Retrieve a list of all handlers in the datastore. This list is not
guaranteed to be in any particular order, and callers should not assume
it will remain in the same order in the future.
| a list of all handlers in the datastore |
Fill a handler info object with information from the datastore.
Note: because of the way the external helper app service currently mixes
OS and user handler info in the same handler info object, this method
takes an existing handler info object (probably retrieved from the OS)
and “fills it in” with information from the datastore, overriding any
existing properties on the object with properties from the datastore.
Ultimately, however, we’re going to separate OS and user handler info
into separate objects, at which point this method should be renamed to
something like “get” or “retrieve”, take a class and type (or perhaps
a type whose class can be determined by querying the type, for example
an nsIContentType which is also an nsIMIMEType or an nsIProtocolScheme),
and return a handler info object representing only the user info.
Note: if you specify an override type, then the service will fill in
the handler info object with information about that type instead of
the type specified by the object’s nsIHandlerInfo::type attribute.
This is useful when you are trying to retrieve information about a MIME
type that doesn’t exist in the datastore, but you have a file extension
for that type, and nsIHandlerService::getTypeFromExtension returns another
MIME type that does exist in the datastore and can handle that extension.
For example, the user clicks on a link, and the content has a MIME type
that isn’t in the datastore, but the link has a file extension, and that
extension is associated with another MIME type in the datastore (perhaps
an unofficial MIME type preceded an official one, like with image/x-png
and image/png).
In that situation, you can call this method to fill in the handler info
object with information about that other type by passing the other type
as the aOverrideType parameter.
Note: if there is no information in the datastore about this type,
this method throws NS_ERROR_NOT_AVAILABLE. Callers are encouraged to
check exists() before calling fillHandlerInfo(), to prevent spamming the
console with XPCOM exception errors.
| aHandlerInfo | the handler info object |
| aOverrideType | a type to use instead of aHandlerInfo::type |
Save the preferred action, preferred handler, possible handlers, and
always ask properties of the given handler info object to the datastore.
Updates an existing record or creates a new one if necessary.
Note: if preferred action is undefined or invalid, then we assume
the default value nsIHandlerInfo::useHelperApp.
| aHandlerInfo | the handler info object |
Whether or not a record for the given handler info object exists
in the datastore. If the datastore is corrupt (or some other error
is caught in the implementation), false will be returned.
| aHandlerInfo | a handler info object |
| whether or not a record exists |
Remove the given handler info object from the datastore. Deletes all
records associated with the object, including the preferred handler, info,
and type records plus the entry in the list of types, if they exist.
Otherwise, it does nothing and does not return an error.
| aHandlerInfo | the handler info object |
Get the MIME type mapped to the given file extension in the datastore.
XXX If we ever support extension -> protocol scheme mappings, then this
method should work for those as well.
Note: in general, you should use nsIMIMEService::getTypeFromExtension
to get a MIME type from a file extension, as that method checks a variety
of other sources besides just the datastore. Use this only when you want
to specifically get only the mapping available in the datastore.
| aFileExtension | the file extension |
| the MIME type, if any; otherwise returns an empty string (""). |