add custom DynamicArrayField to better handle arrays

passbook/lib/fields.py

@@ -0,0 +1,44 @@
+"""passbook lib fields"""
+from itertools import chain
+
+from django import forms
+from django.contrib.postgres.utils import prefix_validation_error
+
+from passbook.lib.widgets import DynamicArrayWidget
+
+
+class DynamicArrayField(forms.Field):
+    """Show array field as a dynamic amount of textboxes"""
+
+    default_error_messages = {"item_invalid": "Item %(nth)s in the array did not validate: "}
+
+    def __init__(self, base_field, **kwargs):
+        self.base_field = base_field
+        self.max_length = kwargs.pop("max_length", None)
+        kwargs.setdefault("widget", DynamicArrayWidget)
+        super().__init__(**kwargs)
+
+    def clean(self, value):
+        cleaned_data = []
+        errors = []
+        value = [x for x in value if x]
+        for index, item in enumerate(value):
+            try:
+                cleaned_data.append(self.base_field.clean(item))
+            except forms.ValidationError as error:
+                errors.append(
+                    prefix_validation_error(
+                        error, self.error_messages["item_invalid"],
+                        code="item_invalid", params={"nth": index}
+                    )
+                )
+        if errors:
+            raise forms.ValidationError(list(chain.from_iterable(errors)))
+        if not cleaned_data and self.required:
+            raise forms.ValidationError(self.error_messages["required"])
+        return cleaned_data
+
+    def has_changed(self, initial, data):
+        if not data and not initial:
+            return False
+        return super().has_changed(initial, data)

passbook/lib/templates/lib/arrayfield.html

@@ -0,0 +1,17 @@
+{% load utils %}
+
+{% spaceless %}
+<div class="dynamic-array-widget">
+    {% for widget in widget.subwidgets %}
+    <div class="array-item input-group">
+        {% include widget.template_name %}
+        <div class="input-group-btn">
+            <button class="array-remove btn btn-danger" type="button">
+                <span class="pficon-delete"></span>
+            </button>
+        </div>
+    </div>
+    {% endfor %}
+    <div><button type="button" class="add-array-item btn btn-default">Add another</button></div>
+</div>
+{% endspaceless %}

passbook/lib/widgets.py

@@ -0,0 +1,36 @@
+"""Dynamic array widget"""
+from django import forms
+
+
+class DynamicArrayWidget(forms.TextInput):
+    """Dynamic array widget"""
+
+    template_name = "lib/arrayfield.html"
+
+    def get_context(self, name, value, attrs):
+        value = value or [""]
+        context = super().get_context(name, value, attrs)
+        final_attrs = context["widget"]["attrs"]
+        id_ = context["widget"]["attrs"].get("id")
+
+        subwidgets = []
+        for index, item in enumerate(context["widget"]["value"]):
+            widget_attrs = final_attrs.copy()
+            if id_:
+                widget_attrs["id"] = "{id_}_{index}".format(id_=id_, index=index)
+            widget = forms.TextInput()
+            widget.is_required = self.is_required
+            subwidgets.append(widget.get_context(name, item, widget_attrs)["widget"])
+
+        context["widget"]["subwidgets"] = subwidgets
+        return context
+
+    def value_from_datadict(self, data, files, name):
+        try:
+            getter = data.getlist
+            return [value for value in getter(name) if value]
+        except AttributeError:
+            return data.get(name)
+
+    def format_value(self, value):
+        return value or []