Javascript – Show pop-ups the most elegant way

angularjsjavascriptmodel-view-controllerpopupshow-hide

I have this AngularJS app. Everything works just fine.

Now I need to show different pop-ups when specific conditions become true, and I was wondering what would be the best way to proceed.

Currently I’m evaluating two options, but I’m absolutely open to other options.

Option 1

I could create the new HTML element for the pop-up, and append to the DOM directly from the controller.

This will break the MVC design pattern. I’m not happy with this solution.

Option 2

I could always insert the code for all the pop-ups in the static HTML file. Then, using ngShow, I can hide / show only the correct pop-up.

This option is not really scalable.

So I’m pretty sure there has to be a better way to achieve what I want.

Best Answer

Based on my experience with AngularJS modals so far I believe that the most elegant approach is a dedicated service to which we can provide a partial (HTML) template to be displayed in a modal.

When we think about it modals are kind of AngularJS routes but just displayed in modal popup.

The AngularUI bootstrap project (http://angular-ui.github.com/bootstrap/) has an excellent $modal service (used to be called $dialog prior to version 0.6.0) that is an implementation of a service to display partial's content as a modal popup.

Native deep cloning

It's called "structured cloning", works experimentally in Node 11 and later, and hopefully will land in browsers. See this answer for more details.

Fast cloning with data loss - JSON.parse/stringify

If you do not use Dates, functions, undefined, Infinity, RegExps, Maps, Sets, Blobs, FileLists, ImageDatas, sparse Arrays, Typed Arrays or other complex types within your object, a very simple one liner to deep clone an object is:

JSON.parse(JSON.stringify(object))

const a = {
  string: 'string',
  number: 123,
  bool: false,
  nul: null,
  date: new Date(),  // stringified
  undef: undefined,  // lost
  inf: Infinity,  // forced to 'null'
  re: /.*/,  // lost
}
console.log(a);
console.log(typeof a.date);  // Date object
const clone = JSON.parse(JSON.stringify(a));
console.log(clone);
console.log(typeof clone.date);  // result of .toISOString()

See Corban's answer for benchmarks.

Reliable cloning using a library

Since cloning objects is not trivial (complex types, circular references, function etc.), most major libraries provide function to clone objects. Don't reinvent the wheel - if you're already using a library, check if it has an object cloning function. For example,

lodash - cloneDeep; can be imported separately via the lodash.clonedeep module and is probably your best choice if you're not already using a library that provides a deep cloning function
AngularJS - angular.copy
jQuery - jQuery.extend(true, { }, oldObject); .clone() only clones DOM elements
just library - just-clone; Part of a library of zero-dependency npm modules that do just do one thing. Guilt-free utilities for every occasion.

ES6 (shallow copy)

For completeness, note that ES6 offers two shallow copy mechanisms: Object.assign() and the spread syntax. which copies values of all enumerable own properties from one object to another. For example:

var A1 = {a: "2"};
var A2 = Object.assign({}, A1);
var A3 = {...A1};  // Spread Syntax

Javascript – the best way to add options to a select from a JavaScript object with jQuery

The same as other answers, in a jQuery fashion:

$.each(selectValues, function(key, value) {   
     $('#mySelect')
         .append($("<option></option>")
                    .attr("value", key)
                    .text(value)); 
});