Npm HTML To PDF Libraries

When are HTML to PDF Libraries Useful?

HTML to PDF libraries are extremely useful in many situations. Here are typical scenarios where they come in handy:

1. Generating Reports: These libraries are very important when you have to generate data reports in PDF format. Generally, these reports are initially designed in HTML due to the ease of design and then converted into PDF for improved presentation, compatibility and portability.
2. Document Management: Most digitally managed documentation, like blogs, receipts, manifests or instructions, is written in HTML. When these documents need to be distributed or printed, converting them to PDF can provide a more suitable format.
3. Invoice Generation: E-commerce websites frequently need to generate invoices. They create the invoice in HTML format (as it is easy to design and customize, and can be viewed directly in a browser), and then convert it into a PDF for the customer to download.

What Functionalities do HTML to PDF Libraries Usually Have?

HTML to PDF libraries usually come with the following features:

1. Preserve the HTML Structure: These libraries should be able to convert HTML to PDF while preserving the web page's original structures, including images, tables, hyperlinks, and text content.
2. Customization: They should allow customization of the PDF pages such as setting the page size, margins, and orientation.
3. Batch Conversion: Some libraries might offer the functionality to convert large numbers of HTML pages to PDF all at once, known as batch conversion.
4. Security: They could offer the ability to set access permissions or create password-protected PDF documents from HTML sources.
5. Header/Footer Handling: Abilities might count manipulation of headers and footers, allowing custom content, pagination, or other personalisation.

Gotchas/Pitfalls to Look Out For

When working with npm packages for HTML to PDF conversion, there are a few potential pitfalls to be aware of:

1. Dependency: Some packages depend on PhantomJS or similar headless browsers which may become an issue due to their large sizes and potential deprecation and non-maintenance.
2. HTML/CSS Support: Not all libraries perfectly render modern HTML and CSS standards. There might be discrepancies in layout or appearances between the original HTML page and the converted PDF.
3. Execution Timeout: For large HTML pages or batch conversions, execution might timeout. Hence, look for packages that let you set a custom timeout duration.
4. Security Risks: Be cautious about packages that are unmaintained or rarely updated, as they might have unaddressed security flaws.
5. Diversity in Platforms: Some libraries might not work consistently across different platforms (like Linux, Windows, MacOS etc.). So, cross-platform testing is essential to ensure proper functioning.