mirror of
https://github.com/adambard/learnxinyminutes-docs.git
synced 2024-11-25 20:14:30 +03:00
269 lines
5.3 KiB
Markdown
269 lines
5.3 KiB
Markdown
---
|
|
language: Jinja
|
|
contributors:
|
|
- ["Adaías Magdiel", "https://github.com/AdaiasMagdiel"]
|
|
filename: learn-jinja.j2
|
|
---
|
|
|
|
## Getting Started with Jinja
|
|
|
|
Jinja is a fast, expressive, and extensible templating engine for Python
|
|
applications.
|
|
|
|
Jinja includes a lot of functionalities, such as:
|
|
- Template inheritance and inclusion;
|
|
- Defining and importing macros within templates;
|
|
- Security mechanisms to prevent XSS attacks;
|
|
- A sandboxed environment that can safely render untrusted templates;
|
|
- Extensible filters, tests, functions, and even syntax.
|
|
|
|
A Jinja template is simply a text file. Jinja doesn't require a specific
|
|
extension, but it's common to use `.j2` or `.jinja` to make it easier for
|
|
some IDEs.
|
|
|
|
There are a few kinds of delimiters. The default Jinja delimiters are configured
|
|
as follows:
|
|
|
|
- `{% ... %}` for Statements
|
|
- `{{ ... }}` for Expressions to print to the template output
|
|
- `{# ... #}` for Comments not included in the template output
|
|
|
|
```jinja
|
|
{# This is an example of a comment. #}
|
|
|
|
{#
|
|
You can use this syntax
|
|
to write multiline comments
|
|
as well.
|
|
#}
|
|
```
|
|
|
|
|
|
## VARIABLES
|
|
|
|
```jinja
|
|
{# You have the option to access variables from the context passed to the template #}
|
|
|
|
{{ foo }}
|
|
|
|
{#
|
|
Additionally, you can use a dot (.) to access attributes of a variable or
|
|
use Python syntax, using []
|
|
#}
|
|
|
|
{{ foo.bar }}
|
|
{{ foo['bar'] }}
|
|
|
|
{# Within the template, you can define variables as well #}
|
|
|
|
{% set name = "Magdiel" %}
|
|
{{ name }}
|
|
```
|
|
|
|
## Loops
|
|
|
|
```html
|
|
<h1>Members</h1>
|
|
<ul>
|
|
{% for user in users %}
|
|
<li>{{ user.username }}</li>
|
|
{% endfor %}
|
|
</ul>
|
|
|
|
|
|
<div>
|
|
{% for key, value in my_dict.items() %}
|
|
<p>{{ key }}</p> - <p>{{ value }}</p>
|
|
{% endfor %}
|
|
</div>
|
|
|
|
|
|
<div>
|
|
{% for idx, url in enumerate(urls) %}
|
|
<a href="{{ url }}">Go to url {{ idx + 1 }}</a>
|
|
{% endfor %}
|
|
</div>
|
|
```
|
|
|
|
## Conditionals
|
|
|
|
The if statement in Jinja is similar to the if statement in Python. It is
|
|
commonly used to check if a variable is defined, not empty, and not false in
|
|
its most basic form.
|
|
|
|
```html
|
|
{% if users %}
|
|
<ul>
|
|
{% for user in users %}
|
|
<li>{{ user.username }}</li>
|
|
{% endfor %}
|
|
</ul>
|
|
{% endif %}
|
|
|
|
|
|
{# For multiple branches, elif and else can be used like in Python. #}
|
|
|
|
|
|
{% if message.status == "error" %}
|
|
<p class="text-red-400">{{ message.content }}</p>
|
|
{% elif message.status == "success" %}
|
|
<p class="text-green-400">{{ message.content }}</p>
|
|
{% else %}
|
|
<p class="text-blue-400">{{ message.content }}</p>
|
|
{% endif %}
|
|
```
|
|
|
|
## Template Inheritance
|
|
|
|
One of the most powerful features of Jinja is template inheritance. You can
|
|
create a base layout with predefined blocks that you can extend in another file
|
|
and override with your own content.
|
|
|
|
```html
|
|
{# file: base.html.j2 #}
|
|
|
|
<!DOCTYPE html>
|
|
<html lang="en">
|
|
<head>
|
|
{% block head %}
|
|
<meta charset="UTF-8">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<title>{% block title %}{% endblock title %} - Learning Jinja</title>
|
|
{% endblock head %}
|
|
</head>
|
|
<body>
|
|
<main>
|
|
{% block content %}{% endblock %}
|
|
{# the endblock tag doesn't need the name of the block #}
|
|
</main>
|
|
</body>
|
|
</html>
|
|
|
|
|
|
|
|
{# file: child.html.j2 #}
|
|
|
|
{% extends "base.html.j2" %}
|
|
|
|
{% block head %}
|
|
{{ super() }}
|
|
<script>
|
|
console.log("There's a console.log here")
|
|
</script>
|
|
{% endblock %}
|
|
|
|
{% block title %}Home{% endblock %}
|
|
|
|
{% block content %}
|
|
<h1>Index</h1>
|
|
<p>Welcome to my home homepage.</p>
|
|
{% endblock %}
|
|
|
|
|
|
|
|
{# RESULT #}
|
|
|
|
<!DOCTYPE html>
|
|
<html lang="en">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<title>Home - Learning Jinja</title>
|
|
<script>
|
|
console.log("There's a console.log here")
|
|
</script>
|
|
</head>
|
|
<body>
|
|
<main>
|
|
<h1>Index</h1>
|
|
<p>Welcome to my home homepage.</p>
|
|
</main>
|
|
</body>
|
|
</html>
|
|
```
|
|
|
|
### Including Content
|
|
|
|
You can include content from another template on your current template using
|
|
the `{% include "template/path" %}` tag.
|
|
|
|
```html
|
|
{# file: footer.html.j2 #}
|
|
|
|
<footer>
|
|
<p>© 2024 - John Doe</p>
|
|
</footer>
|
|
|
|
|
|
|
|
{# file: index.html.j2 #}
|
|
...
|
|
<body>
|
|
<main>
|
|
<h1>Hi! I'm John Doe!</h1>
|
|
</main>
|
|
{% include "footer.html.j2" %}
|
|
</body>
|
|
...
|
|
|
|
|
|
|
|
{# RESULT #}
|
|
|
|
...
|
|
<body>
|
|
<main>
|
|
<h1>Hi! I'm John Doe!</h1>
|
|
</main>
|
|
<footer>
|
|
<p>© 2024 - John Doe</p>
|
|
</footer>
|
|
</body>
|
|
...
|
|
```
|
|
|
|
Variables passed to the main template can also be used in the include, as the
|
|
included template has access to the context of the main template.
|
|
|
|
```html
|
|
{# file: greetings.html.j2 #}
|
|
|
|
<p>I'm the {{ name }} and i like to {{ hobby }}.</p>
|
|
|
|
|
|
|
|
{# file: index.html.j2 #}
|
|
|
|
{% set name = "Captain Nemo" %}
|
|
{% set hobby = "navigate through the depths of the ocean" %}
|
|
|
|
<div>
|
|
{% include "greetings.html.j2" %}
|
|
</div>
|
|
|
|
|
|
|
|
{# RESULT #}
|
|
|
|
<div>
|
|
<p>I'm the Captain Nemo and i like to navigate through the depths of the ocean.</p>
|
|
</div>
|
|
```
|
|
|
|
## Macros
|
|
|
|
Macros are basically like functions in another languages. You can define macros with or without arguments and reuse them in various parts of your template.
|
|
|
|
```html
|
|
{% macro input(value="", type="text", placeholder="") -%}
|
|
<input type="{{ type }}" value="{{ value }}" placeholder="{{ placeholder }}">
|
|
{%- endmacro %}
|
|
|
|
<p>{{ input(placeholder="Your username") }}</p>
|
|
<p>{{ input(type="password") }}</p>
|
|
```
|
|
|
|
## Official Documentation
|
|
|
|
To learn more, access the [official documentation](https://jinja.palletsprojects.com/en/).
|