Provide a result for taskForCompletionOfAllTasks

[jtbthethird]

I want to do multiple asynchronous tasks in parallel, each of which returns a value, and then when all have completed, get an array of those results.

As of now, taskForCompletionOfAllTasks just returns a result of nil.

[adriendulong]

I would like the same thing.
It would be really useful to get the results of my parallel tasks.
Right now I can't use it because I don't get any result.

Thanks !

[goopi]

Same problem here.
One way to get each task result:

[[BFTask taskForCompletionOfAllTasks:tasks] continueWithBlock:^id(BFTask *task) {
    for (int i = 0; i < tasks.count; ++i) {
        NSLog(@"%@", [tasks[i] result]);
    }
    return nil;
}];

[rcbello]

How about this solution:

-(BFTask *)parallelTasksWitResult{

BFTaskCompletionSource *compSource = [BFTaskCompletionSource taskCompletionSource];

NSMutableDictionary *resultInfo = [NSMutableDictionary dictionary];
NSMutableArray *wrapperTasks = [NSMutableArray array];
NSArray *tasksToExecute = // tasks to execute

for (BFTask *task in tasksToExecute) {
    [wrapperTasks addObject:[task continueWithBlock:^id(BFTask *task) {

        //update result info

        return nil;
    }]];
}

[[BFTask taskForCompletionOfAllTasks:wrapperTasks] continueWithBlock:^id(BFTask *task) {
    [compSource setResult:resultInfo];
    return nil;
}];

return compSource.task;

}

[bklimt]

You have access to all of the BFTasks you waited on, so you can get their results, as @goopi demonstrated.

[gazialankus]

In a task chain, the task above has a task array in its closure. The task below needs to get the results of the task array from task.result, but it can't. It can't access the task array either, because the task array is in the scope of the above closure.

In a task chain like this, we don't have access to the BFTasks that we waited on.

Or, you may want to get the task that taskForCompletionOfAllTasks gives, and send it somewhere else in your project. Sending the task array along with it is not a good solution. It's a shame that this issue is closed.

The analogous Parse.Promise.when([p1, p2]).then(f) passes the result array to f. This is the expected behavior. Respectfully summoning the top contributor @nlutsenko

[nlutsenko]

@gazialankus

[nlutsenko]

This issue is probably actually resolved, since we have taskForCompletionAllTasksWithResults: now, which does exactly what you are describing - provides an array of results on successful completion of all tasks. Header reference here

[gazialankus]

OOH my bad! Sorry about that, and thank you for this awesome piece of software your highness :)