Details
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Improvement
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Status: Open
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Minor
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Resolution: Unresolved
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jtsk_2.1
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None
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None
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4217846
Description
Lots of people don't really understand what getEntryClasses, getFieldValues, and getServiceTypes are useful for, in the Lookup Service spec. More explanation would be useful. A starting point might be some variation of the following:
Think of these methods as telling you how to fill in a template to refine your search. That is, you have a template that matches some number of items, and you want to know what you can add to the template to match a subset of those items. For example, start with an empty template, which matches all items in the lookup service. getServiceTypes then tells you what all the possible service types are, and getEntryClasses tells you what all the possible attribute set classes are. Pick one and add it to the template. This reduces the search from matching everything to matching a slightly smaller set of things. Now use one of the methods again to find out what else you could add to the template to further refine your search (i.e., to match a subset of what you currently match).
And to help explain how subclassing fits in, perhaps some variation on this:
Suppose someone defined a generic PrinterStatus superclass and then PrinterJam and TonerLow subclasses of PrinterStatus. You might have an instance of PrinterStatus in your template, which might result in matching multiple printer service items, say one with a PrinterJam and one with a TonerLow. getEntryClasses would tell you that you could add a PrinterJam or a TonerLow to your template, to narrow down to just those printers with jams or toner problems.
More usage information would be useful. How to make it fit with the rest of the spec (which does not offer much in the way of user guidance) is an
open question.