Templates In Backbone.js

Templates in Backbone.js are used to define the structure and layout of views.
They provide a convenient way to separate HTML markup from JavaScript code.
Backbone.js supports various template engines such as Underscore.js templates, Handlebars, and Mustache.
Templates can be precompiled for better performance.

1. What are Templates in Backbone.js?

Templates in Backbone.js are HTML markup combined with embedded JavaScript expressions or logic. They are used to define the structure and appearance of views, allowing developers to separate presentation concerns from application logic. Templates can contain placeholders for dynamic data that will be filled in when the view is rendered.

Example:

<!-- Example Template using Underscore.js -->
<script type="text/template" id="todo-template">
  <div class="todo">
    <input type="checkbox" class="toggle" <%= completed ? 'checked' : '' %>>
    <%= title %>
  </div>
</script>

In this example, an Underscore.js template is defined for rendering todo items. It contains placeholders for the todo title and completion status.

2. Why Use Templates in Backbone.js?

Using templates in Backbone.js promotes a clean separation of concerns between the presentation layer and application logic. It makes the code more maintainable and easier to understand by encapsulating HTML markup in separate template files. Templates also allow for reusability, as the same template can be used to render multiple views with different data.

Example:

// Example View Rendering with Template in Backbone.js
var TodoView = Backbone.View.extend({
  template: _.template($('#todo-template').html()),
  render: function() {
    this.$el.html(this.template(this.model.toJSON()));
    return this;
  }
});

In this example, a Backbone.js view called TodoView renders itself using an Underscore.js template.

3. Implementing Templates in Backbone.js

To implement templates in Backbone.js, developers can use template engines such as Underscore.js templates, Handlebars, or Mustache. They can define templates either inline within HTML script tags or in separate files. Templates are then compiled and rendered by Backbone.js views, which inject dynamic data into the template placeholders.

Example:

<!-- Example Template Compilation in Backbone.js -->
<script type="text/template" id="todo-template">
  <div class="todo">
    <input type="checkbox" class="toggle" <%= completed ? 'checked' : '' %>>
    <%= title %>
  </div>
</script>

In this example, an Underscore.js template is defined inline within an HTML script tag. It can be compiled and rendered by a Backbone.js view.

4. Conclusion

Templates in Backbone.js provide a convenient way to define the structure and layout of views. By separating HTML markup from JavaScript code, templates make the code more maintainable and easier to understand. They also promote reusability and enable efficient rendering of dynamic data.