...

_packages/common-contacts/srv/code-lists.js

@@ -0,0 +1,70 @@
+const cds = require ('@sap/cds')
+const READ='READ', WRITE = ['CREATE','UPDATE']
+
+const intercept = exports.intercept = cds.service.impl (async (srv) => {
+
+    for (let each in srv.entities) {
+
+        // intercept JSON-encoded elements
+        const jsons = await jsonsIn (srv.entities[each].elements)
+        if (jsons) {
+            srv.before (WRITE, each, ({data:row})=>{
+                for (let e of jsons) if (row[e])  row[e] = JSON.stringify (row[e])
+            })
+            srv.after (READ, each, (row)=>{
+                for (let e of jsons) if (row[e])  row[e] = JSON.parse (row[e])
+            })
+        }
+
+        // intercept references
+        const refs = await refsIn (srv.entities[each].elements, srv.model)
+        if (refs) srv.after (READ, each, (rows, req)=>{
+            for (let row of rows) {
+                for (let {element,codelist} of refs) {
+                    const entry = codelist [row[element]]
+                    if (entry) {
+                        const localized = entry.texts [req.user.locale || intercept.locale]
+                        row[element] = localized ? localized.name : entry.name
+                    }
+                }
+            }
+        })
+
+    }
+
+})
+
+
+function jsonsIn (elements) {
+    const jsons=[]; for (let e in elements) {
+        if (elements[e]['@JSON'])  jsons.push(e)
+    }
+    return jsons.length && jsons
+}
+
+async function refsIn (elements, model) {
+    const refs=[]; for (let e in elements) {
+        const $ref = elements[e]['@ref']
+        if ($ref) {
+            const d = model.definitions [$ref['=']]
+            refs.push({
+                element:e,
+                codelist: CodeLists[d.name] || (CodeLists[d.name] = await load(d))
+            })
+        }
+    }
+    return refs.length && refs
+}
+
+const load = exports.load = async (codelist) => {
+    const all = {}
+    const [entries,texts] = await Promise.all ([
+        SELECT.from (codelist),
+        SELECT.from (codelist.elements.texts.target)
+    ])
+    for (let {code,name,descr} of entries) all[code] = {name,descr}
+    for (let {code,locale,name,descr} of texts) (all[code].texts || (all[code].texts={})) [locale] = {name,descr}
+    return all
+}
+
+const CodeLists = {}