Here is one I have been working on. It serializes the object with AMF
so it only needs one table. Note that your classes need to have a
[RemoteClass] metadata tag ( no alias needed) in order for them to be
deserialized correctly. Note that the static initialize method needs
to be called before the class can be instantiated.
package CloudSplitter.CodeGenerator.business
{
import flash.data.SQLConnection;
import flash.data.SQLResult;
import flash.data.SQLStatement;
import flash.errors.SQLError;
import flash.filesystem.File;
import flash.utils.ByteArray;
import mx.controls.Alert;
import mx.utils.Base64Decoder;
import mx.utils.Base64Encoder;
public class PersistanceManager
{
static private var connection:SQLConnection;
private var tableName:String = "persistant_object";
static public function initialize(persistanceDbName:String):void
{
if (connection == null)
{ connection =
createConnection(persistanceDbName);
}
}
static public function getConnection():SQLConnection
{
if (connection == null)
{
throw new Error("PersistanceManager has not
been initialzed");
}
else
{
return connection;
}
}
public function PersistanceManager()
{
if (connection == null)
{
throw new Error("PersistanceManager can not be
instantiated until
it has been initialzed");
}
}
static private function
createConnection(persistanceDbName:String):SQLConnection
{
var connection:SQLConnection = new SQLConnection();
var dbFile:File =
File.applicationStorageDirectory.resolvePath(persistanceDbName);
try
{
connection.open(dbFile);
}
catch (error:SQLError)
{
showError(error);
}
return connection;
}
public function createPersistanceTable():Boolean
{
var createStmt:SQLStatement = new SQLStatement();
createStmt.sqlConnection = connection;
var sql:String =
"CREATE TABLE IF NOT EXISTS " + tableName + " (
" +
tableName + "_id INTEGER PRIMARY KEY
AUTOINCREMENT" +
" ,identifier TEXT UNIQUE NOT NULL" +
" ,object_data BLOB" +
")";
createStmt.text = sql;
try
{
createStmt.execute();
var success:Boolean = true;
}
catch (error:SQLError)
{
showError(error);
success = false;
}
return success;
}
public function persistObject(identifier:String,
object:Object):void
{
var byteArr:ByteArray = new ByteArray();
byteArr.writeObject(object);
var encoder:Base64Encoder = new Base64Encoder();
encoder.encodeBytes(byteArr);
var encoded:String = encoder.toString()
var sqlResult:SQLResult = retrieveRecord(identifier);
if (sqlResult.data == null)
{
var sql:String =
"INSERT INTO " + tableName +
" ( identifier, object_data ) " +
" values ( '" + identifier + "',
'" + encoded + "' )";
}
else
{
sql =
"UPDATE " + tableName +
" SET object_data = '" + encoded
+ "' " +
" where identifier = '" +
identifier + "'";
}
execSql(sql);
}
private function retrieveRecord(identifier:String): SQLResult
{
var sql:String =
"SELECT * FROM " + tableName +
" WHERE identifier = '" + identifier +
"'";
var sqlResult:SQLResult = execSql(sql);
return sqlResult
}
public function retrieveObject(identifier:String):Object
{
var sqlResult:SQLResult = retrieveRecord(identifier);
var retrievedObject:Object;
if (sqlResult.data != null)
{
var encodedObject:String =
sqlResult.data[0].object_data;
var decoder:Base64Decoder = new Base64Decoder();
decoder.decode(encodedObject);
var byteArr:ByteArray = decoder.toByteArray();
retrievedObject = byteArr.readObject();
}
return retrievedObject;
}
public function deleteObject(identifier:String):void
{
var sql:String =
"DELETE FROM " + tableName +
" WHERE identifier = '" + identifier +
"'";
var result:SQLResult = execSql(sql);
}
private function execSql(sql:String):SQLResult
{
var statement:SQLStatement = new SQLStatement();
statement.text = sql;
statement.sqlConnection = connection;
statement.execute();
var sqlResult:SQLResult = statement.getResult();
return sqlResult
}
static private function showError(error:SQLError):void
{
Alert.show("Details: " + error.details, "Error message:
" +
error.message);
}
}
}
--- In flexcoders@yahoogroups.com, "Cameron Childress" <[EMAIL PROTECTED]>
wrote:
>
> Is anyone aware of any Lightweight AIR Persistence mechanisms (in
the spirit
> of Hibernate) for VOs? I am working alot of AIR and SQLite and
mostly when
> I am using SQLite, I'm just mimicking the VO structure for storing
objects
> and then bringing them back out later. It's alot more code than I
like to
> write and it just doesn't feel right.
>
> I'd love to be able to say "myValueObject.save(dbAlias)" or
> "myDBEngine.save(myValueObject)" and have my object stored in a
SQLite DB
> for later retrieval, creating tables on the fly as needed based on
the VO's
> property datatypes. Anyone aware of any efforts along these lines?
>
> Any other ways of looking at this problem that I am simply missing?
>
> -Cameron
>
> --
> Cameron Childress
> Sumo Consulting Inc
> http://www.sumoc.com
> ---
> cell: 678.637.5072
> aim: cameroncf
> email: [EMAIL PROTECTED]
>
