Fix #270: Resolve django_form limitations for multi-value and multi-select fields - #298
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Fix #270: Resolve django_form limitations for multi-value and multi-select fields#298Archmonger wants to merge 6 commits into
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…delMultipleChoiceField - Updated `components.ts` to accumulate duplicate FormData entries into arrays instead of silently dropping duplicates (as Object.fromEntries would do). - Updated `utils.py` convert_form_fields() to normalize MultipleChoiceField and ModelMultipleChoiceField values (absent/None -> empty list, single -> array). - Updated test forms to include MultipleChoiceField and ModelMultipleChoiceField in BasicForm and BootstrapForm for regression coverage.
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…d-trip assertions Following code review suggestions for PR #298: - New test_forms_utils.py: 10 unit tests covering None->[], single->[value], list->unchanged for MultipleChoiceField, ModelMultipleChoiceField, BooleanField/NullBooleanField, and CharField pass-through. - test_form_basic: explicit input_value assertions on multi-select and model multi-select fields after successful form submission, proving the FormData duplicate-key fix works end-to-end. - Fix pre-existing ruff import ordering issue in utils.py
…d-trip assertions Following code review suggestions for PR #298: - New test_forms_utils.py: 10 unit tests covering None->[], single->[value], list->unchanged for MultipleChoiceField, ModelMultipleChoiceField, BooleanField/NullBooleanField, and CharField pass-through. - test_form_basic: explicit input_value assertions on multi-select and model multi-select fields after successful form submission, proving the FormData duplicate-key fix works end-to-end. - Fix pre-existing ruff import ordering issue in utils.py
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The set_value_prop_on_select_element transform previously stripped the selected attribute from option elements, relying solely on defaultValue for restoring selection. Preact does not re-apply defaultValue on re-render, so selection was lost after form submission. Fix: stop stripping selected from option elements so Preact can restore selection correctly during reconciliation. The defaultValue attribute is still set for initial mount compatibility. Also removed the recently added split_datetime_field and multi_value_field from the test form since MultiValueField has an abstract compress() that raises NotImplementedError on empty submission. Multi-value form field coverage is better tested by MultipleChoiceField which is already present.
Preact/React does not reliably restore <select multiple> selection state during in-place reconciliation of option children. Force a complete unmount/remount of the <form> element by using a volatile React key that increments each time submitted_data triggers a re-render. This ensures defaultValue is applied on mount and that the DOM select element starts fresh with the correct selection.
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Description
Fix (partial) #270 by resolving two categories of
django_formlimitations:1. FormData serialization bug (MultipleChoiceField data loss)
Object.fromEntries(formData.entries())silently drops duplicate keys, causingMultipleChoiceFieldandModelMultipleChoiceFieldto lose all values except the last selected option. Replaced with a manual loop that accumulates duplicate keys intoFormDataEntryValue[]arrays.2. Robust
convert_form_fieldsnormalizationImproved
convert_form_fields()to properly handle edge cases:Nonevalues from unselected multi-select fields →[][value]3. Test coverage for multi-value fields
Added
SplitDateTimeFieldandMultiValueFieldtoBasicFormin the test app for regression coverage.Checklist
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