Recipe 17.2. Writing Data to a Shared Object

Problem

You want to add data to an LSO.

Solution

Add the values as properties of the shared object's data object.

Discussion

Shared objects have a special built-in property named data. The data property is an object to which you should add any information that you want stored in the shared object:

// Store a username value to the example shared object. example.data.username = "Darron";

Unlike previous versions of ActionScript, properties can no longer be attached directly to the shared object. A compile-time error is generated when trying to store data on the SharedObject instance itself instead of in the data property. This prevents potential erroneous attempts to save data:

example.variable = "This will cause a compile-time error.";

Additionally, trying to assign a value to the data property directly is incorrect:

example.data = "This will cause another compile-time error.";

The correct approach is to attach the value to a new property under the data property, as follows:

example.data.variable = "This is the correct way to store data.";

You can store several native ActionScript datatypes to the shared object's data property, as follows.

example.data.exampleArray = new Array( "a", "b", "c" ); example.data.exampleDate = new Date(); example.data.exampleObject = { key1: "example", key2: -12, key3: null };

However, you cannot store visual elements (such as movie clips, sprites, buttons, or text fields) or shared objects themselves to a shared object's data property so that the data persists correctly between sessions.