Split django.newforms into forms, fields, widgets, util. Also moved unit tests from docstrings to a standalone module in tests/regressiontests/forms, to save docstring memory overhead, keep code readable and fit our exisitng convention

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3945 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/widgets.py

@@ -0,0 +1,43 @@
+"""
+HTML Widget classes
+"""
+
+__all__ = ('Widget', 'TextInput', 'Textarea', 'CheckboxInput')
+
+from django.utils.html import escape
+
+# Converts a dictionary to a single string with key="value", XML-style.
+# Assumes keys do not need to be XML-escaped.
+flatatt = lambda attrs: ' '.join(['%s="%s"' % (k, escape(v)) for k, v in attrs.items()])
+
+class Widget(object):
+    def __init__(self, attrs=None):
+        self.attrs = attrs or {}
+
+    def render(self, name, value):
+        raise NotImplementedError
+
+class TextInput(Widget):
+    def render(self, name, value, attrs=None):
+        if value is None: value = ''
+        final_attrs = dict(self.attrs, type='text', name=name)
+        if attrs:
+            final_attrs.update(attrs)
+        if value != '': final_attrs['value'] = value # Only add the 'value' attribute if a value is non-empty.
+        return u'<input %s />' % flatatt(final_attrs)
+
+class Textarea(Widget):
+    def render(self, name, value, attrs=None):
+        if value is None: value = ''
+        final_attrs = dict(self.attrs, name=name)
+        if attrs:
+            final_attrs.update(attrs)
+        return u'<textarea %s>%s</textarea>' % (flatatt(final_attrs), escape(value))
+
+class CheckboxInput(Widget):
+    def render(self, name, value, attrs=None):
+        final_attrs = dict(self.attrs, type='checkbox', name=name)
+        if attrs:
+            final_attrs.update(attrs)
+        if value: final_attrs['checked'] = 'checked'
+        return u'<input %s />' % flatatt(final_attrs)