Jinja Filters Reference

Orchid registers 70+ custom Jinja2 filters in orchid/jinja_filters.py. Before writing Python logic inside a template, check here — the filter you need likely already exists.

How to use filters

{# Basic usage #}
{{ value | filter_name }}

{# With arguments #}
{{ value | filter_name(arg1, arg2) }}

{# Chained #}
{{ value | filter_one | filter_two }}

Formatting filters

Display and text

Filter	What it does
capitalize_words	Capitalizes every word: 'hello world' → 'Hello World'
capitalize_first	Capitalizes first character only
bool_readability	Converts boolean to 'Yes' / 'No' / '--'
bool_readability(true_text, false_text)	Custom true/false labels
clean_question_code	Removes pipes from question codes
clean_sort(attr)	Sorts a list of objects by attribute with error handling

Usage examples:

{{ name | capitalize_words }}
{{ field | bool_readability }}
{{ field | bool_readability('Active', 'Inactive') }}
{{ items | clean_sort('name') }}

Contact and address

Filter	Output
address	Multi-line formatted address (street, city, state, zip, country)
phone_readability	Formats as (555) 123-4567
email_logo_url	Public proxy URL for agency logos safe for emails

{{ contact | address }}
{{ user.phone | phone_readability }}
{{ agency | email_logo_url }}

Dates and times

Filter	Output
date_readability	January 15, 2025
time_readability	2:30 PM
from_utc(timezone)	Converts UTC datetime to local timezone

{{ case.created_at | date_readability }}
{{ event.time | time_readability }}
{{ ts | from_utc(timezone) }}

Money

Filter	Output
currency	$1,234.56

{{ amount | currency }}

Case and type mapping

Filter	What it does
case_type_filter	'surrogate' → 'GC Case', 'donor' → 'ED Case', etc.
case_type_short	'surrogate' → 'GC', 'donor' → 'ED', etc.
contract_role	'donor' → 'Egg Donor', 'surrogate' → 'Surrogate', etc.

{{ case.case_type | case_type_filter }}
{{ case.case_type | case_type_short }}
{{ role | contract_role }}

File and media filters

Filter	What it does
cloudfront	Generates a presigned CloudFront URL from an S3 key
file_icon	Returns a CSS class / icon name based on file extension
base64	Base64-encodes a string value

{{ doc.s3_key | cloudfront }}
{{ doc.filename | file_icon }}
{{ value | base64 }}

Caution

The cloudfront filter returns a presigned URL that expires. Never cache these URLs in static HTML. Always render them fresh on each request.

Security filters

Filter	What it does
sanitize_note	Strips dangerous HTML, allows safe tags (bold, italic, links)

{{ note.body | sanitize_note }}

Use sanitize_note whenever rendering user-provided text that may contain HTML. Never use | safe on raw user content.

Adding a new filter

Filters are registered in orchid/jinja_filters.py using the @filters.app_template_filter() decorator:

@filters.app_template_filter('my_filter')
def my_filter(value, arg1=None):
    """Brief docstring explaining what this filter does."""
    if value is None:
        return ''
    return str(value)

Rules for new filters:

• Always handle None input gracefully — templates frequently pass None
• Return a string (be explicit)
• Add the filter to this reference page after adding it to the code
• Keep filters pure — no database queries, no side effects