Inline forms and row_prefix

When using Django inline forms, each row is an independent form instance. Use the __row_prefix__ placeholder to namespace Alpine state keys per row so each row manages its own state independently.

__row_prefix__ follows Django’s own inline field naming convention: <prefix>-<number>-<field>.

Dynamically added rows (via the “Add another” button) are handled automatically — core.js listens for the formset:added event and processes each new row the same way as on initial load.

Usage

class MyInlineForm(AdminAlpineMixin, forms.ModelForm):  # or FormAlpineMixin with custom resolvers
    my_field = forms.CharField(
        widget=forms.TextInput(attrs={
            "x-add-model-data": "__row_prefix__myField",
            "x-field-box-show": "__row_prefix__otherField",
        })
    )

At runtime, __row_prefix__ is replaced with a sanitized version of Django’s row identifier. Hyphens in the row ID are converted to underscores so the result is a valid JavaScript identifier for use with Alpine.js (e.g. items_0_myField, items_1_myField).

Resolution order

  1. Container ID — if the input is inside a tr.form-row or .inline-related element, that element’s id is used, with hyphens replaced by underscores.

    Example: container id items-0 → sanitized items_0 → __row_prefix__myField → items_0_myField.

  2. Element name attribute — if no container is found, the input’s name is parsed with the pattern prefix-number (e.g. items-0-title → prefix items-0), then sanitized.

    Example: name="items-0-my_field" → __row_prefix__myField → items_0_myField.

  3. Empty string — if neither source matches, __row_prefix__ is simply removed.

    Example: __row_prefix__myField → myField.

Empty form templates

Django includes an empty form template row (with __prefix__ in field names and IDs) for dynamically adding new inline rows. Elements containing __prefix__ are automatically skipped and never processed by core.js.

Multiple occurrences

All occurrences of __row_prefix__ in a single attribute value are replaced:

attrs={
    "x-form-row-show": "__row_prefix__fieldA && __row_prefix__fieldB !== ''",
}
# → x-show="items_0_fieldA && items_0_fieldB !== ''"