Base64 is an encoding method commonly used to convert binary data into text format so that it can be transmitted over the network. PDF (Portable Document Format, Portable Document Format) is a format used to present and exchange documents.
In JavaScript programming, we sometimes need to convert Base64 encoded data to PDF format so that we can display or download these PDF documents in the browser. In this article, we will explain how to convert Base64 encoding to PDF format using JavaScript.
First, we need to get the Base64 encoded data. This can be achieved in various ways, such as getting data from a backend server or web API, or from a form or user interaction on the frontend.
In this example, we will use a string variable called base64Data to represent our Base64 encoded data. Here is sample code to represent this data:
var base64Data = "JVBERi0xLjMKJcfs...";
Next, we need to convert the Base64 encoded data back to binary format. This can be achieved by using the window.atob() function, which accepts a Base64 encoded string and returns a string representing the binary data for that string.
The following is a sample code to convert Base64 data to binary format:
var binaryData = window.atob(base64Data);
Next, we need to create a Blob object, It represents an immutable, raw data file-like object. Blob objects are commonly used in AJAX data transfer in web applications.
The following is the sample code to create a Blob object:
var blob = new Blob([binaryData], { type: "application/pdf" });
Here, we pass the binaryData string as an array parameter to the Blob constructor. We also specified the MIME type as "application/pdf", which indicates that we are creating a Blob object in PDF file format.
Once we have created the Blob object, we need to convert it into a URL format so that we can access it through the browser window. We can create this URL using the window.URL.createObjectURL() method.
The following is sample code to convert a Blob object into URL format:
var url = window.URL.createObjectURL(blob);
This will return a URL string representing the Blob object.
Now that we have created a URL, we can link it to a link element on the HTML page so that We can display or download this PDF file in the browser.
The following is the sample code to link a PDF file to a link element on an HTML page:
var link = document.createElement('a'); link.href = url; link.download = "file.pdf"; link.click();
Here, we have created a new link element named "link" and set its href The property is set to the previously created URL. We also specify the download attribute, which allows us to download the file when the link is clicked. Finally, we use link.click() to click on this link element so that we can display or download this PDF file in the browser.
Summary
In this article, we introduced how to use JavaScript to convert Base64-encoded data to PDF format, and display and download these PDF files in the browser. These steps include getting data from Base64 encoding, converting data to binary format, creating Blob objects, creating ObjectURLs and linking PDF files on HTML pages. When doing this, make sure to follow best practices such as data type validation, error handling, and security.
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