PDFPageElement: render event

Syntax

Use the event name in methods like addEventListener(). WebPDF elements have no onrender event handler property.

addEventListener("render", (event) => { })

With event:prefix=type on the <script>, the file or the page, the event is named pdf-page-render instead.

Event type

A CustomEvent. Inherits from Event.

Event properties

This interface also inherits properties from its parent, Event.

detail

An object:

reason

What started the render: an object such as { a: "scale", o: "1", n: "2" } (an attribute, its old and its new value), { file: "src" } or {}, or an array of them when several changes drew at once.

touched

Which parts were drawn again, as booleans: all (the page itself changed), image, text and anno.

Examples

Exporting after each render

const page = document.querySelector("pdf-page");
page.addEventListener("render", async (event) => {
  if (!event.detail.touched.image) return;
  const png = await page.image.export();
  console.log(`${png.size} bytes`);
});

Specifications

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

Browser compatibility

See also

• load
• PDFPageElement.update()