When LockerService is enabled the Lightning Platform prevents the use of unsupported API objects or calls. That means your Lightning components code is allowed to use:
- Features built into JavaScript ("intrinsic" features)
- Published, supported features built into the Lightning Components framework
- Published, supported features built into the LockerService SecureThing objects
This rule deals with the intrinsic APIs in JavaScript, more formally known as ECMAScript.
What exactly are these "intrinsic APIs"? They're the APIs defined in the ECMAScript Language Specification. That is, things built into JavaScript. This includes Annex B of the specification, which deals with legacy browser features that aren't part of the "core" of JavaScript, but are nevertheless still supported for JavaScript running inside a web browser.
Note that some features of JavaScript that you might consider intrinsic—for example, the window and document global variables—are superceded by SecureThing objects, which offer a more constrained API.
This rule verifies that use of the intrinsic JavaScript APIs is according to the published specification. The use of non-standard, deprecated, and removed language features is disallowed.
The following pattern is considered an error:
{
onclick: function (cmp, evt, help) {
Array.prototype.foo();
}
}Example of correct code:
{
onclick: function (cmp, evt, help) {
Array.prototype.slice();
}
}