3.A] Describe the basics of the Django template system. How is it different from other template systems?
Answer:
Django’s template system is designed to separate the presentation layer of a web application from its data.
It allows developers to define the structure and presentation of web pages while keeping the data separate.
Components:
- Variables: Denoted by
{{ variable_name }}, these placeholders are replaced with actual values when the template is rendered. - Template Tags: Enclosed in
{% %}, these provide logic and control structures, such as loops ({% for item in item_list %}) and conditional statements ({% if condition %}). - Filters: Applied using the pipe character (
|), filters modify the display of variables. For example,{{ date|date:"F j, Y" }}formats the date variable.
Example:
<html>
<head><title>Ordering notice</title></head>
<body>
<p>Dear {{ person_name }},</p>
<p>Thanks for placing an order from {{ company }}. It's scheduled to ship on {{ ship_date|date:"F j, Y" }}.</p>
<p>Here are the items you've ordered:</p>
<ul>
{% for item in item_list %}
<li>{{ item }}</li>
{% endfor %}
</ul>
{% if ordered_warranty %}
<p>Your warranty information will be included in the packaging.</p>
{% endif %}
<p>Sincerely,<br />{{ company }}</p>
</body>
</html>
- Variables:
{{ person_name }},{{ company }},{{ ship_date }}are placeholders that are replaced with actual values. - Tags:
{% for item in item_list %}iterates over items, and{% if ordered_warranty %}conditionally displays content. - Filters:
{{ ship_date|date:"F j, Y" }}formats the date variable.
3. Usage:
- Creating Templates: You can define templates directly as strings or load them from files.
- Rendering Templates: Use the
render()method of aTemplateobject to combine the template with context data, producing a fully rendered HTML string.
Differences from Other Template Systems
1. Integrated with Django:
- Separation of Concerns: Django templates are specifically designed to work within Django’s framework, integrating tightly with Django’s data handling and view system. This contrasts with other systems that might be more standalone or less integrated.
2. Built-in Tags and Filters:
- Customizability: Django provides a comprehensive set of built-in template tags and filters and allows for the creation of custom tags and filters, offering flexibility and extensive functionality.
3. Security and Design:
- Auto-escaping: Django templates automatically escape data to prevent XSS attacks, which is a notable security feature compared to some other systems that require explicit escaping.
- Simplicity: The syntax for Django templates is designed to be easy to understand and use, focusing on simplicity and readability.