Migrate custom form fields into nhsuk_forms

lung_cancer_screening/nhsuk_forms/bound_choice_field.py

@@ -0,0 +1,34 @@
+from django import forms
+from django.forms import widgets
+
+from lung_cancer_screening.nhsuk_forms import choice_field
+
+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: "choice_field", 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 component 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)

lung_cancer_screening/nhsuk_forms/choice_field.py

@@ -0,0 +1,35 @@
+from django import forms
+from django.forms import widgets
+
+from .bound_choice_field import BoundChoiceField
+
+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):
+        return "radios.jinja"

lung_cancer_screening/nhsuk_forms/decimal_field.py

@@ -0,0 +1,28 @@
+from django import forms
+
+class DecimalField(forms.DecimalField):
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        kwargs["template_name"] = "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

lung_cancer_screening/nhsuk_forms/imperial_height_form.py

@@ -0,0 +1,76 @@
+from django import forms
+from django.forms import widgets
+
+from lung_cancer_screening.nhsuk_forms.integer_field import IntegerField
+
+
+class ImperialHeightWidget(widgets.MultiWidget):
+    """
+    A widget that splits height into feet and inches inputs.
+    """
+
+    def __init__(self, attrs=None):
+        height_widgets = (
+            widgets.NumberInput(attrs=attrs),
+            widgets.NumberInput(attrs=attrs),
+        )
+        super().__init__(height_widgets, attrs)
+
+    def decompress(self, value):
+        """
+        Convert total inches back to feet and inches for display.
+        """
+        if value:
+            feet = int(value // 12)
+            inches = value % 12
+            return [feet, inches]
+        return [None, None]
+
+    def subwidgets(self, name, value, attrs=None):
+        """
+        Expose data for each subwidget, so that we can render them separately in the template.
+        """
+        context = self.get_context(name, value, attrs)
+        for subwidget in context["widget"]["subwidgets"]:
+            yield subwidget
+
+
+class ImperialHeightField(forms.MultiValueField):
+    """
+    A field that combines feet and inches into a single height value in cm.
+    """
+
+    widget = ImperialHeightWidget
+
+    def __init__(self, *args, **kwargs):
+        error_messages = kwargs.get("error_messages", {})
+
+        feet_kwargs = {
+            "error_messages": {
+                'invalid': 'Feet must be in whole numbers.',
+                **error_messages,
+            },
+        }
+        inches_kwargs = {
+            "error_messages": {
+                'invalid': 'Inches must be in whole numbers.',
+                **error_messages,
+            },
+        }
+        fields = (
+            IntegerField(**feet_kwargs),
+            IntegerField(**inches_kwargs),
+        )
+        kwargs["template_name"] = "imperial-height-input.jinja"
+
+        super().__init__(fields, *args, **kwargs)
+
+    def compress(self, data_list):
+        """
+        Convert feet and inches to total inches.
+        """
+        if data_list and all(data_list):
+            feet, inches = data_list
+            total_inches = feet * 12 + inches
+            return int(total_inches)
+        return None

lung_cancer_screening/nhsuk_forms/imperial_weight_form.py

@@ -0,0 +1,83 @@
+from django import forms
+from django.forms import widgets
+
+from lung_cancer_screening.nhsuk_forms.integer_field import IntegerField
+
+class ImperialWeightWidget(widgets.MultiWidget):
+    """
+    A widget that splits weight into stone and pounds inputs.
+    """
+
+    def __init__(self, attrs=None):
+        weight_widgets = (
+            widgets.NumberInput(attrs=attrs),
+            widgets.NumberInput(attrs=attrs),
+        )
+        super().__init__(weight_widgets, attrs)
+
+    def decompress(self, value):
+        """
+        Convert total pounds back to stone and pounds for display.
+        """
+        if value:
+            stone = int(value // 14)
+            pounds = value % 14
+            return [stone, pounds]
+        return [None, None]
+
+    def subwidgets(self, name, value, attrs=None):
+        """
+        Expose data for each subwidget, so that we can render them separately in the template.
+        """
+        context = self.get_context(name, value, attrs)
+        for subwidget in context["widget"]["subwidgets"]:
+            yield subwidget
+
+
+class ImperialWeightField(forms.MultiValueField):
+    """
+    A field that combines stone and pounds into a single weight value in total pounds.
+    """
+
+    widget = ImperialWeightWidget
+
+    def __init__(self, *args, **kwargs):
+        error_messages = kwargs.get("error_messages", {})
+
+        stone_kwargs = {
+            "min_value": 0,
+            "max_value": 50,
+            "error_messages": {
+                'invalid': 'Stone must be in whole numbers.',
+                'min_value': 'Weight must be between 4 stone and 50 stone.',
+                'max_value': 'Weight must be between 4 stone and 50 stone.',
+                **error_messages,
+            },
+        }
+        pounds_kwargs = {
+            "min_value": 0,
+            "max_value": 13,
+            "error_messages": {
+                'invalid': 'Pounds must be in whole numbers.',
+                'min_value': 'Pounds must be between 0 and 13.',
+                'max_value': 'Pounds must be between 0 and 13.',
+                **error_messages,
+            },
+        }
+        fields = (
+            IntegerField(**stone_kwargs),
+            IntegerField(**pounds_kwargs),
+        )
+        kwargs["template_name"] = "imperial-weight-input.jinja"
+
+        super().__init__(fields, *args, **kwargs)
+
+    def compress(self, data_list):
+        """
+        Convert stone and pounds to total pounds.
+        """
+        if data_list and all(item is not None for item in data_list):
+            stone, pounds = data_list
+            total_pounds = stone * 14 + pounds
+            return int(total_pounds)
+        return None

lung_cancer_screening/nhsuk_forms/integer_field.py

@@ -0,0 +1,29 @@
+from django import forms
+
+
+class IntegerField(forms.IntegerField):
+    def __init__(
+        self,
+        *args,
+        hint=None,
+        label_classes=None,
+        classes=None,
+        **kwargs,
+    ):
+        kwargs["template_name"] = "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