The Electric Imp impCentral™ API JavaScript Library

imp-central-api is a JavaScript (Node.js) wrapper for the impCentral API.

Library Usage

To use imp-central-api, you will need to:

• Install Node.js and the library.
• Instantiate the library.
• Initialize the library with an access token.
• Call impCentral API endpoints.
• Process the results, or
• Process any errors you encountered.

Each of these steps are described in the following sections.

Installation

Node.js version 8 or higher is required. You can download the Node.js pre-built binary for your platform, or install Node.js via package manager. Once node and npm are installed, you need to execute the following command to set up imp-central-api:

npm install -g imp-central-api

Proxy Setup

If imp-central-api is going to connect to the impCentral API via a proxy, one of the following environment variables should be set to a value in URL format:

• HTTPS_PROXY (or https_proxy) — for the proxy which passes HTTPs requests.
• HTTP_PROXY (or http_proxy) — for the proxy which passes HTTP requests.

Note, the default impCentral API base endpoint is working over HTTPs.

Instantiation

To instantiate this library, call the ImpCentralApi class constructor.

By default, imp-central-api works with the following impCentral API base endpoint: https://api.electricimp.com/v5. You can optionally pass an alternative impCentral API base endpoint into the constructor. This can be used to connect to Private impCloud™ installations. The class method apiEndpoint() can be used to obtain the current impCentral API base endpoint.

After instantiation, use ImpCentralApi class methods to obtain the subclasses which provide the methods you will use to access specific impCentral API resources. For example:

const ImpCentralApi = require('imp-central-api');
const impCentralApi = new ImpCentralApi();
impCentralApi.auth.getAccessToken();
impCentralApi.products.list();

Access Authorization

Access to almost every impCentral API endpoint requires authorization: you must supply an access token in an HTTP Authorization header. The library’s Auth class provides several methods to acquire this access token and to refresh it after it has expired. When an access token has expired, any call to the impCentral API will return a 401 error.

• If your access token has not expired, use the method set accessToken() to save it for use with future impCentral API calls.
• If your access token has expired, but you have a refresh token which is typically received after calling login(), use the refreshAccessToken() method to obtain a new access token.
• If you have a login key, call getAccessToken() and pass in your login key.
• Alternatively, you can call login() with an account username and password pair.
  • If two-factor authentication is enabled for your account, call loginWithOtp() with a one-time password.

The login methods will return both a new access token and a refresh token.

For more information, please see the impCentral API documentation.

impCentral API Calls

The Accounts, Auth, Deployments, DeviceGroups, Devices, LogStreams, Products and Webhooks library classes map to the corresponding impCentral API resources. These classes' methods typically map directly to the corresponding impCentral API endpoints.

See the impCentral API Coverage section below for a list of the supported impCentral API endpoints.

Result Processing

All requests are made asynchronously via Promises. Any method which sends a request returns a Promise:

• If the operation succeeds, the Promise resolves with an HTTP response body.
• If the operation fails, the Promise rejects with an error.

Your code needs to parse the returned HTTP response body.

The exact format of HTTP response body for every request can be found here.

Error Processing

Error classes define two types of errors returned by the library:

• InvalidDataError Indicates that the library detected one of the following errors:

  • The library has been wrongly initialized, eg. an access token has not been provided or obtained.
  • The library method has been called with invalid argument(s);
  • Internal library problem(s).

  The error details can be found in the message property. These errors usually happen during an application development. Usually they should be fixed during debugging and therefore should not occur after the application has been deployed.

• ImpCentralApiError Indicates that the request to the impCentral API failed. The error details can be found in the message, statusCode and body properties. The exact body format is described in the impCentral API documentation. This error may occur during the normal execution of an application.

Use the method debug() to enable (debug(true)) or disable (debug(false)) the library debug output (including error logging). This is disabled by default.

impCentral API Coverage

Accounts

Library Class: Accounts

impCentral API Functionality	Library Methods
Retrieve Account information	accounts.get()
List Accounts	accounts.list()
Retrieve Login Keys	accounts.listLoginKeys()
Create a Login Key	accounts.createLoginKey()
Retrieve a Login Key	accounts.getLoginKey()
Delete a Login Key	accounts.deleteLoginKey()
Update a Login Key	accounts.updateLoginKey()

impCentral API: Auth

Library Class: Auth

impCentral API Functionality	Library Methods
Authenticate and Retrieve an Access Token	auth.login(), auth.loginWithOTP()
Exchange a refresh token or a login key for an Access Token	auth.refreshAccessToken(), auth.getAccessToken()
Retrieve Refresh Tokens	auth.getRefreshTokens()
Delete a Refresh Token	auth.deleteRefreshToken()

impCentral API: Deployments

Library Class: Deployments

impCentral API Functionality	Library Methods
List the account’s Deployment history	deployments.list()
Create a Deployment	deployments.create()
Get a specific Deployment	deployments.get()
Update a specific Deployment	deployments.update()
Delete a Deployment	deployments.delete()

impCentral API: Device Groups

Library Class: DeviceGroups

impCentral API Functionality	Library Methods
List existing Device Groups	deviceGroups.list()
Create a Device Group	deviceGroups.create()
Get a specific DeviceGroup	deviceGroups.get()
Update a specific Device Group	deviceGroups.update()
Delete a specific DeviceGroup	deviceGroups.delete()
Restart all the devices in a Device Group	deviceGroups.restartDevices()
Conditionally restart devices in a Device Group	deviceGroups.conditionalRestartDevices()
Update the minimum supported deployment for a Device Group	deviceGroups.updateMinSupportedDeployment()
Assign one or more devices to a Device Group	deviceGroups.addDevices()
Remove one or more devices from a Device Group	deviceGroups.removeDevices()

impCentral API: Devices

Library Class: Devices

impCentral API Functionality	Library Methods
List the Devices owned by the Account	devices.list()
Get a specific Device	devices.get()
Remove a specific device from the account	devices.delete()
Update a Device	devices.update()
Restart a Device	devices.restart()
Conditionally restart a Device	devices.conditionalRestart()
Get historical logs for a specific Device	devices.getLogs()

impCentral API: Logs

Library Class: LogStreams

impCentral API Functionality	Library Methods
Request a new logstream, Retrieve logs from a logstream	logStreams.create()
Add a device to a logstream	logStreams.addDevice()
Remove a device from a logstream	logStreams.removeDevice()

impCentral API: Products

Library Class: Products

impCentral API Functionality	Library Methods
List existing Products	products.list()
Create a Product	products.create()
Retrieve a specific Product	products.get()
Update a specific Product	products.update()
Delete a specific Product	products.delete()

impCentral API: Webhooks

Library Class: Webhooks

impCentral API Functionality	Library Methods
List existing Webhooks	webhooks.list()
Create a Webhook	webhooks.create()
Retrieve a Webhook	webhooks.get()
Update a specific Webhook	webhooks.update()
Delete a specific Webhook	webhooks.delete()

Examples

1. Library initialization using email/password login:

const ImpCentralApi = require('imp-central-api');
const Errors = ImpCentralApi.Errors;
const impCentralApi = new ImpCentralApi();

let token;
impCentralApi.auth.login('<user email for Electric Imp Account>',
                         '<user password for Electric Imp Account>').then(result => {
    token = result.access_token;
}).catch(error => {
    if (error instanceof Errors.InvalidDataError) {
        // Process InvalidDataError
        console.log(error.message);
    }
    else if (error instanceof Errors.ImpCentralApiError) {
        // Process impCentral API HTTP request failure
        console.log(error.statusCode);
        console.log(error.message);
        console.log(error.body);
    }
});

2. Library initialization using an existing access token; product and device group creation:

const ImpCentralApi = require('imp-central-api');
const DeviceGroups = ImpCentralApi.DeviceGroups;
const impCentralApi = new ImpCentralApi();

// The library can be initialized with a non-expired access token,
// if you have one saved from the last time you used the library
impCentralApi.auth.accessToken = token;

let accountId;
// Retrieve account information
impCentralApi.accounts.get('me').then(account => {
    accountId = account.data.id;
    // Create a product
    // 'accountID' is an optional parameter - if it is not provided,
    // the product will be assigned to the current user
    return impCentralApi.products.create({ name : 'test_product'}, accountID);
}).then(product => {
    // Retrieve the newly created product ID
    let productID = product.data.id;
    // Create a device group
    return impCentralApi.deviceGroups.create(
        productID,
        DeviceGroups.TYPE_DEVELOPMENT,
        {name : 'temp_sensors', description : 'temperature sensors'});
}).then(deviceGroup => {
    // Retrieve the newly created device group ID
    let devGroupID = deviceGroup.data.id;
    console.log(devGroupID);
}).catch(error => {
    console.log(error);
});

3. List existing device groups with filters and restart all of the devices in the specified device group:

let filters = {
    [DeviceGroups.FILTER_OWNER_ID] : accountId,
    [DeviceGroups.FILTER_TYPE] : DeviceGroups.TYPE_DEVELOPMENT
};

let devGroupName = 'temp_sensors';

// List existing device groups
impCentralApi.deviceGroups.list(filters).then(devGroups => {
    for (let devGroup of devGroups.data) {
        // Find device group by name and restart associated devices
        if (devGroup.attributes.name === devGroupName) {
            impCentralApi.deviceGroups.restartDevices(devGroup.id);
        }
    }
}).catch(error => {
    console.log(error);
});

4. Get historical logs for a specific device, using pagination:

let deviceID = '<existing Device ID>';
let pageNumber = 1;
let pageSize = 10;
impCentralApi.devices.getLogs(deviceID, pageNumber, pageSize).then(logs => {
    for (let log of logs.data) {
        console.log(log.ts + ': '+ log.msg);
    }
}).catch(error => {
    console.log(error);
});

5. Retrieve the logs from a LogStream for all devices assigned to a device group:

const Devices = ImpCentralApi.Devices;

function logMessage(message) {
    console.log(message);
}

function logState(state) {
    console.log(state);
}

let deviceGroupID = '<existing Device Group ID>';
let logStreamID;
impCentralApi.logStreams.create(logMessage, logState).then(logStream => {
    logStreamID = logStream.data.id;
    return impCentralApi.devices.list({[Devices.FILTER_DEVICE_GROUP_ID] : deviceGroupId});
}).then(devices => {
    return Promise.all(devices.data.map(device => impCentralApi.logStreams.addDevice(logStreamID, device.id)));
}).catch(error => {
    console.log(error);
});

Testing

The library contains Jasmine tests in the spec folder. To set up and run the tests, you will need to:

1. Clone or download the latest version of the imp-central-api repository to a local imp-central-api folder, for example by running the command git clone https://github.com/electricimp/imp-central-api.git imp-central-api.
2. Install imp-central-api dependencies by calling npm install from your local imp-central-api folder.
3. Set the mandatory environment variables:
   • IMP_CENTRAL_USER_EMAIL — Your impCentral account username or email address.
   • IMP_CENTRAL_USER_PASSWORD — The account password.
4. Set optional environment variables, if needed:
   • IMP_CENTRAL_API_DEBUG — If true, displays debug info of the command execution (default: false).
   • IMP_CENTRAL_API_ENDPOINT — The impCentral API endpoint (default: https://api.electricimp.com/v5).
5. Alternatively, instead of setting environment variables directly, you can specify the values of the corresponding variables in your local imp-central-api/spec/config.js file.
6. Run the tests by calling npm test from your local imp-central-api folder.

It is recommended that your devices do not change their state between online and offline during the tests running.

License

This library is licensed under the MIT License.