app.js

(function () {
    const { Component } = owl;
    const { xml } = owl.tags;
    const { whenReady } = owl.utils;
    
    const { useRef, useSubEnv } = owl.hooks;

    // -------------------------------------------------------------------------
    // Model
    // -------------------------------------------------------------------------
    class TaskModel extends owl.core.EventBus {
        nextId = 1
        tasks = [];

        constructor(tasks) {
            super()
            for (let task of tasks) {
                this.tasks.push(task);
                this.nextId = Math.max(this.nextId, task.id + 1);
            }
        }

        addTask(title) {
            const newTask = {
                id: this.nextId++,
                title: title,
                isCompleted: false,
            };
            this.tasks.unshift(newTask);
            this.trigger('update');
        }

        toggleTask(id) {
            const task = this.tasks.find(t => t.id === id);
            task.isCompleted = !task.isCompleted;
            this.tasks.sort(function (a,b) {
                if (a.isCompleted) {
                    if (b.isCompleted) {
                        a.title.localeCompare(b.title)
		    } else {
			return 1;
		    }
		} else {
                    if (b.isCompleted) {
			return -1;
		    } else {
                        a.title.localeCompare(b.title)
		    }
		}
	    });
            this.trigger('update')
        }
 
        deleteTask(id) {
            const index = this.tasks.findIndex(t => t.id === id);
            this.tasks.splice(index, 1);
            this.trigger('update');
        }
    }

    class StoredTaskModel extends TaskModel {
        constructor(storage) {
            const tasks = storage.getItem("todoapp");
            super(tasks ? JSON.parse(tasks) : []);
            this.on('update', this, () => {
                storage.setItem("todoapp", JSON.stringify(this.tasks))
            });
        }
    }

    // -------------------------------------------------------------------------
    // Task Component
    // -------------------------------------------------------------------------
    const TASK_TEMPLATE = xml /* xml */`
      <div class="task" t-att-class="props.task.isCompleted ? 'done' : ''">
        <input type="checkbox" t-att-checked="props.task.isCompleted" t-on-click="toggleTask"/>
        <span><t t-esc="props.task.title"/></span>
        <span class="delete" t-on-click="deleteTask">🗑</span>
      </div>`;

    class Task extends Component {
        static template = TASK_TEMPLATE;
    
        toggleTask() {
            this.env.model.toggleTask(this.props.task.id);
        }

        deleteTask() {
            this.env.model.deleteTask(this.props.task.id);
        }
    }

    // -------------------------------------------------------------------------
    // App Component
    // -------------------------------------------------------------------------
    const APP_TEMPLATE = xml /* xml */`
    <div class="todo-app">
    <input placeholder="Enter a new task" t-on-keyup="addTask" t-ref="add-input"/>  
    <div class="task-list">
          <t t-foreach="env.model.tasks" t-as="task" t-key="task.id">
            <Task task="task"/>
          </t>
       </div>
    </div>`;

    class App extends Component {
        static template = APP_TEMPLATE;
        static components = { Task };

        inputRef = useRef("add-input");
        
        constructor() {
            super();
            
            const model = new StoredTaskModel(this.env.localStorage);
            model.on('update', this, this.render);
            useSubEnv({model});
        }

        mounted() {
            this.inputRef.el.focus();
        }

        addTask(ev) {
            // 13 is keycode for ENTER
            if (ev.keyCode === 13) {
                const title = ev.target.value.trim();
                ev.target.value = "";
                if (title) {
                    this.env.model.addTask(title);
                }
            }
        }

    }

    // Setup code
    function setup() {
      App.env.localStorage = window.localStorage;
      const app = new App();
      app.mount(document.body);
    }
    
    whenReady(setup);
})();