports_infinity() )
return;

$id = self::get_settings()->container;

// Check that we have an id.
if ( empty( $id ) )
return;

// Bail if there are not enough posts for infinity.
if ( ! self::set_last_post_time() )
return;

// Add a class to the body.
add_filter( 'body_class', array( $this, 'body_class' ) );

// Add our scripts.
wp_enqueue_script( 'the-neverending-homepage', plugins_url( 'infinity.js', __FILE__ ), array( 'jquery' ), '20121105' );

// Add our default styles.
wp_enqueue_style( 'the-neverending-homepage', plugins_url( 'infinity.css', __FILE__ ), array(), '20120612' );

add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_spinner_scripts' ) );

add_action( 'wp_head', array( $this, 'action_wp_head' ), 2 );

add_action( 'wp_footer', array( $this, 'action_wp_footer' ), 99999999 );

add_filter( 'infinite_scroll_results', array( $this, 'filter_infinite_scroll_results' ) );
}

/**
* Enqueue spinner scripts.
*/
function enqueue_spinner_scripts() {
wp_enqueue_script( 'jquery.spin' );
}

/**
* Adds an 'infinite-scroll' class to the body.
*/
function body_class( $classes ) {
$classes[] = 'infinite-scroll';

if ( 'scroll' == self::get_settings()->type )
$classes[] = 'neverending';

return $classes;
}

/**
* Grab the timestamp for the last post.
* @return string 'Y-m-d H:i:s' or null
*/
function set_last_post_time( $date = false ) {
global $posts;
$count = count( $posts );

if ( ! empty( $date ) && preg_match( '|\d{4}\-\d{2}\-\d{2}|', $_GET['date'] ) ) {
self::$the_time = "$date 00:00:00";
return self::$the_time;
}

// If we don't have enough posts for infinity, return early
if ( ! $count || $count < self::get_settings()->posts_per_page )
return self::$the_time;

$last_post = end( $posts );

// If the function is called again but we already have a value, return it
if ( null != self::$the_time ) {
return self::$the_time;
}
else if ( isset( $last_post->post_date_gmt ) ) {
// Grab the latest post time in Y-m-d H:i:s gmt format
self::$the_time = $last_post->post_date_gmt;
}

return self::$the_time;
}

/**
* Create a where clause that will make sure post queries
* will always return results prior to (descending sort)
* or before (ascending sort) the last post date.
*
* @param string $where
* @param object $query
* @filter posts_where
* @return string
*/
function query_time_filter( $where, $query ) {
global $wpdb;

$operator = 'ASC' == $query->get( 'order' ) ? '>' : '<';

// Construct the date query using our timestamp
$where .= $wpdb->prepare( " AND post_date_gmt {$operator} %s", self::set_last_post_time() );

return $where;
}

/**
* Let's overwrite the default post_per_page setting to always display a fixed amount.
*
* @global $wp_the_query Used to provide compatibility back to WP 3.2
* @param object $query
* @uses self::archive_supports_infinity, self::get_settings
* @return null
*/
function posts_per_page_query( $query ) {
global $wp_the_query;

if ( self::archive_supports_infinity() && $query === $wp_the_query ) // After 3.3, this line would be: if ( self::archive_supports_infinity() && $query->is_main_query() )
$query->set( 'posts_per_page', self::get_settings()->posts_per_page );
}

/**
* Check if the IS output should be wrapped in a div.
* Setting value can be a boolean or a string specifying the class applied to the div.
*
* @uses self::get_settings
* @return bool
*/
function has_wrapper() {
return (bool) self::get_settings()->wrapper;
}

/**
* Returns the Ajax url
*/
function ajax_url() {
global $wp;

$base_url = home_url( trailingslashit( $wp->request ), is_ssl() ? 'https' : 'http' );

$ajaxurl = add_query_arg( array( 'infinity' => 'scrolling' ), $base_url );

return apply_filters( 'infinite_scroll_ajax_url', $ajaxurl );
}

/**
* Our own Ajax response, avoiding calling admin-ajax
*/
function ajax_response() {
// Only proceed if the url query has a key of "Infinity"
if ( ! self::got_infinity() )
return false;

define( 'DOING_AJAX', true );

@header( 'Content-Type: text/html; charset=' . get_option( 'blog_charset' ) );
send_nosniff_header();

do_action( 'custom_ajax_infinite_scroll' );
die( '0' );
}

/**
* Prints the relevant infinite scroll settings in JS.
*
* @uses self::get_settings, esc_js, esc_url_raw, self::has_wrapper, __, apply_filters, do_action
* @action wp_head
* @return string
*/
function action_wp_head() {
global $wp_query, $wp_rewrite;

// Base JS settings
$js_settings = array(
'id' => self::get_settings()->container,
'ajaxurl' => esc_js( esc_url_raw( self::ajax_url() ) ),
'type' => esc_js( self::get_settings()->type ),
'wrapper' => self::has_wrapper(),
'wrapper_class' => is_string( self::get_settings()->wrapper ) ? esc_js( self::get_settings()->wrapper ) : 'infinite-wrap',
'footer' => is_string( self::get_settings()->footer ) ? esc_js( self::get_settings()->footer ) : self::get_settings()->footer,
'text' => esc_js( __( 'Load more posts', 'jetpack' ) ),
'totop' => esc_js( __( 'Scroll back to top', 'jetpack' ) ),
'order' => 'DESC',
'scripts' => array(),
'styles' => array(),
'google_analytics' => false,
'offset' => $wp_query->get( 'paged' ),
'history' => array(
'host' => preg_replace( '#^http(s)?://#i', '', untrailingslashit( get_option( 'home' ) ) ),
'path' => self::get_request_path(),
'use_trailing_slashes' => $wp_rewrite->use_trailing_slashes
)
);

// Optional order param
if ( isset( $_GET['order'] ) ) {
$order = strtoupper( $_GET['order'] );

if ( in_array( $order, array( 'ASC', 'DESC' ) ) )
$js_settings['order'] = $order;
}

$js_settings = apply_filters( 'infinite_scroll_js_settings', $js_settings );

do_action( 'infinite_scroll_wp_head' );

?>
<script type="text/javascript">
//<![CDATA[
var infiniteScroll = <?php echo json_encode( array( 'settings' => $js_settings ) ); ?>;
//]]>
</script>
<?php
}

/**
* Build path data for current request.
* Used for Google Analytics and pushState history tracking.
*
* @global $wp_rewrite
* @global $wp
* @uses user_trailingslashit, sanitize_text_field, add_query_arg
* @return string|bool
*/
private function get_request_path() {
global $wp_rewrite;

if ( $wp_rewrite->using_permalinks() ) {
global $wp;

// If called too early, bail
if ( ! isset( $wp->request ) )
return false;

// Determine path for paginated version of current request
if ( false != preg_match( '#' . $wp_rewrite->pagination_base . '/\d+/?$#i', $wp->request ) )
$path = preg_replace( '#' . $wp_rewrite->pagination_base . '/\d+$#i', $wp_rewrite->pagination_base . '/%d', $wp->request );
else
$path = $wp->request . '/' . $wp_rewrite->pagination_base . '/%d';

// Slashes everywhere we need them
if ( 0 !== strpos( $path, '/' ) )
$path = '/' . $path;

$path = user_trailingslashit( $path );
}
else {
// Clean up raw $_GET input
$path = array_map( 'sanitize_text_field', $_GET );
$path = array_filter( $path );

$path['paged'] = '%d';

$path = add_query_arg( $path, '/' );
}

return empty( $path ) ? false : $path;
}

/**
* Provide IS with a list of the scripts and stylesheets already present on the page.
* Since posts may contain require additional assets that haven't been loaded, this data will be used to track the additional assets.
*
* @global $wp_scripts, $wp_styles
* @action wp_footer
* @return string
*/
function action_wp_footer() {
global $wp_scripts, $wp_styles;

$scripts = is_a( $wp_scripts, 'WP_Scripts' ) ? $wp_scripts->done : array();
$styles = is_a( $wp_styles, 'WP_Styles' ) ? $wp_styles->done : array();

?><script type="text/javascript">
jQuery.extend( infiniteScroll.settings.scripts, <?php echo json_encode( $scripts ); ?> );
jQuery.extend( infiniteScroll.settings.styles, <?php echo json_encode( $styles ); ?> );
</script><?php
}

/**
* Identify additional scripts required by the latest set of IS posts and provide the necessary data to the IS response handler.
*
* @global $wp_scripts
* @uses sanitize_text_field, add_query_arg
* @filter infinite_scroll_results
* @return array
*/
function filter_infinite_scroll_results( $results ) {
// Don't bother unless there are posts to display
if ( 'success' != $results['type'] )
return $results;

// Parse and sanitize the script handles already output
$initial_scripts = isset( $_GET['scripts'] ) && is_array( $_GET['scripts'] ) ? array_map( 'sanitize_text_field', $_GET['scripts'] ) : false;

if ( is_array( $initial_scripts ) ) {
global $wp_scripts;

// Identify new scripts needed by the latest set of IS posts
$new_scripts = array_diff( $wp_scripts->done, $initial_scripts );

// If new scripts are needed, extract relevant data from $wp_scripts
if ( ! empty( $new_scripts ) ) {
$results['scripts'] = array();

foreach ( $new_scripts as $handle ) {
// Abort if somehow the handle doesn't correspond to a registered script
if ( ! isset( $wp_scripts->registered[ $handle ] ) )
continue;

// Provide basic script data
$script_data = array(
'handle' => $handle,
'footer' => ( is_array( $wp_scripts->in_footer ) && in_array( $handle, $wp_scripts->in_footer ) ),
'extra_data' => $wp_scripts->print_extra_script( $handle, false )
);

// Base source
$src = $wp_scripts->registered[ $handle ]->src;

// Version and additional arguments
if ( null === $wp_scripts->registered[ $handle ]->ver )
$ver = '';
else
$ver = $wp_scripts->registered[ $handle ]->ver ? $wp_scripts->registered[ $handle ]->ver : $wp_scripts->default_version;

if ( isset($wp_scripts->args[ $handle ] ) )
$ver = $ver ? $ver . '&amp;' . $wp_scripts->args[$handle] : $wp_scripts->args[$handle];

// Full script source with version info
$script_data['src'] = add_query_arg( 'ver', $ver, $src );

// Add script to data that will be returned to IS JS
array_push( $results['scripts'], $script_data );
}
}
}

// Parse and sanitize the style handles already output
$initial_styles = isset( $_GET['styles'] ) && is_array( $_GET['styles'] ) ? array_map( 'sanitize_text_field', $_GET['styles'] ) : false;

if ( is_array( $initial_styles ) ) {
global $wp_styles;

// Identify new styles needed by the latest set of IS posts
$new_styles = array_diff( $wp_styles->done, $initial_styles );

// If new styles are needed, extract relevant data from $wp_styles
if ( ! empty( $new_styles ) ) {
$results['styles'] = array();

foreach ( $new_styles as $handle ) {
// Abort if somehow the handle doesn't correspond to a registered stylesheet
if ( ! isset( $wp_styles->registered[ $handle ] ) )
continue;

// Provide basic style data
$style_data = array(
'handle' => $handle,
'media' => 'all'
);

// Base source
$src = $wp_styles->registered[ $handle ]->src;

// Version and additional arguments
if ( null === $wp_styles->registered[ $handle ]->ver )
$ver = '';
else
$ver = $wp_styles->registered[ $handle ]->ver ? $wp_styles->registered[ $handle ]->ver : $wp_styles->default_version;

if ( isset($wp_styles->args[ $handle ] ) )
$ver = $ver ? $ver . '&amp;' . $wp_styles->args[$handle] : $wp_styles->args[$handle];

// Full stylesheet source with version info
$style_data['src'] = add_query_arg( 'ver', $ver, $src );

// Parse stylesheet's conditional comments if present, converting to logic executable in JS
if ( isset( $wp_styles->registered[ $handle ]->extra['conditional'] ) && $wp_styles->registered[ $handle ]->extra['conditional'] ) {
// First, convert conditional comment operators to standard logical operators. %ver is replaced in JS with the IE version
$style_data['conditional'] = str_replace( array(
'lte',
'lt',
'gte',
'gt'
), array(
'%ver <=',
'%ver <',
'%ver >=',
'%ver >',
), $wp_styles->registered[ $handle ]->extra['conditional'] );

// Next, replace any !IE checks. These shouldn't be present since WP's conditional stylesheet implementation doesn't support them, but someone could be _doing_it_wrong().
$style_data['conditional'] = preg_replace( '#!\s*IE(\s*\d+){0}#i', '1==2', $style_data['conditional'] );

// Lastly, remove the IE strings
$style_data['conditional'] = str_replace( 'IE', '', $style_data['conditional'] );
}

// Parse requested media context for stylesheet
if ( isset( $wp_styles->registered[ $handle ]->args ) )
$style_data['media'] = esc_attr( $wp_styles->registered[ $handle ]->args );

// Add stylesheet to data that will be returned to IS JS
array_push( $results['styles'], $style_data );
}
}
}

// Lastly, return the IS results array
return $results;
}

/**
* Runs the query and returns the results via JSON.
* Triggered by an AJAX request.
*
* @global $wp_query
* @uses current_user_can, get_option, self::set_last_post_time, current_user_can, apply_filters, self::get_settings, add_filter, WP_Query, remove_filter, have_posts, wp_head, do_action, add_action, this::render, this::has_wrapper, esc_attr, wp_footer
* @return string or null
*/
function query() {
global $wp_query;

if ( ! isset( $_GET['page'] ) || ! current_theme_supports( 'infinite-scroll' ) )
die;

$page = (int) $_GET['page'];
$sticky = get_option( 'sticky_posts' );

if ( ! empty( $_GET['date'] ) )
self::set_last_post_time( $_GET['date'] );

$post_status = array( 'publish' );
if ( current_user_can( 'read_private_posts' ) )
array_push( $post_status, 'private' );

$order = in_array( $_GET['order'], array( 'ASC', 'DESC' ) ) ? $_GET['order'] : 'DESC';

$query_args = apply_filters( 'infinite_scroll_query_args', array(
'paged' => $page,
'post_status' => $post_status,
'posts_per_page' => self::get_settings()->posts_per_page,
'post__not_in' => ( array ) $sticky,
'order' => $order
) );

// Add query filter that checks for posts below the date
add_filter( 'posts_where', array( $this, 'query_time_filter' ), 10, 2 );

$wp_query = new WP_Query( $query_args );

remove_filter( 'posts_where', array( $this, 'query_time_filter' ), 10, 2 );

$results = array();

if ( have_posts() ) {
// Fire wp_head to ensure that all necessary scripts are enqueued. Output isn't used, but scripts are extracted in self::action_wp_footer.
ob_start();
wp_head();
ob_end_clean();

$results['type'] = 'success';

// First, try theme's specified rendering handler, either specified via `add_theme_support` or by hooking to this action directly.
ob_start();
do_action( 'infinite_scroll_render' );
$results['html'] = ob_get_clean();

// Fall back if a theme doesn't specify a rendering function. Because themes may hook additional functions to the `infinite_scroll_render` action, `has_action()` is ineffective here.
if ( empty( $results['html'] ) ) {
add_action( 'infinite_scroll_render', array( $this, 'render' ) );
rewind_posts();

ob_start();
do_action( 'infinite_scroll_render' );
$results['html'] = ob_get_clean();
}

// If primary and fallback rendering methods fail, prevent further IS rendering attempts. Otherwise, wrap the output if requested.
if ( empty( $results['html'] ) ) {
unset( $results['html'] );
do_action( 'infinite_scroll_empty' );
$results['type'] = 'empty';
}
elseif ( $this->has_wrapper() ) {
$wrapper_classes = is_string( self::get_settings()->wrapper ) ? self::get_settings()->wrapper : 'infinite-wrap';
$wrapper_classes .= ' infinite-view-' . $page;
$wrapper_classes = trim( $wrapper_classes );

$results['html'] = '<div class="' . esc_attr( $wrapper_classes ) . '" id="infinite-view-' . $page . '" data-page-num="' . $page . '">' . $results['html'] . '</div>';
}

// Fire wp_footer to ensure that all necessary scripts are enqueued. Output isn't used, but scripts are extracted in self::action_wp_footer.
ob_start();
wp_footer();
ob_end_clean();
} else {
do_action( 'infinite_scroll_empty' );
$results['type'] = 'empty';
}

echo json_encode( apply_filters( 'infinite_scroll_results', $results ) );
die;
}

/**
* Rendering fallback used when themes don't specify their own handler.
*
* @uses have_posts, the_post, get_template_part, get_post_format
* @action infinite_scroll_render
* @return string
*/
function render() {
while( have_posts() ) {
the_post();

get_template_part( 'content', get_post_format() );
}
}

/**
* Allow plugins to filter what archives Infinite Scroll supports
*
* @uses apply_filters, is_home, is_archive, self::get_settings
* @return bool
*/
private function archive_supports_infinity() {
return (bool) apply_filters( 'infinite_scroll_archive_supported', ( is_home() || is_archive() ), self::get_settings() );
}

/**
* The Infinite Blog Footer
*
* @uses self::get_settings, self::set_last_post_time, self::archive_supports_infinity, __, wp_get_theme, get_current_theme, apply_filters, home_url, esc_attr, get_bloginfo, bloginfo
* @return string or null
*/
function footer() {
// Bail if theme requested footer not show
if ( false == self::get_settings()->footer )
return;

// Bail if there are not enough posts for infinity.
if ( ! self::set_last_post_time() )
return;

// We only need the new footer for the 'scroll' type
if ( 'scroll' != self::get_settings()->type || ! self::archive_supports_infinity() )
return;

$credits = '<a href="#" rel="generator">Top ↑</a> ';
$credits = apply_filters( 'infinite_scroll_credit', $credits );

?>
<div id="infinite-footer">
<div class="container">
<div class="blog-info">
<a id="infinity-blog-title" href="<?php echo home_url( '/' ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home">
<?php bloginfo( 'name' ); ?>
</a>
</div>
<div class="blog-credits">
<?php echo $credits; ?>
</div>
</div>
</div><!-- #infinite-footer -->
<?php
}
};

/**
* Initialize The_Neverending_Home_Page
*/
function the_neverending_home_page_init() {
if ( ! current_theme_supports( 'infinite-scroll' ) )
return;

new The_Neverending_Home_Page;
}
add_action( 'init', 'the_neverending_home_page_init', 20 );

/**
* Check whether the current theme is infinite-scroll aware.
* If so, include the files which add theme support.
*/
function the_neverending_home_page_theme_support() {
$theme_name = get_stylesheet();

$customization_file = apply_filters( 'infinite_scroll_customization_file', dirname( __FILE__ ) . "/themes/{$theme_name}.php", $theme_name );

if ( is_readable( $customization_file ) )
require_once( $customization_file );
}
add_action( 'after_setup_theme', 'the_neverending_home_page_theme_support', 5 );