# lightblink()

Syntax:

    [void] sysinfo.lightblink(String lighttarget, Int duration, Int onduration, Int offduration, Int intensity)

Description:

The `lightblink` method switches the specified target light on and off (blinking) for the specified duration with the brightness defined by a specified light intensity.

Argument:

- `lighttarget`:

  Defines which target light should be blinking. Use one of the supported target light properties to specify a target light.

- `duration`:

  Defines the period during which the target light is set to blink. The period is measured in milliseconds.

  After the duration expires, the light state of the target will be changed to whatever state was caused by the last infinite time duration call. If there has not been a previous infinite time duration call in a session, the default state determined by the inactivity timer (system backlight timeout) is used.

  If `duration` is `lightinfiniteduration`, the target light can be stopped blinking only when some other light control method is called.

  Duration can have the maximum value of `lightmaxduration`.

- `onduration`:

  Defines the period during which the target light is switched on in every blinking cycle. The period is measured in milliseconds.

  `onduration` argument can have the maximum value of `lightmaxduration`.

  `onduration` argument can be the device default cycle duration `lightdefaultcycletime`. However, if either `onduration` or `offduration` is `lightdefaultcycletime`, both arguments must be `lightdefaultcycletime`.

Note: Some devices might not support variable blinking cycle times, in which case the default value will be substituted.

- `offduration`:

  Defines the period during which the target light is switched off in every blinking cycle. The period is measured in milliseconds.

  `offduration` argument can have the maximum value of `lightmaxduration`

  `offduration` argument can be the device default cycle duration `lightdefaultcycletime`. However, if either `onduration` or `offduration` is `lightdefaultcycletime`, both must be `lightdefaultcycletime`.

Note: Some devices might not support variable blinking cycle times, in which case the default value will be substituted.

- `intensity`:

  Defines the intensity (brightness) of the target light when it is switched on.

  Use the `lightminintensity` and the `lightmaxintensity` to detect the range of supported light intensity, and use any value between the range to avoid providing an invalid intensity value.

  `intensity` argument can have the device default value `lightdefaultintensity`.

Note: All devices might not support a user-defined intensity, in which case the device will behave in its default manner.

Return value:

This method does not return a value.

Remarks:

Switching the mobile device lights on consumes energy. Therefore, it is recommended that you carefully consider the need for using the lights.

Example code:

    function callLightBlink()
    {
       // get the Embed element reference
       var sysinfo = document.embeds[0];
       /*********************
       call lightblink() method, which turns on and off the light
       of all displays and keyboard with a defined duration
       and using the default blinking cycle time with the device
       default light intensity
       *********************/
       var target =  sysinfo.lighttargetsystem;
       var duration = 5000; // 5 seconds
       var onDur = sysinfo. lightdefaultcycletime;
       var offDur = sysinfo. lightdefaultcycletime;
       var intensity = sysinfo.lightdefaultintensity;
       sysinfo.lightblink(target, duration, onDur, offDur, intensity);
    }