UIReferenceLibraryViewController hasDictionaryDefinition仅适用于iPhone 5s上的模拟器

Question

When I call this code:

NSString* word = @"hello";
bool response = [UIReferenceLibraryViewController dictionaryHasDefinitionForTerm:word];

...on an iPhone 5s or above I get the correct value into 'response' (a bool depending on whether the variable 'word' is defined in the local dictionary or not. It takes about 500ms to execute on the simulator.

However, when I call it on an iPhone 4s, 5, 6 or 6+ simulator (but not the 5s), then it immediately comes back as false and writes the following to the log:

 +[_UIDictionaryManager _availableDefinitionDictionaries] returned nil. 
Error: Error Domain=ASError Code=21 "The operation couldn’t be completed. 
(ASError error 21 - Unable to copy asset information)" 

The dictionary functionality should work on iOS 5+. I don't have any iPhone 4s/5/6/6+ devices to test this on.

What is going on?

Answer 1

I think I found the answer in the end which is that the message in the console is trying to say that the user has no dictionary installed.

The fact that

[UIReferenceLibraryViewController dictionaryHasDefinitionForTerm:word];

returns false if:

• The word is undefined
• There's no dictionaries installed

That's actually really quite unhelpful. My strategy for handling all this in my particular English-only app use-case is:

1. If [UIReferenceLibraryViewController dictionaryHasDefinitionForTerm:word] returns true then call the present "definition function" and return.

2. However, if it returns false, then call dictionaryHasDefinitionForTerm with a word that should be defined in all English dictionaries, such as "the" or "word".

3. If "the" or "word" return true then there are dictionaries installed, but this word is undefined in the installed dictionaries. Cache the result of "the"/"word" so you don't have to repeat step 2 onwards, but don't save it permanently because the user or the system might delete the dictionary - the whole dictionary system seems very buggy.

4. If "the" or "word" returns false we can take that to mean there are no dictionaries installed. At this point I call the function to present the definition of the original word (which is shown with "no definition" naturally, but it's the only way for the user to access the "manage" dictionaries function in order to install a dictionary!), together with a dialog box explaining that the user needs to click "manage" and install an english-language dictionary if they want word definitions.

A long way from ideal, but not sure what else I can do in my use-case.

Answer 2

Not sure if this really answers the question but here's what you might be interested to know about:

1. If you open UIReferenceLibraryViewController (even outside the app, eg from Safari) and tap Manage there to show the dictionary list (even without downloading anything), the error disappears for the current simulator.
2. Resetting Content and Settings on the simulator gets the error back — until you do #1 again.
3. Strangely, on a device I constantly get YES in dictionaryHasDefinitionForTerm: , even if I then see "No definition found" in the controller.

Some of these must certainly be a bug :-)
I'm very curious to know if anyone has the same behaviour in #3 as it smells worse than littering in the logs.