PDFs are static. In order to dynamically create PDFs, a common solution is to first render it into HTML and then convert the HTML into a PDF using another service. But how do you manage and render a library of HTML templates?
Enter EJS (Embedded Javascript), a useful and simple library for creating javascript templates that can render dynamic data into HTML. EJS allows you to embed JavaScript into HTML, making it a go-to choice for quick and dirty server-side rendering. However, while EJS templates may work for small-scale applications, they often fall short in handling the complexity and scalability required for robust PDF generation applications. Here's why:
Challenges of using EJS for PDF rendering
Styling and layout limitations
- PDFs demand pixel-perfect layouts, precise margins, and consistent styling, which are challenging to achieve with EJS templates. Generating a PDF typically involves converting HTML to PDF using libraries like Puppeteer or wkhtmltopdf, and minor inconsistencies in HTML and CSS can lead to significant rendering issues in the final document.
Dynamic content handling
- EJS is designed for rendering HTML views, not structured documents. Handling dynamic content like tables, images, or multi-page layouts with EJS can quickly become unwieldy. For example, dynamically adjusting content to avoid breaking across pages or ensuring proper alignment of elements requires additional scripting and fine-tuning.
Mixing business logic and presentation
- EJS allows embedding JavaScript directly into templates, which can lead to a tangled mix of business logic and presentation code. As the complexity of the PDF increases, maintaining and debugging such templates becomes increasingly difficult.
Scalability issues
- EJS templates are not inherently modular, making it challenging to reuse components or maintain consistency across a large number of templates. For large-scale applications, this lack of structure can lead to duplication and inefficiencies.
Performance bottlenecks
- Generating PDFs using EJS involves multiple steps: processing large amounts of data, rendering the HTML, and finally converting it to PDF. The PDF generation process is very compute intensive, the time required to generate a PDF often means designing asynchronous systems and sacrificing user experience.
Better ways to generate Dynamic PDFs
Modern tools and libraries offer more efficient and scalable alternatives for generating dynamic PDFs:
Template Engines Built for PDFs
- Libraries like PDFKit and jsPDF allow you to directly create PDFs programmatically, giving you fine-grained control over layouts and styles. While these libraries have a steeper learning curve, they eliminate the need to convert HTML to PDF, improving performance and accuracy.
HTML to PDF libraries
- Libraries such as wkhtmltopdf or using Chrome+Puppeteer are more suitable for converting complex HTML and CSS to PDFs. They support advanced features like page breaks, headers, footers, and media queries for better print styles.
Cloud-based PDF APIs
- APIs like Anvil simplify the process of generating PDFs by offloading the rendering and generation tasks to a cloud service. This eliminates the need to manage server resources, troubleshoot rendering issues and can be extremely performant.
Why choose Anvil as your cloud PDF API provider
Anvil’s cloud-based PDF API offers a robust and developer-friendly solution for generating dynamic PDFs:
- Ease of use: With Anvil, you can create and customize PDF templates through an intuitive interface, reducing development time and effort.
- Dynamic data integration: Anvil allows you to inject dynamic data into templates seamlessly, supporting complex use cases like personalized invoices, contracts, or reports.
- Scalability: Anvil’s cloud infrastructure ensures fast and reliable PDF generation, even for high volumes of requests.
- Advanced features: Anvil supports advanced features such as digital signatures, form filling, and automatic pagination, which are challenging to implement manually.
- Cost-effectiveness: By using a cloud API, you save on developer time, server resources, and maintenance costs, enabling you to focus on your core product features.
Recap
While EJS templates can serve as a quick solution for simple PDF generation, they lack the scalability, flexibility, and performance required for modern applications. By adopting specialized tools or cloud-based APIs like Anvil, you can streamline your PDF generation process, reduce development overhead, and deliver a more reliable and scalable solution. Anvil’s advanced capabilities and user-friendly approach make it a compelling choice for product teams looking to launch and scale their PDF generation workflows.