Optional aInstancePtr: objectA run time mechanism for interface discovery.
NS_OK if the interface is supported by the associated instance, NS_NOINTERFACE if it is not.
aInstancePtr must not be null.
[in] A requested interface IID
[out] A pointer to an interface pointer to receive the result.
Registers an observer that will be notified whenever a preference with the given name is set or removed.
When a set or remove method is called, observers are called after the set or removal completes and after the method's callback is called, and they are called in the same turn of the event loop as the callback.
The service holds a strong reference to the observer, so the observer must be removed later to avoid leaking it.
The name of the preferences to observe. Pass null to observe all preference changes regardless of name.
The observer.
Extracts and returns the domain from the given string representation of a URI. This is how the API extracts domains from URIs passed to it.
If the given string is a valid URI, the domain of that URI is returned. Otherwise, the string itself is returned.
The string representation of a URI, like "http://example.com/foo/bar".
Gets the preference with the given domain and name.
The preference's domain.
The preference's name.
The private-browsing context, if any.
handleResult is called once unless no such preference exists, in which case handleResult is not called at all.
Gets all the preferences with the given name.
The preferences' name.
The private-browsing context, if any.
handleResult is called once for each preference unless no such preferences exist, in which case handleResult is not called at all.
Gets all preferences with the given name whose domains are either the same as or subdomains of the given domain.
The preferences' domain.
The preferences' name.
The private-browsing context, if any.
handleResult is called once for each preference. If no such preferences exist, handleResult is not called at all.
Synchronously retrieves from the in-memory cache the preference with the given domain and name.
In addition to caching preference values, the cache also keeps track of preferences that are known not to exist. If the preference is known not to exist, the value attribute of the returned object will be undefined (nsIDataType::VTYPE_VOID).
If the preference is neither cached nor known not to exist, then null is returned, and get() must be called to determine whether the preference exists.
The preference, or null if no such preference is known to exist.
The preference's domain.
The preference's name.
The private-browsing context, if any.
Synchronously retrieves from the in-memory cache the preference with no domain and the given name.
As with getCachedByDomainAndName, if the preference is cached then it is returned; if the preference is known not to exist, then the value attribute of the returned object will be undefined; if the preference is neither cached nor known not to exist, then null is returned.
The preference, or null if no such preference is known to exist.
The preference's name.
The private-browsing context, if any.
Gets the preference with no domain and the given name.
The preference's name.
The private-browsing context, if any.
handleResult is called once unless no such preference exists, in which case handleResult is not called at all.
Removes all non-global preferences -- in other words, all preferences that have a domain.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all non-global preferences created after and including |since|.
Timestamp in milliseconds.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all global preferences -- in other words, all preferences that have no domain.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all preferences with the given domain.
The preferences' domain.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes the preference with the given domain and name.
The preference's domain.
The preference's name.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all preferences with the given name regardless of domain, including global preferences with the given name.
The preferences' name.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all preferences whose domains are either the same as or subdomains of the given domain.
The preferences' domain.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes all the preferences with the given name whose domains are either the same as or subdomains of the given domain.
The preferences' domain.
The preferences' name.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Removes the preference with no domain and the given name.
The preference's name.
The private-browsing context, if any.
handleCompletion is called when the operation completes.
Unregisters an observer for the given name.
The name for which the observer was registered. Pass null if the observer was added with a null name.
The observer.
Sets a preference.
The preference's domain.
The preference's name.
The preference's value.
The private-browsing context, if any.
handleCompletion is called when the preference has been stored.
Sets a preference with no domain.
The preference's name.
The preference's value.
The private-browsing context, if any.
handleCompletion is called when the preference has been stored.
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Content Preferences
Content preferences allow the application to associate arbitrary data, or "preferences", with specific domains, or web "content". Specifically, a content preference is a structure with three values: a domain with which the preference is associated, a name that identifies the preference within its domain, and a value. (See nsIContentPref below.)
For example, if you want to remember the user's preference for a certain zoom level on www.mozilla.org pages, you might store a preference whose domain is "www.mozilla.org", whose name is "zoomLevel", and whose value is the numeric zoom level.
A preference need not have a domain, and in that case the preference is called a "global" preference. This interface doesn't impart any special significance to global preferences; they're simply name-value pairs that aren't associated with any particular domain. As a consumer of this interface, you might choose to let a global preference override all non- global preferences of the same name, for example, for whatever definition of "override" is appropriate for your use case.
Domain Parameters
Many methods of this interface accept a "domain" parameter. Domains may be specified either exactly, like "example.com", or as full URLs, like "http://example.com/foo/bar". In the latter case the API extracts the full domain from the URL, so if you specify "http://foo.bar.example.com/baz", the domain is taken to be "foo.bar.example.com", not "example.com".
Private-Browsing Context Parameters
Many methods also accept a "context" parameter. This parameter relates to private browsing and determines the kind of storage that a method uses, either the usual permanent storage or temporary storage set aside for private browsing sessions.
Pass null to unconditionally use permanent storage. Pass an nsILoadContext to use storage appropriate to the context's usePrivateBrowsing attribute: if usePrivateBrowsing is true, temporary private-browsing storage is used, and otherwise permanent storage is used. A context can be obtained from the window or channel whose content pertains to the preferences being modified or retrieved.
Callbacks
The methods of callback objects are always called asynchronously.
Observers are called after callbacks are called, but they are called in the same turn of the event loop as callbacks.
See nsIContentPrefCallback2 below for more information about callbacks.