clojure - 我可以将实体及其父组件一直拉到组件树中吗？

Question

是否可以将一个实体和所有组件父级一直拉到树上？

反向递归拉动。

如果没有，我该怎么做？

Answer 1

数据拉动表达式确实支持反向属性导航。假设您的架构如下:

(d/transact conn [{:db/id                 (d/tempid :db.part/db)
                   :db/ident              :node/children
                   :db/valueType          :db.type/ref
                   :db/cardinality        :db.cardinality/many
                   :db.install/_attribute :db.part/db}])

创建树:

(defn node [name & children]
  (cond-> {:db/id  (d/tempid :db.part/user)
           :db/doc name}
    children (assoc :node/children children)))

(d/transact conn [(node "L1"
                        (node "L1.1"
                              (node "L1.1.1")
                              (node "L1.1.2"))
                        (node "L1.2"
                              (node "L1.2.1")))])

使用查询递归地拉取组件父级(注意“_children”):

(d/q '[:find (pull ?e [:db/doc {:node/_children ...}]) .
       :where [?e :db/doc "L1.2.1"]]
     (d/db conn)) 

=> {:db/doc "L1.2.1", :node/_children [{:db/doc "L1.2", :node/_children [{:db/doc "L1"}]}]}