Use

The instanceStore contains a mapping of instances keyed by their id. The instanceStore is used to prevent creating the same instance multiple times, and for finding active instance for a given id. Instances need to be added to this store for this to work. To do this, call addInstanceReference:

// a basic connection
var constructorStore = require("can-connect/constructor/store/");
var constructor = require("can-connect/constructor/");
var dataUrl = require("can-connect/data/url/");
var todoConnection = connect([dataUrl, constructorStore, constructor], {
  url: "/todos"
});

var originalTodo;

// get a todo
todoConnection.get({id: 5}).then(function( todo ){
  // add it to the store
  todoConnection.addInstanceReference(todo);
  originalTodo = todo;
});

Now, if you were to retrieve the same data sometime later, it would be the same instance:

todoConnection.get({id: 5}).then(function( todo ){
  todo === originalTodo // true
});

The .getData response data (underlying the call to todoConnection.get) is passed, along with the existing todo instance (originalTodo) to updatedInstance. That updates the shared instance with the newly retrieved data.

All the referenced instances are held in memory. Use deleteInstanceReference to remove them.

Typically, addInstanceReference is called when something expresses interest in the instance, such as an event binding, and deleteInstanceReference is called when the interest is removed.