firebase-ios-sdk/Firebase/Database/Core/View/FValueEventRegistration.m

/*
 * Copyright 2017 Google
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#import "FValueEventRegistration.h"
#import "FCancelEvent.h"
#import "FDataEvent.h"
#import "FIRDataSnapshot_Private.h"
#import "FIRDatabaseQuery_Private.h"
#import "FQueryParams.h"
#import "FQuerySpec.h"
#import <FirebaseCore/FIRLogger.h>

@interface FValueEventRegistration ()
@property(nonatomic, strong) FRepo *repo;
@property(nonatomic, copy, readwrite) fbt_void_datasnapshot callback;
@property(nonatomic, copy, readwrite) fbt_void_nserror cancelCallback;
@property(nonatomic, readwrite) FIRDatabaseHandle handle;
@end

@implementation FValueEventRegistration

- (id)initWithRepo:(FRepo *)repo
            handle:(FIRDatabaseHandle)fHandle
          callback:(fbt_void_datasnapshot)callbackBlock
    cancelCallback:(fbt_void_nserror)cancelCallbackBlock {
    self = [super init];
    if (self) {
        self.repo = repo;
        self.handle = fHandle;
        self.callback = callbackBlock;
        self.cancelCallback = cancelCallbackBlock;
    }
    return self;
}

- (BOOL)responseTo:(FIRDataEventType)eventType {
    return eventType == FIRDataEventTypeValue;
}

- (FDataEvent *)createEventFrom:(FChange *)change query:(FQuerySpec *)query {
    FIRDatabaseReference *ref =
        [[FIRDatabaseReference alloc] initWithRepo:self.repo path:query.path];
    FIRDataSnapshot *snapshot =
        [[FIRDataSnapshot alloc] initWithRef:ref
                                 indexedNode:change.indexedNode];
    FDataEvent *eventData =
        [[FDataEvent alloc] initWithEventType:FIRDataEventTypeValue
                            eventRegistration:self
                                 dataSnapshot:snapshot];
    return eventData;
}

- (void)fireEvent:(id<FEvent>)event queue:(dispatch_queue_t)queue {
    if ([event isCancelEvent]) {
        FCancelEvent *cancelEvent = event;
        FFLog(@"I-RDB065001", @"Raising cancel value event on %@", event.path);
        NSAssert(
            self.cancelCallback != nil,
            @"Raising a cancel event on a listener with no cancel callback");
        dispatch_async(queue, ^{
          self.cancelCallback(cancelEvent.error);
        });
    } else if (self.callback != nil) {
        FDataEvent *dataEvent = event;
        FFLog(@"I-RDB065002", @"Raising value event on %@",
              dataEvent.snapshot.key);
        dispatch_async(queue, ^{
          self.callback(dataEvent.snapshot);
        });
    }
}

- (FCancelEvent *)createCancelEventFromError:(NSError *)error
                                        path:(FPath *)path {
    if (self.cancelCallback != nil) {
        return [[FCancelEvent alloc] initWithEventRegistration:self
                                                         error:error
                                                          path:path];
    } else {
        return nil;
    }
}

- (BOOL)matches:(id<FEventRegistration>)other {
    return self.handle == NSNotFound || other.handle == NSNotFound ||
           self.handle == other.handle;
}

@end