Controlling Access

Access Values

You can specify these values for the access system attribute.

private

Available within the component, app, interface, event, or method and can’t be referenced outside the resource. This value can only be used for <aura:attribute> or <aura:method>.

Marking an attribute as private makes it easier to refactor the attribute in the future as the attribute can only be used within the resource.

Accessing a private attribute returns undefined unless you reference it from the component in which it’s declared. You can’t access a private attribute from a sub-component that extends the component containing the private attribute.

public

Available within your org only. This is the default access value.

global

Available in all orgs.

Mark your resources, such as a component, with access="global" to make the resource usable outside of your own org. For example, if you want a component to be usable in an installed package or by a Lightning App Builder user or a Community Builder user in another org.

Note

Example

This sample component has global access.

1<aura:component access="global">
2    ...
3</aura:component>

Access Violations

If your code accesses a resource, such as a component or attribute, that doesn’t have an access system attribute allowing you to access it, the code doesn’t execute or returns undefined.

If you enabled debug mode, you also see a popup error message.

Anatomy of an Access Check Error Message

Here is a sample access check error message for an access violation.

1Access  Check  Failed ! ComponentService.getDef():'markup://c:targetComponent' is not visible to 'markup://c:sourceComponent'.

An error message has four parts:

1. The context (who is trying to access the resource). In our example, this is markup://c:sourceComponent.
2. The target (the resource being accessed). In our example, this is markup://c:targetComponent.
3. The type of failure. In our example, this is not visible.
4. The code that triggered the failure. This is usually a class method. In our example, this is ComponentService.getDef(), which means that the target definition (component) was not accessible. A definition describes metadata for a resource, such as a component.

Fixing Access Check Errors

You can fix access check errors using one or more of these techniques.

• Add appropriate access system attributes to the resources that you own.
• Remove references in your code to resources that aren’t available. In the earlier example, markup://c:targetComponent doesn’t have an access value allowing markup://c:sourceComponent to access it.
• Ensure that an attribute that you’re accessing exists by looking at its <aura:attribute> definition. Confirm that you’re using the correct case-sensitive spelling for the name.

  Accessing an undefined attribute or an attribute that is out of scope, for example a private attribute, triggers the same access violation message. The access context doesn’t know whether the attribute is undefined or inaccessible.

Example: is not visible to 'undefined'

1ComponentService.getDef():'markup://c:targetComponent' is not visible to 'undefined'

The key word in this error message is undefined, which indicates that the framework has lost context. This happens when your code accesses a component outside the normal framework lifecycle, such as in a setTimeout() or setInterval() call or in an ES6 Promise.

Fix this error by wrapping the code in a $A.getCallback() call. For more information, see Modifying Components Outside the Framework Lifecycle.

Example: is not visible to 'InvalidComponent ...'

1ComponentService.getDef():'markup://c:targetComponent' is not visible to 'InvalidComponent markup://c:sourceComponent'

The key word in this error message is InvalidComponent, which indicates that c:sourceComponent is invalid and has been destroyed.

Always add an isValid() check if you reference a component in asynchronous code, such as a callback or a timeout. If you navigate elsewhere in the UI while asynchronous code is executing, the framework unrenders and destroys the component that made the asynchronous request. You can still have a reference to that component, but it is no longer valid. Add an isValid() call to check that the component is still valid before processing the results of the asynchronous request.

Example: Cannot read property 'Yb' of undefined

1Action failed: c$sourceComponent$controller$doInit [Cannot read property 'Yb' of undefined]

This error message happens when you reference a property on a variable with a value of undefined. The error can happen in many contexts, one of which is the side-effect of an access check failure. For example, let’s see what happens when you try to access an undefined attribute, imaginaryAttribute, in JavaScript.

1var whatDoYouExpect = cmp.get("v.imaginaryAttribute");

This is an access check error and whatDoYouExpect is set to undefined. Now, if you try to access a property on whatDoYouExpect, you get an error.

1Action failed: c$sourceComponent$controller$doInit [Cannot read property 'Yb' of undefined]

The c$sourceComponent$controller$doInit portion of the error message tells you that the error is in the doInit method of the controller of the sourceComponent component in the c namespace.