node-lwm2m is an implementation of the Open Mobile Alliance's Lightweight M2M protocol (LWM2M).
LWM2M is a profile for device services based on CoAP (RFC 7252). LWM2M defines a simple object model and a number of interfaces and operations for device management. See an overview of the protocol here.
The OMA LWM2M object model is based on a simple 2 level class hierarchy consisting of Objects and Resources:
-
A Resource is a REST endpoint, allowed to be a single value or an array of values of the same data type.
-
An Object is a resource template and container type that encapsulates a set of related resources. An LWM2M Object represents a specific type of information source; for example, there is a LWM2M Device Management object that represents a network connection, containing resources that represent individual properties like radio signal strength.
Source: https://tools.ietf.org/html/draft-ietf-core-resource-directory
See IPSO Registry or OMNA Registry for Object and Resource definitions.
npm install --save lwm2m
var server = require('lwm2m').createServer();
server.on('register', function(params, accept) {
setImmediate(function() {
server
.read(params.ep, '3/0')
.then(function(device) {
console.log(JSON.stringify(device, null, 4));
})
});
accept();
});
server.listen(5683);Please report bugs via the github issue tracker.
Schemas for OMA-defined objects. See oma.
Returns Server object
Returns bootstrap#Server object
Schema resource type definition
Type: Object
Properties
type("String"|"Integer"|"Float"|"Boolean"|"Opaque"|"Time"| ["type"])idnumber Resource IDrequiredboolean? resource is mandatory. Defaults tofalseenumArray?rangeobject?
Schema constructor.
An Schema describes the shape of an LwM2M Object and the type of its resources.
Schemas are used throghout the API for generating/parsing payloads from/to JavaScript values.
See oma directory for default definitions. See also thermostat.js for an example of a composite schema.
Note
LwM2M types will be coerced to JavaScript types and viceversa, e.g. Time will return a Date(),
Opaque a Buffer(), and Integer/Float a number.
Parameters
Examples
// IPSO light controller
var lightControlSchema = new Schema({
onOff: {
type: 'Boolean',
id : 5850,
required: true
},
dimmer: {
type: 'Integer',
id: 5851,
range: { min: 0, max: 100 }
},
units: {
type: 'String',
id: 5701,
}
});
// an object literal matching the schema above
var lightControl = {
onOff: true,
dimmer: 40,
}
// Bad schema
var schema = new Schema({
a: { type: 'String', id: 0 },
b: { type: 'Error', id: 1 },
}); // throws TypeError- Throws any Will throw an error if fails to validate
validates obj with schema.
Parameters
objObject
Examples
var schema = new Schema({
a: { type: String, id: 0 },
b: { type: Buffer, id: 1 },
});
schema.validate({
a: 'foo',
b: Buffer.from('bar'),
}); // OK
schema.validate({
a: 'foo',
b: 'bar',
}); // Throws error- Throws any Will throw an error if fails to validate
Extends EventEmitter
Server constructor.
Events:
register: device registration request.update: device registration update.unregister: device unregistration.
Parameters
optionsObject?
Read path on device with endpoint name endpoint. The optional callback is given
the two arguments (err, res), where res is parsed using schema.
Note:
If no schema is provided will return a Buffer if the payload is TLV-encoded
or opaque, or an String otherwise.
Parameters
endpointString client endpoint namepathString either an LWM2M Object instance or resourceoptionsObject?options.schemaSchema defining resources.
callbackFunction?
Examples
var schema = Schema({
test: { id: 1, type: Number }
});
server.read('test', '/1024/11', { schema }, function(err, res) {
assert(res.hasOwnProperty('test'));
assert(typeof res.test == 'number');
});Returns Promise<(Object | string | Buffer | number)> a promise of the eventual value
Write value into path of device with endpoint name endpoint.
For writing Object Instances, an schema is required.
Note:
schemas can be globally added to lwm2m.schemas.
Parameters
endpointString client endpoint namepathStringvalue(Object | String | Number | Buffer)optionsObjectcallbackFunction?
Examples
var schema = Schema({
foo : {
id: 5,
type: 'String'
},
bar : {
id: 6,
type: 'Number'
},
});
var options = {
schema: schema,
format: 'json',
};
var value = {
foo: 'test',
bar: 42,
};
var promise = server.write('test', '/42/0', value, options)
var promise = server.write('test', '/42/0/5', 'test')
var promise = server.write('test', '/42/0/6', 42)
// add schema for Object ID 42 globally.
lwm2m.schemas[42] = schema;
var promise = server.write('test', '/42/0', value)Returns Promise
Makes an Execute operation over the designed resource ID of the selected device.
Parameters
Returns Promise
Execute a discover operation for the selected resource.
Parameters
Returns Promise<string> a promise with an strng in link-format
Write attributes into path of endpoint endpoint.
Parameters
Examples
var attr = {
"pmin": 5,
"pmax": 10
};
server.writeAttributes('dev0', '3303/0/5700', attr, function(err, res) {
assert.ifError(err);
});Returns Promise
Create a new LWM2M Object for path, where path is an Object ID.
Parameters
endpointString client endpoint namepathStringvalue(Object | String | Number | Buffer)optionsObject?callbackFunction?
Returns Promise
Deletes the LWM2M Object instance in path of endpoint endpoint
Parameters
Returns Promise
Observe changes in path of device with endpoint name endpoint.
The notification behaviour, e.g. periodic or event-triggered reporting, is configured with the
writeAttributes method. The callback is given the two arguments (err, stream),
where stream is a Readable Stream. To stop receiving notifications close() the stream
and (optionally) call cancel() on the same endpoint and path and .
Parameters
Examples
server.observe('dev0', '/1024/10/1', function(err, stream) {
stream.on('data', function(value) {
console.log('new value %s', value);
});
stream.on('end', function() {
console.log('stopped observing');
});
});Returns Promise
Cancel an observation for path of device endpoint.
Parameters
Returns Promise
Extends EventEmitter
Server constructor.
Events
bootstrapRequest: device bootstrap request.
Parameters
optionsObject?
Examples
var bootstrap = require('lwm2m').bootstrap;
var server = bootstrap.createServer();
server.on('error', function(err) {
throw err;
});
server.on('close', function() {
console.log('server is done');
});
server.on('bootstrapRequest', function(params, accept) {
console.log('endpoint %s contains %s', params.ep, params.payload);
accept();
});
// the default CoAP port is 5683
server.listen();Makes a Write operation over the designed resource ID of the selected device.
Parameters
endpointString client endpoint namepathStringvalue(Object | String | Number | Buffer)optionsObject?callbackFunction?
Examples
var schema = Schema({
foo : {
id: 5,
type: 'String'
},
bar : {
id: 6,
type: 'Number'
},
});
var options = {
schema: schema,
format: 'json',
};
var value = {
foo: 'test',
bar: 42,
};
var promise = server.write('test', '/42/3', value, options)Returns Promise
Deletes the LWM2M Object instance in path of endpoint endpoint
Parameters
Returns Promise
Terminate the Bootstrap Sequence previously initiated
Parameters
Returns Promise
Extends EventEmitter
Registry for clients. Default implementation is in-memory.
For production use, extend Registry class and
give new implementations to
_get, _find, _save, _update and _delete.
See examples for a MongoDB-backed registry.
get client by endpoint name
Parameters
get client by location in the registry
Parameters
store a new client in the registry
Parameters
update a client in the registry
Parameters
delete client from the registry
Parameters