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Migration Guide for v4

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Ankur Oberoi edited this page Mar 7, 2018 · 12 revisions

This migration guide helps you transition an application written using the v3.x series of this package, to the v4.x series. This guide focuses specifically on the breaking changes to help get your existing app up and running as quickly as possible. In some cases, there may be better techniques for accomplishing what your app already does by utilizing brand new features or new API. Learn about all the new features in our v4.0.0 release notes if you'd like to go beyond a simple port.

WebClient

Constructor

  • The slackAPIUrl option has been renamed to slackApiUrl. It was confusing to see two acronyms directly next to each other, but with different casing.
  • The transport option has been removed. If you used this option to implement proxy support, use the new agent option as described below. If you used this option for setting custom TLS configuration, use the new tls option as described below. If you were using this for some other reason, please open an issue and describe your use case so we can help you migrate.

All methods

All Web API methods no longer take positional arguments. They each take one argument, an object, in which some properties are required and others are optional (depending on the method). You no longer have to memorize or look up the order of the arguments. The method arguments are described in the API method documentation. If you are using an editor that understands TypeScript or JSDoc annotations, your editor may present you with useful information about these arguments as you type.

If any Web API method is called with a callback parameter, and the call results in an error from the platform, you will no longer get the platform's response as the second argument to the callback. Instead, that response will exist as the .data property on the first argument (the error). You can consolidate this logic by using Promises instead (or continue to use callbacks if you prefer).

Before:

const { WebClient } = require('@slack/client')
const web = new WebClient(token);

web.chat.postMessage(channelId, text, { as_user: true, parse: 'full' }, (error, resp) => {
  if (error) {
    if (resp) {
      // a platform error occurred, `resp.error` contains the error information
    }
    // some other error occurred
    return;
  }

  // success
});

After:

// a new export, ErrorCode, is a dictionary of known error types
const { WebClient, ErrorCode } = require('@slack/client')
const web = new WebClient(token);

web.chat.postMessage({ channel: channelId, text, as_user: true, parse: 'full' })
  .then((resp) => { /* success */ })
  .catch((error) => {
    if (error.code === ErrorCode.PlatformError) {
      // a platform error occurred, `error.message` contains error information, `error.data` contains the entire resp
    } else {
      // some other error occurred
    }
  });

dm

This family of methods was always a duplicate of those under the .im family. These duplicates have been removed.

mpdm

This family of methods was always a duplicate of those under the .mpim family. These duplicates have been removed.

RTMClient

Constructor

  • The slackAPIUrl option has been renamed to slackApiUrl. It was confusing to see two acronyms directly next to each other, but with different casing.
  • The dataStore option has been removed.
  • The useRtmConnect option now has a default value of true. We recommend querying for additional data using a WebClient after this client is connected. If that doesn't help, then you can set this option to false.
  • The socketFn option has been removed. If you used this option to implement proxy support, use the new agent option as described below. If you used this option for setting custom TLS configuration, use the new tls option as described below. If you were using this for some other reason, please open an issue and describe your use case so we can help you migrate.
  • The wsPingInterval and maxPongInterval options have been replaced with clientPingTimeout and serverPongTimeout. Most likely, you can replace these values respectively, or drop using them all together.

dataStore

The data store has been removed from the RTMClient. See the DataStore v3.x Migration Guide for more details on this change.

reconnect()

This method has been removed, but it can be substituted by using disconnect(), waiting for the disconnected event, and then calling start(options). Reconnecting using the method was rarely used by developers, and its implementation increased the complexity of state management in the client.

Before:

rtm.reconnect();

After:

rtm.disconnect();
// You will need to store the start options from the first time you connect and then reuse them here.
rtm.once('disconnected', () => rtm.start(options));

updateMessage()

This method has been removed from the RTMClient, but can be substituted by using the WebClient.

Before:

const message = { ts: '999999999.0000000', channel: 'C123456', text: 'updated message text' };
rtm.updateMessage(message).then(console.log);

After:

// We recommend that you initialize this object at the same time you would have initialized the RTMClient
const web = new WebClient(token);

const message = { ts: '999999999.0000000', channel: 'C123456', text: 'updated message text' };
web.chat.update(message).then(console.log);

send()

This method has be repurposed, and in most cases you will instead rely on addOutgoingEvent(awaitReply, type, body).

The main difference is that if you want to know when the message is acknowledged by the server (you were using the optional callback parameter to send()), you'll only be able to do so using the returned Promise. If you prefer callbacks, you can translate the interface using a library like Bluebird (see: http://bluebirdjs.com/docs/api/ascallback.html) or the Node util.callbackify() since v8.2.0.

As an added benefit, you will be able to send the message without worrying whether the client is in a connected state or not.

Before:

const message = { type: 'message_type', key: 'value', foo: 'bar' };
rtm.send(message, (error, resp) => {
  if (error) {
    // error handling
    return;
  }
  // success handling
});

After:

const message = { type: 'message_type', key: 'value', foo: 'bar' };
rtm.addOutgoingEvent(true, message.type, message)
  .then((resp) => {
    // success handling
  })
  .catch((error) => {
    // error handling
  });

Events

The RTMClient now has more well-defined states (and substates) that you may observe using the EventEmitter API pattern. The following table helps describe the relationship between events in the v3.x series and events in the v4.x series.

Event Name (v4) Event Name (v3) Description
disconnected disconnect The client is not connected to the platform. This is a steady state - no attempt to connect is occurring.
connecting connecting / attempting_reconnect The client is in the process of connecting to the platform.
authenticated authenticated The client has authenticated with the platform. The rtm.connect or rtm.start response is emitted as an argument. This is a sub-state of connecting.
connected The client is connected to the platform and incoming events will start being emittied.
ready open The client is ready to send outgoing messages. This is a sub-state of connected
disconnecting The client is no longer connected to the platform and cleaning up its resources. It will soon transition to disconnected.
reconnecting The client is no longer connected to the platform and cleaning up its resources. It will soon transition to connecting.
error ws_error An error has occurred. The error is emitted as an argument. The v4 event is a superset of the v3 event. To test whether the event is a websocket error, check error.code === ErrorCodes.RTMWebsocketError
unable_to_rtm_start unable_to_rtm_start A problem occurred while connecting, a reconnect may or may not occur. Use of this event is discouraged since disconnecting and reconnecting are more meaningful.
slack_event An incoming Slack event has been received. The event type and event body are emitted as the arguments.
{type} {type} An incoming Slack event of type {type} has been received. The event is emitted as an argument. An example is message for all message events
{type}::{subtype} {type}::{subtype} An incoming Slack event of type {type} and subtype {subtype} has been received. The event is emitted as an argument. An example is message::bot_message for all bot messages.
raw_message raw_message A websocket message arrived. The message (unparsed string) is emitted as an argument. Use of this event is discouraged since slack_event is more useful.
ws_opening This event is no longer emitted, and the state of the underlying websocket is considered private.
ws_opened This event is no longer emitted, and the state of the underlying websocket is considered private.
ws_close This event is no longer emitted, and the state of the underlying websocket is considered private.

Proxy Support with agent

In order to pass outgoing requests from WebClient or RTMClient through an HTTP proxy, you'll first need to install an additional package in your application:

$ npm install --save https-proxy-agent

Next, use the agent option in the client constructor to configure with your proxy settings.

const HttpsProxyAgent = require('https-proxy-agent');
const { WebClient, RTMClient } = require('@slack/client');

// in this example, we read the token from an environment variable. its best practice to keep sensitive data outside
// your source code.
const token = process.env.SLACK_TOKEN;

// its common to read the proxy URL from an environment variable, since it also may be sensitive.
const proxyUrl = process.env.http_proxy || 'http://12.34.56.78:9999';

// To use Slack's Web API:
const web = new WebClient(token, { agent: new HttpsProxyAgent(proxyUrl) });

// To use Slack's RTM API:
const rtm = new RTMClient(token, { agent: new HttpsProxyAgent(proxyUrl) });

// NOTE: for a more complex proxy configuration, see the https-proxy-agent documentation:
// https://github.com/TooTallNate/node-https-proxy-agent#api

Custom TLS Configuration

You may want to use a custom TLS configuration if your application needs to send requests through a server with a self-signed certificate.

Example:

const { WebClient, RTMClient } = require('@slack/client');

// in this example, we read the token from an environment variable. its best practice to keep sensitive data outside
// your source code.
const token = process.env.SLACK_TOKEN;

// Configure TLS options
const tls = {
  key: fs.readFileSync('/path/to/key'),
  cert: fs.readFileSync('/path/to/cert'),
  ca: fs.readFileSync('/path/to/cert'),
};

const web = new WebClient(token, { slackApiUrl: 'https://fake.slack.com/api', tls });
const rtm = new RTMClient(token, { slackApiUrl: 'https://fake.slack.com/api', tls });
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