Fix some widget param mappings

test/__init__.py

@@ -2,7 +2,7 @@
 
 from flask import Flask
 from jinja2 import ChoiceLoader, PackageLoader
-from tna_frontend_jinja.wtforms.widgets import WTFormsHelpers
+from tna_frontend_jinja.wtforms.helpers import WTFormsHelpers
 
 from .components import bp as components_bp
 from .forms import bp as forms_bp

test/forms/routes.py

@@ -23,26 +23,26 @@
     SubmitField,
     TextAreaField,
 )
-from wtforms.validators import Email, InputRequired, Length
+from wtforms.validators import InputRequired, Length
 
 
 class ExampleForm(FlaskForm):
-    email_address = StringField(
-        "Email address",
+    username = StringField(
+        "Username",
         widget=TnaTextInput(),
         validators=[
             InputRequired(message="Enter an email address"),
             Length(
                 max=256, message="Email address must be 256 characters or fewer"
             ),
-            Email(
-                message="Enter an email address in the correct format, like [email protected]"
-            ),
         ],
         description="We’ll only use this to send you a receipt",
     )
     password = StringField(
         "Password",
+        validators=[
+            InputRequired(message="Enter a password"),
+        ],
         widget=TnaPasswordInput(),
     )
     remember = BooleanField(
@@ -51,29 +51,45 @@ class ExampleForm(FlaskForm):
     )
     shopping = SelectMultipleField(
         "Shopping list",
+        validators=[
+            InputRequired(message="Select an item"),
+        ],
         choices=[("cpp", "C++"), ("py", "Python"), ("text", "Plain Text")],
         widget=TnaCheckboxesInput(),
     )
     day = RadioField(
         "Day",
         choices=[("mon", "Monday"), ("tue", "Tuesday"), ("wed", "Wednesday")],
+        validators=[
+            InputRequired(message="Select a day"),
+        ],
         widget=TnaRadioInput(),
     )
     birthday = DateField(
         "Birthday",
+        validators=[
+            InputRequired(message="Enter a date"),
+        ],
         widget=TnaDateInput(),
     )
     message = TextAreaField(
         "Message",
+        validators=[
+            InputRequired(message="Enter a message"),
+        ],
         widget=TnaTextArea(),
     )
     order = SelectField(
         "Order",
         choices=[
+            ("", "None"),
             ("date", "Date"),
             ("relevance", "Relevance"),
             ("popularity", "Popularity"),
         ],
+        validators=[
+            InputRequired(message="Select an order"),
+        ],
         widget=TnaSelect(),
     )
 
@@ -84,5 +100,5 @@ class ExampleForm(FlaskForm):
 def index():
     form = ExampleForm()
     if form.validate_on_submit():
-        return redirect(url_for("forms.index"))
+        return redirect(url_for("forms.index", status="Success"))
     return render_template("example-form.html", form=form)

test/forms/test-templates/example-form.html

@@ -22,10 +22,8 @@ <h1 class="tna-heading-xl">Example form</h1>
     <form action="" method="post" novalidate>
       {{ form.csrf_token }}
 
-      {{ form.email_address(params={
+      {{ form.username(params={
         'headingLevel': 2,
-        'type': 'email',
-        'autofill': 'email',
         'spellcheck': False
       }) }}
 

test/templates/routes.py

@@ -6,6 +6,6 @@
 
 @bp.route("/base")
 def base():
-    params = request.args.get("params")
-    context = json.loads(params) if params else {}
-    return render_template("layouts/base.html", context=context)
+    params_str = request.args.get("params")
+    params = json.loads(params_str) if params_str else {}
+    return render_template("layouts/base.html", context=params)

tna_frontend_jinja/wtforms/helpers.py

@@ -0,0 +1,71 @@
+from deepmerge import Merger
+
+merger = Merger(
+    # pass in a list of tuple, with the
+    # strategies you are looking to apply
+    # to each type.
+    [(list, ["append"]), (dict, ["merge"])],
+    # next, choose the fallback strategies,
+    # applied to all other types:
+    ["override"],
+    # finally, choose the strategies in
+    # the case where the types conflict:
+    ["override"],
+)
+
+
+def flatten_errors(errors, prefix="", id_map={}):
+    """Return list of errors from form errors."""
+    error_list = []
+    if isinstance(errors, dict):
+        for key, value in errors.items():
+            # Recurse to handle subforms.
+            if key in id_map:
+                key = id_map[key]
+            error_list += flatten_errors(
+                value, prefix=f"{prefix}{key}-", id_map=id_map
+            )
+    elif isinstance(errors, list) and isinstance(errors[0], dict):
+        for idx, error in enumerate(errors):
+            error_list += flatten_errors(
+                error, prefix=f"{prefix}{idx}-", id_map=id_map
+            )
+    elif isinstance(errors, list):
+        error_list.append(
+            {"text": errors[0], "href": "#{}".format(prefix.rstrip("-"))}
+        )
+    else:
+        error_list.append(
+            {"text": errors, "href": "#{}".format(prefix.rstrip("-"))}
+        )
+    return error_list
+
+
+def wtforms_errors(form, params={}):
+    wtforms_params = {"title": "There is a problem", "items": []}
+
+    id_map = {}
+    for field_name in form._fields.keys():
+        field = getattr(form, field_name, None)
+        if field and hasattr(field, "id"):
+            id_map[field_name] = field.id
+
+    wtforms_params["items"] = flatten_errors(form.errors, id_map=id_map)
+
+    return merger.merge(wtforms_params, params)
+
+
+class WTFormsHelpers(object):
+    """WTForms helpers
+
+    Register some template helpers to allow developers to
+    map WTForms elements to the GOV.UK jinja macros
+    """
+
+    def __init__(self, app=None):
+        self.app = app
+        if app is not None:
+            self.init_app(app)
+
+    def init_app(self, app):
+        app.add_template_global(wtforms_errors)