JSDraw provides custom plug-in architecture. With the plug-in architecture, you can implement your code with the editor. One most common use case for this is to create a custom toolbar button to load structure from your corporation database using a corporation compound ID.
The example below is to get SMILES and show it in a dialog:
(Check the right button on the toolbar)
JSDraw.create('test', { plugins: [{ iconurl: 'plugins/word.gif', tooltips: 'Get SMILES', onclick: foo}] });
function foo(jsdraw) {
var smiles = jsdraw.getSmiles();
alert("SMILS: " + smiles);
}