How Can I Check if Dynamically Loaded Elements Are Visible After Scrolling?

Resolving Visibility of Dynamically Loaded Elements after Scrolling

Problem Statement:

When dynamically loading elements through AJAX, it can be challenging to determine if they appear within the visible area of the page, especially if the page requires scrolling.

Solution:

To determine an element's visibility after scrolling, we can leverage a JavaScript function called isScrolledIntoView():

function isScrolledIntoView(elem) {
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

Alternative Approach:

An alternative utility function, Utils.isElementInView(), provides both a fullyInView and partiallyInView option:

function Utils() {}

Utils.prototype = {
    constructor: Utils,
    isElementInView: function(element, fullyInView) {
        var pageTop = $(window).scrollTop();
        var pageBottom = pageTop + $(window).height();
        var elementTop = $(element).offset().top;
        var elementBottom = elementTop + $(element).height();

        if (fullyInView === true) {
            return ((pageTop < elementTop) && (pageBottom > elementBottom));
        } else {
            return ((elementTop <= pageBottom) && (elementBottom >= pageTop));
        }
    }
};

var Utils = new Utils();

Usage:

var isElementInView = Utils.isElementInView($('#flyout-left-container'), false);

if (isElementInView) {
    console.log('in view');
} else {
    console.log('out of view');
}

The above is the detailed content of How Can I Check if Dynamically Loaded Elements Are Visible After Scrolling?. For more information, please follow other related articles on the PHP Chinese website!