thing.md

Thing

The Module iotdb-thing is the API for implementing a Thing. It is based around the concept of bands and understands how to semantically manipulate the istate and ostate bands using the Thing's Model in the model band.

Creation

For the most part, Thing objects will be created for you and you just manipulate them as per below.

IOTDB

In this example, things will be populated with the various WeMo things as they are found.

const iotdb = require("iotdb")
iotdb.use("homestar-wemo")

iotdb.connect("WeMoSocket")
iotdb.connect("WeMoInsight")

const things = iotdb.things()

Standalone

You can just create Thing objects from band data:

const thing_maker = require("iotdb-thing").thing;
const thing_1 = thing_maker.make()
const thing_2 = thing_maker.make({
    "model": …,
    "meta": …,
    "istate": …,
    "ostate": …,
    "connection": …,
});

Working with Data

Bands

ostate

The ostate is used to manipulate a thing - it's the output state.

get the ostate

const ostate_1 = thing_1.band("ostate");

see the current values

const d = ostate_1.state();

set a value semantically

const promise = ostate_1.set(":on", true);

set a value non-semantically

const promise = ostate_1.set("power", true);

change a whole bunch of values (non-semantic). Note that update is always non-semantic, it's dealing the raw underlying data.

const promise = ostate_1.update({
    "power": true,
    "level": 50,
})

istate

The istate is used to current the current readings from a thing - it's the input state.

Get the istate object

const istate_1 = thing_1.band("istate");

See the current values

const d = istate_1.state();

Get a particular value semantically. first and list guarentee a non-array or an array respectively, get just returns what is there

const is_on_get = istate_1.get(":on")
const is_on_first = istate_1.first(":on")
const is_on_list = istate_1.list(":on")

Get a particular value non-semantically

const is_on_get = istate_1.get("powered")
const is_on_first = istate_1.first("powered")
const is_on_list = istate_1.list("powered")

Listen for a change semantically

istate_1.on(":on", function(_thing, _band, _new_value) {
});

Listen for a change non-semantically

istate_1.on("powered", function(_thing, _band, _new_value) {
});

Paramaterized Data

Because we have a strong idea of data types, you can parameterize values being passed into things; and you can coerce output values.

Helper functions parametization

ostate_1.set("level", 50, iotdb.as.percent());
ostate_1.set("level", .5, iotdb.as.unit());
ostate_1.set("temperature", 22, iotdb.as.celsius());

Coercing output value

istate_1.get("temperature", iotdb.as.celsius());

Getting type definitions

This will return a semantic description describing this particular attribute of the Thing.

thing_1.attribute("temperature")

or with a coercion

thing_1.attribute("temperature", iotdb.as.celsius());