multiparameter

Flexible serialization with MultiParamTypeClasses

由 拜拜、爱过 提交于 2020-03-26 05:55:22
问题 I'm playing around with an idea for an extensible serialization library. I have the following typeclass: class Monoid m => BuilderS m a where cstr :: String -> a -> m The idea is that people can define instances for pairs of different serializers/types, like this: import qualified Data.Serialize.Builder as B instance Serialize a => BuilderS B.Builder a where cstr _ = B.fromByteString . encode And a usage example: sfPut :: (BuilderS a b, Monoid a) => WriterT a Identity () sfPut = do tell $

How do ruby on rails multi parameter attributes *really* work (datetime_select)

由 冷暖自知 提交于 2019-12-17 23:37:46
问题 I believe that datetime_select is black magic. What I'm really trying to figure out is the whole 1i , 2i , 3i , 4i ... multiple parameters stuff. Specifically how is it handled in the back end (activerecord, something else?). What's with the 'i' after the order-number? Is it a type-specifier? If so what are other types that are available? I've read the source of date_helper.rb and it's quite opaque. Here's my motivation: I've got a :datetime column in my model and I want to input in the view

Use border-width like parameter in LESS

由 烂漫一生 提交于 2019-12-13 04:29:33
问题 I'm still discovering the utility of this technology. Please I have a question if someone can answer me. I'm trying to create a function like: .advancedBorder( @color, @size ) { border: @size solid @color; } div { .advancedBorder( #FFF, 1px 0px 1px 0px); } So, I tried in many ways to make it possible but without any success. The real reason is to create a function that can be added to any box and setting for it any border size and color I prefer with minimum lines of code. Can someone show me

What Does ActiveRecord::MultiparameterAssignmentErrors Mean?

由 心不动则不痛 提交于 2019-11-30 07:10:24
问题 I have a rails form with a datetime_select field. When I try to submit the form, I get the following exception: ActiveRecord::MultiparameterAssignmentErrors in WidgetsController#update 1 error(s) on assignment of multiparameter attributes If it's a validation error, why don't I see an error on the page? This is in Rails 2.0.2 回答1: It turns out that rails uses something called Multi-parameter assignment to transmit dates and times in small parts that are reassembled when you assign params to

What Does ActiveRecord::MultiparameterAssignmentErrors Mean?

由 ⅰ亾dé卋堺 提交于 2019-11-29 01:30:21
I have a rails form with a datetime_select field. When I try to submit the form, I get the following exception: ActiveRecord::MultiparameterAssignmentErrors in WidgetsController#update 1 error(s) on assignment of multiparameter attributes If it's a validation error, why don't I see an error on the page? This is in Rails 2.0.2 Jason Wadsworth It turns out that rails uses something called Multi-parameter assignment to transmit dates and times in small parts that are reassembled when you assign params to the model instance. My problem was that I was using a datetime_select form field for a date

How do ruby on rails multi parameter attributes *really* work (datetime_select)

由 断了今生、忘了曾经 提交于 2019-11-28 20:33:48
I believe that datetime_select is black magic. What I'm really trying to figure out is the whole 1i , 2i , 3i , 4i ... multiple parameters stuff. Specifically how is it handled in the back end (activerecord, something else?). What's with the 'i' after the order-number? Is it a type-specifier? If so what are other types that are available? I've read the source of date_helper.rb and it's quite opaque. Here's my motivation: I've got a :datetime column in my model and I want to input in the view via two text_field s: one for date and one for time. They need to be validated, merged together, then
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