This API is available on Firefox OS for internal applications only.
Summary
Sets up a callback function to be notified when a specific setting's value changes.
Note: If you want to listen for and react to any change to any setting, you can directly set a callback function using the onsettingchange property of the SettingsManager object.
Syntax
SettingsManager.addObserver(settingName, callback);
Parameters
settingName- A string specifying the name of the setting to observe. The exact list of possible strings is device-dependent. Each Gaia build can have its own list of settings. For an up-to-date list of those strings, take a look at the Gaia source code.
callback- The function to be called each time the value of the setting is changed. This function will receive as input a
MozSettingsEventproviding details about the change that occurred.
Example
// Listen to changes on the wifi.enabled setting
navigator.mozSettings.addObserver('wifi.enabled', function (event) {
console.log('wifi.enabled: ' + event.settingValue);
});
Specification
Not part of any specification yet; however, this API will be discussed at W3C as part of the System Applications Working Group.