我不理解示例undefined behavior:
def value_from_datadict(self, data, files, name):
datelist = [
widget.value_from_datadict(data, files, name + '_%s' % i)
for i, widget in enumerate(self.widgets)]
try:
D = date(
day=int(datelist[0]),
month=int(datelist[1]),
year=int(datelist[2]),
)
except ValueError:
return ''
else:
return str(D)
具体来说,我不明白何时应该使用widget.value_from_datadict()
以及我们如何使用它。如果您查看源代码本身,则根本没有记录(django\forms\widgets.py
):
def value_from_datadict(self, data, files, name):
return [widget.value_from_datadict(data, files, name + '_%s' % i) for i, widget in enumerate(self.widgets)]
答案 0 :(得分:3)
value_from_datadict()
是Widget
抽象类的一种方法,根据其doc字符串:
java.lang.UnsupportedOperationException: Schema for type AnyRef is not supported
at org.apache.spark.sql.catalyst.ScalaReflection$class.schemaFor(ScalaReflection.scala:718)
at org.apache.spark.sql.catalyst.ScalaReflection$.schemaFor(ScalaReflection.scala:30)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$schemaFor$1.apply(ScalaReflection.scala:693)
at org.apache.spark.sql.catalyst.ScalaReflection$$anonfun$schemaFor$1.apply(ScalaReflection.scala:691)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.immutable.List.foreach(List.scala:318)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
at scala.collection.AbstractTraversable.map(Traversable.scala:105)
at org.apache.spark.sql.catalyst.ScalaReflection$class.schemaFor(ScalaReflection.scala:691)
at org.apache.spark.sql.catalyst.ScalaReflection$.schemaFor(ScalaReflection.scala:30)
at org.apache.spark.sql.catalyst.ScalaReflection$class.schemaFor(ScalaReflection.scala:630)
at org.apache.spark.sql.catalyst.ScalaReflection$.schemaFor(ScalaReflection.scala:30)
at org.apache.spark.sql.UDFRegistration.register(UDFRegistration.scala:119)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:32)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:37)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:39)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:41)
at $iwC$$iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:43)
at $iwC$$iwC$$iwC$$iwC$$iwC.<init>(<console>:45)
at $iwC$$iwC$$iwC$$iwC.<init>(<console>:47)
at $iwC$$iwC$$iwC.<init>(<console>:49)
at $iwC$$iwC.<init>(<console>:51)
在您的具体案例中 - 来自docs我假设
def value_from_datadict(self, data, files, name):
"""
Given a dictionary of data and this widget's name, returns the value
of this widget. Returns None if it's not provided.
"""
return data.get(name)
def value_from_datadict(self, data, files, name):
datelist = [
widget.value_from_datadict(data, files, name + '_%s' % i)
for i, widget in enumerate(self.widgets)]
try:
D = date(
day=int(datelist[0]),
month=int(datelist[1]),
year=int(datelist[2]),
)
它与MultiWidget
表单字段一起使用,该字段采用单个值,因此
我们已经覆盖了这个方法来组合所有的数据 子小部件变为
DateField
。该方法从中提取数据datetime.date
字典并构造并验证日期。如果有效, 我们返回字符串,否则,我们返回一个空字符串 导致POST
返回form.is_valid
。