Struct CKSyncEngineRecordZoneChangeBatch

Source

pub struct CKSyncEngineRecordZoneChangeBatch { /* private fields */ }

Available on crate feature CKSyncEngineRecordZoneChangeBatch only.

Expand description

A batch of record zone changes that CKSyncEngine will send to the server in a single request.

Implementations§

Source §

impl CKSyncEngineRecordZoneChangeBatch

Source

pub unsafe fn initWithPendingChanges_recordProvider( this: Allocated<Self>, pending_changes: &NSArray<CKSyncEnginePendingRecordZoneChange>, record_provider: &DynBlock<dyn Fn(NonNull<CKRecordID>) -> *mut CKRecord + '_>, ) -> Option<Retained<Self>>

Available on crate features CKRecord and CKRecordID and CKSyncEngineState and block2 only.

Creates a batch of record zone changes according to a list of pending changes.

This will iterate over the pending changes in order and add them to the batch until it reaches the max batch size.

When it sees a pending save, it will ask the record provider for the actual CKRecord to send to the server. If you return nil from the record provider, this will skip to the next pending change.

This will return nil if there are no pending changes to send.

§Safety

record_provider block must be sendable.

Source

pub unsafe fn initWithRecordsToSave_recordIDsToDelete_atomicByZone( this: Allocated<Self>, records_to_save: Option<&NSArray<CKRecord>>, record_i_ds_to_delete: Option<&NSArray<CKRecordID>>, atomic_by_zone: bool, ) -> Retained<Self>

Available on crate features CKRecord and CKRecordID only.

Creates a batch of record zone changes to send to the server with a specific set of changes.

If you’d like to construct your own custom batches of changes to send to the server, you can do so with this initializer.

§Batch size limitations

When creating your own batches, you need to consider batch size limitations. There is a maximum count and size of records that can be sent to the server in a single batch. If you supply too many changes, or if the total size of the records is too large, then you might get a CKError/limitExceeded.

Tip: These batch size limitations are handled automatically by the initWithPendingChanges:recordProvider: initializer.

Source

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

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pub unsafe fn new() -> Retained<Self>

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pub unsafe fn recordsToSave(&self) -> Retained<NSArray<CKRecord>>

Available on crate feature CKRecord only.

The records to save to the server.

Source

pub unsafe fn recordIDsToDelete(&self) -> Retained<NSArray<CKRecordID>>

Available on crate feature CKRecordID only.

The IDs of the records to delete from the server.

Source

pub unsafe fn atomicByZone(&self) -> bool

If set to true, the sync engine will modify these records atomically by zone.

If this is true, and if any record change fails, then any other changes from that zone in this batch will also fail with CKError/batchRequestFailed.

Records that exist in different zones will not be modified together atomically.

Source

pub unsafe fn setAtomicByZone(&self, atomic_by_zone: bool)

Setter for atomicByZone.

Methods from Deref<Target = NSObject>§

Source

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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

Dynamically find the class of this object.

§Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

§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());

Source

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.

Source

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`
    }
}