Initial commit.

server/services/follows.service.js

@@ -0,0 +1,153 @@
+"use strict";
+
+const { MoleculerClientError } = require("moleculer").Errors;
+const DbService = require("../mixins/db.mixin");
+
+module.exports = {
+	name: "follows",
+	mixins: [DbService("follows")],
+
+	/**
+	 * Default settings
+	 */
+	settings: {
+
+	},
+
+	/**
+	 * Actions
+	 */
+	actions: {
+
+		/**
+		 * Create a new following record
+		 * 
+		 * @actions
+		 * 
+		 * @param {String} user - Follower username
+		 * @param {String} follow - Followee username
+		 * @returns {Object} Created following record
+		 */
+		add: {
+			params: {
+				user: { type: "string" },
+				follow: { type: "string" },
+			},
+			handler(ctx) {
+				const { follow, user } = ctx.params;
+				return this.findByFollowAndUser(follow, user)
+					.then(item => {
+						if (item)
+							return this.Promise.reject(new MoleculerClientError("User has already followed"));
+
+						return this.adapter.insert({ follow, user, createdAt: new Date() })
+							.then(json => this.entityChanged("created", json, ctx).then(() => json));
+					});
+			}
+		},
+
+		/**
+		 * Check the given 'follow' user is followed by 'user' user.
+		 * 
+		 * @actions
+		 * 
+		 * @param {String} user - Follower username
+		 * @param {String} follow - Followee username
+		 * @returns {Boolean} 
+		 */
+		has: {
+			cache: {
+				keys: ["article", "user"]
+			},
+			params: {
+				user: { type: "string" },
+				follow: { type: "string" },
+			},
+			handler(ctx) {
+				return this.findByFollowAndUser(ctx.params.follow, ctx.params.user)
+					.then(item => !!item);
+			}
+		},
+
+		/**
+		 * Count of following.
+		 * 
+		 * @actions
+		 * 
+		 * @param {String?} user - Follower username
+		 * @param {String?} follow - Followee username
+		 * @returns {Number}
+		 */
+		count: {
+			cache: {
+				keys: ["article", "user"]
+			},
+			params: {
+				follow: { type: "string", optional: true },
+				user: { type: "string", optional: true },
+			},
+			handler(ctx) {
+				let query = {};
+				if (ctx.params.follow) 
+					query = { follow: ctx.params.follow };
+				
+				if (ctx.params.user) 
+					query = { user: ctx.params.user };
+
+				return this.adapter.count({ query });
+			}
+		},
+
+		/**
+		 * Delete a following record
+		 * 
+		 * @actions
+		 * 
+		 * @param {String} user - Follower username
+		 * @param {String} follow - Followee username
+		 * @returns {Number} Count of removed records
+		 */
+		delete: {
+			params: {
+				user: { type: "string" },
+				follow: { type: "string" },
+			},
+			handler(ctx) {
+				const { follow, user } = ctx.params;
+				return this.findByFollowAndUser(follow, user)
+					.then(item => {
+						if (!item)
+							return this.Promise.reject(new MoleculerClientError("User has not followed yet"));
+
+						return this.adapter.removeById(item._id)
+							.then(json => this.entityChanged("removed", json, ctx).then(() => json));
+					});
+			}
+		}
+	},
+
+	/**
+	 * Methods
+	 */
+	methods: {
+		/**
+		 * Find the first following record by 'follow' or 'user' 
+		 * @param {String} follow - Followee username
+		 * @param {String} user - Follower username
+		 */
+		findByFollowAndUser(follow, user) {
+			return this.adapter.findOne({ follow, user });
+		},
+	},
+
+	events: {
+		"cache.clean.follows"() {
+			if (this.broker.cacher)
+				this.broker.cacher.clean(`${this.name}.*`);
+		},
+		"cache.clean.users"() {
+			if (this.broker.cacher)
+				this.broker.cacher.clean(`${this.name}.*`);
+		}
+	}	
+};