restserver-api

Example program This example shows basic restserver-api usage.

const restAPI = require('restserver-api');
 
const { Lwm2m } = restAPI;
const { RESOURCE_TYPE, encodeResource, decodeResource } = Lwm2m.TLV;
 
console.log('Initialize service and endpoint');
const service = new restAPI.Service();
const device = new restAPI.Device(service, 'urn:uuid:17200d69-ec9b-43b3-9051-73df2207907c');
 
console.log('Encode resource to TLV format');
const tlvBuffer = encodeResource({
  identifier: 3,
  type: RESOURCE_TYPE.INTEGER,
  value: 60
});
 
console.log('Start service');
service.start().then(() => {
  console.log('Service started');
  console.log('Writing into device\'s resource');
  device.write('/3/0/7', (status) => {
    console.log('Received response with status: ', status);
    console.log('Stopping service');
    service.stop().then(() => {
      console.log('Service stopped');
    });
  }, tlvBuffer);
});

Classes

Device

This class represents device (endpoint).

Service

This class represents REST API service.

Constants

TYPE

Represents LwM2M variable (identifier) types (OBJECT_INSTANCE, MULTIPLE_RESOURCE, RESOURCE_INSTANCE, RESOURCE).

RESOURCE_TYPE

Represents resource type (NONE, BOOLEAN, INTEGER, FLOAT, STRING, OPAQUE).

Functions

getDictionaryByValue(dictionaryList, keyName, value) ⇒ Object | string | number

Gets dictionary by given name of the key and value.

encodeResourceValue(resource) ⇒ object

Encodes value of the resource.

decodeResourceValue(buffer, resource) ⇒ Object | string | number | boolean

Decodes value of the resource.

encode(object) ⇒ object

Encodes ant type of instance (Object instance, multiple resources, resources instance, resource).

encodeResourceInstance(resourceInstance) ⇒ object

Encodes resource instance to TLV buffer.

encodeMultipleResourcesTLV(resources) ⇒ object

Encodes multiple resource values to TLV buffer.

encodeResource(resource) ⇒ object

Encodes resource to TLV buffer.

encodeObjectInstance(objectInstance) ⇒ object

Encodes LwM2M object instance to TLV buffer.

encodeObject(object) ⇒ object

Encodes LwM2M object to TLV buffer.

decode(buffer) ⇒ object

Decodes any TLV buffer.

decodeResourceInstance(buffer, resources) ⇒ object

Decodes resource instance.

decodeResourceInstanceValue(buffer, resourceInstance) ⇒ object

Decodes resource instance value

decodeResource(buffer, resource) ⇒ object

Decodes resource.

decodeObjectInstance(buffer, objectInstance) ⇒ object

Decodes object instance from TLV buffer.

decodeObject(buffer, object) ⇒ object

Decodes LwM2M object to TLV buffer.

Device

This class represents device (endpoint).

Kind: global class

• Device
  • new Device(service, id)
  • .getObjects() ⇒ Promise
  • .read(path, callback) ⇒ Promise
  • .write(path, callback, payload, type) ⇒ Promise
  • .execute(path, callback, payload, type) ⇒ Promise
  • .observe(path, callback) ⇒ Promise
  • .cancelObserve(path) ⇒ Promise

new Device(service, id)

Constructor initiliazes given service object, device's id and starts listening for events emited by service (when device registers, updates, deregisters, sends data), handles "async responses" and emits "register", "update", "deregister" events.

Param	Type	Description
service	object	Service object
id	string	Endpoint id

Example

const restAPI = require('restserver-api');
 
const service = new restAPI.Service(serviceOptions);
const device = new restAPI.Device(service, 'deviceId');

device.getObjects() ⇒ Promise

Sends request to get all device's objects.

Kind: instance method of Device
Returns: Promise - Promise object with device's objects
Example

device.getObjects().then((resp) => {
  // resp = [ { uri: '/1/0' }, { uri: '/2/0' }, ... ]
}).catch((err) => {
  // err - exception message object or status code
});

device.read(path, callback) ⇒ Promise

Sends request to read device's resource data.

Kind: instance method of Device
Returns: Promise - Promise with async response id

Param	Type	Description
path	string	Resource path
callback	function	Callback which will be called when async response is received

Example

device.read(path, (status, payload) => {
  // status = 200
  // payload = 4RbaAA==
}).then((asyncResponseId) => {
  // asyncResponseId = 1533889157#42f26784-1a8d-4861-36aa-d88f
}).catch((err) => {
  // err - exception object or status code
});

device.write(path, callback, payload, type) ⇒ Promise

Sends request to write a value into device's resource.

Kind: instance method of Device
Returns: Promise - Promise with async response id

Param	Type	Default	Description
path	string		Resource path
callback	function		Callback which will be called when async response is received
payload	buffer		Data (optional)
type	string	"application/vnd.oma.lwm2m+tlv"	Content type (optional)

Example

device.write(path, (status) => {
  // status = 202
}, payload).then((asyncResponseId) => {
  // asyncResponseId = 1533889926#870a3f17-3e21-b6ad-f63d-5cfe
}).catch((err) => {
  // err - exception object or status code
});

device.execute(path, callback, payload, type) ⇒ Promise

Sends request to execute device's resource.

Kind: instance method of Device
Returns: Promise - Promise with async response id

Param	Type	Default	Description
path	string		Resource path
callback	function		Callback which will be called when async response is received
payload	buffer		Data (optional)
type	string	"text/plain"	Content type (optional)

Example

device.execute(path, (status) => {
  // status = 202
}).then((asyncResponseId) => {
  // asyncResponseId = 1533889926#870a3f17-3e21-b6ad-f63d-5cfe
}).catch((err) => {
  // err - exception object or status code
});

device.observe(path, callback) ⇒ Promise

Sends request to subscribe to resource.

Kind: instance method of Device
Returns: Promise - Promise with async response id

Param	Type	Description
path	string	Resource path
callback	function	Callback which will be called when async response is received

Example

device.observe(path, (status, payload) => {
  // status = 200
  // payload = 4RbaAA==
}).then((asyncResponseId) => {
  // asyncResponseId = 1533889157#42f26784-1a8d-4861-36aa-d88f
}).catch((err) => {
  // err - exception object or status code
});

device.cancelObserve(path) ⇒ Promise

Sends request to cancel subscriptions.

Kind: instance method of Device
Returns: Promise - Promise with HTTP status code

Param	Type	Description
path	string	Resource path

Example

device.cancelObserve(path).then((status) => {
  // status - status code
}).catch((err) => {
  // err - exception object
});

Service

This class represents REST API service.

Kind: global class

• Service
  • new Service(opts)
  • .start(opts) ⇒ Promise
  • .stop() ⇒ Promise
  • .authenticate() ⇒ Promise
  • .registerNotificationCallback() ⇒ Promise
  • .deleteNotificationCallback() ⇒ Promise
  • .checkNotificationCallback() ⇒ Promise
  • .pullNotification() ⇒ Promise
  • .getDevices() ⇒ Promise
  • .getVersion() ⇒ Promise
  • .get(path) ⇒ Promise
  • .put(path, argument, type) ⇒ Promise
  • .delete(path) ⇒ Promise
  • .post(path, argument, type) ⇒ Promise

new Service(opts)

Initializes default configurations. Reconfigures with given options.

Param	Type	Description
opts	object	Options object (optional)

Example

const options = {
  // REST server's address
  host: 'http://localhost:8888',
  // CA certificate
  ca: '',
  // authentication (true or false)
  authentication: false,
  username: '',
  password: '',
  // notification polling (true or false)
  polling: false,
  // time between each poll in miliseconds
  interval: 1234,
  // port for socket listener (not relevant if polling is enabled)
  port: 5728,
};
new Service(options);

service.start(opts) ⇒ Promise

(Re)starts authentication, socket listener creation and notification callback registration or notification polling processes.

Kind: instance method of Service
Returns: Promise - Promise which fulfills when service is started

Param	Type	Description
opts	object	Options object (optional)

Example

service.start().then(() => {
  // started service
}).catch((err) => {
  // err - exception object
});

Example (Passing options object)

const options = {
  // REST server's address
  host: 'http://localhost:8888',
  // CA certificate
  ca: '',
  // authentication (true or false)
  authentication: false,
  username: '',
  password: '',
  // notification polling (true or false)
  polling: false,
  // time between each poll in miliseconds
  interval: 1234,
  // port for socket listener (not relevant if polling is enabled)
  port: 5728,
};
service.start(options);

service.stop() ⇒ Promise

Stops receiving and processing events Stops this service and all it's subservices that were started in start(). Cleans up resources

Kind: instance method of Service
Returns: Promise - Promise which fulfills when service is stopped
Example

service.stop().then(() => {
  // stopped service
});

service.authenticate() ⇒ Promise

Sends request to authenticate user.

Kind: instance method of Service
Returns: Promise - Promise with authentication data (token and after what time it expires)
Example

service.authenticate().then((resp) => {
  // resp = { access_token: 'token-value', expires_in: 3600 }
}).catch((err) => {
  // err - exception message object or status code
});

service.registerNotificationCallback() ⇒ Promise

Sends request to register notification callback.

Kind: instance method of Service
Returns: Promise - Promise which fulfills when notification callback is registered
Example

service.registerNotificationCallback().then(() => {
  // notification callback has been registered
}).catch((err) => {
  // err - exception object or status code
});

service.deleteNotificationCallback() ⇒ Promise

Sends request to delete notification callback.

Kind: instance method of Service
Returns: Promise - Promise with HTTP status code
Example

service.deleteNotificationCallback().then((status) => {
  // status - status code
}).catch((err) => {
  // err - exception object
});

service.checkNotificationCallback() ⇒ Promise

Sends request to check whether or not notification callback is registered.

Kind: instance method of Service
Returns: Promise - Promise with notification callback data
Example

service.checkNotificationCallback().then((resp) => {
  // resp = { url: 'http://localhost:5728/notification', headers: {} }
}).catch((err) => {
  // err - exception message object or status code
});

service.pullNotification() ⇒ Promise

Sends request to get pending/queued notifications.

Kind: instance method of Service
Returns: Promise - Promise with notification data (registrations, deregistrations, updates, async responses)
Example

service.pullNotification().then((resp) => {
  // resp = { registrations: [...], 'reg-updates': [...], ... }
}).catch((err) => {
  // err - exception object
});

service.getDevices() ⇒ Promise

Sends request to get all registered endpoints.

Kind: instance method of Service
Returns: Promise - Promise with a list of endpoints
Example

service.getDevices().then((resp) => {
  // resp = [ { name: 'uuid-4567', type: '8dev_3700', ... }, ... ]
}).catch((err) => {
  // err - exception message object or status code
});

service.getVersion() ⇒ Promise

Sends request to get REST server version.

Kind: instance method of Service
Returns: Promise - Promise with REST server's version
Example

service.getVersion().then((resp) => {
  // resp = '1.0.0'
}).catch((err) => {
  // err - exception object
});

service.get(path) ⇒ Promise

Performs GET requests with given path.

Kind: instance method of Service
Returns: Promise - Promise with data and response object

Param	Type	Description
path	string	Request path

Example

service.get(path).then((dataAndResponse) => {
  // dataAndResponse.data - data object
  // dataAndResponse.resp - response object
}).catch((err) => {
  // err - exception object
});

service.put(path, argument, type) ⇒ Promise

Performs PUT requests with given path, data and data type.

Kind: instance method of Service
Returns: Promise - Promise with data and response object

Param	Type	Default	Description
path	string		Request path
argument	object		Data which will be sent (optional)
type	string	"application/vnd.oma.lwm2m+tlv"	Data type (optional)

service.delete(path) ⇒ Promise

Performs DELETE requests with given path.

Kind: instance method of Service
Returns: Promise - Promise with data and response object

Param	Type	Description
path	string	Request path

service.post(path, argument, type) ⇒ Promise

Performs POST requests with given path, data and data type.

Kind: instance method of Service
Returns: Promise - Promise with data and response object

Param	Type	Default	Description
path	string		Request path
argument	object		Data which will be sent (optional)
type	string	"application/vnd.oma.lwm2m+tlv"	Data type (optional)

TYPE

Represents LwM2M variable (identifier) types (OBJECT_INSTANCE, MULTIPLE_RESOURCE, RESOURCE_INSTANCE, RESOURCE).

Kind: global constant

RESOURCE_TYPE

Represents resource type (NONE, BOOLEAN, INTEGER, FLOAT, STRING, OPAQUE).

Kind: global constant

getDictionaryByValue(dictionaryList, keyName, value) ⇒ Object | string | number

Gets dictionary by given name of the key and value.

Kind: global function
Returns: Object | string | number - dictionary

Param	Type	Description
dictionaryList	object	Dictionary list.
keyName	Object | string	Name of the key
value	Object | string | number	Value

encodeResourceValue(resource) ⇒ object

Encodes value of the resource.

Kind: global function
Returns: object - buffer - Buffer of encoded value.

Param	Type	Description
resource	object	Object which stores resource value and value's type.

Example

const resource = {
 type: TLV.RESOURCE_TYPE.INTEGER,
 value: 1
};
 
const encodedValue = encodeResourceValue(resource);
// encodedValue = <Buffer 01>

decodeResourceValue(buffer, resource) ⇒ Object | string | number | boolean

Decodes value of the resource.

Kind: global function
Returns: Object | string | number | boolean - value - Decoded value in specified type

Param	Type	Description
buffer	object	Buffer which will be decoded.
resource	object	Object which stores resource value's type.

Example

const buffer = Buffer.from([0x01]);
const resource = {
  type: TLV.RESOURCE_TYPE.INTEGER,
};
 
const decodedValue = decodeResourceValue(buffer, resource);
// decodedValue = 1

encode(object) ⇒ object

Encodes ant type of instance (Object instance, multiple resources, resources instance, resource).

Kind: global function
Returns: object - buffer - encoded TLV buffer.

Param	Type	Description
object	object	object which stores type, identifier and value.

Example

const resource = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
  value: true
};
 
const encoded = encode({
  type: TYPE.RESOURCE,
  identifier: resource.identifier,
  value: encodeResourceValue(resource),
});
// encoded = <Buffer e1 16 da 01>

encodeResourceInstance(resourceInstance) ⇒ object

Encodes resource instance to TLV buffer.

Kind: global function
Returns: object - buffer - Buffer in TLV format

Param	Type	Description
resourceInstance	object	Object which stores resource identifier, value and it's type.

Example

const resourceInstance = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
  value: true
};
 
const encoded = encodeResourceInstance(resourceInstance);
// encoded = <Buffer e1 16 da 01>

encodeMultipleResourcesTLV(resources) ⇒ object

Encodes multiple resource values to TLV buffer.

Kind: global function
Returns: object - buffer - TLV buffer.

Param	Type	Description
resources	object	Object which stores identifier, resource type, and multiple values.

Example

const resources = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
  value: [true, false]
};
 
const encoded = encodeMultipleResources(resources);
// encoded = <Buffer a6 16 da 41 00 01 41 01 00>

encodeResource(resource) ⇒ object

Encodes resource to TLV buffer.

Kind: global function
Returns: object - buffer - TLV buffer.

Param	Type	Description
resource	object	Object which stores resource identifier, type and value.

Example

const resource = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
  value: true
};
 
const encoded = encodeResourcez(resource);
// encoded = <Buffer e1 16 da 01>

encodeObjectInstance(objectInstance) ⇒ object

Encodes LwM2M object instance to TLV buffer.

Kind: global function
Returns: object - buffer - TLV buffer.

Param	Type	Description
objectInstance	object	LwM2M object.

Example

const objectInstance = {
  identifier: 0,
  resources: [
    {
      identifier: 5815,
      type: TLV.RESOURCE_TYPE.FLOAT,
      value: 999.99
    }
  ]
};
 
const encoded = encodeObjectInstanceTLV(objectInstance);
// encoded = <Buffer 07 00 e4 16 b7 44 79 ff 5c>

encodeObject(object) ⇒ object

Encodes LwM2M object to TLV buffer.

Kind: global function
Returns: object - buffer - TLV buffer.

Param	Type	Description
object	object	LwM2M object.

Example

const object = {
  identifier: 3305,
  objectInstances: [{
    identifier: 0,
    resources: [
      {
        identifier: 5815,
        type: TLV.RESOURCE_TYPE.FLOAT,
        value: 999.99
      }
    ]
  }]
};
 
const encoded = encodeObject(object);
// encoded = <Buffer 07 00 e4 16 b7 44 79 ff 5c>

decode(buffer) ⇒ object

Decodes any TLV buffer.

Kind: global function
Returns: object - object - Decoded object.

Param	Type	Description
buffer	object	encoded TLV buffer.

Example

const buffer = Buffer.from([0xe1, 0x16, 0xda, 0x01]);
 
const decoded = TLV.decode(buffer);
// decoded = { type: 3, identifier: 5850, value: <Buffer 01>, tlvSize: 4 }

decodeResourceInstance(buffer, resources) ⇒ object

Decodes resource instance.

Kind: global function
Returns: object - decodedResource - Object which stores resource identifier, tlvSize resource type and value.

Param	Type	Description
buffer	object	Resource instance TLV buffer.
resources	object	Object which stores resource identifier and resource type.

Example

const buffer = Buffer.from([0x61, 0x16, 0xda, 0x01]);
const resources = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
};
 
const decoded = decodeResourceInstance(buffer, resources);
// decoded = { identifier: 5850, tlvSize: 4, type: TLV.RESOURCE_TYPE.BOOLEAN, value: true }

decodeResourceInstanceValue(buffer, resourceInstance) ⇒ object

Decodes resource instance value

Kind: global function
Returns: object - decodedResourceValue - Decoded resource value

Param	Type	Description
buffer	object	Resource instance value TLV buffer
resourceInstance	object	Object which stores resource type

Example

const buffer = Buffer.from([0x01]);
const resourceInstance = {
  type: TLV.RESOURCE_TYPE.INTEGER,
};
 
const decoded = decodeResourceInstance(buffer, resources);
// decoded = 1

decodeResource(buffer, resource) ⇒ object

Decodes resource.

Kind: global function
Returns: object - buffer - Decoded resource.

Param	Type	Description
buffer	object	Resource TLV buffer
resource	object	Object which stores identifier and resource type.

Example

const buffer = Buffer.from([0xe1, 0x16, 0xda, 0x01]);
const resource = {
  identifier: 5850,
  type: TLV.RESOURCE_TYPE.BOOLEAN,
};
 
const decoded = decodeResource(buffer, resource);
// decoded = { identifier: 5850, type: 1, value: true, tlvSize: 4 }

decodeObjectInstance(buffer, objectInstance) ⇒ object

Decodes object instance from TLV buffer.

Kind: global function
Returns: object - object - Decoded object instance.

Param	Type	Description
buffer	object	TLV buffer.
objectInstance	object	Object which stores object instance identifier and resources.

Example

const buffer = Buffer.from([0x07, 0x00, 0xe4, 0x16, 0xb7, 0x44, 0x79, 0xff, 0x5c]);
const objectInstance: {
  identifier: 0,
  resources: [ 
    {
      identifier: 5815,
      type: TLV.RESOURCE_TYPE.FLOAT,
    },
  ]
};
 
const decoded = decodeObjectInstance(buffer, objectInstance);
// decoded = { identifier: 0, resources: [ { identifier: 5815, type: 3 } ] }

decodeObject(buffer, object) ⇒ object

Decodes LwM2M object to TLV buffer.

Kind: global function
Returns: object - object - Decoded object.

Param	Type	Description
buffer	object	TLV buffer.
object	object	Object which stores object instances with their resources.

Example

const buffer = Buffer.from([0x07, 0x00, 0xe4, 0x16, 0xb7, 0x44, 0x79, 0xff, 0x5c]);
const object = {
  identifier: 3305,
  objectInstances: [{
    identifier: 0,
    resources: [
      {
        identifier: 5815,
        type: TLV.RESOURCE_TYPE.FLOAT,
      },
    ]
  }]
};
 
const decoded = decodeObject(buffer, object);
/*
decoded = {
  identifier: 3305,
  objectInstances: [
    {
      identifier: 0,
      resources: [
        {
          identifier: 5815,
          type: 3,
          value: 999.989990234375,
          tlvSize: 7
        }
      ]
    }
  ]
}
*/