|
| 1 | +from django import forms |
| 2 | +from django.core.exceptions import ValidationError |
| 3 | +from django.db.models import Model |
| 4 | +from django.forms import formset_factory, model_to_dict |
| 5 | +from django.forms.models import modelform_factory |
| 6 | +from django.utils.html import format_html, format_html_join |
| 7 | +from django.utils.translation import gettext_lazy as _ |
| 8 | + |
| 9 | + |
| 10 | +class MultipleEmbeddedModelFormField(forms.Field): |
| 11 | + default_error_messages = {"incomplete": _("Enter all required values.")} |
| 12 | + |
| 13 | + def __init__(self, model, prefix, max_length=None, *args, **kwargs): |
| 14 | + kwargs.pop("base_field") |
| 15 | + self.model = model |
| 16 | + self.prefix = prefix |
| 17 | + self.model_form_cls = modelform_factory(model, fields="__all__") |
| 18 | + self.formset = formset_factory( |
| 19 | + form=self.model_form_cls, can_delete=True, max_num=max_length |
| 20 | + ) |
| 21 | + kwargs["widget"] = MultipleEmbeddedModelWidget(self.model_form_cls.__name__) |
| 22 | + super().__init__(*args, **kwargs) |
| 23 | + |
| 24 | + def clean(self, value): |
| 25 | + if not value: |
| 26 | + return [] |
| 27 | + formset = self.formset(value, prefix=self.prefix) |
| 28 | + if not formset.is_valid(): |
| 29 | + raise ValidationError(formset.errors + formset.non_form_errors()) |
| 30 | + cleaned_data = [] |
| 31 | + for data in formset.cleaned_data: |
| 32 | + if data.get("DELETE", True): |
| 33 | + continue |
| 34 | + data.pop("DELETE") |
| 35 | + cleaned_data.append(self.model_form_cls._meta.model(**data)) |
| 36 | + return cleaned_data |
| 37 | + |
| 38 | + def has_changed(self, initial, data): |
| 39 | + formset_initial = [] |
| 40 | + for initial_data in initial or []: |
| 41 | + formset_initial.append(forms.model_to_dict(initial_data)) |
| 42 | + formset = self.formset(data, initial=formset_initial, prefix=self.prefix) |
| 43 | + return formset.has_changed() |
| 44 | + |
| 45 | + def get_bound_field(self, form, field_name): |
| 46 | + return MultipleEmbeddedModelBoundField(form, self, field_name) |
| 47 | + |
| 48 | + |
| 49 | +class MultipleEmbeddedModelBoundField(forms.BoundField): |
| 50 | + def __init__(self, form, field, name): |
| 51 | + super().__init__(form, field, name) |
| 52 | + data = self.data if form.is_bound else None |
| 53 | + formset_initial = [] |
| 54 | + if self.initial is not None: |
| 55 | + for initial in self.initial: |
| 56 | + if isinstance(initial, Model): |
| 57 | + formset_initial.append(model_to_dict(initial)) |
| 58 | + self.formset = field.formset(data, initial=formset_initial, prefix=self.html_name) |
| 59 | + |
| 60 | + def __getitem__(self, idx): |
| 61 | + if not isinstance(idx, (int | slice)): |
| 62 | + raise TypeError |
| 63 | + return self.formset[idx] |
| 64 | + |
| 65 | + def __iter__(self): |
| 66 | + yield from self.formset |
| 67 | + |
| 68 | + def __str__(self): |
| 69 | + table = format_html_join( |
| 70 | + "\n", "<tbody>{}</tbody>", ((form.as_table(),) for form in self.formset) |
| 71 | + ) |
| 72 | + table = format_html("\n<table>" "\n{}" "\n</table>", table) |
| 73 | + return format_html("{}\n{}", table, self.formset.management_form) |
| 74 | + |
| 75 | + def __len__(self): |
| 76 | + return len(self.formset) |
| 77 | + |
| 78 | + |
| 79 | +class MultipleEmbeddedModelWidget(forms.Widget): |
| 80 | + def __init__(self, field_id, attrs=None): |
| 81 | + self.field_id = field_id |
| 82 | + super().__init__(attrs) |
| 83 | + |
| 84 | + def render(self, name, value, attrs=None, renderer=None): |
| 85 | + raise NotImplementedError("This widget is not meant to be rendered.") |
| 86 | + |
| 87 | + def id_for_label(self, id_): |
| 88 | + return f"{id_}-0-{self.field_id}" |
| 89 | + |
| 90 | + def value_from_datadict(self, data, files, name): |
| 91 | + return {key: data[key] for key in data if key.startswith(name)} |
| 92 | + |
| 93 | + def value_omitted_from_data(self, data, files, name): |
| 94 | + return any(key.startswith(name) for key in data) |
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