Use

A can-view-scope represents a lookup context and parent contexts that can be used to look up a key value.

If no parent scope is provided, only the scope’s context will be explored for values. For example:

const data = { name: { first: "Justin" } };
const scope = new Scope( data );

scope.get( "name.first" ); //-> "Justin"
scope.get( "length" );     //-> undefined

However, if a parent scope is provided, key values can be found in the parent’s context by prefixing the key with "../". find can also be used to search in the parent’s context after the initial context is explored. For example:

var list = [{name: "Justin"}, {name: "Brian"}];
var justin = list[0];

var listScope = new Scope(list);
var curScope = new Scope(justin, listScope);

// use `get` to find a value in an explicit context
curScope.get("name") //-> "Justin"
curScope.get("../length") //-> 2

// use `find` to search for a value in any context
curScope.find("name") //-> "Justin"
curScope.find("../length") //-> 2

Use add to easily create a new scope from a parent scope like:

const list = [ { name: "Justin" }, { name: "Brian" } ];
const justin = list[ 0 ];

const curScope = new Scope( list ).add( justin );

curScope.find( "name" ); //-> "Justin"
curScope.find( "length" ); //-> 2