feat(storage): new Local and WebSQL/SQLite key value storage service

ionic/storage/sql.ts

@@ -0,0 +1,128 @@
+import {StorageStrategy} from './storage';
+
+import * as util from 'ionic/util';
+
+const DB_NAME = '__ionicstorage';
+
+export class SQLStorage extends StorageStrategy {
+  static BACKUP_LOCAL =  2
+  static BACKUP_LIBRARY = 1
+  static BACKUP_DOCUMENTS = 0
+
+  constructor(options) {
+    super();
+
+    let dbOptions = util.defaults({
+      name: DB_NAME,
+      backupFlag: SQLStorage.BACKUP_NONE,
+      existingDatabase: false
+    }, options);
+
+
+    if(window.sqlitePlugin) {
+      let location = this._getBackupLocation(dbOptions);
+
+      this._db = window.sqlitePlugin.openDatabase(util.extend({
+        name: dbOptions.name,
+        location: location,
+        createFromLocation: dbOptions.existingDatabase ? 1 : 0
+      }, dbOptions));
+    } else {
+      console.warn('Storage: SQLite plugin not installed, falling back to WebSQL. Make sure to install cordova-sqlite-storage in production!');
+
+      this._db = window.openDatabase(dbOptions.name, '1.0', 'database', 5 * 1024 * 1024);
+    }
+    this._tryInit();
+  }
+
+  _getBackupLocation(dbFlag) {
+    switch(dbFlag) {
+      case SQLStorage.BACKUP_LOCAL:
+        return 2;
+      case SQLStorage.BACKUP_LIBRARY:
+        return 1;
+      case SQLStorage.BACKUP_DOCUMENTS:
+        return 0;
+      default:
+        throw Error('Invalid backup flag: ' + dbFlag);
+    }
+  }
+
+  // Initialize the DB with our required tables
+  _tryInit() {
+    this._db.transaction((tx) => {
+      tx.executeSql('CREATE TABLE IF NOT EXISTS kv (key text primary key, value text)', [], (tx, res) => {
+      }, (tx, err) => {
+        console.error('Storage: Unable to create initial storage tables', tx, err);
+      });
+    });
+  }
+
+  get(key) {
+    return new Promise((resolve, reject) => {
+      try {
+
+        this._db.transaction(tx => {
+          tx.executeSql("select key, value from kv where key = ? limit 1", [key], (tx, res) => {
+            if(res.rows.length > 0) {
+              let item = res.rows.item(0);
+              resolve(item.value);
+            }
+            resolve(null);
+          }, (tx, err) => {
+            reject({
+              tx: tx,
+              err: err
+            });
+          })
+        }, err => {
+          reject(err);
+        });
+
+      } catch(e) {
+        reject(e);
+      }
+    });
+  }
+  set(key, value) {
+    return new Promise((resolve, reject) => {
+      try {
+        this._db.transaction(tx => {
+          tx.executeSql('insert or replace into kv(key, value) values (?, ?)', [key, value], (tx, res) => {
+            resolve();
+          }, (tx, err) => {
+            reject({
+              tx: tx,
+              err: err
+            });
+          })
+        }, err => {
+          reject(err);
+        });
+      } catch(e) {
+        reject(e);
+      }
+    });
+  }
+  remove(key) {
+    return new Promise((resolve, reject) => {
+      try {
+        this._db.transaction(tx => {
+          tx.executeSql('delete from kv where key = ?', [key], (tx, res) => {
+            resolve();
+          }, (tx, err) => {
+            reject({
+              tx: tx,
+              err: err
+            });
+          })
+        }, err => {
+          reject(err);
+        });
+      } catch(e) {
+        reject(e);
+      }
+    });
+
+  }
+}