Twig Introductory Guide

PlusAuth uses Twig as the templating language for its Email and SMS templates. Twig is a powerful template engine that allows you to embed logic inside text and generate dynamic, personalized content (e.g., inserting usernames, applying conditions, formatting values).

This document provides an introductory guide to using Twig within PlusAuth. It highlights the supported syntax, available filters and functions (including es-toolkit utilities), and the differences from standard Twig.

For the complete reference, see the official Twig documentation .

Key Differences from Standard Twig

• Features like extends, block, import, and use are not supported in PlusAuth. Every template is self-contained.

• If you reference a variable that does not exist, it will resolve to null instead of throwing an error. This means you can safely use {{ user.profile.first_name }} without breaking the template if user or profile is missing.

• In addition to the built-in Twig filters/functions, all functions from es-toolkit are available as Twig filters and functions. Example:

  {{ "hello world"|camelCase }}
  {{ range(1,10)|sum }}

Basic Syntax

Twig has three types of delimiters:

• {{ ... }} — expressions (output the result)
• {% ... %} — statements (logic, loops, conditionals)
• {# ... #} — comments (ignored in output)

Example:

<h1>Hello {{ user.email }}</h1>

{% if user.email_verified %}
  <p>Your email is verified</p>
{% else %}
  <p>Please verify your email</p>
{% endif %}

{# This is a comment #}

Variables

Variables are provided by PlusAuth depending on context (user, application, session, etc.).

• Dot syntax is used to access nested values:

  {{ user.profile.family_name }}

• Missing variables resolve to null silently.

Operators

Twig supports a variety of operators to work with values and expressions. Operators can be combined and grouped with parentheses (...) for clarity.

Arithmetic Operators

{{ 1 + 2 }}       {# → 3 #}
{{ 5 - 3 }}       {# → 2 #}
{{ 2 * 3 }}       {# → 6 #}
{{ 8 / 2 }}       {# → 4 #}
{{ 7 % 3 }}       {# → 1 (modulus) #}
{{ 20 // 7 }}     {# → 2 (floor division) #}
{{ 2 ** 3 }}      {# → 8 (exponentiation) #}

Comparison Operators

{{ 5 == 5 }}      {# → true #}
{{ 5 != 3 }}      {# → true #}
{{ 4 > 3 }}       {# → true #}
{{ 3 < 2 }}       {# → false #}
{{ 5 >= 5 }}      {# → true #}
{{ 2 <= 1 }}      {# → false #}

Containment Operators

{{ 'a' in 'apple' }}        {# → true #}
{{ 2 in [1,2,3] }}          {# → true #}
{{ 'x' not in 'apple' }}    {# → true #}
{{ 'Hello' starts with 'H' }}  {# → true #}
{{ 'World' ends with 'd' }}    {# → true #}

Other Useful Operators

{{ "Hello " ~ "World" }}   {# → "Hello World" (concatenation) #}
{{ user.name ?? 'Guest' }} {# → first non-null value #}

Logic

Twig supports common logical operators. They evaluate to boolean values (true or false).

{% if user.active and user.verified %}
  User is active and verified
{% endif %}

{% if user.role == 'admin' or user.role == 'owner' %}
  Has elevated privileges
{% endif %}

{% if not user.suspended %}
  Account is in good standing
{% endif %}

Examples

{{ true and false }}   {# → false #}
{{ true or false }}    {# → true #}
{{ true xor true }}    {# → false (only one side must be true) #}
{{ not false }}        {# → true #}

Filters

Filters transform values and are applied with the | operator. You can chain multiple filters together to process a value step by step.

{{ user.email|lower }}
{{ "hello world"|title|replace({'Hello':'Hi'}) }}

Using es-toolkit as Filters

In PlusAuth, all es-toolkit functions are also available as Twig filters. When used as filters:

• The value being piped is passed as the first argument to the function.
• Any additional arguments are passed inside the parentheses after the filter name.

{{ "user_name"|camelCase }}        {# → userName #}
{{ 150|clamp(0, 100) }}            {# → 100 #}

This makes it easy to use es-toolkit utilities naturally in your templates.

Functions

Functions are called with parentheses and can take one or more arguments. They return values that can be rendered directly or passed through filters.

{{ range(1,5) }}   {# → [1,2,3,4,5] #}
{{ min(4, 10) }}   {# → 4 #}

Using es-toolkit as Functions

es-toolkit utilities are also available as Twig functions. Unlike filters (which implicitly pass the value on the left as the first argument), functions are called explicitly with all their arguments.

{{ isEmpty([]) }}               {# → true #}
{{ uniq([1,1,2,3]) }}           {# → [1,2,3] #}
{{ clamp(150, 0, 100) }}        {# → 100 #}
{{ padStart("42", 5, "0") }}    {# → "00042" #}

This allows you to directly leverage the full power of es-toolkit inside templates.

Whitespace Control

You can trim spaces around tags:

{%- if active -%}Yes{%- endif -%}