emailservice

Email Service

The service is responsible for sending an email with the order confirmation after checkout completion. The HTML generation required for the Email formatting is done using ballerina's built-in XML feature. The email-sending part is handled by the Gmail connector.

service "EmailService" on new grpc:Listener(9097) {
    remote function SendOrderConfirmation(stubs:SendOrderConfirmationRequest request) returns stubs:Empty|error {

        gmail:MessageRequest messageRequest = {
            recipient: request.email,
            subject: "Your Confirmation Email",
            messageBody: (check getConfirmationHtml(request.'order)).toString(),
            contentType: gmail:TEXT_HTML
        };
        gmail:Message|error sendMessageResponse = self.gmailClient->sendMessage(messageRequest);
        ...
        return {};
    }
    
    function getConfirmationHtml(OrderResult res) returns xml {
        ...
        xml items = from stubs:OrderItem item in result.items
            select xml `<tr>
                <td>#${item.item.product_id}</td>
                <td>${item.item.quantity}</td> 
                ...
                </tr>`;
                
        items = xml `<tr>
              <th>Item No.</th>
              <th>Quantity</th> 
              <th>Price</th>
            </tr>` + items;   
        
        ...
        
        xml emailContent = ...

        return emailContent;
    }
}

This service requires sensitive Gmail credentials, to use in the Gmail connector. This also is done with the help of Ballerina's configurable feature. The sample code and the Config.toml file can be found below.

type GmailConfig record {|
    string refreshToken;
    string clientId;
    string clientSecret;
|};

configurable GmailConfig gmail = ?;

[gmail]
refreshToken = ""
clientId = ""
clientSecret =  ""

However, as this Config.toml contains sensitive information we need to load this as a secret to the kubernetes cluster. You can do that by adding the following entry to the Cloud.toml.

[[cloud.secret.files]]
file="./Config.toml"