learning-jsdp/ch07/mediator-event-aggregator.html at main · addyosmani/learning-jsdp · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Mediator Pattern with Event Aggregator Interactive Example</title>
    <style>
        button {
            margin-bottom: 10px;
        }
    </style>
</head>

<body>
    <h1>Mediator Pattern with Event Aggregator Interactive Example</h1>
    <button id="addEmployee">Add New Employee</button>
    <div id="app"></div>
    <script>
        // Event Aggregator
        class EventAggregator {
            constructor() {
                this.events = {};
            }

            on(event, callback) {
                this.events[event] = callback;
            }

            trigger(event, data) {
                if (this.events[event]) {
                    this.events[event](data);
                }
            }
        }

        const eventAggregator = new EventAggregator();

        // Mediator
        class OrgChart {
            constructor(eventAggregator) {
                this.eventAggregator = eventAggregator;
                this.employees = [];
                this.eventAggregator.on('employee:complete', this.assignManager.bind(this));
                this.eventAggregator.on('manager:save', this.saveEmployee.bind(this));
            }

            addNewEmployee() {
                this.getEmployeeDetail();
            }

            getEmployeeDetail() {
                const detailContainer = document.createElement('div');
                const nameInput = document.createElement('input');
                nameInput.placeholder = 'Employee Name';
                detailContainer.appendChild(nameInput);
                const roleInput = document.createElement('input');
                roleInput.placeholder = 'Employee Role';
                detailContainer.appendChild(roleInput);
                const submitBtn = document.createElement('button');
                submitBtn.textContent = 'Submit';
                detailContainer.appendChild(submitBtn);

                submitBtn.addEventListener('click', () => {
                    const employee = new Employee(nameInput.value, roleInput.value);
                    this.eventAggregator.trigger('employee:complete', employee);
                });

                document.getElementById('app').appendChild(detailContainer);
            }

            assignManager(employee) {
                const managerContainer = document.createElement('div');
                const managerInput = document.createElement('input');
                managerInput.placeholder = 'Manager Name';
                managerContainer.appendChild(managerInput);
                const saveBtn = document.createElement('button');
                saveBtn.textContent = 'Save';
                managerContainer.appendChild(saveBtn);

                saveBtn.addEventListener('click', () => {
                    employee.manager = managerInput.value;
                    this.eventAggregator.trigger('manager:save', employee);
                });

                document.getElementById('app').appendChild(managerContainer);
            }

            saveEmployee(employee) {
                employee.save();
                this.employees.push(employee);
                console.log('Employee saved:', employee);
            }
        }

        // Employee class
        class Employee {
            constructor(name, role) {
                this.name = name;
                this.role = role;
                this.manager = null;
            }

            save() {
                console.log(`${this.name} (${this.role}) saved with manager ${this.manager}`);
            }
        }

        // Instantiate the OrgChart mediator with the EventAggregator
        const orgChart = new OrgChart(eventAggregator);

        // Add event listener to the Add New Employee button
        document.getElementById('addEmployee').addEventListener('click', () => {
            orgChart.addNewEmployee();
        });

    </script>
</body>

</html>