README.md

Comment Service

The main function of the Comment service is to create and fetch comments of a post and the count of comments.

Database (comment)

Although noSQL database is used but a proper Schema is maintained.

ValidPostCollection

Attribute	Type	Description
_id	ObjectId	postId of a valid Post (Primary Key)

CommentCollection

Attribute	Type	Description
_id	ObjectId	commentId of the comment (Primary Key)
postId	ObjectId	postId of the post on which comment is made
userId	ObjectId	userId of the user who made the comment
text	string	the content of the comment

API Reference

Create a new comment on post with id postId and publishes a CommentCreatedEvent.

  POST /api/comment/:postId

Get the comments on a post with id postId

  POST /api/comment/:postId?anchorId=

Query Param	Type	Description
anchorId	string	The returned commentsId should be greater than anchorId. (pagination)

Returns the count of comments on a post with id postId.

  GET /api/comment/:postId/count

Gets the current user

  POST /api/auth/currentUser

Events

CommentCreatedEvent

It is fired whenever a new comment is created .

Attribute	Type	Description
commentId	string	_id field of a valid CommentCollection document

Handlers

Handlers consumes events from NATS stream and processes them.

PostCreated Handler

It captures the PostCreatedEvent and processes it and add the postId to the _id field of the ValidPostCollection .

Architecture Diagram