Template Engine

Azu uses Crinja, a Jinja2-compatible template engine.

Basic Syntax

Variables

Output variables with {{ }}:

<h1>{{ title }}</h1>
<p>{{ user.name }}</p>
<p>{{ items[0] }}</p>

Comments

{# This is a comment #}

{#
  Multi-line
  comment
#}

Control Structures

if / elif / else

{% if user.admin %}
  <span class="badge">Admin</span>
{% elif user.moderator %}
  <span class="badge">Moderator</span>
{% else %}
  <span class="badge">User</span>
{% endif %}

for

Loop over collections:

{% for item in items %}
  <li>{{ item.name }}</li>
{% endfor %}

{% for item in items %}
  <li>{{ item }}</li>
{% else %}
  <li>No items found</li>
{% endfor %}

Loop Variables:

Variable

Description

loop.index

Current iteration (1-indexed)

loop.index0

Current iteration (0-indexed)

loop.first

True on first iteration

loop.last

True on last iteration

loop.length

Total number of items

loop.revindex

Iterations until end (1-indexed)

{% for user in users %}
  <tr class="{% if loop.first %}first{% endif %}">
    <td>{{ loop.index }}</td>
    <td>{{ user.name }}</td>
  </tr>
{% endfor %}

for with conditions

{% for user in users if user.active %}
  <li>{{ user.name }}</li>
{% endfor %}

Template Inheritance

extends

Extend a base template:

{% extends "layouts/base.html" %}

block

Define overridable blocks:

<!-- layouts/base.html -->
<!DOCTYPE html>
<html>
<head>
  <title>{% block title %}Default Title{% endblock %}</title>
</head>
<body>
  {% block content %}{% endblock %}
</body>
</html>

<!-- pages/home.html -->
{% extends "layouts/base.html" %}

{% block title %}Home Page{% endblock %}

{% block content %}
<h1>Welcome!</h1>
{% endblock %}

super

Access parent block content:

{% block content %}
{{ super() }}
<p>Additional content</p>
{% endblock %}

Includes

include

Include another template:

{% include "partials/header.html" %}
{% include "partials/footer.html" %}

include with context

{% include "partials/user_card.html" with user=current_user %}
{% include "partials/item.html" with item=item, index=loop.index %}

include with ignore missing

{% include "partials/optional.html" ignore missing %}

Macros

Define macros

{% macro input(name, value="", type="text") %}
<input type="{{ type }}" name="{{ name }}" value="{{ value }}" class="form-input">
{% endmacro %}

Use macros

{{ input("username") }}
{{ input("email", user.email, "email") }}
{{ input("password", type="password") }}

Import macros

{% import "macros/forms.html" as forms %}
{{ forms.input("name") }}

Filters

Filters transform values:

{{ name | upper }}
{{ name | lower }}
{{ name | capitalize }}
{{ name | title }}

String Filters

Filter

Description

Example

upper

Uppercase

`{{ "hello"

lower

Lowercase

`{{ "HELLO"

capitalize

Capitalize first

`{{ "hello"

title

Title case

`{{ "hello world"

trim

Remove whitespace

`{{ " hello "

truncate(n)

Truncate to n chars

`{{ text

replace(a, b)

Replace substring

`{{ name

striptags

Remove HTML tags

`{{ html

Number Filters

Filter

Description

Example

abs

Absolute value

`{{ -5

round

Round number

`{{ 3.7

round(n)

Round to n decimals

`{{ 3.14159

List Filters

Filter

Description

Example

length

Get length

`{{ items

first

First item

`{{ items

last

Last item

`{{ items

join(sep)

Join with separator

`{{ items

sort

Sort list

`{{ items

reverse

Reverse list

`{{ items

Escape Filters

Filter

Description

escape / e

HTML escape

safe

Mark as safe (no escape)

urlencode

URL encode

Default Filter

{{ value | default("N/A") }}
{{ user.name | default("Anonymous") }}

Chaining Filters

{{ name | trim | lower | truncate(20) }}

Tests

Test values with is:

{% if number is even %}
{% if name is defined %}
{% if items is empty %}
{% if value is none %}
{% if text is string %}

Available Tests

Test

Description

defined

Variable is defined

undefined

Variable is undefined

none

Value is nil

empty

Collection is empty

even

Number is even

odd

Number is odd

string

Value is string

number

Value is number

iterable

Value is iterable

Operators

Comparison

{% if age >= 18 %}
{% if status == "active" %}
{% if name != "" %}

Logical

{% if user and user.active %}
{% if admin or moderator %}
{% if not banned %}

Math

{{ price * quantity }}
{{ total / items }}
{{ count + 1 }}
{{ index % 2 }}

String Concatenation

{{ first_name ~ " " ~ last_name }}

In Operator

{% if "admin" in roles %}
{% if user.id in allowed_ids %}

Whitespace Control

Remove whitespace with -:

{% for item in items -%}
  {{ item }}
{%- endfor %}

Raw Output

Disable processing:

{% raw %}
  This {{ will not }} be processed
{% endraw %}

Template Engine

Basic Syntax

Variables

Tags

Comments

Control Structures

if / elif / else

for

for with conditions

Template Inheritance

extends

block

super

Includes

include

include with context

include with ignore missing

Macros

Define macros

Use macros

Import macros

Filters

String Filters

Number Filters

List Filters

Escape Filters

Default Filter

Chaining Filters

Tests

Available Tests

Operators

Comparison

Logical

Math

String Concatenation

In Operator

Whitespace Control

Raw Output

See Also

hashtagBasic Syntax

hashtagVariables

hashtagTags

hashtagComments

hashtagControl Structures

hashtagif / elif / else

hashtagfor

hashtagfor with conditions

hashtagTemplate Inheritance

hashtagextends

hashtagblock

hashtagsuper

hashtagIncludes

hashtaginclude

hashtaginclude with context

hashtaginclude with ignore missing

hashtagMacros

hashtagDefine macros

hashtagUse macros

hashtagImport macros

hashtagFilters

hashtagString Filters

hashtagNumber Filters

hashtagList Filters

hashtagEscape Filters

hashtagDefault Filter

hashtagChaining Filters

hashtagTests

hashtagAvailable Tests

hashtagOperators

hashtagComparison

hashtagLogical

hashtagMath

hashtagString Concatenation

hashtagIn Operator

hashtagWhitespace Control

hashtagRaw Output

hashtagSee Also

Basic Syntax

Variables

Tags

Comments

Control Structures

if / elif / else

for

for with conditions

Template Inheritance

extends

block

super

Includes

include

include with context

include with ignore missing

Macros

Define macros

Use macros

Import macros

Filters

String Filters

Number Filters

List Filters

Escape Filters

Default Filter

Chaining Filters

Tests

Available Tests

Operators

Comparison

Logical

Math

String Concatenation

In Operator

Whitespace Control

Raw Output

See Also