SnapHTML – HTML to Image Converter

SnapHTML is a utility library built in OutSystems to convert HTML content into downloadable images or Base64 strings using the html2canvas JavaScript library.

It provides easy-to-use client actions to:

• Capture DOM elements or HTML strings as images

• Output as PNG, JPEG, or WebP

• Choose resolution (scale) and background color

• Either download the image or return it as Base64
  
  Client Actions Overview

  Action Name	Description
  CaptureElementToImageDownload	Captures an element by ID and downloads the image
  CaptureHtmlToImageDownload	Renders provided HTML string and downloads the image
  CaptureElementToBase64	Captures an element by ID and returns the image as Base64
  CaptureHtmlToBase64	Renders HTML string and returns the image as Base64

  
  
  Input Parameters
  

  Parameter	Type	Required	Description	Example / Allowed Values
  ElementID	Text	✅ (Element-based)	ID of the HTML element to capture (use in CaptureElement... actions)	"myWidget"
  HtmlString	Text	✅ (HTML-based)	Valid HTML string to render and capture (used in CaptureHtml... actions)	"<div>Hello</div>"
  Format	Text	❌	Image format to generate	"png" (default), "jpeg", "webp"
  Scale	Decimal	❌	Zoom level for image rendering. Controls resolution.	1.0 to 10.0 (default: 2)
  BackgroundColor	Text	❌	Background fill color for image. Must be a valid CSS color string.	"#ffffff", "transparent"
  FileName	Text	❌	File name used when downloading image (no extension needed)	"my-capture"

  
  Output Parameters
  

  Action Name	Output Parameter	Type	Description
  CaptureElementToBase64	ImageBase64	Text	Base64 representation of the captured image
  CaptureHtmlToBase64	ImageBase64	Text	Base64 representation of the rendered HTML
  All Actions	Error	Text	Empty if success; otherwise contains message

  
  Library Dependency
  Ensure the wb_html2canvasLib web block is added to your screen or layout where these actions are used. This loads the html2canvas JavaScript library required for rendering.
  

  
  

• The html2canvas library is distributed under the:

  MIT License (Massachusetts Institute of Technology)

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  What This License Allows:

  • Commercial use – You can use html2canvas in commercial applications (e.g., OutSystems apps)