Slider

Who it’s for

Anyone setting a continuous value from a dashboard — a setpoint, a dimmer level, a valve position, a target speed. The operator is choosing a number within a known range, and dragging to it is faster and less error-prone than typing it.

What it does

The Slider sends a value to the device as the operator drags the thumb along a range. The initial position is fetched by a configured action and each change sends its own, so the control starts from the device’s current setting rather than from zero.

• Drag to a value within a defined range, which prevents out-of-range settings by construction rather than by validation.
• The starting position is read back from the device — an attribute, a telemetry key or an RPC call — so the slider opens showing the current setpoint.
• Range ticks and tick marks make the scale explicit, so the operator knows what the ends mean.
• Decimals control the granularity of what is sent, which is what separates a percentage from a precise setpoint.
• Left and right icons caption the ends, which is often clearer than numbers for brightness, speed or volume.
• A disabled condition greys the control out, so a setpoint cannot be changed while a condition holds.
• The Slider sends on change: it has no confirm step, so a control where the wrong value is expensive belongs on a stepper or a button.

How to set up

Data keys

The Slider takes no data keys — its value and commands come from its configured actions.

Attribute	Scope	Operation	Description
Configured key	Any for read, Shared / Server for write	Read + Write	With Initial value set to Get attribute the slider reads this key; with On value change set to Set attribute it writes it.

Method	Direction	Parameters	Sent when
Value change method	One-way or two-way, as configured	The slider’s value, or the result of a convert function	Whenever the operator changes the slider

Range

Setting	Default	Effect
Initial value	Unset	How the starting position is fetched
On value change	Unset	The action triggered when the value changes
Range min / max	0 / 100	The ends of the slider
Value decimals	0	The precision of the value sent and displayed
Range ticks	Off	Prints the end values
Tick marks	Off	Draws marks along the track
Disabled state	Unset	An action deciding when the control is greyed out

Set the range to what the device will actually accept. The slider cannot send a value outside it, which is the main safety this control provides — and a range wider than the device’s makes that protection meaningless.

How to customize

• To start from the device’s current setting — set Initial value to the action matching how the device reports its setpoint.
• To command the device — set On value change to an RPC call, an attribute write or a time series write.
• To constrain what can be sent — set Range min and Range max to the device’s real limits.
• To control granularity — set the value decimals, which decides both what is displayed and what is sent.
• To make the scale explicit — turn on Range ticks, and Tick marks where intermediate positions matter.
• To caption the ends — set the Left icon and Right icon, which read faster than numbers for brightness or speed.
• To block changes under a condition — configure the Disabled state action.
• To match the card — set the Colors for the main and background track, and the disabled state’s own pair.

Tips

• Set the decimals to the precision the device actually honours. A slider offering two decimals on a device that rounds to whole numbers sends values that come straight back changed, and operators read that as the control fighting them.
• Choose a stepper over a slider when each change costs something — a physical actuator movement, a metered command, a device that wakes on receipt. A slider fires on every change during a drag, which is exactly wrong for anything expensive.