sequence generator

Author: Hage Yaapa

db.json

@@ -1,6 +1,6 @@
 {
   "ids": {
-    "Color": 12
+    "Color": 14
   },
   "models": {
     "Color": {
@@ -14,7 +14,9 @@
       "8": "{\"id\":8,\"value\":\"lolol\"}",
       "9": "{\"id\":9,\"value\":\"ahaha\"}",
       "10": "{\"id\":10,\"value\":\"greeen\"}",
-      "11": "{\"id\":11,\"value\":\"emerald\"}"
+      "11": "{\"id\":11,\"value\":\"emerald\"}",
+      "12": "{\"id\":12,\"value\":\"gold\"}",
+      "13": "{\"id\":13,\"value\":\"gold\"}"
     }
   }
 }

lib/sequence-generator.js

@@ -0,0 +1,60 @@
+'use strict';
+
+const { decorate, metadata, param } = require('../lib/helpers.js');
+const context = require("@loopback/context");
+const rest = require("@loopback/rest");
+const SequenceActions = rest.RestBindings.SequenceActions;
+
+module.exports = function (options) {
+  const { name: sequenceName, handler } = options;
+  let classes = {};
+  classes[sequenceName] = class {
+    constructor(findRoute, parseParams, invoke, send, reject) {
+      this.findRoute = findRoute;
+      this.parseParams = parseParams;
+      this.invoke = invoke;
+      this.send = send;
+      this.reject = reject;
+    }
+    async handle(context) {
+      const sequence = {
+        findRoute: this.findRoute,
+        parseParams: this.parseParams,
+        invoke: this.invoke,
+        send: this.send,
+        reject: this.reject
+      };
+      try {
+        if (handler) {
+          handler.call(sequence, context);
+        } else {
+          const { request, response } = context;
+          const route = this.findRoute(request);
+          const args = await this.parseParams(request, route);
+          const result = await this.invoke(route, args);
+          this.send(response, result);
+        }
+      }
+      catch (err) {
+        this.reject(context, err);
+      }
+    }
+  };
+
+  let SequenceClass = classes[sequenceName];
+  SequenceClass.sequenceName = sequenceName;
+  Object.defineProperty(SequenceClass, 'name', { writable: true });
+  SequenceClass.name = sequenceName;
+  Object.defineProperty(SequenceClass, 'name', { writable: false });
+
+  SequenceClass = decorate([
+    param(0, context.inject(SequenceActions.FIND_ROUTE)),
+    param(1, context.inject(SequenceActions.PARSE_PARAMS)),
+    param(2, context.inject(SequenceActions.INVOKE_METHOD)),
+    param(3, context.inject(SequenceActions.SEND)),
+    param(4, context.inject(SequenceActions.REJECT)),
+    metadata('design:paramtypes', [Function, Function, Function, Function, Function])
+  ], SequenceClass);
+
+  return SequenceClass;
+}

server/sequence.js

@@ -1,39 +1,17 @@
 'use strict';
 
-const { decorate, metadata, param } = require('../lib/helpers.js');
-const context = require("@loopback/context");
-const rest = require("@loopback/rest");
-const SequenceActions = rest.RestBindings.SequenceActions;
-
-class MySequence {
-  constructor(findRoute, parseParams, invoke, send, reject) {
-    this.findRoute = findRoute;
-    this.parseParams = parseParams;
-    this.invoke = invoke;
-    this.send = send;
-    this.reject = reject;
-  }
-  async handle(context) {
+const generateSequence = require('../lib/sequence-generator.js');
+module.exports = generateSequence({
+  name: 'MySequence',
+  handler: async function (context) {
     try {
       const { request, response } = context;
       const route = this.findRoute(request);
       const args = await this.parseParams(request, route);
       const result = await this.invoke(route, args);
       this.send(response, result);
-    }
-    catch (err) {
+    } catch (err) {
       this.reject(context, err);
     }
   }
-};
-
-MySequence = decorate([
-  function (target, key) { context.inject(SequenceActions.FIND_ROUTE)(target, key, 0); },
-  function (target, key) { context.inject(SequenceActions.PARSE_PARAMS)(target, key, 1); },
-  function (target, key) { context.inject(SequenceActions.INVOKE_METHOD)(target, key, 2); },
-  function (target, key) { context.inject(SequenceActions.SEND)(target, key, 3); },
-  function (target, key) { context.inject(SequenceActions.REJECT)(target, key, 4); },
-  metadata("design:paramtypes", [Function, Function, Function, Function, Function])
-], MySequence);
-
-module.exports = MySequence;
+});