Simple todo application

Question

I have been learning HTML/JavaScript and CSS. I have gone through some of the online tutorials, PDFs and books as well. Though, now I am familiar with syntactical stuff, I wasn't sure how I should design or structure code, so I started with a small ToDo application. I didn't want to use any frameworks. As I am still learning, I thought I should spend sometime learning the basics before using any frameworks.

GitHub

{
(function (){
 //Create a modal, which contains an array to hold list of todos
 var modal = {
 init: function () {
 this.todolist = [];
 this.todolist = JSON.parse(localStorage.getItem("tododata"));
 if (this.todolist === null)
 this.todolist = [];
 },
 getTodoList: function () {
 return this.todolist;
 },
 setTodoState: function (intodoid) {
 //Set status
 this.todolist[intodoid].status === "closed" ?
 this.todolist[intodoid].status = "open" : this.todolist[intodoid].status = "closed";
 localStorage.setItem("tododata", JSON.stringify(this.todolist));
 },
 setNewTodo: function (inval) {
 this.todolist.push({
 id: this.todolist.length,
 name: inval,
 status: "open"
 });
 localStorage.setItem("tododata", JSON.stringify(this.todolist));
 this.myFirebaseRef.push({id: this.todolist.length, name: inval, status: "open"});
 },
 clearall: function () {
 this.todolist = [];
 }
 }
 //Create a View, which interacts with Controller and alters the display in HTML
 var view = {
 init: function () {
 this.todolst = $('#todolistelm');
 this.todolst.html(' ');
 view.render();
 $('#clearall').click(function () {
 localStorage.clear();
 controller.clearall();
 view.render();
 });
 },
 render: function () {
 var htmlStr = '';
 var clr = true;
 var todoelem = $('#todolistelm');
 todoelem.html('');
 if (controller.getTodoList().length === 0) {
 $("#cleanmsg").css("visibility", "visible");
 $("#displaysection").css("visibility", "hidden")
 } else {
 $("#cleanmsg").css("visibility", "hidden");
 $("#displaysection").css("visibility", "visible")
 }
 controller.getTodoList().forEach(function (todo) {
 //DOM elements
 var elemId = ' ';
 var lielem = $('<li></li>');
 var spanelem = $('<span></span>');
 var taskid = "#task" + todo.id;
 //Create <li> element and add required classes
 lielem.addClass("list-group-item");
 //Set status of the todo item
 todo.status === "closed" ? lielem.addClass("completed") : lielem.addClass("");
 //Set alternate color
 clr === true ? lielem.addClass("colored") : lielem.addClass("");
 clr = !clr;
 //Create <span> and add required classes and IDs
 spanelem.addClass("glyphicon");
 spanelem.addClass("glyphicon-ok pull-right");
 spanelem.addClass("todocomplete");
 spanelem.attr('id', "task" + todo.id);
 //Append span and name to <li>
 lielem.append(spanelem);
 lielem.append(todo.name);
 //Append <li> to main list
 $(todoelem).append(lielem);
 //Add event handlers
 $(taskid).click(function (todoid) {
 return function () {
 controller.setTodoState(todoid);
 view.render();
 };
 }(todo.id));
 });
 //Set focus on input textbox by default
 $('#intodo').focus();
 }
 };
 //Create a controller, which acts as a mediator between View and Modal
 var controller = {
 init: function () {
 //Initialize view and modal
 modal.init();
 view.init();
 },
 getTodoList: function () {
 return modal.getTodoList();
 },
 setTodoState: function (intodoid) {
 modal.setTodoState(intodoid);
 },
 setNewTodo: function (inval) {
 modal.setNewTodo(inval);
 },
 clearall: function () {
 modal.clearall();
 }
 };
 //Set ENTER key on the input text box
 $('#intodo').keypress(function (e) {
 if (((e.which && e.which == 13) ||
 (e.keyCode && e.KeyCode == 13)) &&
 $("#intodo").val().trim().length > 0) {
 controller.setNewTodo($("#intodo").val());
 view.render();
 $("#intodo").val('');
 }
 });
 //Set the controller to start the work
 controller.init();
})();
}

Can someone go through this code and let me know if this follows the best practices or not, as well as any areas that I should probably be focusing on?

Answer 1

From a quick once over:

• Your first line creates an anonymous function, it offers you the opportunity to pick a great function name that conveys to the reader what he is about to be exposed to like (function todoApp(){

• This

  init: function () {
   this.todolist = [];
   this.todolist = JSON.parse(localStorage.getItem("tododata"));
   if (this.todolist === null)
   this.todolist = [];
  },
  

  could be

  init: function () {
   this.todolist = JSON.parse(localStorage.getItem("tododata")) || [];
  }
  

  essentially you were overwriting this.todolist = [] with
  this.todolist = JSON.parse(localStorage.getItem("tododata"));
  furthermore you should never drop the curly braces after an if block

• You are copy pasting this line of code all over the place, you should have a dedicated function for this:
  localStorage.setItem("tododata", JSON.stringify(this.todolist));

• This:

  setTodoState: function (intodoid) {
   //Set status
   this.todolist[intodoid].status === "closed" ?
   this.todolist[intodoid].status = "open" : this.todolist[intodoid].status = "closed";
   localStorage.setItem("tododata", JSON.stringify(this.todolist));
  },
  

  has a few problems, intodoid is an unfortunate name because it is not lowerCamelCase and because it smells like Hungarian notation. Also the repetition of this.todolist[intodoid].status is too much. I would suggest something like this:

  toggleTodoState: function (todoId) {
   //Toggle status
   var status = this.todolist[todoId].status;
   this.todolist[todoId].status = status == "closed" ? "open" : "closed";
   updateTodoData();
  },