nsIContentPrefService

From MDC

nsIContentPrefService offers a way for extensions and browser code to save preferences for specific URIs. Preferences are saved as key/value pairs on a per-URI basis. See Using content preferences for examples.

Contents 1 Method overview 2 Attributes 3 Methods 3.1 getPref() 3.1.1 Parameters 3.1.2 Return value 3.2 setPref() 3.2.1 Parameters 3.3 hasPref() 3.3.1 Parameters 3.3.2 Return value 3.4 removePref() 3.4.1 Parameters 3.5 getPrefs() 3.5.1 Parameters 3.5.2 Return value 3.6 addObserver() 3.6.1 Parameters 3.7 removeObserver() 3.7.1 Parameters 4 See also

nsIContentPrefService is defined in toolkit/components/contentprefs/public/nsIContentPrefService.idl. It is scriptable and unfrozen (hasn't changed since Mozilla 1.9).

Inherits from: nsISupports

Implemented by: @mozilla.org/content-pref/service;1. To create an instance, use:

var prefService = Components.classes["@mozilla.org/content-pref/service;1"]
                  .getService(Components.interfaces.nsIContentPrefService);

[edit] Method overview

void addObserver(in AString aName, in nsIContentPrefObserver aObserver);

nsIVariant getPref(in nsIURI aURI, in AString aName);

nsIPropertyBag2 getPrefs(in nsIURI aURI);

boolean hasPref(in nsIURI aURI, in AString aName);

void removeObserver(in AString aName, in nsIContentPrefObserver aObserver);

void removePref(in nsIURI aURI, in AString aName);

void setPref(in nsIURI aURI, in AString aName, in nsIVariant aValue);

[edit] Attributes

Attribute	Type	Description
grouper	nsIContentURIGrouper	The component that the service uses to determine the groups to which URIs belong. By default, this is the "hostname grouper," which groups URIs by full hostname (in otherwords, by site).

[edit] Methods

[edit] getPref()

Returns the value of a preference saved for a particular URI.

 nsIVariant getPref(
   in nsIURI aURI,
   in AString aName
 );

[edit] Parameters

aURI

The URI for which to retrieve a preference. Specify null to get the preference from the global preference space; those preferences apply to all URIs.

aName

The name of the preference whose value is to be retrieved.

[edit] Return value

The preference's value is returned; this value may be a string, integer, boolean, or any other value. The result may be null (nsIDataType:VTYPE_EMPTY) if the preference's value is either null, or undefined (nsIDataType:VTYPE_VOID) if there is no saved preference by the specified name.

[edit] setPref()

Sets the value of a preference for a particular URI.

 nsIVariant setPref(
   in nsIURI aURI,
   in AString aName,
   in nsIVariant aValue
 );

[edit] Parameters

aURI

The URI for which to set a preference. Specify null to set the preference in the global preference space; those preferences apply to all URIs.

aName

The name of the preference whose value is to be set.

aValue

The value to assign to the preference.

[edit] hasPref()

Determines whether or not a preference exists.

 boolean hasPref(
   in nsIURI aURI,
   in AString aName
 );

[edit] Parameters

aURI

The URI for which to check for the existence of a preference, or null to check the global preference space.

aName

The name of the preference whose existence is to be determined.

[edit] Return value

true if the preference exists; otherwise false.

[edit] removePref()

Removes the specified preference.

 void removePref(
   in nsIURI aURI,
   in AString aName
 );

[edit] Parameters

aURI

The URI for which the preference is to be removed, or null to remove the preference from the global preference space.

aName

The name of the preference to delete.

[edit] getPrefs()

Returns an nsIPropertyBag2 containing all preferences and their values for the specified URI.

 nsIPropertyBag2 getPrefs(
   in nsIURI aURI,
 );

[edit] Parameters

aURI

The URI whose preferences you wish to retrieve, or null to retrieve the global preferences.

[edit] Return value

The result is an nsIPropertyBag2 containing the preferences and their values.

[edit] addObserver()

Adds an observer that monitors a preference for changes.

 void addObserver(
   in AString aName,
   in nsIContentPrefObserver aObserver
 );

[edit] Parameters

aName

The name of the preference to observe. You may specify null to add a generic observer that is notified of all preference changes.

aObserver

The name of an object implementing nsIContentPrefObserver that will receive notifications of changes to the preference's value.

[edit] removeObserver()

Removes an observer that's presently monitoring a preference for changes.

 void addObserver(
   in AString aName,
   in nsIContentPrefObserver aObserver
 );

[edit] Parameters

aName

The name of the preference to stop observing. You may specify null to remove a generic observer that is monitoring all preference changes.

aObserver

The name of the observer that will cease receive notifications of changes to the preference's value.

[edit] See also

nsIContentPrefObserver, Using content preferences