ArticleZip > Html5 Javascript Dataurl To Blob Blob To Dataurl

Html5 Javascript Dataurl To Blob Blob To Dataurl

HTML5 comes with powerful features that allow you to work with dataURLs and blobs effectively in your JavaScript code. Understanding how to convert between dataURLs and blobs can help you manipulate images, files, and other data types seamlessly in your web applications. In this article, we will dive into the process of converting from a dataURL to a blob and vice versa, helping you harness the full potential of these functionalities.

Converting DataURL to Blob:

To convert a dataURL to a blob in JavaScript, you can follow these steps:

1. First, you need to extract the data part from the dataURL. This is typically the part after the comma in the dataURL string.
2. Use the `atob()` function to decode the base64-encoded data.
3. Create an array buffer from the decoded data using the `ArrayBuffer` constructor.
4. Finally, create a blob from the array buffer by specifying the MIME type of the data.

Here's an example code snippet that demonstrates how to convert a dataURL to a blob:

Javascript

function dataURLToBlob(dataURL) {
  const byteString = atob(dataURL.split(',')[1]);
  const arrayBuffer = new ArrayBuffer(byteString.length);
  let uintArray = new Uint8Array(arrayBuffer);
  
  for (let i = 0; i < byteString.length; i++) {
    uintArray[i] = byteString.charCodeAt(i);
  }

  return new Blob([uintArray], { type: 'image/png' }); // Specify the MIME type as per your data
}

Converting Blob to DataURL:

Converting a blob to a dataURL involves a similar process, but in reverse. Follow these steps to achieve the conversion:

1. Create a new file reader object using `FileReader()`.
2. Use the `readAsDataURL()` method of the file reader object and pass the blob as an argument.
3. Set an event listener on the file reader to handle the completion of the read operation.
4. Access the dataURL from the `result` attribute of the file reader in the event listener.

Here's a sample code snippet for converting a blob to a dataURL:

Javascript

function blobToDataURL(blob, callback) {
  const reader = new FileReader();
  
  reader.onload = function(event) {
    callback(event.target.result);
  };
  
  reader.readAsDataURL(blob);
}

blobToDataURL(blob, function(dataURL) {
  console.log(dataURL); // Use the dataURL as needed
});

By mastering the conversion between dataURLs and blobs in HTML5 and JavaScript, you can enhance your web development projects with rich media handling capabilities. Whether you are working with images, files, or other data types, these techniques provide you with the flexibility to manipulate data efficiently. Experiment with these methods in your code and explore the possibilities of working with dataURLs and blobs seamlessly in your web applications.

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