metamodel.clj

; CRUD UI
{identity                                                   ; pass through query params, decoded from URL
 [{:hfnet/domains                                           ; virtual attribute, resolves to a collection queried
   [(:domain/ident {:hf/a :domains/edit})                   ; :hf/a means hyperlink to a detail view, not specified here
    {:domain/fiddle-database
     [:database/uri]}]}
  {(hf/new $domains)                                        ; allocates a tempid for a new entity to be created in database $domains
   [:db/id
    :domain/ident
    {:domain/fiddle-database
     [:database/uri]}
    {(hf/new $domains :domain/fiddle-database)              ; this new entity is attached to its parent entity
     [:db/id]}]}]

 nil                                                        ; no query params
 [{:hfnet/database-options-list                             ; picklist query
   [:db/id
    :database/uri]}]}

; Queries
{:hfnet/domains
 [:in $domains
  :find (pull $domains ?domain [:db/id])
  :where
  [$domains ?domain :domain/ident]]

 :hfnet/database-options-list
 [:in $domains
  :find (pull $domains ?e [:db/id])
  :where
  [$domains ?e :database/uri ?uri]]

 :hfnet/another-query                                       ; just an example of how server code eval might work
 (->> (d/datoms (d/db *conn*) :avet :domain/ident %)
      (map :e)
      (map (partial d/entity db)))}

; Schema
[{:db/ident :database/uri,
  :db/valueType :db.type/uri,
  :db/cardinality :db.cardinality/one,
  :db/unique :db.unique/identity,
  :db/doc "Datomic connection URI"}
 {:db/ident :domain/fiddle-database,
  :db/valueType :db.type/ref,
  :db/cardinality :db.cardinality/one,
  :db/doc "Database to store your fiddles. It is probably also assigned a name above, so your fiddles can query it, for example to generate site maps."}
 {:db/ident :domain/ident,
  :db/valueType :db.type/string,
  :db/cardinality :db.cardinality/one,
  :db/unique :db.unique/identity,
  :db/doc "Hyperfiddle Cloud subdomain."}
 {:db/ident :domain.database/name,
  :db/valueType :db.type/string,
  :db/cardinality :db.cardinality/one,
  :db/doc "Name of this database in Datomic query :in clause"}]

; Validation
(s/def :domain/fiddle-database (s/keys :req [:database/uri]))

; View progressive enhancement
(defmethod hf/render #{:domain/fiddle-database}
  [ctx props]
  [hfui/select ctx
   {:options :hfnet/database-options-list
    :option-label (comp str :database/uri)}])