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pryv: JS library for Pryv.io

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JavaScript library and add-ons for writing Node.js and browser apps connecting to a Pryv.io platform. It follows the Pryv.io app guidelines.

Table of Contents

  1. Usage
    1. Importing
    2. Quick example
    3. Obtaining a pryv.Connection
    4. API calls
    5. Get events streamed
    6. Events with attachments
    7. High Frequency (HF) events
    8. Service information and assets
    9. pryv.Browser & visual assets
    10. Customize the authentication process
    11. Running examples locally
  2. Contributing
    1. Installation
    2. Dev environment basics
    3. Building for the browser
    4. Testing
    5. Publishing
  3. Changelog
  4. License

Usage

Importing

NPM

npm install --save pryv, then in your code:

const pryv = require('pryv');

<script> tag

<script src="https://api.pryv.com/lib-js/pryv.js"></script>

Other distributions available:

  • ES6: https://api.pryv.com/lib-js/pryv-es6.js
  • Library bundled with Socket.IO and Monitor add-ons: https://api.pryv.com/lib-js/pryv-socket.io-monitor.js.

Add-ons

Quick example

Obtaining a pryv.Connection

A connection is an authenticated link to a Pryv.io account.

With an API endpoint

The format of the API endpoint can be found in your platform's service information under the api property. It usually looks like: https://{token}@{hostname}

const apiEndpoint = 'https://[email protected]';
const connection = new pryv.Connection(apiEndpoint);

With username & token (knowing the service information URL)

const service = new pryv.Service('https://reg.pryv.me/service/info');
const apiEndpoint = await service.apiEndpointFor(username, token);
const connection = new pryv.Connection(apiEndpoint);

Within a web page with a login button

Here is an implementation of the Pryv.io authentication process:

<!doctype html>
<html>
<head>
  <title>Pryv authentication example</title>
  <script src="https://api.pryv.com/lib-js/pryv.js"></script>
</head>
<body>
  <span id="pryv-button"></span>
  <script>
    var connection = null;

    var authSettings = {
      spanButtonID: 'pryv-button', // id of the <span> that will be replaced by the service-specific button
      onStateChange: authStateChanged, // event listener for authentication steps
      authRequest: { // See: https://api.pryv.com/reference/#auth-request
        requestingAppId: 'lib-js-test',
        languageCode: 'fr', // optional (default: 'en')
        requestedPermissions: [
          {
            streamId: 'test',
            defaultName: 'test',
            level: 'manage'
          }
        ],
        clientData: {
          'app-web-auth:description': {
            'type': 'note/txt', 'content': 'This is a consent message.'
          }
        },
        // referer: 'my test with lib-js', // optional string to track registration source
      }
    };
    var serviceInfoUrl = 'https://api.pryv.com/lib-js/examples/service-info.json';
    (async function () {
      var service = await pryv.Auth.setupAuth(authSettings, serviceInfoUrl);
    })();

    function authStateChanged(state) { // called each time the authentication state changes
      console.log('# Auth state changed:', state);
      if (state.id === pryv.Auth.AuthStates.AUTHORIZED) {
        connection = new pryv.Connection(state.apiEndpoint);
        logToConsole('# Browser succeeded for user ' + connection.apiEndpoint);
      }
      if (state.id === pryv.Auth.AuthStates.SIGNOUT) {
        connection = null;
        logToConsole('# Signed out');
      }
    }
  </script>
</body>
</html>

Fetching access info

API reference.

const apiEndpoint = 'https://[email protected]';
const connection = new pryv.Connection(apiEndpoint);
const accessInfo = await connection.accessInfo();

Using pryv.Service.login() (trusted apps only)

API reference

const serviceInfoUrl = 'https://reg.pryv.me/service/info';
const appId = 'lib-js-sample';
const service = new pryv.Service(serviceInfoUrl);
const connection = await service.login(username, password, appId);

API calls

API calls are based on the "batch" call specification: Call batch API reference

Simple usage

const apiCalls = [
  {
    "method": "streams.create",
    "params": { "id": "heart", "name": "Heart" }
  },
  {
    "method": "events.create",
    "params": { "time": 1385046854.282, "streamIds": ["heart"], "type": "frequency/bpm", "content": 90 }
  },
  {
    "method": "events.create",
    "params": { "time": 1385046854.283, "streamIds": ["heart"], "type": "frequency/bpm", "content": 120 }
  }
]

try {
  const result = await connection.api(apiCalls)
} catch (e) {
  // handle error
}

Advanced usage with optional individual result and progress callbacks

let count = 0;
// the following will be called on each API method result it was provided for
function handleResult(result) { console.log('Got result ' + count++ + ': ' + JSON.stringify(result)); }

function progress(percentage) { console.log('Processed: ' + percentage + '%'); }

const apiCalls = [
  {
    method: 'streams.create',
    params: { id: 'heart', name: 'Heart' }
  },
  {
    method: 'events.create',
    params: { time: 1385046854.282, streamIds: ['heart'], type: 'frequency/bpm', content: 90 },
    handleResult: handleResult
  },
  {
    method: 'events.create',
    params: { time: 1385046854.283, streamIds: ['heart'], type: 'frequency/bpm', content: 120 },
    handleResult: handleResult
  }
]

try {
  const result = await connection.api(apiCalls, progress)
} catch (e) {
  // handle error
}

Get events streamed

When events.get will provide a large result set, it is recommended to use a method that streams the result instead of the batch API call.

pryv.Connection.getEventsStreamed() parses the response JSON as soon as data is available and calls the forEachEvent callback for each event object.

The callback is meant to store the events data, as the function does not return the API call result, which could overflow memory in case of JSON deserialization of a very large data set. Instead, the function returns an events count and possibly event deletions count as well as the common metadata.

Example

const now = (new Date()).getTime() / 1000;
const queryParams = { fromTime: 0, toTime: now, limit: 10000};
const events = [];
function forEachEvent(event) {
  events.push(event);
}

try {
  const result = await connection.getEventsStreamed(queryParams, forEachEvent);
} catch (e) {
  // handle error
}

result:

{
  eventsCount: 10000,
  meta:
  {
      apiVersion: '1.4.26',
      serverTime: 1580728336.864,
      serial: '2019061301'
  }
}

Example including deletions

const now = (new Date()).getTime() / 1000;
const queryParams = { fromTime: 0, toTime: now, includeDeletions: true, modifiedSince: 0};
const events = [];
function forEachEvent(event) {
  events.push(event);
  // events with `deleted` or/and `trashed` properties can be tracked here
}

try {
  const result = await connection.getEventsStreamed(queryParams, forEachEvent);
} catch (e) {
  // handle error
}

result:

{
  eventDeletionsCount: 150,
  eventsCount: 10000,
  meta:
  {
      apiVersion: '1.4.26',
      serverTime: 1580728336.864,
      serial: '2019061301'
  }
}

Events with attachments

You can create an event with an attachment in a single API call.

Node.js

const filePath = './test/my_image.png';
const result = await connection.createEventWithFile({
  type: 'picture/attached',
  streamIds: ['data']
}, filePath);

Or from a Buffer:

const filePath = './test/my_image.png';
const bufferData = fs.readFileSync(filePath);

const result = await connection.createEventWithFileFromBuffer({
  type: 'picture/attached',
  streamIds: ['data']
}, bufferData, 'my_image.png' /* ← filename */);

Browser

From an <input>:

<input type="file" id="file-upload"><button onClick='uploadFile()'>Save Value</button>

<script>
  var formData = new FormData();
  formData.append('file0', document.getElementById('create-file').files[0]) ;

  connection.createEventWithFormData({
    type: 'file/attached',
    streamIds: ['test']
  }, formData).then(function (res, err) {
    // handle result
  });
</script>

Programmatically created content:

var formData = new FormData();
var blob = new Blob(['Hello'], { type: "text/txt" });
formData.append("file", blob);

connect.createEventWithFormData({
  type: 'file/attached',
  streamIds: ['data']
}, formData).then(function (res, err) {
  // handle result
});

// Alternative with a filename

connect.createEventWithFileFromBuffer({
  type: 'file/attached',
  streamIds: ['data']
}, blob /* ← here we can directly use the blob*/, 'filename.txt').then(function (res, err) {
  // handle result
});

High Frequency (HF) events

API reference

function generateSeries() {
  const series = [];
  for (let t = 0; t < 100000, t++) { // t will be the deltaTime in seconds
    series.push([t, Math.sin(t/1000)]);
  }
  return series;
}
const pointsA = generateSeries();
const pointsB = generateSeries();

function postHFData(points) { // must return a Promise
   return async function (result) { // will be called each time an HF event is created
    return await connection.addPointsToHFEvent(result.event.id, ['deltaTime', 'value'], points);
  }
}

const apiCalls = [
  {
    method: 'streams.create',
    params: { id: 'signal1', name: 'Signal1' }
  },
  {
    method: 'streams.create',
    params: { id: 'signal2', name: 'Signal2' }
  },
  {
    method: 'events.create',
    params: { streamIds: ['signal1'], type: 'series:frequency/bpm' },
    handleResult: postHFData(pointsA)
  },
  {
    method: 'events.create',
    params: { streamIds: ['signal2'], type: 'series:frequency/bpm' },
    handleResult: postHFData(pointsB)
  }
];

try {
  const result = await connection.api(apiCalls);
} catch (e) {
  // handle error
}

Service information and assets

Each Pryv.io platform is considered a "service"; for example Pryv Lab, which is deployed on the pryv.me domain. It is described by a service information settings object (see the service info API reference).

pryv.Service exposes tools to interact with Pryv.io at the "platform" level.

Initializing with a service info URL

const service = new pryv.Service('https://reg.pryv.me/service/info');

Initializing with a service info settings object

Service information properties can be overridden, which can be useful to test new designs on production platforms.

const serviceInfoUrl = 'https://reg.pryv.me/service/info';
const overrides = {
  name: 'Pryv Lab 2',
  assets: {
    definitions: 'https://pryv.github.io/assets-pryv.me/index.json'
  }
}
const service = new pryv.Service(serviceInfoUrl, overrides);

Methods

  • service.info() returns the service information in a Promise
    // get the name of the platform
    const serviceName = await service.info().name
  • service.infoSync() returns the cached service info; requires service.info() to be called beforehand
  • service.apiEndpointFor(username, token) returns the corresponding API endpoint for the provided credentials (token is optional)

pryv.Browser & visual assets

Retrieving the service info from a query parameter

A single web app might need to run on different Pryv.io platforms (this is the case of most Pryv.io example apps).

The Pryv.io platform can be specified by passing the service information URL in a query parameter pryvServiceInfoUrl (as per the Pryv app guidelines), which can be extracted with pryv.Browser.serviceInfoFromUrl().

For example: https://api.pryv.com/app-web-access/?pryvServiceInfoUrl=https://reg.pryv.me/service/info

let defaultServiceInfoUrl = 'https://reg.pryv.me/service/info';
// if present, override serviceInfoURL from query param `pryvServiceInfoUrl`
serviceInfoUrl = pryv.Browser.serviceInfoFromUrl() || defaultServiceInfoUrl;

(async function () {
	var service = await pryv.Auth.setupAuth(authSettings, serviceInfoUrl, serviceCustomizations);
})();

Visual assets

To customize visual assets, please refer to the pryv.me assets repository. For example, see how to customize the sign-in button.

(await service.assets()).setAllDefaults() loads the css and favicon properties of assets definitions:

(async function () {
  const service = await pryv.Auth.setupAuth(authSettings, serviceInfoUrl);
  (await service.assets()).setAllDefaults(); // will load the default favicon and CSS for this platform
})();

Customize the authentication process

You can customize the authentication process (API reference) at different levels:

  • Using a custom login button
  • Using a custom UI, including the flow of app-web-auth3

Using a custom login button

You will need to implement a class that instanciates an AuthController object and implements a few methods. We will go through this guide using the Browser's default login button provided with this library as example.

Initialization

You should provide auth settings (see obtaining a pryv.Connection) and an instance of pryv.Service at initialization. As this phase might contain asynchronous calls, we like to split it between the constructor and an async init() function. In particular, you will need to instanciate an AuthController object.

constructor(authSettings, service) {
  this.authSettings = authSettings;
  this.service = service;
  this.serviceInfo = service.infoSync();
}

async init () {
  // initialize button visuals
  // ...

  // set cookie key for authorization data - browser only
  this._cookieKey = 'pryv-libjs-' + this.authSettings.authRequest.requestingAppId;

  // initialize controller
  this.auth = new AuthController(this.authSettings, this.service, this);
  await this.auth.init();
}
Authorization data

At initialization, the AuthController will attempt to fetch persisted authorization credentials, using LoginButton.getAuthorizationData(). In the browser, we are using a client-side cookie. For other frameworks, use an appropriate secure storage.

getAuthorizationData () {
  return Cookies.get(this._cookieKey);
}
Authentication lifecycle

The authentication process implementation on the frontend can go through the following states:

  1. LOADING: while the visual assets are loading
  2. INITIALIZED: visuals assets are loaded, or when polling concludes with Result: Refused
  3. NEED_SIGNIN: from the response of the auth request through polling
  4. AUTHORIZED: When polling concludes with Result: Accepted
  5. SIGNOUT: when the user triggers a deletion of the client-side authorization credentials, usually by clicking the button after being signed in
  6. ERROR: see message for more information

You will need to provide a function to react depending on the state. The states NEED_SIGNIN and AUTHORIZED carry the same properties as the auth process polling responses. LOADING, INITIALIZED and SIGNOUT only have status. The ERROR state carries a message property.

async onStateChange (state) {
  switch (state.status) {
    case AuthStates.LOADING:
      this.text = getLoadingMessage(this);
      break;
    case AuthStates.INITIALIZED:
      this.text = getInitializedMessage(this, this.serviceInfo.name);
      break;
    case AuthStates.NEED_SIGNIN:
      const loginUrl = state.authUrl || state.url; // .url is deprecated
      if (this.authSettings.authRequest.returnURL) { // open on same page (no Popup)
        location.href = loginUrl;
        return;
      } else {
        startLoginScreen(this, loginUrl);
      }
      break;
    case AuthStates.AUTHORIZED:
      this.text = state.username;
      this.saveAuthorizationData({
        apiEndpoint: state.apiEndpoint,
        username: state.username
      });
      break;
    case AuthStates.SIGNOUT:
      const message = this.messages.SIGNOUT_CONFIRM ? this.messages.SIGNOUT_CONFIRM : 'Logout ?';
      if (confirm(message)) {
        this.deleteAuthorizationData();
        this.auth.init();
      }
      break;
    case AuthStates.ERROR:
      this.text = getErrorMessage(this, state.message);
      break;
    default:
      console.log('WARNING Unhandled state for Login: ' + state.status);
  }
  if (this.loginButtonText) {
    this.loginButtonText.innerHTML = this.text;
  }
}
Button actions

The button actions should be handled by the AuthController in the following way:

// LoginButton.js
onClick () {
  this.auth.handleClick();
}
// AuthController.js
async handleClick () {
  if (isAuthorized.call(this)) {
    this.state = { status: AuthStates.SIGNOUT };
  } else if (isInitialized.call(this)) {
    this.startAuthRequest();
  } else if (isNeedSignIn.call(this)) {
    // reopen popup
    this.state = this.state;
  } else {
    console.log('Unhandled action in "handleClick()" for status:', this.state.status);
  }
}
Custom button usage

You must then provide this class as follows:

let service = await pryv.Auth.setupAuth(
  authSettings, // See https://github.com/pryv/lib-js#within-a-webpage-with-a-login-button
  serviceInfoUrl,
  serviceCustomizations,
  MyLoginButton,
);

You will find a working example here, and try it running there. To run these examples locally, see below.

For a more advanced scenario, you can check the default button implementation in ./src/Browser/LoginButton.js.

Redirect user to the authentication page

There is a possibility that you would like to register the user in another page. You can find an example here, and try it running there. Again, to run these examples locally, see below.

Running examples locally

You can find HTML examples in the ./examples directory. You can run them in two ways:

  1. With backloop.dev, which allows to run local code with a valid SSL certificate (you must have run just build beforehand):
    just serve
    
    then open the desired example page (e.g. https://l.backloop.dev:9443/examples/auth.html
  2. As a simple HTML file, passing service information as JSON to avoid CORS issues

Contributing

Installation

Prerequisites: Node.js 16, just

Then:

  1. just setup-dev-env
  2. just install to install node modules
  3. just build for the initial webpack build

Running just with no argument displays the available commands (defined in justfile).

Dev environment basics

The project is structured as a monorepo with components (a.k.a. workspaces in NPM), each component defining its package.json, tests, etc. in components/:

  • pryv: the library
  • pryv-socket.io: Socket.IO add-on
  • pryv-monitor: Monitor add-on

The code follows the Semi-Standard style.

Building for the browser

just build[-watch]

to build the library, add-ons and examples into dist/, and the browser tests into test-browser/

Testing

Node.js

just test <component> [...params]
  • component is an existing component's name, or all to run tests on all components
  • Extra parameters at the end are passed on to Mocha (default settings are defined in .mocharc.js files)
  • Replace test with test-debug, test-cover for common presets

By default, tests are run against Pryv Lab with service information URL https://reg.pryv.me/service/info.

To run the tests against another Pryv.io platform, set the TEST_PRYVLIB_SERVICEINFO_URL environment variable; for example:

TEST_PRYVLIB_SERVICEINFO_URL="https://reg.${DOMAIN}/service/info" just test all

To run the tests against in-development API server components (e.g. open-source or Entreprise), set TEST_PRYVLIB_DNSLESS_URL; for example:

TEST_PRYVLIB_DNSLESS_URL="http://l.backloop.dev:3000/ just test all

Browser

Assuming browser files have been built (see above):

just test-browser

to run the tests in a browser window.

  • Update on CDN: After running setup and build scripts, run npm run gh-pages ${COMMIT_MESSAGE}. If this fails, run npm run clear to rebuild a fresh dist/ folder

Publishing

Assuming browser files are built and everything is up-to-date, including the READMEs and changelog:

just version <version>

to update the version number of the lib and add-ons in lockstep, git commit and tag included

just publish-npm

to publish the new versions of the lib and add-ons to NPM

just publish-browser

to commit and push the gh-pages branch from dist/, publishing the browser files to be served via CDN on api.pryv.com/lib-js

License

BSD-3-Clause