我在bacon.js中构建可自定义的表单。我有一个问题,可选字段可以为空,例如有时需要电话或有时可选。
field_events = _.merge(
_.mapValues(@form, @_build_field_streams), dynamic_field_events
)
valid_streams = _.pluck(_.values(field_events), 0)
all_invalid = Bacon.all(valid_streams).not().toProperty()
data_prop = Bacon.combineTemplate(
_.mapValues(field_events, ([is_valid, value_stream]) -> value_stream)
)
submit_stream = @$el
.asEventStream('click', @submit_selector)
.doAction(".preventDefault")
.alwaysSkipWhile(all_invalid)
@actions = Bacon.when(
[data_prop, submit_stream],
(data) -> {action: 'submit', param: data}
)
data_prop被懒惰地评估,因此如果电话流没有任何价值,我们将无法提交表格。有没有办法为流提供默认值或从combineTemplate
过滤空流?
其余代码:
_build_field_streams: ({selector, validator}, field) =>
value_stream = Bacon.mergeAll(
@_get_field_change_streams(selector)
).map((e) ->
$(e.currentTarget).val()
)
if _.isString validator
validator = exports.validators[validator]()
# optional field are valid by default and for empty values
is_optional_field = field not in @mandatory_field
curr_validator = validator || @noop_validator
validator_fun = (x) -> if is_optional_field and not x
return true
else
return curr_validator(x)
validator_stream = value_stream.map(validator_fun)
is_valid = validator_stream.map(_.isEmpty).toProperty(is_optional_field).log('field')
[ok_events, bad_events] = validator_stream.split(_.isEmpty)
bad_events = bad_events.debounce(@invalid_delay)
defocus = @$el.asEventStream('blur', selector)
# TODO: Might be good to instantly go bad _if_ it was already valid.
Bacon.when(
[ok_events], true
[is_valid, bad_events], ((valid) -> valid),
[is_valid, defocus], ((valid) -> valid)
).onValue( (valid) =>
if valid
@render_field_valid(selector)
else
@render_field_invalid(selector)
)
return [is_valid, value_stream]
_get_field_change_streams: (selector) ->
# Hopefully these 2 cover most things. Can always add more if we need.
return _.map ['change', 'keyup'], (handler) =>
@$el.asEventStream(handler, selector)
答案 0 :(得分:0)
使用当前代码,我必须在每个输入中键入内容。如果Bacon.when( [data_prop, submit_stream]
为非空属性并且我们收到data_prop
事件,那么我的理解是submit_stream
会触发。为什么data_prop
未被评估?我相信Bacon.combineTemplate
不会创建具有值的属性,除非所有value_stream
都有事件。
我将流转换为具有默认值
的道具data_prop = Bacon.combineTemplate(
_.mapValues(field_events, ([is_valid, value_stream]) -> value_stream.toProperty(''))
)