Move Date of birth validation to a form

Author: Themitchell

lung_cancer_screening/core/form_fields.py

@@ -0,0 +1,304 @@
+import datetime
+
+from django import forms
+from django.core import validators
+from django.forms import Textarea, ValidationError, widgets
+from django.utils.translation import gettext
+from django.utils.translation import gettext_lazy as _
+
+from .utils.date_formatting import format_date
+
+
+class SplitDateWidget(widgets.MultiWidget):
+    """
+    A widget that splits a date into 3 number inputs.
+    Adapted from https://github.com/ministryofjustice/django-govuk-forms/blob/master/govuk_forms/widgets.py
+    """
+
+    def __init__(self, attrs=None):
+        date_widgets = (
+            widgets.NumberInput(attrs=attrs),
+            widgets.NumberInput(attrs=attrs),
+            widgets.NumberInput(attrs=attrs),
+        )
+        super().__init__(date_widgets, attrs)
+
+    def decompress(self, value):
+        if value:
+            return [value.day, value.month, value.year]
+        return [None, None, None]
+
+    def subwidgets(self, name, value, attrs=None):
+        """
+        Expose data for each subwidget, so that we can render them separately in the template.
+
+        For some reason, as of Django 5.2, `MultiWidget` does not actually override the default
+        implementation provided by `Widget`, which means you can't call `form.date.0` `form.date.1`
+        to access the individual parts.
+        (see https://stackoverflow.com/questions/24866936/render-only-one-part-of-a-multiwidget-in-django)
+        """
+        context = self.get_context(name, value, attrs)
+        for subwidget in context["widget"]["subwidgets"]:
+            yield subwidget
+
+
+class SplitHiddenDateWidget(SplitDateWidget):
+    """
+    A widget that splits a date into 3 number inputs (hidden variant)
+    Adapted from https://github.com/ministryofjustice/django-govuk-forms/blob/master/govuk_forms/widgets.py
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        for widget in self.widgets:
+            widget.input_type = "hidden"
+
+
+class SplitDateField(forms.MultiValueField):
+    """
+    A form field that can be rendered as 3 inputs using the dateInput component in the design system.
+    Adapted from https://github.com/ministryofjustice/django-govuk-forms/blob/master/govuk_forms/fields.py
+    """
+
+    widget = SplitDateWidget
+    hidden_widget = SplitHiddenDateWidget
+    default_error_messages = {"invalid": _("Enter a valid date.")}
+
+    def __init__(self, *args, **kwargs):
+        max_value = kwargs.pop("max_value", datetime.date.today())
+        min_value = kwargs.pop("min_value", datetime.date(1900, 1, 1))
+        self.hint = kwargs.pop("hint", None)
+
+        day_bounds_error = gettext("Day should be between 1 and 31.")
+        month_bounds_error = gettext("Month should be between 1 and 12.")
+        year_bounds_error = gettext(
+            "Year should be between %(min_year)s and %(max_year)s."
+        ) % {"min_year": min_value.year, "max_year": max_value.year}
+
+        day_kwargs = {
+            "min_value": 1,
+            "max_value": 31,
+            "error_messages": {
+                "min_value": day_bounds_error,
+                "max_value": day_bounds_error,
+                "invalid": gettext("Enter day as a number."),
+            },
+        }
+        month_kwargs = {
+            "min_value": 1,
+            "max_value": 12,
+            "error_messages": {
+                "min_value": month_bounds_error,
+                "max_value": month_bounds_error,
+                "invalid": gettext("Enter month as a number."),
+            },
+        }
+        year_kwargs = {
+            "min_value": min_value.year,
+            "max_value": max_value.year,
+            "error_messages": {
+                "min_value": year_bounds_error,
+                "max_value": year_bounds_error,
+                "invalid": gettext("Enter year as a number."),
+            },
+        }
+
+        self.fields = [
+            IntegerField(**day_kwargs),
+            IntegerField(**month_kwargs),
+            IntegerField(**year_kwargs),
+        ]
+
+        kwargs["template_name"] = "forms/date-input.jinja"
+
+        super().__init__(self.fields, *args, **kwargs)
+
+        self.validators.append(
+            validators.MinValueValidator(
+                min_value, f"Enter a date after {format_date(min_value)}"
+            )
+        )
+        self.validators.append(
+            validators.MaxValueValidator(
+                max_value, f"Enter a date before {format_date(max_value)}"
+            )
+        )
+
+    def compress(self, data_list):
+        if data_list:
+            try:
+                if any(item in self.empty_values for item in data_list):
+                    raise ValueError
+                return datetime.date(data_list[2], data_list[1], data_list[0])
+            except ValueError:
+                raise ValidationError(
+                    self.error_messages["invalid"], code="invalid")
+        return None
+
+    def widget_attrs(self, widget):
+        attrs = super().widget_attrs(widget)
+        if not isinstance(widget, SplitDateWidget):
+            return attrs
+        for subfield, subwidget in zip(self.fields, widget.widgets):
+            if subfield.min_value is not None:
+                subwidget.attrs["min"] = subfield.min_value
+            if subfield.max_value is not None:
+                subwidget.attrs["max"] = subfield.max_value
+        return attrs
+
+
+class CharField(forms.CharField):
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        widget = kwargs.get("widget")
+        if (isinstance(widget, type) and widget is Textarea) or isinstance(
+            widget, Textarea
+        ):
+            kwargs["template_name"] = "forms/textarea.jinja"
+        else:
+            kwargs["template_name"] = "forms/input.jinja"
+
+        self.hint = hint
+        self.classes = classes
+        self.label_classes = label_classes
+
+        super().__init__(*args, **kwargs)
+
+    def widget_attrs(self, widget):
+        attrs = super().widget_attrs(widget)
+
+        # Don't use maxlength even if there is a max length validator.
+        # This attribute prevents the user from seeing errors, so we don't use it
+        attrs.pop("maxlength", None)
+
+        return attrs
+
+
+class IntegerField(forms.IntegerField):
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        kwargs["template_name"] = "forms/input.jinja"
+
+        self.hint = hint
+        self.classes = classes
+        self.label_classes = label_classes
+
+        super().__init__(*args, **kwargs)
+
+    def widget_attrs(self, widget):
+        attrs = super().widget_attrs(widget)
+
+        # Don't use min/max/step attributes.
+        attrs.pop("min", None)
+        attrs.pop("max", None)
+        attrs.pop("step", None)
+
+        return attrs
+
+
+class BoundChoiceField(forms.BoundField):
+    """
+    Specialisation of BoundField that can deal with conditionally shown fields,
+    and divider content between choices.
+    This can be used to render a set of radios or checkboxes with text boxes to capture
+    more details.
+    """
+
+    def __init__(self, form: forms.Form, field: "ChoiceField", name: str):
+        super().__init__(form, field, name)
+
+        self._conditional_html = {}
+        self.dividers = {}
+
+    def add_conditional_html(self, value, html):
+        if isinstance(self.field.widget, widgets.Select):
+            raise ValueError(
+                "select comonent does not support conditional fields")
+
+        self._conditional_html[value] = html
+
+    def conditional_html(self, value):
+        return self._conditional_html.get(value)
+
+    def add_divider_after(self, previous, divider):
+        self.dividers[previous] = divider
+
+    def get_divider_after(self, previous):
+        return self.dividers.get(previous)
+
+
+class ChoiceField(forms.ChoiceField):
+    """
+    A ChoiceField that renders using NHS.UK design system radios/select
+    components.
+    """
+
+    widget = widgets.RadioSelect
+    bound_field_class = BoundChoiceField
+
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        kwargs["template_name"] = ChoiceField._template_name(
+            kwargs.get("widget", self.widget)
+        )
+
+        self.hint = hint
+        self.classes = classes
+        self.label_classes = label_classes
+
+        super().__init__(*args, **kwargs)
+
+    @staticmethod
+    def _template_name(widget):
+        if (isinstance(widget, type) and widget is widgets.RadioSelect) or isinstance(
+            widget, widgets.RadioSelect
+        ):
+            return "forms/radios.jinja"
+        elif (isinstance(widget, type) and widget is widgets.Select) or isinstance(
+            widget, widgets.Select
+        ):
+            return "forms/select.jinja"
+
+
+class MultipleChoiceField(forms.MultipleChoiceField):
+    """
+    A MultipleChoiceField that renders using the NHS.UK design system checkboxes
+    component.
+    """
+
+    widget = widgets.CheckboxSelectMultiple
+    bound_field_class = BoundChoiceField
+
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        kwargs["template_name"] = "forms/checkboxes.jinja"
+
+        self.hint = hint
+        self.classes = classes
+        self.label_classes = label_classes
+
+        super().__init__(*args, **kwargs)

lung_cancer_screening/core/jinja2/forms/date-input.jinja

@@ -0,0 +1,43 @@
+{% from 'components/date-input/macro.jinja' import dateInput as dateInput %}
+{% if field.errors %}
+  {% set error_message = {"text": field.errors | first} %}
+{% endif %}
+{% set unbound_field = field.field %}
+{% set hint = unbound_field.hint %}
+{{ dateInput({
+  "name": field.html_name,
+  "fieldset":  {
+    "legend": {
+      "text": field.label,
+      "classes": "nhsuk-fieldset__legend--m",
+      "isPageHeading": false
+    }
+  } if field.label,
+  "errorMessage": error_message,
+  "hint": {
+    "html": hint|e
+  } if hint,
+  "items": [
+    {
+      "name": field.subwidgets.0.data.name,
+      "label": "Day",
+      "classes": "nhsuk-input--width-2",
+      "value": field.subwidgets.0.data.value,
+      "id": field.auto_id
+    },
+    {
+      "name": field.subwidgets.1.data.name,
+      "label": "Month",
+      "classes": "nhsuk-input--width-2",
+      "value": field.subwidgets.1.data.value,
+      "id": field.auto_id ~ "_1"
+    },
+    {
+      "name": field.subwidgets.2.data.name,
+      "label": "Year",
+      "classes": "nhsuk-input--width-4",
+      "value": field.subwidgets.2.data.value,
+      "id": field.auto_id ~ "_2"
+    }
+  ]
+}) }}

lung_cancer_screening/core/tests/acceptance/test_participant_out_of_age_range.py

@@ -47,9 +47,9 @@ def test_participant_out_of_age_range(self):
 
         age = datetime.now() - relativedelta(years=20)
 
-        page.fill("input[name='day']", str(age.day))
-        page.fill("input[name='month']", str(age.month))
-        page.fill("input[name='year']", str(age.year))
+        page.get_by_label("Day").fill(str(age.day))
+        page.get_by_label("Month").fill(str(age.month))
+        page.get_by_label("Year").fill(str(age.year))
 
         page.click("text=Continue")
 

lung_cancer_screening/core/tests/acceptance/test_questionnaire.py

@@ -46,9 +46,9 @@ def test_full_questionaire_user_journey(self):
 
         age = datetime.now() - relativedelta(years=55)
 
-        page.fill("input[name='day']", str(age.day))
-        page.fill("input[name='month']", str(age.month))
-        page.fill("input[name='year']", str(age.year))
+        page.get_by_label("Day").fill(str(age.day))
+        page.get_by_label("Month").fill(str(age.month))
+        page.get_by_label("Year").fill(str(age.year))
 
         page.click("text=Continue")