Twig Filters & Functions

FOSSBilling uses Twig across themes, email templates, and PDFs. This page lists the project-specific and third-party filters and functions you can rely on while building against it.

Standard Twig

FOSSBilling includes all default Twig filters, plus the Intl Extra Extension for internationalization and the Markdown Extra Extension for Markdown rendering.

Common bundled filters include:

Filter	Description
format_currency	Format a number as currency, for example {{ 29.99 | format_currency('USD') }}.
format_date	Format a date using the configured locale and date format.
format_datetime	Format a date and time using the configured locale and time zone.
markdown_to_html	Convert Markdown to HTML with FOSSBilling's safe CommonMark renderer.

FOSSBilling Custom Filters

Project-specific filters and functions are defined in these classes:

• FOSSBilling\Twig\Extension\ApiExtension
• FOSSBilling\Twig\Extension\FOSSBillingExtension
• FOSSBilling\Twig\Extension\LegacyExtension
• FOSSBilling\Twig\Extension\DebugBarExtension

Translation & Localization

Filter	Description
trans	Translate a string using FOSSBilling's translation system.
timeago	Show how long ago a date was (e.g., "2 hours ago"). Accepts ISO 8601 format.
daysleft	Show days until a date. Accepts ISO 8601 format.
period_title	Display a translated period title (e.g., 1M → "1 Month").
ip_country_name	Show the country name for an IP address.
ip_country_code	Show the ISO 2-letter country code for an IP address.

URLs & Links

Filter	Description
url	Generate a URL for the current area, or pass area: 'admin' / area: 'client'.
api_url	Generate a URL for an API endpoint. Defaults to the current area; pass role: 'admin', role: 'client', or role: 'guest' when needed.

Assets & Resources

Filter	Description
asset_url	Get the URL for a theme asset.
library_url	Get the URL for the library folder.
mod_asset_url	Get the URL for a module asset. Use the asset path as the filtered value and the module name as the argument.
script_tag	Generate an HTML <script> tag.
stylesheet_tag	Generate an HTML <link> tag for CSS.

Utilities

Filter	Description
file_size	Convert bytes to a human-readable size (KB, MB, GB, etc.).
hash	Hash a value. Defaults to xxh128; pass another PHP-supported algorithm if needed.
truncate	Truncate a string to a maximum length.

FOSSBilling Custom Functions

Function	Description
fb_api	Refer to JavaScript Wrapper for documentation.
fb_api_form	Refer to JavaScript Wrapper for documentation.
fb_api_link	Refer to JavaScript Wrapper for documentation.
render_widgets	Render widgets registered for a slot.
svg_sprite	Render the current theme's SVG icon sprite when available.
has_permission	Check whether the logged-in admin has a module permission.
antispam_honeypot	Return the antispam honeypot configuration array.

Usage Examples

{# Format money #}
{{ 29.99 | format_currency('USD') }}  {# $29.99 #}

{# Generate URL #}
<a href="{{ 'client/manage' | url }}">Manage</a>                   {# client area #}
<a href="{{ 'client/manage' | url({area: 'admin'}) }}">Manage</a>  {# admin area #}

{# Generate API URL #}
{{ 'profile/update' | api_url }}
{{ 'client/login' | api_url(role: 'guest') }}

{# Parse Markdown #}
{{ product.description | markdown_to_html }}

{# Time ago #}
{{ order.created_at | timeago }}  {# 2 hours ago #}

{# Theme and module assets #}
<link rel="stylesheet" href="{{ 'css/theme.css'|asset_url }}">
<script src="{{ 'js/widget.js'|mod_asset_url('Example') }}"></script>

{# API form handled by Api/API.js #}
<form action="{{ 'profile/update'|api_url }}" {{ fb_api_form({ message: 'Saved'|trans }) }}>
  <input type="text" name="first_name">
  <button type="submit">{{ 'Save'|trans }}</button>
</form>

{# API link with a confirmation modal #}
<a href="{{ 'client/delete'|api_url(query: { id: client.id }, role: 'admin') }}"
   {{ fb_api_link({ modal: { type: 'confirm', title: 'Are you sure?'|trans }, reload: true }) }}>
  {{ 'Delete'|trans }}
</a>

See JavaScript API Wrapper for the data-fb-api options and CSRF behavior.