Adds custom field parser support

onegov/form/parser/core.py

@@ -2,6 +2,7 @@
     Form,
     with_options
 )
+from onegov.form.utils import label_to_field_id
 from onegov.form.parser.grammar import document
 from wtforms import PasswordField, StringField, TextAreaField
 from wtforms.widgets import TextArea
@@ -12,7 +13,7 @@
 doc = document()
 
 
-def parse_form(text):
+def parse_form(text, custom_fields={}):
     """ Takes the given form text, parses it and returns a WTForms form
     class (not an instance of it).
 
@@ -51,6 +52,15 @@ class (not an instance of it).
                 label=block.label,
                 required=block.required
             )
+        elif block.type == 'custom':
+            if block.custom_id in custom_fields:
+                builder.add_field(
+                    field_class=custom_fields[block.custom_id],
+                    label=block.label,
+                    required=block.required
+                )
+            else:
+                raise NotImplementedError
         else:
             raise NotImplementedError
 
@@ -85,7 +95,7 @@ def add_field(self, field_class, label, required, **kwargs):
         if required:
             validators.insert(0, InputRequired())
 
-        field_id = label.lower().replace(' ', '_')
+        field_id = label_to_field_id(label)
 
         setattr(self.form_class, field_id, field_class(
             label=label,

onegov/form/tests/test_parser.py

@@ -1,5 +1,8 @@
+import pytest
+
 from onegov.form.parser import parse_form
 from textwrap import dedent
+from wtforms.fields.html5 import EmailField
 
 
 def test_parse_text():
@@ -67,3 +70,16 @@ def test_parse_fieldsets():
     assert fieldsets[2].label is None
     assert not fieldsets[2].is_visible
     assert fieldsets[2]['comment'].label.text == 'Comment'
+
+
+def test_parse_custom_fields():
+
+    with pytest.raises(NotImplementedError):
+        form = parse_form("E-Mail = /E-Mail")
+
+    form = parse_form("E-Mail = /E-Mail", custom_fields={
+        'e-mail': EmailField
+    })()
+
+    assert form.e_mail.label.text == 'E-Mail'
+    assert isinstance(form.e_mail, EmailField)

onegov/form/utils.py

@@ -0,0 +1,12 @@
+import re
+
+from unidecode import unidecode
+
+_unwanted_characters = re.compile(r'[^a-zA-Z0-9]+')
+
+
+def label_to_field_id(label):
+    clean = unidecode(label).strip(' ').lower()
+    clean = _unwanted_characters.sub('_', clean)
+
+    return clean

setup.py

@@ -36,7 +36,8 @@ def get_long_description():
     install_requires=[
         'pyparsing',
         'wtforms',
-        'wtforms-components[color]'
+        'wtforms-components[color]',
+        'unidecode'
     ],
     extras_require=dict(
         test=[