Blog Engine

081_blog.cell

// ============================================================================
// 081 — Blog Engine
// ============================================================================
// A simple blog with posts and listing.
//
// Run:   soma run 081_blog.cell demo
// Expect:
//   Published: Introduction to Soma
//   Published: Building Web Apps
//   Published: State Machines 101
//   === Blog Posts (newest first) ===
//   [3] State Machines 101 by Carol
//   [2] Building Web Apps by Bob
//   [1] Introduction to Soma by Alice

cell Blog {

    memory {
        posts: Map<String, String> [persistent, consistent]
        meta: Map<String, Int> [persistent, consistent]
    }

    on publish(title: String, author: String, body: String) {
        let current = meta.get("next_id")
        if current == () {
            meta.set("next_id", 1)
        }
        let id = meta.get("next_id")
        meta.set("next_id", id + 1)
        let id_str = to_string(id)

        let post = map("id", id, "title", title, "author", author, "body", body)
        posts.set(id_str, to_json(post))
        return post
    }

    on list_posts() {
        let keys = posts.keys()
        let result = list()
        for key in keys {
            result = list(result, from_json(posts.get(key)))
        }
        return result |> sort_by("id", "desc")
    }

    on get_post(id: String) {
        let raw = posts.get(id)
        if raw == () {
            return response(404, map("error", "post not found"))
        }
        return from_json(raw)
    }

    on demo() {
        let p1 = publish("Introduction to Soma", "Alice", "Soma is a declarative language...")
        print("Published: {p1.title}")

        let p2 = publish("Building Web Apps", "Bob", "With soma serve, you can...")
        print("Published: {p2.title}")

        let p3 = publish("State Machines 101", "Carol", "State machines define valid transitions...")
        print("Published: {p3.title}")

        let all = list_posts()
        print("=== Blog Posts (newest first) ===")
        for post in all {
            print("[{post.id}] {post.title} by {post.author}")
        }

        return "done"
    }
}