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13.10 PlanetPress Talk Expressions for Dynamic Images that Reference
External Images
What do I need to take into account when I construct a PlanetPress Talk expression for a dynamic image that
references external images? What are some examples of these expressions?
The PlanetPress Talk expression you define references a selection of input data so that as the input data
varies, so does the image that appears in the picture object.
When the document executes, it must retrieve the external images associated with each dynamic image in the
document. These images must thus be accessible in the execution environment of the document.
When you construct the PlanetPress Talk expression that resolves to a pathname for an image, you therefore
need to consider:
1. The physical location of the images you want to associate with the dynamic image.
2. Whether the document executes host-based or printer-based.
3. The image format or formats in which the images exist.
You may have to adjust one or more of these prior to document execution to make the images available to the
document at runtime, in a format it can handle.
13.10.1 Physical Location of Dynamic Images
The pathname you define for an external image must resolve to one of three physical locations: the printer on
which the document executes, the local PlanetPress Design Suite virtual disk on the host on which the
document executes, or any folder on the host on which the document executes. The local PlanetPress Design
Suite virtual disk is a virtual disk PlanetPress Design creates and maintains on the hard disk of the computer
on which it is running.
13.10.2 Host-Based or Printer-Based Document Execution
When you preview a document in PlanetPress Design, or set up a PlanetPress Watch/Server process to
execute a document, you specify whether you want the document to run host-based, or printer-based. The
physical dynamic image locations available to the document at runtime depend on whether it executes host-
based or printer-based.
A document that executes printer-based executes completely on that printer. In this case the document exists
and executes on the printer, and the only dynamic image location available to it at runtime is the printer.
A document that executes host-based, executes either partially or completely on the host. If the document
does not produce printer output, it executes entirely on the host. If it produces printer output, the host
partially executes the document and then sends the result to a printer; the document completes execution on
the printer. The partial execution that takes place on the host includes the retrieval of dynamic images. A
document that executes host-based must exist on the host; you cannot run a document that is installed on a
printer, host-based. If a document executes host-based, and it contains dynamic images that reference
external images, those images can exist on the local PlanetPress Design Suite virtual disk on the host on
which the document is executing, or in any folder on the host on which the document is executing. If the
document completes execution on a printer, the external images can also exist on the printer. In this case if
the document cannot find an external image on the host, it looks for it on the printer.
There are only two ways to execute a document host-based. The first is to perform a preview in PlanetPress
Design, and select Run locally in the options for that preview. The second is to install the document in
PlanetPress Watch/Server and set up a PlanetPress Watch/Server process that executes the document host-
based. See the PlanetPress Watch/Server User Guide for help understanding and creating PlanetPress Watch/
Server processes.
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