A ConsultTopic is the class of TopicEntry that is used with a Consultable. Just as an AskTopic, for example, provides a response to commands such as ASK CURATOR ABOUT MUSEUM, so a ConsultTopic would provide a response to CONSULT HISTORY BOOK ABOUT MUSEUM or LOOK UP MUSUEM IN BOOK.
Although ConsultTopic inherits all the methods and properties of TopicEntry, there is usually less reason to override any of them. A typical Consultable, such as a book, is a fairly static object that will always provide the same information on any given topic, regardless of the state of the game. You could, perhaps, combine a TopicEntry with an EventList class to provide a series of responses, perhaps representing the player character reading further on the same topic, particularly if you want your Consultable to provide a large amount of information on the topic and it is better broken up into smaller chunks; but then you'd probably want to make it abundantly clear that there was more to read on a given topic rather than leaving the player to guess. Again, you could have a more complex Consultable, such a computer, where the information displayed might change with circumstances, in which case you might want to use some of the techniques we have already seen in connection with TopicEntries on actors (such as AltTopics and the use of isActive).
In the present game, however, we'll keep things at their simplest and just add a number of basic ConsultTopics to our history book:
+ ConsultTopic [ghost, statue, tBenedict]
"According to the book, Benedict the Banana-Bearer lived 537 years ago
and was responsible for bearing the Golden Banana of Discord from
Hell Fire Cavern. Although many at the time (and since) reckoned
that the ordeal drove him mad, this was no obstacle to his becoming
king, for many reckoned his deed to be a feat of great daring. A golden
statue commemorating the glorious memory of King Benedict can still be
found on the western side of the lake.
+ ConsultTopic @goldenBanana
"The Golden Banana of Discord is a talisman of great power. Snatched
from the demons of hell fire cavern some 537 years ago it enabled
mad Benedict to become king. No one since King Benedict has been
quite sure what powers the Golden Banana wields, but its value and
significance remain unquestioned. For obvious reasons great care
has always been taken to ensure that this artifact does not fall into
the wrong hands. "
+ ConsultTopic @tHellFireCavern
"Deep in the bowels of the earth, Hell Fire Cavern is a name that has
long struck fear and dread into the souls of mortals. Inhabited by vile
demons, and polluted by the putrid flames of Mount Gloom, the cavern is
as near to being an authentic underworld as one could hope - or fear -
to encounter. Only one man - Benedict the Banana-Bearer - has been known
to return from the Hell Fire Cavern alive. "
+ ConsultTopic @tMuseum
"According to the book, the Museum of Curious Antiquities was set up from
a benefaction of King Benedict the Banana-Bearer himself. Although the
museum has always had a certain historical interest, its exhibits tend
towards the eccentric and the bizarre. Should you find yourself on the
southern side of the lake, however, the museum is well worth a visit
if only for its curiosity value. "
tBenedict : Topic 'benedict';
tHellFireCavern: Topic 'hell fire cavern';
Note the use of the list of matchable topics in the first ConsultTopic, since the player might become aware of Benedict through either the statue or the ghost. Again, since the statue does not match the word 'benedict' and the ghost may not either, we also supply a tBenedict topic to ensure that the word 'benedict' will always match this ConsultTopic (along with such other words as 'statue' and 'ghost' that may also do so).
Note also that there's no such thing as a SuggestedConsultTopic. With a suitable amount of ingenuity it might be possible to devise a SuggestedConsultTopic class that worked, but this would be non-trivial, since the library currently assumes that SuggestedTopics work only with actors. If you want to suggest to the player what topics might be available in the book, it might be simpler to list them in the readDesc (e.g. ""It's too long to read from cover to cover right now, but you could consult it on specific topics, such as Benedict, the Golden Banana of Discord, the museum and Hell Fire Cavern "), or else perhaps in the DefaultConsultTopic, (e.g. "The book doesn't seem to have anything useful to say in that, but a quick check in the index suggests you could look up...). We'll return to the second possibility shortly.