The pdflayer API is a quick and seamless way to automate your HTML to PDF conversion in any application. Its lightweight RESTful infrastructure uses an efficient combination of the most powerful PDF rendering engines available. This makes it the most cost-effective and reliable option for anyone looking to quickly process a small or large number of documents.
The pdflayer API also has a full set of customizable functions. These include document configuration, a series of layout adjustment options, and authentication and security, design as well as branding tweaks, and much more.
In this article, we look at how you can use the REST-based pdflayer API in a low-code Windows application to convert HTML to PDF.
Table of Contents
What are some use cases for converting HTML to PDFs?
There are many different use cases for converting HTML to PDFs. PDF to HTML conversions are useful in everything from legal settings to corporate environments. You can use it to capture the look and feel of a website or to create customized reports with watermarks. It is also useful for developers to turn HTML reports into PDFs for easier consumption or storage. These are just a few of the example use cases for HTML to PDF conversion.
How easy is it to convert HTML to PDFs?
It’s pretty darn easy, let’s take a look at how.
Access & Specification
To authenticate with the pdflayer API, simply attach your access_key to the base endpoint URL:
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http://api.pdflayer.com/api/convert?access_key=YOUR_ACCESS_KEY |
To get your Access Key, sign up here https://pdflayer.com/product
The pdflayer API uses simple URL-based HTTP requests for maximum compatibility with any existing programming language. The next three steps outline how to build a basic API request.
Step 1: Base URL
Each API request is based on the following URL:
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http://api.pdflayer.com/api/convert |
Step 2: Required parameters
First, authenticate with the API by adding your access_key and providing either a URL using the document_url parameter or raw HTML code using the document_html parameter.
| Parameter | Description |
|---|---|
access_key |
Key to authenticate with the API – find it in your Account Dashboard |
document_url |
The full URL (including the HTTP Protocol) of the website you want to convert to a PDF document, e.g. http://example.com/invoice.html |
document_html |
HTTP POST only – raw HTML code you would like to convert to a PDF document. |
Step 3: Optional parameters
In addition to the required parameters, there are a series of functions and parameters you can use to configure and customize your PDF document. Here is a summary:
Configuration
| Parameter | Description | Default |
|---|---|---|
document_name |
specify a PDF name of up to 180 characters. | pdflayer.pdf |
custom_unit |
set to px (Pixels), pt (Points), in (Inches) or mm (Millimeters) |
px |
user_agent |
set to your preferred User-Agent header string | See below |
accept_lang |
set to your preferred Accept-Language header string | en-US |
text_encoding |
set to your preferred text encoding string | utf-8 |
ttl |
the time (in seconds) a generated PDF is cached | 2,592,000 |
force |
set to 1 to force new PDF |
– |
inline |
set to 1 to display PDF document inline |
Attachment triggers download |
auth_user |
specify username used to access password-protected site | – |
auth_pass |
specify password used to access password-protected site | – |
encryption |
set to 40 (40-bit) or 128 (128-bit) |
– |
owner_password |
specify owner password to password protect PDF | – |
user_password |
specify user password to password protect PDF | – |
| Misc Options | a series of configuration options [Learn more] | – |
| Permissions | a series of permission options [Learn more] | – |
Layout
| Parameter | Description | Default |
|---|---|---|
page_size |
set to preferred page size, e.g. A4, A5, etc. |
A4 |
page_width |
specify page width (numeric), e.g. 200 (overrides page_size) |
A4 width |
page_height |
specify page height (numeric), e.g. 600 (overrides page_size) |
A4 height |
orientation |
set to portrait or landscape |
portrait |
margin_top |
set to preferred top margin value (numeric), e.g. 5 |
– |
margin_bottom |
set to preferred bottom margin value (numeric), e.g. 5 |
– |
margin_left |
set to preferred left margin value (numeric), e.g. 5 |
– |
margin_right |
set to preferred right margin value (numeric), e.g. 5 |
– |
header_spacing |
set to preferred header spacing value (numeric), e.g. 10 |
– |
header_text |
set to preferred header text, e.g. This is my heading |
– |
header_align |
set to left, center or right |
center |
header_url |
set to (urlencoded) URL containing your preferred header HTML elements | – |
header_html |
HTTP POST only – specify raw HTML as header element | – |
footer_spacing |
set to preferred footer spacing value (numeric), e.g. 10 |
– |
footer_text |
set to preferred footer text, e.g. This is my footer |
– |
footer_align |
set to left, center or right |
center |
footer_url |
set to (urlencoded) URL containing your preferred footer HTML elements | – |
footer_html |
HTTP POST only – specify raw HTML as footer element | – |
viewport |
Set to preferred viewport “width x height”, e.g. 320x480 |
1440x900 |
Customization
| Parameter | Description | Default |
|---|---|---|
css_url |
inject a custom CSS stylesheet using a (urlencoded) URL | – |
delay |
specify a delay (in seconds) before PDF is captured | – |
dpi |
specify the DPI resolution (numerical) between 10 and 10000 |
96 |
zoom |
specify page zoom factor between 0 and 50 |
– |
watermark_url |
specify a watermark URL (urlencoded) containing a PNG or JPG image | – |
watermark_offset_x |
specify a horizontal watermark offset, e.g. 10 |
– |
watermark_offset_y |
specify a vertical watermark offset, e.g. 10 |
– |
watermark_opacity |
specify watermark opacity percentage (numeric) between 0 and 100 |
20 |
watermark_in_background |
set to 1 to place watermark behind text |
– |
| Page Numbering | Page numbering options including dynamic tags [Learn more] | – |
Document Details
| Parameter | Description | Default |
|---|---|---|
title |
specify a PDF document title of 150 characters max. | – |
subject |
specify a PDF document subject of 150 characters max. | – |
creator |
specify a PDF document creator name of 150 characters max. | pdflayer.com |
author |
specify a PDF document author name of 150 characters max. | – |
For more details, you can also read the full documentation.
How can we access pdflayer API using a Low-Code Windows Client?
- Download Delphi here or the free non-commercial use edition here.
- Use Microsoft Edge as the PDF viewer inside of the application.
You must include the WebView2Loader.dll in the same location as the EXE for the Microsoft Edge browser to function.
Download the WebView2Loader.dll: https://getitnow.embarcadero.com/EdgeView2SDK-1.0.664.37/
Install the Microsoft Edge browser from: https://www.microsoftedgeinsider.com/en-us/downloadH
Here is the example code:
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procedure TMainForm.Button1Click(Sender: TObject); var lPdfDownload: TDownloadURL; lstream: TMemoryStream; begin lPdfDownload := TDownloadURL.Create; lstream := TMemoryStream.Create; try lPdfDownload.DownloadRawBytes( 'http://api.pdflayer.com/api/convert?access_key=YOUR_ACCESS_KEY&document_url='+Edit1.Text, lstream ); lstream.Position := 0; lstream.SaveToFile(ExtractFilePath(ParamStr(0)) + 'mypdf.pdf'); WebBrowser1.URL := ExtractFilePath(ParamStr(0)) + 'mypdf.pdf'; finally lstream.Free; lPdfDownload.Free; end; end; |
How well does the HTML to PDF conversion work?
Whether you have a simple HTML and CSS page with just text or a complex HTML page featuring rich media like XML, SVG, or JavaScript, everything visible in a browser should show up in the PDF.
You can set the dimensions, margins, page numbers, custom CSS, encryption, viewport, delay, and much more of your PDF output. This lets you customize the output PDF to your needs.
You can even customizable the background or foreground watermark images for your final PDF document. This is great in a corporate or enterprise environment to bring a professional edge to your PDFs.
Ready to get started converting HTML to PDFs?
In this article, we demonstrated how easy it is to convert HTML to PDF using the pdflayer API. We also showed you how to create a low-code Windows application for the pdflayer API. Full source code is provided for the Windows application so you can jump right in and get started implementing the API in your own projects.
Head over and download the full source code for the Windows client here.
