From e0ba9712d463ad71aef2142b74e000ecfc180fea Mon Sep 17 00:00:00 2001
From: "Jeremy Wall (zaphar)" <jeremy@marzhillstudios.com>
Date: Tue, 16 Apr 2013 22:46:16 -0500
Subject: [PATCH] A basic IndexedDb wrapper api.

* Init method for Initializing the Database.
* Basic CRUD methods.
* Session and Transaction Methods
   * for doing operations on an open database
   * and/or in a transaction.
---
 js/db.js | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 js/db.js

diff --git a/js/db.js b/js/db.js
new file mode 100644
index 00000000..0651f71d
--- /dev/null
+++ b/js/db.js
@@ -0,0 +1,134 @@
+// TODO(jwall): Use RequireJS http://requirejs.org/docs/jquery.html
+if (typeof dynamicbible == "undefined") {
+    dynamicbible = {};
+}
+
+// dynamicbible.db implements a basic wrapper for IndexedDB databases.
+// See http://www.w3.org/TR/IndexedDB/ for more details about the
+// IDB* interfaces referenced below.
+dynamicbible.db = {
+    version: 1,
+    dbName: "localdata",
+    stores: ['settings', 'verselists'],
+    debug: false,
+    // Initialize database. If debug is true then logging will be turned on.
+    Init: function(debug) {
+        var self = this;
+        self.debug = debug;
+        self.Session(
+            function(e) {
+                self.debug && console.log("Database Init complete");
+            });
+        return self;
+    },
+    // Internal method not for external use.
+    handleError: function(e) {
+        this.debug && console.log("Error: ", e);
+    },
+    // Internal method not for external use.
+    handleUpdate: function(e) {
+        var db = e.target.result;
+        e.target.transaction.onerror = this.handleError;
+        for (i in this.stores) {
+            if (db.objectStoreNames.contains(this.stores[i])) {
+                // TODO(jwall): handle this more gracefully?
+                db.deleteObjectStore(this.stores[i]);
+            }
+            var store = db.createObjectStore(this.stores[i],
+                                             {keyPath: "key"});
+        }
+    },
+    // Do operations on an open database.
+    // ops is expected to be a function taking an IDBDatabase object
+    // as a parameter.
+    Session: function(ops) {
+        var self = this;
+        var req = indexedDB.open(this.dbname, this.version);
+        // HandleUpgrades
+        req.onupgradeneeded = function(e) {
+          self.handleUpdate(e);
+        };
+        req.onsuccess = function(e) {
+          ops(e.target.result);
+        };
+    },
+    // Do operations on an open transaction scoped to the list of stores.
+    // ops is expected to be a function taking an IDBTransation object
+    // as a parameter.
+    // type is an optional transaction type. values should be one of the
+    // following: readonly or readwrite
+    Transaction: function(stores, ops, type) {
+        var self = this;
+        var transType = type || "readonly";
+        self.debug && console.log(
+            "running", transType, "transaction on stores",
+            stores);
+        self.Session(
+            function(db) {
+                // Figure this api out.
+                var trans = db.transaction(stores, transType);
+                ops(trans);
+            });
+    },
+    // Get a key from the the object store.
+    // success is expected to be a function taking an IDBRequest object
+    // as a parameter.
+    // error is optional and expected to be a function taking an IDBRequest
+    // object as a parameter.
+    Get: function(storeName, key, success, error) {
+        var self = this;
+        self.Transaction(
+            [storeName], function(trans) {
+                var store = trans.objectStore(storeName);
+                var req = store.get(key);
+                req.onsuccess = success;
+                req.onerror = error || self.handleError;
+            });
+    },
+    // Store or update a key with data in an object store.
+    // success is expected to be a function taking an IDBRequest object
+    // as a parameter.
+    // error is optional and expected to be a function taking an IDBRequest
+    // object as a parameter.
+    Update: function(storeName, key, data, success, error) {
+        var self = this;
+        self.Transaction(
+            [storeName], function(trans) {
+                var store = trans.objectStore(storeName);
+                var req = store.put({"key": key, "data": data});
+                req.onsuccess = success;
+                req.onerror = error || self.handleError;
+            }, "readwrite");
+    },
+    // Delete a key from an object store.
+    // success is expected to be a function taking an IDBRequest object
+    // as a parameter.
+    // error is optional and expected to be a function taking an IDBRequest
+    // object as a parameter.
+    Delete: function(storeName, key, success, error) {
+        var self = this;
+        self.Transaction(
+            [storeName], function(trans) {
+                var store = trans.objectStore(storeName);
+                var req = store.delete(key);
+                req.onsuccess = success;
+                req.onerror = error || self.handleError;
+            }, "readwrite");
+    },
+    // Query a range of values from an object store.
+    // range is expected to be an IDBKeyRange.
+    // success is expected to be a function taking an IDBRequest object
+    // as a parameter.
+    // error is optional and expected to be a function taking an IDBRequest
+    // object as a parameter.
+    Query: function(storeName, range, success, error) {
+        var self = this;
+        self.Transaction(
+            [storeName], function(trans) {
+                var store = trans.objectStore(storeName);
+                var req = store.openCursor(range);
+                req.onsuccess = success;
+                req.onerror = error || self.handleError;
+            });
+    }
+};