Accessing +and modifying system information

The SystemInfo +Service API of WRT 1.1 allows widgets to +access and modify system information on a device. System information is represented +as a set of system attributes. You can use the SystemInfo Service to create widgets that:

Read and modify system attribute values
Notify the user when system attribute values change
+

The system attributes are grouped into the following categories:

Battery
Connectivity
Device
Display
Features
General
Memory
Network

Only a few system attributes are modifiable and support change notifications. +For more information about system attributes, see section System attributes

Accessing the API and supported methods

To create a service +object for the SystemInfo Service API, use Service.SysInfo to +identify the service provider and ISysInfo to identify +the supported interface:

+ +

var so = device.getServiceObject("Service.SysInfo", "ISysInfo");

The ISysInfo interface provides the following methods:

GetInfo()
+ +
Use the GetInfo() method to retrieve information +about a system attribute.
+ +
SetInfo()
+ +
Use the SetInfo() method to modify the value of +a system attribute.
+ +
GetNotification()
+ +
Use the GetNotification() method to receive a notification +when the value of a system attribute is changed.
+ +
Cancel()
+ +
Use the Cancel() method to cancel an ongoing asynchronous +call. This method is valid for any asynchronous call made through the SystemInfo +Service API.
+ +

Using the service in a widget

To access and modify system information using the SystemInfo Service +API:

Create a service +object for the API using device.getServiceObject().
+
Define the +tasks you want to perform and choose the correct methods for them.
+
Optionally, +define how you want the results filtered.
Define methods +to process the results.
Retrieve the +results using the methods from step 2. Use asynchronous methods together with callback().
+
Process the +results using the methods defined in step 4.

For the complete source of a sample widget that demonstrates how to +use this service, see the +full example.