Javascript blob filename without link

javascript

blob

file-handling

javascript-libraries

byNikita Barsukov·Sep 16, 2024

Here's a to-the-point solution to generate a downloadable file from a Blob object with a specified filename:

// Create a Blob, like a philosopher's stone but for text
const blob = new Blob(["Text content"], { type: 'text/plain' });

// It's a little magic trick: download without adding a link
const url = URL.createObjectURL(blob);
const a = document.createElement('a');
a.style = "display: none";
a.href = url;
a.download = "desiredFilename.txt"; // ta-da, the rabbit is out of the hat!
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);

This method creates a blob, assigns a URL to it, and uses a hidden a element with the download attribute to prompt a download with the specified filename.

Understanding the Blob

To effectively work with Blob objects in JavaScript, familiarize yourself with various aspects such as their properties, methods, and relevant browser compatibility issues.

Saving JSON data securely

Safe practices recommend saving blobs containing JSON data as .txt files. It prevents accidental execution in the browser context, providing a safety blanket for your code.

Consider Browser Compatibility

The download attribute used here may not be supported natively by some older browsers. In such cases, fallbacks like the FileSaver.js library could ensure a seamless user experience.

Boost Performance with Libraries

For larger file operations, using libraries like FileSaver.js can handle edge cases more efficiently than a custom script, making it an ideal choice for production environments.

Playing Nice with Internet Explorer

For Internet Explorer users, alternative approaches like using navigator.msSaveBlob or window.navigator.msSaveOrOpenBlob could be necessary to prompt downloads.

Clean after Yourself

Don't forget to revoke the object URL after triggering the download! It's like cleaning up the dining table after a festive feast, freeing up valuable resources.

Creating a Helper Function

Consider creating a saveFile(blob, filename) function to handle the download process. It makes your code more readable and easier to maintain.

Implement Efficient File Delivery

An efficient file delivery system keeps user experience in mind, anticipates errors, and performs proper garbage collection.

Minimize Resource Usage

Ensure your application uses minimal resources. Clean up invisible a elements and revoke blob URLs to keep your application lean and healthy.

Enhance Functionality

Why stick to basics when you can offer more? Consider implementing progress indicators or performing data operations like compression before creating the download blob.

The Excellence of FileSaver.js

When it comes to file handling in JavaScript, FileSaver.js is a star player! It handles inconsistencies across different browsers, offers reliable fallbacks, and sets correct mime types for blobs.

explain-codes / Javascript / Javascript blob filename without link

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