ballerinax/trigger.google.mail Ballerina library

Overview

The Gmail Ballerina Trigger supports to listen to the changes of Gmail mailbox such as receiving a new message, receiving a new thread, adding a new label to a message, adding star to a message, removing label from a message, removing star from a message, and receiving a new attachment with the following trigger methods: onNewEmail, onNewThread, onEmailLabelAdded, onEmailStarred, onEmailLabelRemoved,onEmailStarRemoved, onNewAttachment.

This module supports Gmail API v1.

Prerequisites

Before using this connector in your Ballerina application, complete the following:

1. Create a Google account. (If you already have one, you can use that.)

2. Obtain tokens

• Follow this guide

  Note : Enable Cloud Pub/Sub API or user setup service account with pubsub admin role. Create a service account with pubsub admin

Quickstart

To use the Gmail Trigger in your Ballerina application, update the .bal file as follows:

Step 1: Import the Gmail Ballerina Trigger library

Import the ballerinax/trigger.google.mail module into the Ballerina project.

import ballerinax/trigger.google.mail;

Step 2: Initialize the Gmail Webhook Listener

Initialize the Trigger by providing the listener config & port number/httpListener object.

mail:ListenerConfig config = {
    clientId: "xxxx",
    clientSecret: "xxxx",
    refreshUrl: "https://oauth2.googleapis.com/token",
    refreshToken: "xxxx",
    pushEndpoint: "xxxx",
    project: "xxxx"
};
listener mail:Listener webhookListener = new(config, 8090);

NOTE :

Here

• project is the Id of the project which is created in Google Cloud Platform to create credentials (clientId and clientSecret).
• pushEndpoint is the endpoint URL of the listener.

Step 3: Use the correct service type to implement the service

Initialize the GmailService as below.

service mail:GmailService on webhookListener {

    remote function onEmailLabelAdded(mail:ChangedLabel changedLabel) returns error? {
        return;
    }

    remote function onEmailLabelRemoved(mail:ChangedLabel changedLabel) returns error? {
        return;
    }

    remote function onEmailStarRemoved(mail:Message message) returns error? {
        return;
    }

    remote function onEmailStarred(mail:Message message) returns error? {
        log:printInfo(message.toString());
        return;
    }

    remote function onNewAttachment(mail:MailAttachment attachment) returns error? {
        return;
    }

    remote function onNewEmail(mail:Message message) returns error? {
        return;
    }

    remote function onNewThread(mail:MailThread thread) returns error? {
        return;
    }
}

Step 4: Provide remote functions corresponding to the events which you are interested on

The remote functions can be provided as follows.

remote function onNewEmail(mail:Message message) returns error? {
    log:printInfo("Received new email", eventPayload = message);
}