如何更新使用离子框架制作的待办事项列表应用程序中的特定项目或任务

I'm making a todo list app using ionic framework with update feature. Whenever we click on an item a new update modal popups and ask for update.I have made till this point but don't know how to make it functional(means how to actually update the item) . I have searched all over the internet but didn't find anything helpful. I'm sharing the code of index.html,app.js and contollers.js Index.htmlI'm making a todo list app using ionic framewor