The following code snippet contains WORKING code for printing a page using 
WEUpdate. It is intended to go inside your print loop, after all of the print 
manager stuff has been done.

workText is a WEHandle to the document you're printing
printPort is a Ptr to the printer's GrafPort
docRect is a LongRect used for calculation
wToScroll is the amount (pixels) to scroll horizontally to view this page
hToScroll is the amount (pixels) to scroll vertically to view this page
resetOffscreen is Boolean, indicating whether we turned off offscreen drawing

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 GetPort(&savePort);
 SetPort(printPort);

 // make the printer port the one associated with this text
 WESetInfo(wePort, (Ptr) &printPort, workText);
 WERectToLongRect(&(printPort->portRect), &docRect);
 WESetViewRect(&docRect, workText);
 WESetDestRect(&docRect, workText);
 WECalText(workText);
 WEScroll(-wToScroll, -hToScroll, workText);

 resetOffscreen = WEFeatureFlag(weFDrawOffscreen, weBitTest, workText);
 if (resetOffscreen)
  WEFeatureFlag(weFDrawOffscreen, weBitClear, workText);
  
 WEUpdate(nil, workText);

 if (resetOffscreen)
  WEFeatureFlag(weFDrawOffscreen, weBitSet, workText);

 SetPort(savePort);
