Repository: wtforms/wtforms (python)

Issue:
Use HTML 5 widgets
The HTML 5 widgets are kept in their own section and not used by default, but this distinction doesn't make sense today. "HTML 5" is just "HTML" now. No supported browser doesn't understand those input types, and ones that aren't supported fall back to text anyway.

I already sort of started this by making the required validators add the `required` flag, and I'm taking it further with #406 for more complex flags. Fields should default to using the more specific widgets where possible.

Pull request description:
HTML5 widgets by default
This patch is based upon #467, the changes are in the last commit 44a1cec.
It fixes #594 


Patch:
diff --git a/CHANGES.rst b/CHANGES.rst
index 50f43a2..a199f46 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -34,7 +34,7 @@ Unreleased
 -   Render attribute names like ``for_`` and ``class_`` are normalized
     consistently so later values override those specified earlier.
     :issue:`449`, :pr:`596`
-
+-   Flags can take non-boolean values. :issue:`406` :pr:`467`
 
 Version 2.3.1
 -------------
diff --git a/docs/fields.rst b/docs/fields.rst
index ed047ce..0bd3e32 100644
--- a/docs/fields.rst
+++ b/docs/fields.rst
@@ -182,10 +182,10 @@ The Field base class
 
     .. attribute:: flags
 
-        An object containing boolean flags set either by the field itself, or
+        An object containing flags set either by the field itself, or
         by validators on the field. For example, the built-in
         :class:`~wtforms.validators.InputRequired` validator sets the `required` flag.
-        An unset flag will result in :const:`False`.
+        An unset flag will result in :const:`None`.
 
         .. code-block:: html+django
 
@@ -220,10 +220,14 @@ refer to a single input from the form.
 
 .. autoclass:: DateTimeField(default field arguments, format='%Y-%m-%d %H:%M:%S')
 
-    For better date/time fields, see the :mod:`dateutil extension <wtforms.ext.dateutil.fields>`
+.. autoclass:: DateTimeLocalField(default field arguments, format='%Y-%m-%d %H:%M:%S')
 
 .. autoclass:: DecimalField(default field arguments, places=2, rounding=None, use_locale=False, number_format=None)
 
+.. autoclass:: DecimalRangeField(default field arguments)
+
+.. autoclass:: EmailField(default field arguments)
+
 .. autoclass:: FileField(default field arguments)
 
     Example usage::
@@ -252,6 +256,8 @@ refer to a single input from the form.
 
 .. autoclass:: IntegerField(default field arguments)
 
+.. autoclass:: IntegerRangeField(default field arguments)
+
 .. autoclass:: RadioField(default field arguments, choices=[], coerce=str)
 
     .. code-block:: jinja
@@ -323,6 +329,8 @@ refer to a single input from the form.
     a list of fields each representing an option. The rendering of this can be
     further controlled by specifying `option_widget=`.
 
+.. autoclass:: SearchField(default field arguments)
+
 .. autoclass:: SelectMultipleField(default field arguments, choices=[], coerce=str, option_widget=None)
 
    The data on the SelectMultipleField is stored as a list of objects, each of
@@ -338,6 +346,13 @@ refer to a single input from the form.
 
         {{ form.username(size=30, maxlength=50) }}
 
+.. autoclass:: TelField(default field arguments)
+
+.. autoclass:: TimeField(default field arguments, format='%H:%M')
+
+.. autoclass:: URLField(default field arguments)
+
+
 Convenience Fields
 ------------------
 
@@ -559,40 +574,3 @@ Additional Helper Classes
     .. attribute:: text
 
         The original label text passed to the field's constructor.
-
-HTML5 Fields
-------------
-
-In addition to basic HTML fields, WTForms also supplies fields for the HTML5
-standard. These fields can be accessed under the :mod:`wtforms.fields.html5` namespace.
-In reality, these fields are just convenience fields that extend basic fields
-and implement HTML5 specific widgets. These widgets are located in the :mod:`wtforms.widgets.html5`
-namespace and can be overridden or modified just like any other widget.
-
-.. module:: wtforms.fields.html5
-
-.. autoclass:: SearchField(default field arguments)
-
-.. autoclass:: TelField(default field arguments)
-
-.. autoclass:: URLField(default field arguments)
-
-.. autoclass:: EmailField(default field arguments)
-
-.. autoclass:: DateTimeField(default field arguments,  format='%Y-%m-%d %H:%M:%S')
-
-.. autoclass:: DateField(default field arguments, format='%Y-%m-%d')
-
-.. autoclass:: MonthField(default field arguments, format='%Y-%m')
-
-.. autoclass:: TimeField(default field arguments, format='%H:%M')
-
-.. autoclass:: DateTimeLocalField(default field arguments, format='%Y-%m-%d %H:%M:%S')
-
-.. autoclass:: IntegerField(default field arguments)
-
-.. autoclass:: DecimalField(default field arguments)
-
-.. autoclass:: IntegerRangeField(default field arguments)
-
-.. autoclass:: DecimalRangeField(default field arguments)
diff --git a/docs/validators.rst b/docs/validators.rst
index cdb9627..818c018 100644
--- a/docs/validators.rst
+++ b/docs/validators.rst
@@ -177,22 +177,21 @@ which will then be available on the :attr:`field's flags object
 
 To specify flags on your validator, set the ``field_flags`` attribute on your
 validator. When the Field is constructed, the flags with the same name will be
-set to True on your field. For example, let's imagine a validator that
+set on your field. For example, let's imagine a validator that
 validates that input is valid BBCode. We can set a flag on the field then to
 signify that the field accepts BBCode::
 
     # class implementation
     class ValidBBCode(object):
-        field_flags = ('accepts_bbcode', )
-
-        pass # validator implementation here
+        def __init__(self):
+            self.field_flags = {'accepts_bbcode': True}
 
     # factory implementation
     def valid_bbcode():
         def _valid_bbcode(form, field):
             pass # validator implementation here
 
-        _valid_bbcode.field_flags = ('accepts_bbcode', )
+        _valid_bbcode.field_flags = {'accepts_bbcode': True}
         return _valid_bbcode
 
 Then we can check it in our template, so we can then place a note to the user:
@@ -206,7 +205,10 @@ Then we can check it in our template, so we can then place a note to the user:
 
 Some considerations on using flags:
 
-* Flags can only set boolean values, and another validator cannot unset them.
-* If multiple fields set the same flag, its value is still True.
+* Boolean flags will set HTML valueless attributes (e.g. `{required: True}`
+  will give `<input type="text" required>`). Other flag types will set regular
+  HTML attributes (e.g. `{maxlength: 8}` will give `<input type="text" maxlength="8">`).
+* If multiple validators set the same flag, the flag will have the value set
+  by the first validator.
 * Flags are set from validators only in :meth:`Field.__init__`, so inline
   validators and extra passed-in validators cannot set them.
diff --git a/docs/widgets.rst b/docs/widgets.rst
index 81b96c0..5c4f009 100644
--- a/docs/widgets.rst
+++ b/docs/widgets.rst
@@ -14,36 +14,30 @@ recognize as not needing to be auto-escaped.
 Built-in widgets
 ----------------
 
-.. autoclass:: wtforms.widgets.ListWidget
-.. autoclass:: wtforms.widgets.TableWidget
+.. autoclass:: wtforms.widgets.ColorInput
+.. autoclass:: wtforms.widgets.CheckboxInput
+.. autoclass:: wtforms.widgets.DateTimeInput
+.. autoclass:: wtforms.widgets.DateTimeLocalInput
+.. autoclass:: wtforms.widgets.DateInput
+.. autoclass:: wtforms.widgets.EmailInput
+.. autoclass:: wtforms.widgets.FileInput
+.. autoclass:: wtforms.widgets.HiddenInput
 .. autoclass:: wtforms.widgets.Input
-.. autoclass:: wtforms.widgets.TextInput()
+.. autoclass:: wtforms.widgets.ListWidget
+.. autoclass:: wtforms.widgets.MonthInput
+.. autoclass:: wtforms.widgets.NumberInput
 .. autoclass:: wtforms.widgets.PasswordInput
-.. autoclass:: wtforms.widgets.HiddenInput()
-.. autoclass:: wtforms.widgets.CheckboxInput()
-.. autoclass:: wtforms.widgets.FileInput()
-.. autoclass:: wtforms.widgets.SubmitInput()
-.. autoclass:: wtforms.widgets.TextArea
+.. autoclass:: wtforms.widgets.RangeInput
+.. autoclass:: wtforms.widgets.SubmitInput
+.. autoclass:: wtforms.widgets.SearchInput
 .. autoclass:: wtforms.widgets.Select
-
-HTML5 widgets
--------------
-
-.. module:: wtforms.widgets.html5
-
-.. autoclass:: wtforms.widgets.html5.ColorInput
-.. autoclass:: wtforms.widgets.html5.DateTimeInput
-.. autoclass:: wtforms.widgets.html5.DateTimeLocalInput
-.. autoclass:: wtforms.widgets.html5.DateInput
-.. autoclass:: wtforms.widgets.html5.EmailInput
-.. autoclass:: wtforms.widgets.html5.MonthInput
-.. autoclass:: wtforms.widgets.html5.NumberInput
-.. autoclass:: wtforms.widgets.html5.RangeInput
-.. autoclass:: wtforms.widgets.html5.SearchInput
-.. autoclass:: wtforms.widgets.html5.TelInput
-.. autoclass:: wtforms.widgets.html5.TimeInput
-.. autoclass:: wtforms.widgets.html5.URLInput
-.. autoclass:: wtforms.widgets.html5.WeekInput
+.. autoclass:: wtforms.widgets.TableWidget
+.. autoclass:: wtforms.widgets.TelInput
+.. autoclass:: wtforms.widgets.TextArea
+.. autoclass:: wtforms.widgets.TextInput
+.. autoclass:: wtforms.widgets.TimeInput
+.. autoclass:: wtforms.widgets.URLInput
+.. autoclass:: wtforms.widgets.WeekInput
 
 Widget-Building Utilities
 -------------------------
diff --git a/src/wtforms/fields/__init__.py b/src/wtforms/fields/__init__.py
index 1f770d3..e429631 100644
--- a/src/wtforms/fields/__init__.py
+++ b/src/wtforms/fields/__init__.py
@@ -3,6 +3,5 @@ from wtforms.fields.core import Field
 from wtforms.fields.core import Flags
 from wtforms.fields.core import Label
 from wtforms.fields.core import SelectFieldBase
-from wtforms.fields.html5 import *
 from wtforms.fields.simple import *
 from wtforms.utils import unset_value as _unset_value
diff --git a/src/wtforms/fields/core.py b/src/wtforms/fields/core.py
index d835092..8724356 100644
--- a/src/wtforms/fields/core.py
+++ b/src/wtforms/fields/core.py
@@ -2,6 +2,7 @@ import datetime
 import decimal
 import inspect
 import itertools
+import warnings
 
 from markupsafe import escape
 from markupsafe import Markup
@@ -15,18 +16,25 @@ from wtforms.validators import ValidationError
 __all__ = (
     "BooleanField",
     "DecimalField",
+    "DecimalRangeField",
     "DateField",
     "DateTimeField",
+    "DateTimeLocalField",
+    "EmailField",
     "FieldList",
     "FloatField",
     "FormField",
     "IntegerField",
+    "IntegerRangeField",
     "RadioField",
+    "SearchField",
     "SelectField",
     "SelectMultipleField",
     "StringField",
+    "TelField",
     "TimeField",
     "MonthField",
+    "URLField",
 )
 
 
@@ -143,9 +151,21 @@ class Field:
             self.widget = widget
 
         for v in itertools.chain(self.validators, [self.widget]):
-            flags = getattr(v, "field_flags", ())
-            for f in flags:
-                setattr(self.flags, f, True)
+            flags = getattr(v, "field_flags", {})
+
+            # check for legacy format, remove eventually
+            if isinstance(flags, tuple):
+                warnings.warn(
+                    "Flags should be stored in dicts and not in tuples. "
+                    "The next version of WTForms will abandon support "
+                    "for flags in tuples.",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
+                flags = {flag_name: True for flag_name in flags}
+
+            for k, v in flags.items():
+                setattr(self.flags, k, v)
 
     def __str__(self):
         """
@@ -408,15 +428,15 @@ class UnboundField:
 
 class Flags:
     """
-    Holds a set of boolean flags as attributes.
+    Holds a set of flags as attributes.
 
-    Accessing a non-existing attribute returns False for its value.
+    Accessing a non-existing attribute returns None for its value.
     """
 
     def __getattr__(self, name):
         if name.startswith("_"):
             return super().__getattr__(name)
-        return False
+        return None
 
     def __contains__(self, name):
         return getattr(self, name)
@@ -670,7 +690,7 @@ class IntegerField(Field):
     is ignored and will not be accepted as a value.
     """
 
-    widget = widgets.TextInput()
+    widget = widgets.NumberInput()
 
     def __init__(self, label=None, validators=None, **kwargs):
         super().__init__(label, validators, **kwargs)
@@ -721,7 +741,7 @@ class DecimalField(LocaleAwareNumberField):
         format for the locale.
     """
 
-    widget = widgets.TextInput()
+    widget = widgets.NumberInput(step="any")
 
     def __init__(
         self, label=None, validators=None, places=unset_value, rounding=None, **kwargs
@@ -842,7 +862,7 @@ class DateTimeField(Field):
     A text field which stores a `datetime.datetime` matching a format.
     """
 
-    widget = widgets.TextInput()
+    widget = widgets.DateTimeInput()
 
     def __init__(
         self, label=None, validators=None, format="%Y-%m-%d %H:%M:%S", **kwargs
@@ -871,6 +891,8 @@ class DateField(DateTimeField):
     Same as DateTimeField, except stores a `datetime.date`.
     """
 
+    widget = widgets.DateInput()
+
     def __init__(self, label=None, validators=None, format="%Y-%m-%d", **kwargs):
         super().__init__(label, validators, format, **kwargs)
 
@@ -889,6 +911,8 @@ class TimeField(DateTimeField):
     Same as DateTimeField, except stores a `time`.
     """
 
+    widget = widgets.TimeInput()
+
     def __init__(self, label=None, validators=None, format="%H:%M", **kwargs):
         super().__init__(label, validators, format, **kwargs)
 
@@ -908,6 +932,8 @@ class MonthField(DateField):
     with `day = 1`.
     """
 
+    widget = widgets.MonthInput()
+
     def __init__(self, label=None, validators=None, format="%Y-%m", **kwargs):
         super().__init__(label, validators, format, **kwargs)
 
@@ -1189,3 +1215,59 @@ class FieldList(Field):
     @property
     def data(self):
         return [f.data for f in self.entries]
+
+
+class SearchField(StringField):
+    """
+    Represents an ``<input type="search">``.
+    """
+
+    widget = widgets.SearchInput()
+
+
+class TelField(StringField):
+    """
+    Represents an ``<input type="tel">``.
+    """
+
+    widget = widgets.TelInput()
+
+
+class URLField(StringField):
+    """
+    Represents an ``<input type="url">``.
+    """
+
+    widget = widgets.URLInput()
+
+
+class EmailField(StringField):
+    """
+    Represents an ``<input type="email">``.
+    """
+
+    widget = widgets.EmailInput()
+
+
+class DateTimeLocalField(DateTimeField):
+    """
+    Represents an ``<input type="datetime-local">``.
+    """
+
+    widget = widgets.DateTimeLocalInput()
+
+
+class IntegerRangeField(IntegerField):
+    """
+    Represents an ``<input type="range">``.
+    """
+
+    widget = widgets.RangeInput()
+
+
+class DecimalRangeField(DecimalField):
+    """
+    Represents an ``<input type="range">``.
+    """
+
+    widget = widgets.RangeInput(step="any")
diff --git a/src/wtforms/fields/html5.py b/src/wtforms/fields/html5.py
deleted file mode 100644
index 26d7efa..0000000
--- a/src/wtforms/fields/html5.py
+++ /dev/null
@@ -1,121 +0,0 @@
-from . import core
-from ..widgets import html5 as widgets
-
-__all__ = (
-    "DateField",
-    "DateTimeField",
-    "DateTimeLocalField",
-    "DecimalField",
-    "DecimalRangeField",
-    "EmailField",
-    "IntegerField",
-    "IntegerRangeField",
-    "SearchField",
-    "TelField",
-    "TimeField",
-    "URLField",
-)
-
-
-class SearchField(core.StringField):
-    """
-    Represents an ``<input type="search">``.
-    """
-
-    widget = widgets.SearchInput()
-
-
-class TelField(core.StringField):
-    """
-    Represents an ``<input type="tel">``.
-    """
-
-    widget = widgets.TelInput()
-
-
-class URLField(core.StringField):
-    """
-    Represents an ``<input type="url">``.
-    """
-
-    widget = widgets.URLInput()
-
-
-class EmailField(core.StringField):
-    """
-    Represents an ``<input type="email">``.
-    """
-
-    widget = widgets.EmailInput()
-
-
-class DateTimeField(core.DateTimeField):
-    """
-    Represents an ``<input type="datetime">``.
-    """
-
-    widget = widgets.DateTimeInput()
-
-
-class DateField(core.DateField):
-    """
-    Represents an ``<input type="date">``.
-    """
-
-    widget = widgets.DateInput()
-
-
-class TimeField(core.TimeField):
-    """
-    Represents an ``<input type="time">``.
-    """
-
-    widget = widgets.TimeInput()
-
-
-class MonthField(core.MonthField):
-    """
-    Represents an ``<input type="month">``.
-    """
-
-    widget = widgets.MonthInput()
-
-
-class DateTimeLocalField(core.DateTimeField):
-    """
-    Represents an ``<input type="datetime-local">``.
-    """
-
-    widget = widgets.DateTimeLocalInput()
-
-
-class IntegerField(core.IntegerField):
-    """
-    Represents an ``<input type="number">``.
-    """
-
-    widget = widgets.NumberInput()
-
-
-class DecimalField(core.DecimalField):
-    """
-    Represents an ``<input type="number">``.
-    """
-
-    widget = widgets.NumberInput(step="any")
-
-
-class IntegerRangeField(core.IntegerField):
-    """
-    Represents an ``<input type="range">``.
-    """
-
-    widget = widgets.RangeInput()
-
-
-class DecimalRangeField(core.DecimalField):
-    """
-    Represents an ``<input type="range">``.
-    """
-
-    widget = widgets.RangeInput(step="any")
diff --git a/src/wtforms/validators.py b/src/wtforms/validators.py
index 2d6bea2..059f32c 100644
--- a/src/wtforms/validators.py
+++ b/src/wtforms/validators.py
@@ -114,6 +114,8 @@ class Length:
         Error message to raise in case of a validation error. Can be
         interpolated using `%(min)d` and `%(max)d` if desired. Useful defaults
         are provided depending on the existence of min and max.
+
+    When supported, sets the `minlength` and `maxlength` attributes on widgets.
     """
 
     def __init__(self, min=-1, max=-1, message=None):
@@ -124,6 +126,11 @@ class Length:
         self.min = min
         self.max = max
         self.message = message
+        self.field_flags = {}
+        if self.min != -1:
+            self.field_flags["minlength"] = self.min
+        if self.max != -1:
+            self.field_flags["maxlength"] = self.max
 
     def __call__(self, form, field):
         length = field.data and len(field.data) or 0
@@ -174,12 +181,19 @@ class NumberRange:
         Error message to raise in case of a validation error. Can be
         interpolated using `%(min)s` and `%(max)s` if desired. Useful defaults
         are provided depending on the existence of min and max.
+
+    When supported, sets the `min` and `max` attributes on widgets.
     """
 
     def __init__(self, min=None, max=None, message=None):
         self.min = min
         self.max = max
         self.message = message
+        self.field_flags = {}
+        if self.min is not None:
+            self.field_flags["min"] = self.min
+        if self.max is not None:
+            self.field_flags["max"] = self.max
 
     def __call__(self, form, field):
         data = field.data
@@ -215,9 +229,9 @@ class Optional:
     :param strip_whitespace:
         If True (the default) also stop the validation chain on input which
         consists of only whitespace.
-    """
 
-    field_flags = ("optional",)
+    Sets the `optional` attribute on widgets.
+    """
 
     def __init__(self, strip_whitespace=True):
         if strip_whitespace:
@@ -225,6 +239,8 @@ class Optional:
         else:
             self.string_check = lambda s: s
 
+        self.field_flags = {"optional": True}
+
     def __call__(self, form, field):
         if (
             not field.raw_data
@@ -256,12 +272,13 @@ class DataRequired:
 
     :param message:
         Error message to raise in case of a validation error.
-    """
 
-    field_flags = ("required",)
+    Sets the `required` attribute on widgets.
+    """
 
     def __init__(self, message=None):
         self.message = message
+        self.field_flags = {"required": True}
 
     def __call__(self, form, field):
         if not field.data or isinstance(field.data, str) and not field.data.strip():
@@ -281,12 +298,13 @@ class InputRequired:
     Note there is a distinction between this and DataRequired in that
     InputRequired looks that form-input data was provided, and DataRequired
     looks at the post-coercion data.
-    """
 
-    field_flags = ("required",)
+    Sets the `required` attribute on widgets.
+    """
 
     def __init__(self, message=None):
         self.message = message
+        self.field_flags = {"required": True}
 
     def __call__(self, form, field):
         if not field.raw_data or not field.raw_data[0]:
diff --git a/src/wtforms/widgets/core.py b/src/wtforms/widgets/core.py
index 3e2a2eb..a0e0e61 100644
--- a/src/wtforms/widgets/core.py
+++ b/src/wtforms/widgets/core.py
@@ -3,17 +3,30 @@ from markupsafe import Markup
 
 __all__ = (
     "CheckboxInput",
+    "ColorInput",
+    "DateInput",
+    "DateTimeInput",
+    "DateTimeLocalInput",
+    "EmailInput",
     "FileInput",
     "HiddenInput",
     "ListWidget",
+    "MonthInput",
+    "NumberInput",
+    "Option",
     "PasswordInput",
     "RadioInput",
+    "RangeInput",
+    "SearchInput",
     "Select",
     "SubmitInput",
     "TableWidget",
     "TextArea",
     "TextInput",
-    "Option",
+    "TelInput",
+    "TimeInput",
+    "URLInput",
+    "WeekInput",
 )
 
 
@@ -148,6 +161,7 @@ class Input:
     """
 
     html_params = staticmethod(html_params)
+    validation_attrs = ["required"]
 
     def __init__(self, input_type=None):
         if input_type is not None:
@@ -158,8 +172,10 @@ class Input:
         kwargs.setdefault("type", self.input_type)
         if "value" not in kwargs:
             kwargs["value"] = field._value()
-        if "required" not in kwargs and "required" in getattr(field, "flags", []):
-            kwargs["required"] = True
+        flags = getattr(field, "flags", {})
+        for k in dir(flags):
+            if k in self.validation_attrs and k not in kwargs:
+                kwargs[k] = getattr(flags, k)
         return Markup("<input %s>" % self.html_params(name=field.name, **kwargs))
 
 
@@ -169,6 +185,7 @@ class TextInput(Input):
     """
 
     input_type = "text"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
 
 
 class PasswordInput(Input):
@@ -181,6 +198,7 @@ class PasswordInput(Input):
     """
 
     input_type = "password"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
 
     def __init__(self, hide_value=True):
         self.hide_value = hide_value
@@ -196,9 +214,12 @@ class HiddenInput(Input):
     Render a hidden input.
     """
 
-    field_flags = ("hidden",)
     input_type = "hidden"
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.field_flags = {"hidden": True}
+
 
 class CheckboxInput(Input):
     """
@@ -238,6 +259,7 @@ class FileInput(Input):
     """
 
     input_type = "file"
+    validation_attrs = ["required", "accept"]
 
     def __init__(self, multiple=False):
         super().__init__()
@@ -275,10 +297,14 @@ class TextArea:
     `rows` and `cols` ought to be passed as keyword args when rendering.
     """
 
+    validation_attrs = ["required", "maxlength", "minlength"]
+
     def __call__(self, field, **kwargs):
         kwargs.setdefault("id", field.id)
-        if "required" not in kwargs and "required" in getattr(field, "flags", []):
-            kwargs["required"] = True
+        flags = getattr(field, "flags", {})
+        for k in dir(flags):
+            if k in self.validation_attrs and k not in kwargs:
+                kwargs[k] = getattr(flags, k)
         return Markup(
             "<textarea %s>\r\n%s</textarea>"
             % (html_params(name=field.name, **kwargs), escape(field._value()))
@@ -297,6 +323,8 @@ class Select:
     `(value, label, selected)`.
     """
 
+    validation_attrs = ["required"]
+
     def __init__(self, multiple=False):
         self.multiple = multiple
 
@@ -304,8 +332,10 @@ class Select:
         kwargs.setdefault("id", field.id)
         if self.multiple:
             kwargs["multiple"] = True
-        if "required" not in kwargs and "required" in getattr(field, "flags", []):
-            kwargs["required"] = True
+        flags = getattr(field, "flags", {})
+        for k in dir(flags):
+            if k in self.validation_attrs and k not in kwargs:
+                kwargs[k] = getattr(flags, k)
         html = ["<select %s>" % html_params(name=field.name, **kwargs)]
         for val, label, selected in field.iter_choices():
             html.append(self.render_option(val, label, selected))
@@ -338,3 +368,141 @@ class Option:
         return Select.render_option(
             field._value(), field.label.text, field.checked, **kwargs
         )
+
+
+class SearchInput(Input):
+    """
+    Renders an input with type "search".
+    """
+
+    input_type = "search"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
+
+
+class TelInput(Input):
+    """
+    Renders an input with type "tel".
+    """
+
+    input_type = "tel"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
+
+
+class URLInput(Input):
+    """
+    Renders an input with type "url".
+    """
+
+    input_type = "url"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
+
+
+class EmailInput(Input):
+    """
+    Renders an input with type "email".
+    """
+
+    input_type = "email"
+    validation_attrs = ["required", "maxlength", "minlength", "pattern"]
+
+
+class DateTimeInput(Input):
+    """
+    Renders an input with type "datetime".
+    """
+
+    input_type = "datetime"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class DateInput(Input):
+    """
+    Renders an input with type "date".
+    """
+
+    input_type = "date"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class MonthInput(Input):
+    """
+    Renders an input with type "month".
+    """
+
+    input_type = "month"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class WeekInput(Input):
+    """
+    Renders an input with type "week".
+    """
+
+    input_type = "week"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class TimeInput(Input):
+    """
+    Renders an input with type "time".
+    """
+
+    input_type = "time"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class DateTimeLocalInput(Input):
+    """
+    Renders an input with type "datetime-local".
+    """
+
+    input_type = "datetime-local"
+    validation_attrs = ["required", "max", "min", "step"]
+
+
+class NumberInput(Input):
+    """
+    Renders an input with type "number".
+    """
+
+    input_type = "number"
+    validation_attrs = ["required", "max", "min", "step"]
+
+    def __init__(self, step=None, min=None, max=None):
+        self.step = step
+        self.min = min
+        self.max = max
+
+    def __call__(self, field, **kwargs):
+        if self.step is not None:
+            kwargs.setdefault("step", self.step)
+        if self.min is not None:
+            kwargs.setdefault("min", self.min)
+        if self.max is not None:
+            kwargs.setdefault("max", self.max)
+        return super().__call__(field, **kwargs)
+
+
+class RangeInput(Input):
+    """
+    Renders an input with type "range".
+    """
+
+    input_type = "range"
+    validation_attrs = ["required", "max", "min", "step"]
+
+    def __init__(self, step=None):
+        self.step = step
+
+    def __call__(self, field, **kwargs):
+        if self.step is not None:
+            kwargs.setdefault("step", self.step)
+        return super().__call__(field, **kwargs)
+
+
+class ColorInput(Input):
+    """
+    Renders an input with type "color".
+    """
+
+    input_type = "color"
diff --git a/src/wtforms/widgets/html5.py b/src/wtforms/widgets/html5.py
deleted file mode 100644
index 2a9ea76..0000000
--- a/src/wtforms/widgets/html5.py
+++ /dev/null
@@ -1,143 +0,0 @@
-from .core import Input
-
-__all__ = (
-    "ColorInput",
-    "DateInput",
-    "DateTimeInput",
-    "DateTimeLocalInput",
-    "EmailInput",
-    "MonthInput",
-    "NumberInput",
-    "RangeInput",
-    "SearchInput",
-    "TelInput",
-    "TimeInput",
-    "URLInput",
-    "WeekInput",
-)
-
-
-class SearchInput(Input):
-    """
-    Renders an input with type "search".
-    """
-
-    input_type = "search"
-
-
-class TelInput(Input):
-    """
-    Renders an input with type "tel".
-    """
-
-    input_type = "tel"
-
-
-class URLInput(Input):
-    """
-    Renders an input with type "url".
-    """
-
-    input_type = "url"
-
-
-class EmailInput(Input):
-    """
-    Renders an input with type "email".
-    """
-
-    input_type = "email"
-
-
-class DateTimeInput(Input):
-    """
-    Renders an input with type "datetime".
-    """
-
-    input_type = "datetime"
-
-
-class DateInput(Input):
-    """
-    Renders an input with type "date".
-    """
-
-    input_type = "date"
-
-
-class MonthInput(Input):
-    """
-    Renders an input with type "month".
-    """
-
-    input_type = "month"
-
-
-class WeekInput(Input):
-    """
-    Renders an input with type "week".
-    """
-
-    input_type = "week"
-
-
-class TimeInput(Input):
-    """
-    Renders an input with type "time".
-    """
-
-    input_type = "time"
-
-
-class DateTimeLocalInput(Input):
-    """
-    Renders an input with type "datetime-local".
-    """
-
-    input_type = "datetime-local"
-
-
-class NumberInput(Input):
-    """
-    Renders an input with type "number".
-    """
-
-    input_type = "number"
-
-    def __init__(self, step=None, min=None, max=None):
-        self.step = step
-        self.min = min
-        self.max = max
-
-    def __call__(self, field, **kwargs):
-        if self.step is not None:
-            kwargs.setdefault("step", self.step)
-        if self.min is not None:
-            kwargs.setdefault("min", self.min)
-        if self.max is not None:
-            kwargs.setdefault("max", self.max)
-        return super().__call__(field, **kwargs)
-
-
-class RangeInput(Input):
-    """
-    Renders an input with type "range".
-    """
-
-    input_type = "range"
-
-    def __init__(self, step=None):
-        self.step = step
-
-    def __call__(self, field, **kwargs):
-        if self.step is not None:
-            kwargs.setdefault("step", self.step)
-        return super().__call__(field, **kwargs)
-
-
-class ColorInput(Input):
-    """
-    Renders an input with type "color".
-    """
-
-    input_type = "color"


Test patch:
diff --git a/tests/test_fields.py b/tests/test_fields.py
index f36ce71..0986534 100644
--- a/tests/test_fields.py
+++ b/tests/test_fields.py
@@ -119,7 +119,7 @@ class TestFlags:
     def test_existing_values(self, flags):
         assert flags.required is True
         assert "required" in flags
-        assert flags.optional is False
+        assert flags.optional is None
         assert "optional" not in flags
 
     def test_assignment(self, flags):
@@ -1373,3 +1373,111 @@ class TestHTML5Fields:
             if field.data != item["data"]:
                 tmpl = "Field {key} data mismatch: {field.data!r} != {data!r}"
                 raise AssertionError(tmpl.format(field=field, **item))
+
+
+class TestFieldValidatorsTest:
+    class F(Form):
+        v1 = [validators.Length(min=1)]
+        v2 = [validators.Length(min=1, max=3)]
+        string1 = StringField(validators=v1)
+        string2 = StringField(validators=v2)
+        password1 = PasswordField(validators=v1)
+        password2 = PasswordField(validators=v2)
+        textarea1 = TextAreaField(validators=v1)
+        textarea2 = TextAreaField(validators=v2)
+        search1 = SearchField(validators=v1)
+        search2 = SearchField(validators=v2)
+
+        v3 = [validators.NumberRange(min=1)]
+        v4 = [validators.NumberRange(min=1, max=3)]
+        integer1 = IntegerField(validators=v3)
+        integer2 = IntegerField(validators=v4)
+        integerrange1 = IntegerRangeField(validators=v3)
+        integerrange2 = IntegerRangeField(validators=v4)
+        decimal1 = DecimalField(validators=v3)
+        decimal2 = DecimalField(validators=v4)
+        decimalrange1 = DecimalRangeField(validators=v3)
+        decimalrange2 = DecimalRangeField(validators=v4)
+
+    def test_minlength_maxlength(self):
+        form = self.F()
+        assert (
+            form.string1()
+            == '<input id="string1" minlength="1" name="string1" type="text" value="">'
+        )
+
+        assert (
+            form.string2() == '<input id="string2" maxlength="3" minlength="1"'
+            ' name="string2" type="text" value="">'
+        )
+
+        assert (
+            form.password1() == '<input id="password1" minlength="1"'
+            ' name="password1" type="password" value="">'
+        )
+
+        assert (
+            form.password2() == '<input id="password2" maxlength="3" minlength="1"'
+            ' name="password2" type="password" value="">'
+        )
+
+        assert (
+            form.textarea1() == '<textarea id="textarea1" minlength="1"'
+            ' name="textarea1">\r\n</textarea>'
+        )
+
+        assert (
+            form.textarea2() == '<textarea id="textarea2" maxlength="3" minlength="1"'
+            ' name="textarea2">\r\n</textarea>'
+        )
+
+        assert (
+            form.search1() == '<input id="search1" minlength="1"'
+            ' name="search1" type="search" value="">'
+        )
+
+        assert (
+            form.search2() == '<input id="search2" maxlength="3" minlength="1"'
+            ' name="search2" type="search" value="">'
+        )
+
+    def test_min_max(self):
+        form = self.F()
+        assert (
+            form.integer1()
+            == '<input id="integer1" min="1" name="integer1" type="number" value="">'
+        )
+        assert (
+            form.integer2() == '<input id="integer2" max="3" min="1"'
+            ' name="integer2" type="number" value="">'
+        )
+
+        assert (
+            form.integerrange1() == '<input id="integerrange1" min="1"'
+            ' name="integerrange1" type="range" value="">'
+        )
+
+        assert (
+            form.integerrange2() == '<input id="integerrange2" max="3" min="1"'
+            ' name="integerrange2" type="range" value="">'
+        )
+
+        assert (
+            form.decimal1() == '<input id="decimal1" min="1"'
+            ' name="decimal1" step="any" type="number" value="">'
+        )
+
+        assert (
+            form.decimal2() == '<input id="decimal2" max="3" min="1"'
+            ' name="decimal2" step="any" type="number" value="">'
+        )
+
+        assert (
+            form.decimalrange1() == '<input id="decimalrange1" min="1"'
+            ' name="decimalrange1" step="any" type="range" value="">'
+        )
+
+        assert (
+            form.decimalrange2() == '<input id="decimalrange2" max="3" min="1"'
+            ' name="decimalrange2" step="any" type="range" value="">'
+        )
diff --git a/tests/test_validators.py b/tests/test_validators.py
index dd4613c..4e373ff 100644
--- a/tests/test_validators.py
+++ b/tests/test_validators.py
@@ -31,7 +31,7 @@ def test_data_required(dummy_form, dummy_field):
     validator = data_required()
     dummy_field.data = "foobar"
     validator(dummy_form, dummy_field)
-    assert validator.field_flags == ("required",)
+    assert validator.field_flags == {"required": True}
 
 
 @pytest.mark.parametrize("bad_val", [None, "", " ", "\t\t"])
@@ -85,7 +85,7 @@ def test_input_required(dummy_form, dummy_field):
     dummy_field.raw_data = ["foobar"]
 
     validator(dummy_form, dummy_field)
-    assert validator.field_flags == ("required",)
+    assert validator.field_flags == {"required": True}
 
 
 def test_input_required_raises(dummy_form, dummy_field):
@@ -141,7 +141,7 @@ def test_input_optional_raises(data_v, raw_data_v, dummy_form, dummy_field):
 
     with pytest.raises(StopValidation):
         validator(dummy_form, dummy_field)
-        assert validator.field_flags == ("optional",)
+        assert validator.field_flags == {"optional": True}
 
     dummy_field.errors = ["Invalid Integer Value"]
     assert len(dummy_field.errors) == 1
diff --git a/tests/test_widgets.py b/tests/test_widgets.py
index 9bedec6..a9b7cd3 100644
--- a/tests/test_widgets.py
+++ b/tests/test_widgets.py
@@ -7,14 +7,14 @@ from wtforms.widgets.core import HiddenInput
 from wtforms.widgets.core import html_params
 from wtforms.widgets.core import Input
 from wtforms.widgets.core import ListWidget
+from wtforms.widgets.core import NumberInput
 from wtforms.widgets.core import PasswordInput
 from wtforms.widgets.core import RadioInput
+from wtforms.widgets.core import RangeInput
 from wtforms.widgets.core import Select
 from wtforms.widgets.core import TableWidget
 from wtforms.widgets.core import TextArea
 from wtforms.widgets.core import TextInput
-from wtforms.widgets.html5 import NumberInput
-from wtforms.widgets.html5 import RangeInput
 
 
 class TestHTMLParams: