clientPDFTileGeneration

Use this parameter to render PDF documents on the client.

In IBM® Daeja® ViewONE Virtual, the default main document display is composed of image tiles.

The clientPDFTileGeneration parameter allows you to enable rendering PDF documents and generating the image tiles directly on the client inside the browser. The PDF document is cached on the ViewONE server and then the entire document is delivered to the client where the individual pages are rendered on demand.

Rendering PDF document on the client provides a number of advantages:
  • The viewer retrieves the rendered page image from the rendering engine on the client, which removes the need to fetch these images from the server and reduces the network traffic.
  • Processing load on the server is reduced, freeing up resources for other tasks.
  • Navigation performance is less impacted by server load. The server is only responsible for the initial delivery of the entire document to the client.
  • Retrieving page images directly from the client improves performance of page navigation, especially where network performance is slow.
  • Rendered pages are no longer generated and cached on the server, which reduces the disk access and usage.
  • The document is rendered at a higher fidelity especially when the pages are zoomed in.
  • It enables to open hyperlinks in the document which has external websites(URL) as targets. You can click on the link and the targeted website will open in a new tab.
Note: Before V5.0.6, documents could be rendered on the server by setting the parameter to false. Image tiles were generated for each page. In this case, the viewer fetched these images from the server across the network, which produced many network requests. The page displaying speed was bounded by the performance of the network between the client and server, and the available resources on the server. Rendering PDF documents on the server is deprecated.
Client-rendering presents the following differences with server-side rendering:
  • The entire document must be delivered to the client before the first page can be rendered.
  • For PDF documents that have non-embedded fonts, the text that is rendered might differ. It depends on the operating system, browser, and fonts available on the client machine. This means there might be slight differences in the rendered image when viewed from different browsers or client machines.
  • Native PDF annotations might appear slightly differently.
  • Printing of PDF documents are done on the server and uses the rendering engine on the server. Depending on your printing options, the generated printable PDF can have slight differences to the image seen on the client.
  • For faster navigation through pages, image tiles are always generated for the 7 pages before and the 7 pages after the current page.
Limitations:
  • Invert is not supported for PDF documents rendered on the client.
  • Enhancement mode is not supported for PDF documents rendered on the client. The pages are rendered at a higher fidelity and anti-aliasing is no longer required.
  • Zooming is capped at 10 times the actual size. This is rendered at high fidelity. Zooming beyond this scale stretches the image to the required size.
If you are using a version when the parameter is set to false, you cannot use the following features:
  • Text searching in PDF documents.
  • PDF Text Selection Mode or Text Copy for client-side rendered documents.
  • Support for password protected PDF documents.

Sample syntax

<param name="clientPDFTileGeneration" value="false" />

Default setting: true