Eclipse SmartHome has a strict separation between the physical world (the “things”, see below) and the application, which is built around the notion of “items” (also called the virtual layer).
Items represent functionality that is used by the application (mainly user interfaces or automation logic). Items have a state and are used through events.
The following item types are currently available (alphabetical order):
|Item Name||Description||Command Types|
|Color||Color information (RGB)||OnOff, IncreaseDecrease, Percent, HSB|
|Contact||Item storing status of e.g. door/window contacts||OpenClose|
|DateTime||Stores date and time||-|
|Dimmer||Item carrying a percentage value for dimmers||OnOff, IncreaseDecrease, Percent|
|Group||Item to nest other items / collect them in groups||-|
|Image||Holds the binary data of an image||-|
|Location||Stores GPS coordinates||Point|
|Number||Stores values in number format||Decimal|
|Player||Allows to control players (e.g. audio players)||PlayPause, NextPrevious, RewindFastforward|
|Rollershutter||Typically used for blinds||UpDown, StopMove, Percent|
|Switch||Typically used for lights (on/off)||OnOff|
Group items collect other items into groups. Group items can themselves be members of other group items. Cyclic membership is not forbidden but strongly not recommended. User interfaces might display group items as single entries and provide navigation to its members.
Example for a Group item as a simple collection of other items:
Group groundFloor Switch kitchenLight (groundFloor) Switch livingroomLight (groundFloor)
Derive Group State from Member Items
Group items can derive their own state from their member items. To derive a state the group item must be constructed using a base item and a group function. When calculating the state, group functions recursively traverse the group’s members and also take members of subgroups into account. If a subgroup however defines a state on its own (having base item & group function set) traversal stops and the state of the subgroup member is taken.
Available group functions:
|EQUALITY||-||<all>||Sets the state of the members if all have equal state. Otherwise UNDEF is set.|
|AND, OR, NAND, NOR||<all> (must match active & passive state)||Sets the <activeState>, if the member state <activeState> evaluates to
|SUM, AVG, MIN, MAX||-||Number||Sets the state according to the arithmetic function over all member states.|
|COUNT||Number||Sets the state to the number of members matching the given regular expression with their states.|
Examples for derived states on group items when declared in the item DSL:
Group:Number:COUNT(".*")counts all members of the group matching the given regular expression, here any character or state (simply count all members).
Group:Number:AVGcalculates the average value over all member states which can be interpreted as
Group:Switch:OR(ON,OFF)sets the group state to
ONif any of its members has the state
OFFif all are off.
Group:Switch:AND(ON,OFF)sets the group state to
ONif all of its members have the state
OFFif any of the group members has a different state than
State and Command Type Formatting
StringType objects store a simple Java String.
DateTimeType objects are parsed using Java’s
SimpleDateFormat.parse() using the first matching pattern:
PercentType objects use Java’s
BigDecimal constructor for conversion.
PercentType values range from 0 to 100.
HSB string values consist of three comma-separated values for hue (0-360°), saturation (0-100%), and value (0-100%) respectively, e.g.
240,100,100 for blue.
PointType strings consist of three
DecimalTypes separated by commas, indicating latitude and longitude in degrees, and altitude in meters respectively.
A note on items which accept multiple state data types
There are a number of items which accept multiple state data types, for example
DimmerItem, which accepts
RollershutterItem, which accepts
ColorItem, which accepts
Since an item has a SINGLE state, these multiple data types can be considered different views to this state.
The data type carrying the most information about the state is usually used to keep the internal state for the item, and other datatypes are converted from this main data type.
This main data type is normally the first element in the list returned by
Here is a short table demonstrating conversions for the examples above:
|Item Name||Main Data Type||Additional Data Types Conversions|