hyperfiddle-metamodel.edn

; This is the next iteration of the CRUD metamodel that powers Hyperfiddle
; Just a design sketch, the current metamodel in prod is different

; CRUD definition
{identity                                                   ; Pass through URL params to query
 [{:dustingetz/event-registration                           ; virtual attribute identifying a query
   [:db/id
    (:dustingetz/email {:hf/a :dustingetz/registrant-edit}) ; hyperlink to detail form
    :dustingetz/name
    {:dustingetz/gender
     [:db/ident]}
    {:dustingetz/shirt-size
     [:db/ident]}]}]

 nil                                                        ; no query params
 [{:dustingetz/genders                                      ; picklist for genders
   [:db/ident]}]

 ((hf/new) {:hf/tx :dustingetz/register})                   ; generate a Datomic tempid and wire up a transaction
 [:db/id
  :dustingetz/email
  :dustingetz/name
  {:dustingetz/gender
   [:db/ident
    {:dustingetz/shirt-sizes                                ; shirt-size options depend on gender
     [:db/ident]}]}
  {:dustingetz/shirt-size
   [:db/ident]}]}

; Queries
{:dustingetz/genders
 [:find (pull ?e [:db/ident])
  :where
  [?e :db/ident ?i]
  [(namespace ?i) ?ns]
  [(ground "dustingetz.gender") ?ns]]

 :dustingetz/shirt-sizes
 [:in $ ?gender
  :find (pull ?e [:db/ident])
  :where
  [?e :db/ident ?i]
  [?e :dustingetz.reg/gender ?gender]
  [(namespace ?i) ?ns]
  [(ground "dustingetz.shirt-size") ?ns]]

 :dustingetz/another-query                                  ; just an example of how server code eval might work
 (->> (d/q '[:in $ ?e
             :find ?a ?v ?tx ?x
             :where
             [?e ?a ?v ?tx ?x]]
           (d/history *$*)
           %)
      (map #(assoc % 0 (:db/ident (d/entity db (get % 0)))))
      (group-by #(nth % 2))
      (map-values #(sort-by first %))
      (sort-by first))}

; Validation
(s/def :dustingetz/register (s/keys :req [:dustingetz/email
                                          :dustingetz/name]
                                    :opt [:dustingetz/gender
                                          :dustingetz/shirt-size]))

; View progressive enhancement
(defmethod hyperfiddle.api/render #{:dustingetz/gender}     ; custom renderer for ::gender
  [ctx props]
  [hfui/select ctx                                          ; present as picklist
   {:options :dustingetz/genders                            ; Wire up picklist options to named query
    :option-label :db/ident}])                              ; picklist label

(defmethod hyperfiddle.api/render #{:dustingetz/shirt-size} ; custom renderer for ::shirt-size
  [ctx props]
  [hfui/select ctx                                          ; second picklist
   {:options :dustingetz/shirt-sizes
    :option-label :db/ident}])

; Transactions
(defmethod hyperfiddle.api/tx :dustingetz/register [ctx [e a v] props]
  [[:db/add v :dustingetz/registered-date (js/Date.)]])

; Schema
[{:db/ident :dustingetz/name,
  :db/valueType :db.type/string,
  :db/cardinality :db.cardinality/one,
  :db/doc "Registrant's name"}
 {:db/ident :dustingetz/email,
  :db/valueType :db.type/string,
  :db/cardinality :db.cardinality/one,
  :db/unique :db.unique/identity,
  :db/doc "Registrant's email"}
 {:db/ident :dustingetz/gender,
  :db/valueType :db.type/ref,
  :db/cardinality :db.cardinality/one,
  :db/doc "Registrant's gender (for shirt size)"}
 {:db/ident :dustingetz/shirt-size,
  :db/valueType :db.type/ref,
  :db/cardinality :db.cardinality/one,
  :db/doc "Selected tee-shirt size"}]