efficiently loading jquery and javascript files in django templates

Question

In one of my django projects i am using lots of custom jquery scripts and lots of open source jquery plugins. Now if i load all the jquery scripts in my base template, I will be loading a lot of unused javascript code in the templates which do not require any/some of the jquery files that have been loaded which will affect the page load time of that particular template.

So, The current approach i am taking is

• Load the basic jquery scripts in the base template (ones that are required by each template)
• Define a block for js in the base template and selectively load needed javascripts for each templates.e.g {% block selective_js %}{% endblock selective_js %}

The above approach works well, but the only problem I see is a lot of code repetition in the templates. Say for example:

• I have the following javascript files

  <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.1.js"></script>
  <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.2.js"></script>
  <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.3.js"></script>
  <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.4.js"></script>
  <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.5.js"></script>
  

• Now in more than one templates, I need all the above mentioned javascript files included and also want to initialize some of the methods within the mentioned scripts. So currently, I have to do this in all the templates:

  {% block selective_js %}
  
      <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.1.js"></script>
      <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.2.js"></script>
      <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.3.js"></script>
      <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.4.js"></script>
      <script type="text/javascript" src="{{ STATIC_URL }}js/jquery.5.js"></script>
  
      <!-- Initialize Methods -->
      <script type="text/javascript">
          $(document).ready(function() {
              $('some_element').initializeScript();
          });
      </script>
  
  {% endblock selective_js %}
  

Which means there is a lot of code repetition within the templates.

Question:

How can I prevent repeating code without having to load unused javascript code in an efficient manner ?

Answer 1

Define a block in your parent template where you include your "default" JavaScript files and then extend the block as needed:

# base.html

{% block js %}
    <script src="{{ STATIC_URL }}js/jquery.1.js"></script>
    <script src="{{ STATIC_URL }}js/jquery.2.js"></script>
    <script src="{{ STATIC_URL }}js/jquery.3.js"></script>
    <script src="{{ STATIC_URL }}js/jquery.4.js"></script>
    <script src="{{ STATIC_URL }}js/jquery.5.js"></script>
{% endblock %}


# child.html

{% extends "base.html %}

{% block js %}
    {{ block.super }} {# includes previous content in block #}
    {# view-specific imports here #}
{% endblock %}

This will prevent repetition in your templates. Check out: template inheritance for more information about templates and inheritance.

You can use django-compressor to combine and minify CSS and JS imports and cache them for efficient loading.