使用Prismatic模式验证多个多态值 [英] Validating multiple polymorphic values using Prismatic Schema

问题描述

稍后我问关于简单多态模式的问题，答案一直很好。

A little while ago I asked about simple polymorphic schemas, and the answer there worked well for a time.

现在，我想验证的地图有一个额外的值，这取决于另一个键的值。

Now the map I wish to validate has an additional value which is dependent upon another key's value.

的对象：

{:type      :foo         {:type      :bert        {:type      :foo
 :foo-param :bar          :bert-size :medium       :foo-param :bar
 :method    :baz          :method    :baz          :method    :bang
 :baz-rate  :max}         :baz-rate  :max}         :bangness  :considerable}

这里的鉴别符是：type 和：方法，每个都有自己的一组有效的同级键和值。

The discriminators here are :type and :method, each of which has its own set of valid sibling keys and values.

：type 存在，并且以下工作：

Previously only :type existed, and the following worked:

(def ^:private test-base-schema {:type (s/enum :foo :abc :banana)})

(def test-schema
  (s/conditional #(= (:type %) :foo)
                 (merge test-base-schema {:foo-param s/Keyword})
                 ; other conditions here
                 ))

但是现在有多个鉴别器，条件分支将是组合的。

However now that there is more than one discriminator, the number of conditional branches would be combinatorial.

一个选项是允许 {s / Any s / Any} 映射和使用 s / both ，但我不能允许模式是'松散'，因为意外的键/值应被视为无效。

One option is to allow {s/Any s/Any} in the maps and using s/both, but I cannot allow the schemas to be 'loose', as unexpected key/values should be seen as invalid.

我也不想更改正在验证的地图的结构，只允许验证使用此库。

I also do not want to change the structure of the map being validated just to allow validation to work using this library.

sane的方式来实现严格验证的地图有多个条件子模式？

Is there a sane way to achieve strict validation of maps that have multiple conditional sub-schemas?

推荐答案

一个snarky的答案是，这可能是一个嗅觉你的数据模型不太理想，你应该考虑重构它具有像

A snarky answer is that this may be a smell that your data model is less than ideal, and you should consider refactoring it to have nested structure like

{:type-info {:type :foo :foo-param :bar}
 :method-info {:method :baz :baz-rate :max}}

（也许）更有帮助的答案是，我不认为这是很容易与开箱即用的模式集，除了只写一个自定义谓词验证。

A (perhaps) more helpful answer is that I don't think this is easy with the out-of-the-box set of schemas, besides just writing a custom predicate for validation.

如果这是不可取的，我想你需要引入一个新的模式类型。幸运的是，这在用户代码（或第三方库）中很容易做到。不幸的是，我没有看到一个简单的方法来以清晰和正交的方式（不将它们组合成一个条件联合模式，或者具有条件感知联合）来表示这两个概念（严格联合和条件映射结构）。我相信有一种方法，但首先看不明显。

If this isn't desirable, I guess you need to introduce a new schema type. Fortunately, this is easy to do in user code (or a third-party library). Unfortunately, I don't see an easy way to represent these two concepts (strict union and conditional map structure) in a crisp and orthogonal way (without combining them into a single conditional-union schema, or having union be conditional-aware). I believe there's a a way, but it's not obvious to me at first look.

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