Re: htmlfill, errors and examples

Index: htmlfill.py
===================================================================
--- htmlfill.py	(reviso 2104)
+++ htmlfill.py	(cpia de trabalho)
@@ -130,6 +130,14 @@
     error = error.replace('\n', '<br>\n')
     return error
 
+def default_example_formatter(example):
+    """
+    Formatter that escapes the example message, wraps it in a span with
+    class ``example-message``, with parentesis and adds a ``<br>``
+    """
+    return '<span class="example-message">(Ex.: %s)</span><br/>\n' % html_quote(example)
+
+
 class FillingParser(HTMLParser.HTMLParser):
     r"""
     Fills HTML with default values, as in a form.
@@ -165,7 +173,7 @@
     def __init__(self, defaults, errors=None, use_all_keys=False,
                  error_formatters=None, error_class='error',
                  add_attributes=None, listener=None,
-                 auto_error_formatter=None,
+                 auto_error_formatter=None, examples=None,
                  text_as_default=False):
         HTMLParser.HTMLParser.__init__(self)
         self._content = []
@@ -177,6 +185,7 @@
         self.in_select = None
         self.skip_next = False        
         self.errors = errors or {}
+        self.examples = examples or {}
         if isinstance(self.errors, (str, unicode)):
             self.errors = {None: self.errors}
         self.in_error = None
@@ -327,6 +336,10 @@
         if error:
             error = self.error_formatters[formatter](error)
             self.write_text(error)
+        else:
+            example = self.examples.get(name, '')
+            if example:
+                self.write_text(default_example_formatter(example))
         self.skip_next = True
         self.used_errors[name] = 1

Index: schema.py
===================================================================
--- schema.py	(reviso 2104)
+++ schema.py	(cpia de trabalho)
@@ -287,6 +287,10 @@
         result.extend(self.fields.values())
         return result
 
+    def examples(cls):
+        return dict([(name, getattr(validator, 'example', None)) for name, validator in cls.fields.items()])
+    examples = classmethod(examples)
+
 def format_compound_error(v, indent=0):
     if isinstance(v, Exception):
         try:

from formencode.schema import Schema
from formencode.htmlfill import FillingParser
from formencode import validators
from formencode.api import  Invalid

class MySchema(Schema):
    name = validators.String()
    birth = validators.String(not_empty=True, example='2006-11-23')

htmlForm = '''\
Name: <input type="submit" name="name"> <form:error name="name"><br>
Birth: <input type="submit" name="birth"> <form:error name="birth"><br>
'''

# rendering the form a first time, when you do not passed values
# to the form, note that here we change the error wildcard of the birth
# field by his example defined on the schema
parser = FillingParser({}, errors={}, examples=MySchema.examples())
parser.feed(htmlForm)
parser.close()
print parser.text()

print '-----------------'

# now we simulate an error on the schema and render the form with
# the error, in this case the example is suppressed and the error
# is shown in place of it
try:
    MySchema.to_python({'name':'Michel', 'birth':''})
except Invalid, e:
    parser = FillingParser({}, errors=e.unpack_errors(), examples=MySchema.examples())
    parser.feed(htmlForm)
    parser.close()
    print parser.text()

# note that the example message can be define in the validator class, in the validator
# instantiation and if it is not defined, the example is suppressed