Struct WKContentWorld

#[repr(C)]
pub struct WKContentWorld { /* private fields */ }

Available on crate feature WKContentWorld only.

A WKContentWorld object allows you to separate your application’s interaction with content displayed in a WKWebView into different roles that cannot interfere with one another.

WKContentWorld objects should be treated as namespaces. This is useful for keeping your application’s web content environment separate from the environment of the web page content itself, as well as managing multiple different environments within your own application. For example:

• If you have complex scripting logic to bridge your web content to your application but your web content also has complex scripting libraries of its own, you avoid possible conflicts by using a client WKContentWorld.
• If you are writing a general purpose web browser that supports JavaScript extensions, you would use a different client WKContentWorld for each extension.

Since a WKContentWorld object is a namespace it does not contain any data itself. For example:

• If you store a variable in JavaScript in the scope of a particular WKContentWorld while viewing a particular web page document, after navigating to a new document that variable will be gone.
• If you store a variable in JavaScript in the scope of a particular WKContentWorld in one WKWebView, that variable will not exist in the same world in another WKWebView.

See also Apple’s documentation

Implementations

impl WKContentWorld

pub unsafe fn new(mtm: MainThreadMarker) -> Retained<Self>

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

pub unsafe fn pageWorld(mtm: MainThreadMarker) -> Retained<WKContentWorld>

Retrieve the main world that page content itself uses.

When interacting with page content in a WKWebView using the page content world you can disrupt the operation of page content (e.g. by conflicting with variable names in JavaScript set by the web page content itself).

pub unsafe fn defaultClientWorld( mtm: MainThreadMarker, ) -> Retained<WKContentWorld>

Retrieve the default world for API client use.

When using a content world different from the page content world you can still manipulate the DOM and built-in DOM APIs but without conflicting with other aspects of the page content (e.g. JavaScript from the web page content itself) Repeated calls will retrieve the same WKContentWorld instance.

pub unsafe fn worldWithName( name: &NSString, mtm: MainThreadMarker, ) -> Retained<WKContentWorld>

Retrieves a named content world for API client use.

Parameter name: The name of the WKContentWorld to retrieve.

When using a content world different from the page content world you can still manipulate the DOM and built-in DOM APIs but without conflicting with other aspects of the page content (e.g. JavaScript from the web page content itself) As long as a particular named WKContentWorld instance has not been deallocated, repeated calls with the same name will retrieve that same WKContentWorld instance. Each named content world is distinct from all other named content worlds, the defaultClientWorld, and the pageWorld. The name can be used to keep distinct worlds identifiable anywhere a world might be surfaced in a user interface. For example, the different worlds used in your application will be surfaced by name in the WebKit Web Inspector.

pub unsafe fn name(&self) -> Option<Retained<NSString>>

The name of the WKContentWorld

The pageWorld and defaultClientWorld instances will have a nil name. All other instances will have the non-nil name they were accessed by.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AsRef<AnyObject> for WKContentWorld

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for WKContentWorld

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<WKContentWorld> for WKContentWorld

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for WKContentWorld

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for WKContentWorld

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for WKContentWorld

const NAME: &'static str = "WKContentWorld"

The name of the Objective-C class that this type represents.

type Super = NSObject

The superclass of this class.

type ThreadKind = dyn MainThreadOnly

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for WKContentWorld

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for WKContentWorld

type Target = NSObject

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for WKContentWorld

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for WKContentWorld

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for WKContentWorld

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for WKContentWorld

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for WKContentWorld

const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for WKContentWorld

impl Eq for WKContentWorld