# Jinja filters

In addition to the [built-in Jinja filters](https://jinja.palletsprojects.com/templates/#filters) Atfinity defines more useful filters you can use in your templates:

| Name                        | Description                                                                                                                                                   |
| --------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `value_or_nothing`          | Returns an empty string if the value is `None`.                                                                                                               |
| `is_known`                  | Returns `True` if the value is not `None` (i.e. known).                                                                                                       |
| `is_unknown`                | Returns `True` if the value is `None` (i.e. unknown).                                                                                                         |
| `format_date`               | Formats a date with the given format string, e.g. `{{p.date_of_birth \| format_date('DD/MM/YYYY')}}`. Uses the document language.                             |
| `format_date_speaking`      | Formats a date in a human-readable format (`D. MMMM YYYY`). Uses the document language.                                                                       |
| `format_date_time`          | Formats a datetime with optional `date_format` and `time_format` arguments. Uses the document language.                                                       |
| `format_date_time_speaking` | Formats a datetime in a human-readable format. Uses the document language.                                                                                    |
| `yyyymmdd`                  | Converts a date to the `yyyyMMdd` string format.                                                                                                              |
| `yes_or_nothing`            | Returns `"Yes"` for `True`, empty string otherwise.                                                                                                           |
| `yes_or_no`                 | Returns `"Yes"` for `True`, `"No"` for `False`.                                                                                                               |
| `skip_digits`               | Removes all digits from a string.                                                                                                                             |
| `extract_digits`            | Returns only the digits from a string.                                                                                                                        |
| `format_map`                | Formats a string using named placeholders, e.g. `{{template_string \| format_map(name='Thorben')}}`. Missing placeholders are left as-is.                     |
| `deep_get`                  | Retrieves a nested value from a dictionary using a dot-separated key path, e.g. `{{data \| deep_get('address.city')}}`. Returns `None` if any key is missing. |
| `to_ascii`                  | Converts a Unicode string to ASCII by removing accents and transliterating ligatures (e.g. `ü` → `u`, `ß` → `ss`).                                            |


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