PDFFileElement: ium property

Value

A boolean value: the effective one, also when the file inherits it from the WebPDF <script>. The default is false.

With its own ium, the file's pages default to canvas "ium": PDFium, the engine of Chrome, compiled to WebAssembly and run in a worker. On the script, a bare ium only makes PDFium available: pages draw with PDF.js until one asks for PDFium, and ium=+ also makes it the default of every file. PDFium (about 2.4 MB) loads with the first page that needs it, and one PDFium document serves all the file's pages. Without ium, PDFium is never used, even on a page with canvas=ium.

The attribute is multi-homed: when the file has none, it follows the WebPDF <script>; its pages can set their own.

Setting false writes ium=-; null removes the attribute. Changing it loads the file again.

Examples

Drawing a file with PDFium

HTML

<pdf-file id=f src=//pdf.ist/web.pdf ium></pdf-file>
<pdf-page of=f scale=0.4></pdf-page>

Result

Specifications

Not part of any specification. <pdf-file> and <pdf-page> are autonomous custom elements defined by WebPDF.pro.

Browser compatibility

See also

• PDFPageElement.canvas
• Choosing a renderer
• The ium attribute