• Draw a page to the canvas.

  rasterizeHTML.drawURL( url [, canvas] [, options] [, callback] )

• Draw a HTML string to the canvas.

  rasterizeHTML.drawHTML( html [, canvas] [, options] [, callback] )

• Draw a Document to the canvas.

  rasterizeHTML.drawDocument( document [, canvas] [, options] [, callback] )

Parameters:

• url a URL, or
• html a string of HTML, or
• document a Document object.

Optional parameters:

• canvas a HTML5 canvas node
• options key/value pairs of further options
  • width the width of the rendered image, by default the width of the canvas, or '300' if not provided
  • height the height of the rendered image, by default the height of the canvas, or '200' if not provided
  • baseUrl the URL base of the HTML document which relative resources will be based on, default: null.
  • executeJs if set to true, it will execute JavaScript in the page/HTML string and wait for the onload event before drawing the content (not available for drawDocument), default: false.
  • cache allows fine-tuning caching behaviour:
    • 'none' forces requested pages not to be cached by the browser by adding a unique query string in the form of "?_=[timestamp]" to each request,
    • 'repeated' forces a non-cached load for initial calls and caches repeated calls to the same URL,
    • 'all' will not employ any cache busting (default).
  • cacheBucket an object holding the library's own in-memory cache. Only effective in reuse between several calls to the API. Should be initialized with '{}'.
• callback(image, failedResources) callback function, called when the HTML has been rendered.
  • image the rendered image
  • failedResources a list of resources that failed to load. See below.

The list of failed resources is returned in the following form: { resourceType: "TYPE_OF_RESOURCE", url: "THE_FAILED_URL", msg: "A_HUMAN_READABLE_MSG" }

Resource types:

• image an <img href="">
• stylesheet a <link rel="stylesheet" href="">
• backgroundImage a background-image: url("");
• fontFace a @font-face { src: url("") }
• script a <script src="">
• scriptExecution a script execution error message (no url specified)
• document a Document object (general error when the whole Document failed to render, no url specified)
• page a HTML page (passed to rasterizeHTML.drawURL())

rasterizeHTML.js is still in early development and as such might be subject to API changes.

The library exposes some further methods whose interfaces will not be guaranteed to be stable over time.