How to delete local image javascript

When using local images in a website or application, we sometimes need to delete certain images. In JavaScript, there are several ways to delete local images. This article will detail how to delete local images using JavaScript.

Method 1: Use URL.revokeObjectURL()

In JavaScript, use URL.createObjectURL() to create a URL object to load local images. Since a URL object is essentially created to display an image in a page, you can use the URL.revokeObjectURL() method to delete the image when it is no longer needed to be displayed.

The following is a sample code for loading a local image using URL.createObjectURL():

const fileInput = document.getElementById("file-input");
const imgPreview = document.getElementById("img-preview");

fileInput.addEventListener("change", function () {
  const file = fileInput.files[0];
  if (file) {
    const blobUrl = URL.createObjectURL(file);
    imgPreview.src = blobUrl;
  }
});

In the above code, when the user selects a file and uploads it, we store the URL of the file in the blobUrl variable middle. We then set the blobUrl as the image source into the imgPreview element.

If you want to delete a loaded image, simply call the URL.revokeObjectURL() method:

URL.revokeObjectURL(blobUrl);
imgPreview.src = '';

In the above code snippet, we first call the URL.revokeObjectURL() method , passing it along with the previously stored blobUrl variable. This immediately deletes the URL object that was created. We then set the src attribute of the imgPreview element to an empty string to clear the image.

Method 2: Use a combination of URL.createObjectURL() and URL.revokeObjectURL()

A slightly different method can be used to completely remove the image from the website. We will describe it in detail in the code snippet below:

const fileInput = document.getElementById("file-input");
const imgPreview = document.getElementById("img-preview");
let blobUrl;

fileInput.addEventListener("change", function () {
  const file = fileInput.files[0];
  if (file) {
    blobUrl = URL.createObjectURL(file);
    if (imgPreview.src) {
      URL.revokeObjectURL(imgPreview.src);
    }
    imgPreview.src = blobUrl;
  }
});

In the above code, we use the same method as before to store the URL of the file in the blobUrl variable and set it as the image source to the imgPreview element middle. However, we added another extra step.

Before we add a new image source to the imgPreview element, we check if the image source already exists in the imgPreview element. If there is already an image source in the imgPreview element, you need to call the URL.revokeObjectURL() method to remove it first, because the browser will not automatically clear the previous URL before redefining the src attribute.

In this combined method, we can update the image by simply modifying the value of the variable blobUrl as shown below:

blobUrl = URL.createObjectURL(file);
if (imgPreview.src) {
  URL.revokeObjectURL(imgPreview.src);
}
imgPreview.src = blobUrl;

If you want to completely remove the image from the website or application, please Use the previous code snippet and store the URL of the current image source in the blobUrl variable. When we need to delete an image, we simply call the URL.revokeObjectURL() method and pass the previously stored image URL.

Conclusion:

There may be many ways to delete local images in JavaScript, but using the URL.createObjectURL() and URL.revokeObjectURL() methods is one of the more common and most efficient methods. We can use this method to add or update local images and delete images if needed.

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