I want to reload the table at the end of asynchronous communication.

I have a question about how to implement it in MVVM.

Model uses AFNetWorking to obtain JSON.
I would like to reload the View table when AFNetWorking's asynchronous communication ends, but in the case of MVVM, I understand that the Model does not operate the View.
Please tell me how to update the View in this case.

//Model
[manager POST:testAPI
   parameters —parameters
      success:^(NSURLSessionDataTask*task, id responseObject)
 {

     // Register Response in DB

     // TODO: I want to update the View after DB registration


 } failure:^(NSURLSessionDataTask*task, NSError*error)
 {
 }];

[delegate]
~~Even model.delegate=self in View will be nil when AFNetWorking blocks...~~
I just made a mistake in creating an instance of the Model.

ockblocks <
This is the flow of View→ViewModel→Model...

//View
    [_viewModel sampleMethod1:^{
        self refresh;
    }];

// ViewModel 
- (void)sampleMethod1:(void(^)(void))refreshView{
    [_model sampleMethod2:^{
    refreshView();
}];

// Model 
- (void)sampleMethod2:(void(^)(void))refreshView{
    ..........

    [manager POST:testAPI
       parameters —parameters
          success:^(NSURLSessionDataTask*task, id responseObject)
     {

         // Performs the process of registering a response to DB
         .......

         // TODO: After the above DB registration process, I want to update the View process.
         refreshView();

     } failure:^(NSURLSessionDataTask*task, NSError*error)
     {
     }];

}
Therefore, the processing from V to VM was further passed to M, and I felt that it was redundant.
I think there is a better way to write, but I don't know...

I don't know how to write in the case of Blocks, but I think I could implement it with delete.

ios objective-c mvvm

2022-09-30 21:12

1 Answers

There are about two ways to inform you that the processing of the methods in the model has been completed.
(Write if asynchronous processing is included)

Make your own delete and call the delete method after processing is complete
Put Block syntax in method arguments

Each characteristic is

[Delegate Features]

Less nested sources
Optional eliminates the need to write the receiving process on the transfer side and prevents the source from becoming rough when using it in multiple locations
Cannot keep track of the source in series

BlCharacteristics of Block Syntax <

Easy to follow source processing in series (&write processing in series)
Reduce the number of methods in the model (delegate adds as many methods as needed)
Reduce the number of objects defined on the calling side of the model
Deep source nesting

and so on.
At first, I think it's okay to use either of them.

In my case, I use both, but
To use it differently,

Not consecutive asynchronous processing→delegate
Continuous asynchronous processing → Block syntax

In many cases, it may be

How do I write
[How to write delete]

Model.h as below

//Define Deligate
@protocol WebClientDelegate<NSObject>

- (void) didSuccess: (NSDictionary* response);
- (void) didFailure: (NSError* error);

@end

@ interface Model:NSObject

/// Properties for Reference at Deligated Destination
@property(assign,nonatomic)id<ModelDelegate>delegate;
....

@end

Model.m using the following methods:

 - (void) sampleMethod
 {
        [manager POST:testAPI
           parameters —parameters
              success:^(NSURLSessionDataTask*task, id responseObject)
        {

            // Register Response in DB

            // TODO: I want to update the View after DB registration
            NSDictionary* result = "Some result"
            if([self.delegate responsesToSelector:@selector(didSuccess:)]){
                [self.delegate didSuccess:result];
            }
        } failure:^(NSURLSessionDataTask*task, NSError*error){
            if([self.delegate responsesToSelector:@selector(didFailure:)]){
                [self.delegate didFailure:error];
            }
        }];
}

】How to write Block syntax /

-(void)sampleMethod:(void(^)(NSDictionary*response)) success 
             failure: (void(^)(NSError*error)) failure
 {
        [manager POST:testAPI
           parameters —parameters
              success:^(NSURLSessionDataTask*task, id responseObject)
        {

            // Register Response in DB

            // TODO: I want to update the View after DB registration
            NSDictionary* result = "Some result"
            success(result);
        } failure:^(NSURLSessionDataTask*task, NSError*error){
            failure(error);
        }];
}

will be

I hope this will be helpful.

2022-09-30 21:12

If you have any answers or tips

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