# new base/ConnectionPoller(checkStatus, onStatusChange, optsopt)
Internet or network connection poller.
Configuration
There are two ways to configure the poller.
- Parameters in the constructor.
- Configuration parameters.
Connection poller will be initialised with default value if parameters cannot be found in the constructor and configuration. In XDK3, the configuration parameters is set at a per-device-package level, which means the configuration for device package A can be different from device package B.
Consecutive Failure Threshold
It defines how many polling failures before XDK considers it is disconnected from the internet.
| Attribute | Value |
|---|---|
| Type | Number |
| Default | 3 |
| Constructor parameter | opts.consecFailureThreshold |
| Configuration parameter | `device-details.${package-name}.network.polling.consec-failure-threshold` |
Polling Interval
It defines how often, in seconds, that the connection poller should call the connection-checking function.
| Attribute | Value |
|---|---|
| Type | Number |
| Default | 30 |
| Constructor parameter | opts.pollingInterval |
| Configuration parameter | `device-details.${package-name}.network.polling.interval` |
Initial Network State
Define whether the connection poller should assume the device is connected to the internet before the first check.
| Attribute | Value |
|---|---|
| Type | Boolean |
| Default | True |
| Constructor parameter | opts.networkStatus |
| Configuration parameter | Not Available |
Verbosity of Connection Poller
Control whether the regular polling log should be logged to console or not. See module:base/console for further details.
| Attribute | Value |
|---|---|
| Type | Boolean |
| Default | False |
| Constructor parameter | Not Available |
| Configuration parameter | "console.log.ConnectionPoller" |
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
checkStatus |
CheckNetworkStatus
|
Connection-checking function. |
||
onStatusChange |
OnNetworkStatusChange
|
Callback that handles network status changed. |
||
opts |
Object
|
<optional> |
Optional parameter. |
|
networkStatus |
Boolean
|
<optional> |
true | The assumed network state before the first check. Set it to false to assume the device is originally disconnected from the internet. |
consecFailureThreshold |
Number
|
<optional> |
3 | How many polling failures before XDK considers it is disconnected from the internet. |
pollingInterval |
Number
|
<optional> |
30 | Number of seconds between two polling calls. |
- base/ConnectionPoller.event:EVT_STATUS_CHANGED
Example
Initialise connection poller with a fictional device API.
var myConfig = {
consecFailureThreshold: 1,
pollingInterval: 30
}
function myChecker(checkStatus) {
checkStatus(dummyDeviceAPI.isConnected());
}
function myListener(newConnectionStatus) {
system.dispatchEvent(ISystem.EVT_NETWORK_STATUS_CHANGED, newStatus);
}
var myPoller = new ConnectionPoller(myChecker, myListener, myConfig);
myPoller.startPolling(); // Start polling
myPoller.stopPolling(); // Stop polling.Classes
Members
# static constant POLLING_INTERVAL_LOWER_BOUND
The default polling interval, which will be used in various places within this module.
Methods
# protected _checkStatus(checkStatus)
Reference to the CheckNetworkStatus callback, provided during the construction of the connection poller.
Parameters:
| Name | Type | Description |
|---|---|---|
checkStatus |
OnNetworkCheckDone
|
Callback that takes the latest connection status. |
# protected _onStatusChange(newStatus)
Reference to the OnNetworkStatusChange callback, provided during the construction of the connection poller.
Parameters:
| Name | Type | Description |
|---|---|---|
newStatus |
Boolean
|
The new connection status. True means connected, false otherwise. |
# isConnected() → {Boolean}
Get the latest connection status from polling.
True when connected, false otherwise.
Boolean
# setPollingInterval(interval) → {Boolean}
Set the polling interval. If the parameter provide is invalid, the existing interval value will not be updated.
If the interval is smaller than the lower bound recommended, which is 30 seconds, a warning message will be printed to the console. but the new value will still be applied in the next polling call.
Otherwise, the value will simply be updated.
Parameters:
| Name | Type | Description |
|---|---|---|
interval |
Number
|
New polling interval, in seconds. |
True when set, false otherwise.
Boolean
Type Definitions
# CheckNetworkStatus(checkStatus)
The function that is responsible for checking whether the application is connected to the internet. The poller is designed this way to allow the checking function to be created specifically for the targeted device.
The callback OnNetworkCheckDone will be passed as the parameter, the caller should call this callback, with the latest connection status, once the check is done.
Parameters:
| Name | Type | Description |
|---|---|---|
checkStatus |
OnNetworkCheckDone
|
Callback that takes the latest connection status. |
# OnNetworkCheckDone(newStatus)
The callback that is passed into CheckNetworkStatus. This callback should be called, with the latest connection status, once the check is done.
Parameters:
| Name | Type | Description |
|---|---|---|
newStatus |
Boolean
|
The new connection status. True means connected, false otherwise. |
# OnNetworkStatusChange(newStatus)
The callback that will be executed by the connection poller whenever the new connection status is different from the previous check.
Parameters:
| Name | Type | Description |
|---|---|---|
newStatus |
Boolean
|
The new connection status. True means connected, false otherwise. |