jQuery / JavaScript – Coding Wiki

if (typeof car.color === 'undefined') { 
      // color is undefined 
}

May 5, 2022May 12, 2022

Animate elements if visible in viewport (page scroll)

Development, Front End, jQuery / JavaScript

Using IntersectionObserver API

The IntersectionObserver API provides a way to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document’s viewport.

Here’s an example that triggers a function when an Element is in viewport:

const inViewport = (entries, observer) => {
	entries.forEach(entry => {
		if(entry.isIntersecting && entry.target.id=="php"){
			php.setValueAnimated(9, 3);
		}
	});
};

const Obs = new IntersectionObserver(inViewport);
const obsOptions = {}; //See: https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API#Intersection_observer_options

// Attach observer to every [data-inviewport] element:
const ELs_inViewport = document.querySelectorAll('.gauge-container');
ELs_inViewport.forEach(EL => {
	Obs.observe(EL, obsOptions);
});

Here’s an example that triggers a classList toggle when an Element is in viewport:

const inViewport = (entries, observer) => {
  entries.forEach(entry => {
    entry.target.classList.toggle("is-inViewport", entry.isIntersecting);
  });
};

const Obs = new IntersectionObserver(inViewport);
const obsOptions = {}; //See: https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API#Intersection_observer_options

// Attach observer to every [data-inviewport] element:
const ELs_inViewport = document.querySelectorAll('[data-inviewport]');
ELs_inViewport.forEach(EL => {
  Obs.observe(EL, obsOptions);
});

[data-inviewport] { /* THIS DEMO ONLY */
  width:100px; height:100px; background:#0bf; margin: 150vh 0; 
}

/* inViewport */

[data-inviewport="scale-in"] { 
  transition: 2s;
  transform: scale(0.1);
}
[data-inviewport="scale-in"].is-inViewport { 
  transform: scale(1);
}

[data-inviewport="fade-rotate"] { 
  transition: 2s;
  opacity: 0;
}
[data-inviewport="fade-rotate"].is-inViewport { 
  transform: rotate(180deg);
  opacity: 1;
}

Scroll down...
<div data-inviewport="scale-in"></div>
<div data-inviewport="fade-rotate"></div>

October 8, 2019January 29, 2022

JS: Non UX Intrusive way to stop Mobile Scroll

Development, Front End, jQuery / JavaScript

Check this out homies,
A slick JS way to stop iOS (and other devices that use touch) from scrolling


        // Disable scrolling.
        document.ontouchmove = function (e) {
            e.preventDefault();
        }
        // Enable scrolling.
        document.ontouchmove = function (e) {
            return true;
        }

October 4, 2019January 29, 2022

jQuery – detect click event on pseudo-element

Development, Front End, jQuery / JavaScript

How it works:

It grabs the height, width, top, and left positions(based on the position away from the edge of the window) of the parent element and grabs the height, width, top, and left positions(based on the edge of the parent container) and compares those values to determine where the pseudo-element is on the screen.

It then compares where the mouse is. As long as the mouse is in the newly created variable range then it returns true.

Note:

It is wise to make the parent element RELATIVE positioned. If you have an absolute positioned pseudo-element, this function will only work if it is positioned based on the parent’s dimensions(so the parent has to be relative…maybe sticky or fixed would work too….).

Code:

function pseudoClick(parentElem) {

    var beforeClicked,
      afterClicked;

  var parentLeft = parseInt(parentElem.getBoundingClientRect().left, 10),
      parentTop = parseInt(parentElem.getBoundingClientRect().top, 10);

  var parentWidth = parseInt(window.getComputedStyle(parentElem).width, 10),
      parentHeight = parseInt(window.getComputedStyle(parentElem).height, 10);

  var before = window.getComputedStyle(parentElem, ':before');

  var beforeStart = parentLeft + (parseInt(before.getPropertyValue("left"), 10)),
      beforeEnd = beforeStart + parseInt(before.width, 10);

  var beforeYStart = parentTop + (parseInt(before.getPropertyValue("top"), 10)),
      beforeYEnd = beforeYStart + parseInt(before.height, 10);

  var after = window.getComputedStyle(parentElem, ':after');

  var afterStart = parentLeft + (parseInt(after.getPropertyValue("left"), 10)),
      afterEnd = afterStart + parseInt(after.width, 10);

  var afterYStart = parentTop + (parseInt(after.getPropertyValue("top"), 10)),
      afterYEnd = afterYStart + parseInt(after.height, 10);

  var mouseX = event.clientX,
      mouseY = event.clientY;

  beforeClicked = (mouseX >= beforeStart && mouseX <= beforeEnd && mouseY >= beforeYStart && mouseY <= beforeYEnd ? true : false); afterClicked = (mouseX >= afterStart && mouseX <= afterEnd && mouseY >= afterYStart && mouseY <= afterYEnd ? true : false);

  return {
    "before" : beforeClicked,
    "after"  : afterClicked

  };      

}

Usage:

$('.user-details-expand').click(function (e) {
  // console.log("Logging the object..." + JSON.stringify(pseudoClick(this)));
  // console.log("Before has been click..." + pseudoClick(this).before);
  // console.log("After has been clicked..." + pseudoClick(this).after);
  if ( pseudoClick(this).after==true) {
    $(this).hide();
  }
});

Support:

IT SEEMS TO WORK WELL IN ALL BROWSERS IF DIMENSIONS ARE SET IN CSS. So…set your height and width on your pseudo-elements and only move them with top and left. I recommend using it on things that you are okay with it not working on. Like an animation or something. Chrome works…as usual.

January 16, 2018January 29, 2022

Posting Message From An Embed or iFrame to Parent Page

Development, Front End, jQuery / JavaScript

You can post a JS message to the parent page using window.parent.postMessage() function. I didn’t know this was possible. Developer Mozilla window post message

Can be used to interact between the windows. There is security concerns with this if the targetOrigin parameter is not set to the target with this function.

Category: jQuery / JavaScript

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Animate elements if visible in viewport (page scroll)

Using IntersectionObserver API

JS: Non UX Intrusive way to stop Mobile Scroll

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jQuery – detect click event on pseudo-element

Posting Message From An Embed or iFrame to Parent Page