SimpleChatTC:IDBHelper: Move core indexedDB helper as a module

ie opening db as well as a transaction to access a store within
the db.

tools/server/public_simplechat/idb.mjs

@@ -0,0 +1,45 @@
+//@ts-check
+// Helpers to handle indexedDB provided by browsers
+// by Humans for All
+//
+
+
+/**
+ * Allows the db connection to be openned.
+ * @param {string} dbName
+ * @param {string} storeName
+ * @param {string} callerTag
+ */
+export function db_open(dbName, storeName, callerTag="") {
+    let tag = `iDB:${callerTag}`
+    return new Promise((resolve, reject) => {
+        const dbConn = indexedDB.open(dbName, 1);
+        dbConn.onupgradeneeded = (ev) => {
+            console.debug(`DBUG:${tag}:Conn:Upgrade needed...`)
+            dbConn.result.createObjectStore(storeName);
+            dbConn.result.onerror = (ev) => {
+                console.info(`ERRR:${tag}:Db:Op failed [${ev}]...`)
+            }
+        };
+        dbConn.onsuccess = (ev) => {
+            console.debug(`INFO:${tag}:Conn:Opened...`)
+            resolve(dbConn.result);
+        }
+        dbConn.onerror = (ev) => {
+            console.info(`ERRR:${tag}:Conn:Failed [${ev}]...`)
+            reject(ev);
+        }
+    });
+}
+
+/**
+ * Get hold of a transaction wrt a specified store in the db
+ * @param {IDBDatabase} db
+ * @param {string} storeName
+ * @param {IDBTransactionMode} opMode
+ */
+export function db_trans_store(db, storeName, opMode) {
+    let dbTrans = db.transaction(storeName, opMode);
+    let dbOS = dbTrans.objectStore(storeName);
+    return dbOS
+}

tools/server/public_simplechat/toolsdbworker.mjs

@@ -4,44 +4,21 @@
 // by Humans for All
 //
 
+import * as mIdb from './idb.mjs'
+
+
 /**
  * Expects to get a message with cid, tcid, (f)name and args
  * Posts message with cid, tcid, (f)name and data if any
  */
 
 
-/**
- * Allows the db connection to be openned.
- */
-function db_open() {
-    return new Promise((resolve, reject) => {
-        const dbConn = indexedDB.open('TCDB', 1);
-        dbConn.onupgradeneeded = (ev) => {
-            console.debug("DBUG:WWDb:Conn:Upgrade needed...")
-            dbConn.result.createObjectStore('theDB');
-            dbConn.result.onerror = (ev) => {
-                console.info(`ERRR:WWDb:Db:Op failed [${ev}]...`)
-            }
-        };
-        dbConn.onsuccess = (ev) => {
-            console.debug("INFO:WWDb:Conn:Opened...")
-            resolve(dbConn.result);
-        }
-        dbConn.onerror = (ev) => {
-            console.info(`ERRR:WWDb:Conn:Failed [${ev}]...`)
-            reject(ev);
-        }
-    });
-}
-
-
 self.onmessage = async function (ev) {
     try {
         console.info(`DBUG:WWDb:${ev.data.name}:OnMessage started...`)
         /** @type {IDBDatabase} */
-        let db = await db_open();
+        let db = await mIdb.db_open("TCDB", "theDB", "WWDb");
-        let dbTrans = db.transaction('theDB', 'readwrite');
+        let dbOS = mIdb.db_trans_store(db, "theDB", 'readwrite');
-        let dbOS = dbTrans.objectStore('theDB');
         let args = ev.data.args;
         switch (ev.data.name) {