I'm a little behind on Nevow changes, and I just came across this change to the Choice interface. It looks cool (deferred support is a big plus), but so far all the examples I've seen involve declaring the available choices as part of the interface definition, e.g.: class MyInterface(TypedInterface): pickOne = Choice(lambda c,d: [1,2,3,4]) What I do (fairly regularly) with my application involves declaring the available choices as part of the _implementing_ class, not as part of the interface. I typically used choicesAttribute to do this, and was working on something along the lines of a choicesMethod, but now it seems that this behavior has been deprecated. So, what is the new recommended syntax for a Choice where the implementing class can change the choices dynamically? On Thu, Dec 16, 2004 at 01:49:29PM -0500, Donovan Preston wrote:

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Author: dp Date: Thu Dec 16 13:49:28 2004 New Revision: 962

Modified: trunk/examples/formbuilder.py trunk/examples/formpost2.py trunk/formless/annotate.py trunk/formless/webform.py Log: One billion times better Choice implementation; supports lazy choices from a function, a deferred, etc. Has valueToKey and keyToValue methods which are used to serialize/unserialize the choice instead of the index into the list.

Modified: trunk/examples/formbuilder.py ============================================================================== --- trunk/examples/formbuilder.py (original) +++ trunk/examples/formbuilder.py Thu Dec 16 13:49:28 2004 @@ -10,6 +10,9 @@ from formless import webform from formless import configurable

+from twisted.python import reflect + + class BuilderCore(configurable.Configurable): def __init__(self): configurable.Configurable.__init__(self, None) @@ -32,10 +35,11 @@

allTypes = [annotate.String, annotate.Text, annotate.Integer, annotate.Real, annotate.Password] +typeChoice = annotate.Choice(choices=allTypes, valueToKey=reflect.qual, keyToValue=reflect.namedAny, stringify=lambda x: x.__name__)

class IFormBuilder(annotate.TypedInterface): - def addElement(self, name=annotate.String(required=True), type=annotate.Choice(choices=allTypes)): + def addElement(self, name=annotate.String(required=True), type=typeChoice): """Add Element

Add an element to this form.

Modified: trunk/examples/formpost2.py ============================================================================== --- trunk/examples/formpost2.py (original) +++ trunk/examples/formpost2.py Thu Dec 16 13:49:28 2004 @@ -3,15 +3,24 @@ from nevow import loaders from nevow import rend from nevow import tags +from nevow import inevow

from formless import annotate from formless import webform

+from twisted.internet import defer + + +oldChoicesWay = annotate.Choice(choicesAttribute='theChoices') # Doing this gives you a DeprecationWarning now +# If you still want to use an attribute or method of some other object, you should use a function as shown below, +# but look up IResource(ctx) or IConfigurable(ctx), whichever is more appropriate. +newChoicesWay = annotate.Choice(lambda c, d: range(30)) +deferChoicesWay = annotate.Choice(lambda c, d: defer.succeed(['abcd', 'efgh', 'ijkl']))

class IMyForm(annotate.TypedInterface): foo = annotate.Integer()

- def bar(self, baz=annotate.Integer()): + def bar(self, baz=annotate.Integer(), bamf=oldChoicesWay, slam=newChoicesWay, ham=deferChoicesWay): pass bar = annotate.autocallable(bar)

@@ -21,8 +30,10 @@

foo = 5

- def bar(self, baz): - print "baz!", baz + def bar(self, baz, bamf, slam, ham): + return "You called bar! %s %s %s %s" % (baz, bamf, slam, ham) + + theChoices = [1, 2, 3]

class FormPage(rend.Page): @@ -31,12 +42,19 @@

child_webform_css = webform.defaultCSS

+ def render_hand(self, ctx, data): + hand = inevow.IHand(ctx, default=None) + if hand is not None: + return ctx.tag[hand] + return '' + docFactory = loaders.stan( tags.html[ tags.head[ tags.link(rel='stylesheet', type='text/css', href='/webform_css'), ], tags.body[ + tags.h3(render=render_hand, style="color: red; font-size: xx-large"), "Hello! Here is a form:",

# We want to render forms defined by the Implementation instance.

Modified: trunk/formless/annotate.py ============================================================================== --- trunk/formless/annotate.py (original) +++ trunk/formless/annotate.py Thu Dec 16 13:49:28 2004 @@ -10,6 +10,7 @@ import copy import inspect import types +import warnings

from nevow import inevow from nevow import util @@ -238,28 +239,29 @@ are configuring. The elements of the list will be rendered by calling the function passed to stringify, which is by default "str". """ - def __init__(self, choices=None, choicesAttribute=None, stringify=str, *args, **kw): + def __init__(self, choices=None, choicesAttribute=None, stringify=str, valueToKey=str, keyToValue=str, *args, **kw): Typed.__init__(self, *args, **kw) - if choices is None: - self.choices = [] - else: - self.choices = choices - self.choicesAttribute = choicesAttribute + self.choices = choices + if choicesAttribute: + self.choicesAttribute = choicesAttribute + if getattr(self, 'choicesAttribute', None): + warnings.warn( + "Choice.choicesAttribute is deprecated. Please pass a function to choices instead.", + DeprecationWarning, + stacklevel=2) + def findTheChoices(ctx, data): + return getattr(iformless.IConfigurable(ctx).original, self.choicesAttribute) + self.choices = findTheChoices + self.stringify = stringify + self.valueToKey=valueToKey + self.keyToValue=keyToValue

def coerce(self, val, binding): """Coerce a value with the help of an object, which is the object we are configuring. """ - try: - val = int(val) - except ValueError: - raise InputError("%r is an invalid choice." % val) - if self.choicesAttribute is not None: - choices = getattr(binding, self.choicesAttribute) - else: - choices = self.choices - return choices[val] + return self.keyToValue(val)

class Any(object):

Modified: trunk/formless/webform.py ============================================================================== --- trunk/formless/webform.py (original) +++ trunk/formless/webform.py Thu Dec 16 13:49:28 2004 @@ -62,6 +62,7 @@ def rend(self, context, data): defaults = context.locate(iformless.IFormDefaults) value = defaults.getDefault(context.key, context) + context.remember(data.typedValue, iformless.ITyped)

if data.typedValue.getAttribute('immutable'): inp = span(id=keyToXMLID(context.key))[value] @@ -145,32 +146,45 @@ _class='freeform-input-file')]

+class ICurrentlySelectedValue(compy.Interface): + """The currently-selected-value for the ITypedRenderer being rendered. + """ + + +csv = ICurrentlySelectedValue +def valToKey(c, d): + return iformless.ITyped(c).valueToKey(d) + + +def isSelected(c, d): + if csv(c) == valToKey(c, d): + return c.tag(selected='selected') + return c.tag + + +default_select = select(id=slot('id'), name=slot('name'), render=directive('sequence'), foo="bar")[ + option(pattern="item", + value=valToKey, + render=isSelected)[ + lambda c, d: iformless.ITyped(c).stringify(d)]] + + class ChoiceRenderer(BaseInputRenderer): def input(self, context, slot, data, name, value): tv = data.typedValue - if tv.choicesAttribute: - choices = getattr(context.locate(iformless.IConfigurable).boundTo, tv.choicesAttribute) - else: - choices = tv.choices + choices = tv.choices

- numChoices = len(choices) - if numChoices == 0: - return None + if value: + context.remember(self.original.valueToKey(value), csv) + else: + context.remember('', csv)

try: selector = context.tag.patternGenerator( 'selector' ) except NodeNotFound: - selector = select - - selector = selector(id=keyToXMLID(context.key), name=name) - stringify = tv.stringify + selector = default_select

- for index, val in enumerate(choices): - if val == value: - selector[option(value=str(index), selected="selected")[stringify(val)]] - else: - selector[option(value=str(index))[stringify(val)]] - return slot[selector] + return selector(data=choices)

class ObjectRenderer(compy.Adapter): @@ -259,6 +273,7 @@ class PropertyBindingRenderer(BaseBindingRenderer): def rend(self, context, data): context.remember(data, iformless.IBinding) + context.remember(data.typedValue, iformless.ITyped) typedRenderer = iformless.ITypedRenderer(data.typedValue, defaultBindingRenderer, persist=False) if typedRenderer.complexType: return invisible(data=data, render=typedRenderer) @@ -337,11 +352,13 @@ except NodeNotFound: default_content_pattern = freeformDefaultContentPattern content_pattern = default_content_pattern + renderer = iformless.ITypedRenderer( + argument.typedValue, defaultBindingRenderer, persist=False) pat = content_pattern( key=argument.name, data=argument, - render= iformless.ITypedRenderer( - argument.typedValue, defaultBindingRenderer, persist=False)) + render=renderer, + remember={iformless.ITyped: argument.typedValue}) context.fillSlots( 'argument!!%s' % argument.name, pat ) yield pat

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