Javascript enables web developers to create PDF documents on the fly. This allows them to generate printable documents, invoices, bills, or reports directly from the web page without needing to write the content manually.
PDF with Javascript
To generate a PDF with Javascript, the developer adds code to their HTML and Javascript which will create the PDF document on the server side.
// Generate PDF
let doc = new jsPDF();
doc.text("Hello World", 10, 10);
doc.save("test.pdf");
This code snippet initializes a new jsPDF document, adds some text, and saves it with the .pdf extension. The jsPDF library handles the PDF generation behind the scenes.
The PDF can be customized by setting properties like page size, margins, orientation, and fonts. Password protection can also be added to restrict access. Once created, the PDF can be downloaded by the user directly on the webpage.
Saving and Storing PDFs
After generating a PDF with Javascript, it needs to be properly saved and stored for users to access later. The file should be saved to a secure server location that users have permission to access.
The code must securely store the PDF without errors or corruption. This ensures users can retrieve the original document.
// Save PDF
let data = doc.output();
let blob = new Blob([data], {type: "application/pdf"});
let link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
link.download = "test.pdf";
link.click();
This code gets the output PDF data, creates a blob object to hold it, generates a download link, and simulates a click to start the PDF download.
Proper user permissions and secure handling of the saved PDF file is crucial for sensitive documents like financial statements or medical records.
Tips for Successful PDF Generation
Here are some best practices for creating PDFs with Javascript:
- Use functions and variables for clean, readable code
- Let users preview the PDF before downloading
- Validate and sanitize inputs for security
- Ensure the server has write permissions for saving PDFs
- Add a progress bar for better user experience
Following coding best practices and security standards will lead to successful Javascript PDF generation.
Troubleshooting Common Issues
Some common problems faced when generating PDFs with Javascript include:
- Browser compatibility – Some browsers may not fully support PDF generation using Javascript. Test across browsers.
- Plugin conflicts – Browser extensions/add-ons can sometimes block PDF creation. Check for errors.
- File permissions – The server may not have write access to save PDFs. Verify permissions are set properly.
- Data formats – Ensure PDF data is not corrupted by testing with different file formats.
- Debugging – Use browser developer tools to step through the Javascript code and identify bugs.
Addressing these potential pitfalls ahead of time will help avoid problems when generating PDFs.
Alternatives to Javascript PDFs
If Javascript PDF generation is not working, some alternatives options include:
- Server-side languages like PHP, ASP, and Java to generate static PDFs
- Libraries like iText and PDFBox that handle PDF creation on the backend
- iText and PDFBox work across platforms and browsers
- Library usage is more secure as code runs server-side
- Open-source libraries have strong community support
These alternatives can help developers avoid common Javascript issues when creating PDFs.
Why Use Javascript for PDFs?
There are many advantages of using Javascript for PDF generation:
- Works across all major browsers and devices
- Integrates seamlessly with HTML and CSS
- Very high execution speeds
- Reusable code across web and mobile apps
- Strong ecosystem of JS libraries and frameworks
- Interactive PDFs with dynamic content
Javascript is ubiquitous in web development today, making it a great choice for generating PDFs.
Conclusion
Javascript enables creating PDFs directly within the browser that can be saved and downloaded by users. While alternatives exist, Javascript is fast, flexible, and benefits from close integration with other web technologies. Following best practices around code quality, security, and user experience will allow taking full advantage of Javascript for on-the-fly PDF generation.
by the Bito team. 
