Posta

A lightweight social backend API built with SurrealDB for authors to manage their content.

Features

This project provides a simple yet powerful platform for users to:

Author Management: Secure sign-up and login functionality for new authors
Subscriptions: Curate your own feed by subscribing to your favorite authors
Comments: Create and edit comments and control who can comment on your own posts
Post Management: Create, edit, and delete own posts
Starring System: Like or star other authors' posts to show support and engagement
Full Text Search: Powerful text searching through all posts

Design

Schema graph:

Usage

Here are a handful of code snippets and usages.

New user

curl -X POST -H "Accept: application/json" -d '{
    "ns":"posta",
    "db":"posta",
    "ac":"Author",
    "user":"john.doe",
    "email_address":"john.doe@example.com",
    "pass":"123456"
}' http://localhost:8000/signup

User Signup

Implementation within Posta:

DEFINE ACCESS Author ON DATABASE TYPE RECORD
    SIGNIN (
        SELECT * FROM Author WHERE email IS $email AND crypto::argon2::compare(pass, $pass)
    )
    SIGNUP (
        CREATE Author CONTENT {
            name: $name,
            email_address: $email_address,
            pass: crypto::argon2::generate($pass),
        }
    );

ACCESS

New Post

Using a built-in function to make a new post

fn::Post::new($body, $title, $tags)

Function definition in schema:

DEFINE FUNCTION fn::Post::new($body: string, $title: string, $tags: array<string>) -> object {
    LET $post = CREATE ONLY Post CONTENT {
        body: $body,
        title: $title,
    } RETURN AFTER;

    FOR $tag IN $tags {
        LET $tag = string::lowercase($tag);
        -- Make new `Tag` if `$tag` doesn't exist
        IF (array::is_empty(SELECT * FROM Tag WHERE tag IS $tag)) {
            CREATE ONLY Tag CONTENT { tag: $tag };
        };

        LET $post_id = $post.id;
        LET $tag_id = (SELECT id FROM Tag WHERE tag IS $tag);

        RELATE $post_id->tagged->$tag_id;
    };

    RETURN $post;
} PERMISSIONS FULL;

FUNCTION

Edit Post

UPDATE $post_id MERGE {body: $body}

EVENT that checks for authorization and creates a diff object when a post is edited.

DEFINE EVENT post_edited ON TABLE Post WHEN $event IS "UPDATE" THEN {
    IF array::is_empty(SELECT id FROM published WHERE in IS $auth.id AND out IS $value.id) {
        THROW "Cannot edit unowned resource";
    };

    RELATE ($auth.id)->edited->($value.id) CONTENT {
        diff_ops: value::diff($before, $after)
    };
};

New Comment

Using SurrealQL to make a comment

RELATE ($auth.id)->comment->$post CONTENT { message: $message }

Text Search

Searching titles

SELECT * FROM Post WHERE title @@ 'SurrealDB';

Rank-searching for Post content

SELECT search::score(1) AS score FROM Post
    WHERE body @1@ 'graph-based database'
    ORDER BY score DESC;

Search functions

siph/posta