CODEWITHSUNDEEP
javascriptarrays
Tomek Buszewski
Tomek Buszewski

Reputation: 7955

Element from array being removed too early?

I'm making a simple images lazy loading mechanism. I start with an array of images to process, and when I load each one, I want to remove the said image from array.

My code is as follows:

  const removeFromArray = (id) => {
    const position = images.indexOf(id);

    if (id.classList.contains(classes.loaded)) {
      images.splice(id, 1);
    }
  }

  const setHeight = (img, target) => {
    const parentWidth = img.parentNode.offsetWidth;
    const initw = target.width;
    const inith = target.height;

    return (parentWidth / initw) * inith;
  }

  const loadImage = (img) => {
    const image = new Image();

    img.classList.add(classes.loading);
    image.src = img.getAttribute('data-lazy-img');
    image.onload = function(e) {
      const target = e.target || e.srcElement;

      img.style.height = `${setHeight(img, target)}px`;
      img.classList.add(classes.loaded);
      img.classList.remove(classes.loading);
      img.src = img.getAttribute('data-lazy-img');

      removeFromArray(img);
    }
  }

Problem is, sometimes the wrong image gets removed (especially when I remove the latter ones).

My whole code is here: http://codepen.io/tomekbuszewski/pen/LbRQxq?editors=0011

What can I do?

Upvotes: 1

Views: 52

Answers (1)

janos
janos

Reputation: 124704

It seems to make no sense to call splice with an image id as parameter:

 images.splice(id, 1);

You probably meant to do this:

 images.splice(position, 1);

Upvotes: 1

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