javascript模板引擎有什么意义？ [关闭]

Question

I know the answers people typically give, but I need a concrete example as to why they are needed.

The latest impression I'm getting (mostly from underscore.js) is that it makes the code more PHP like in that you can have <% %> like ?> in PHP

The idea is to make your code less like spaghetti and have a clear difference between presentation and logic. That's what everyone says, but I'm not sure why this warrants the need for a templating engine.

Why can't you just do this in pure javascript? All you need is a function that takes in data as arguments and you can do keep javascript syntax without inventing a new language, which seems ridiculous. For example you can just do:

populateTable(obj) {
    $('#model').html('
    <h2>' + obj.title + '</h2>' +
    <ul> ... </ul>
}

This seems fine to me. It's a function dedicated to rendering a table using some model data that you pass into it. Why do we need to invent new syntax?

Answer 1

One reason for me is that I prefer writing this:

<div class="entry">
  <h1>{{title}}</h1>
  <div class="body">
    {{body}}
  </div>
</div>

Over writing this:

var createEntryTemplate = function(obj) {
  return '<div class="entry">' +
    '<h1>' + obj.title + '</h1>' +
    '<div class="body">' + obj.body +
    '</div>' +
    '</div>';
};

The latter method is also more error prone - if not for you then maybe for another person. Imagine you're working with a designer who doesn't have a lot of programming experience and he needs to go in and replace a significant chunk of HTML.

Oh crap...