iOS 8 Share extension loadItemForTypeIdentifier:options:completionHandler: completion closure not executing

Question

I\'m using the loadItemForTypeIdentifier:options:completionHandler: method on an NSItemProvider object to extract a url from Safari via a Share extension in iOS 8.

Answer 1

I was never managed completionHandler to work properly for Share extension with no user interface (in such case extension's class is a subclass on NSObject).

Despite the [itemProvider hasItemConformingToTypeIdentifier:(NSString *)kUTTypeURL] returns YES the completionHandler is never called both on the device or simulator.

After trying different approaches I ended up with workaround based on javascript passing URL back to extension (sorry as I use ObjC not Swift for my example).

Info.plist NSExtension portion:

NSExtension

    NSExtensionAttributes
    
        NSExtensionActivationRule
        
            NSExtensionActivationSupportsWebURLWithMaxCount
            1
        
        NSExtensionJavaScriptPreprocessingFile
        Action
    
    NSExtensionPointIdentifier
    com.apple.services
    NSExtensionPrincipalClass
    ActionRequestHandler

---

Javascript Action.js file:

var Action = function() {};
Action.prototype = {
    run: function(arguments) {
        arguments.completionFunction({ "currentURL" : window.location.href })
    },
    finalize: function(arguments) {
    }
};
var ExtensionPreprocessingJS = new Action

---

ActionRequestHandler.h header file:

@interface ActionRequestHandler : NSObject 

@end

---

ActionRequestHandler.m based on default Action extension template:

#import "ActionRequestHandler.h"
#import 

@interface ActionRequestHandler ()

@property (nonatomic, strong) NSExtensionContext *extensionContext;

@end

@implementation ActionRequestHandler

- (void)beginRequestWithExtensionContext:(NSExtensionContext *)context {
    // Do not call super in an Action extension with no user interface
    self.extensionContext = context;

    BOOL found = NO;

    // Find the item containing the results from the JavaScript preprocessing.
    for (NSExtensionItem *item in self.extensionContext.inputItems) {
        for (NSItemProvider *itemProvider in item.attachments) {
            if ([itemProvider hasItemConformingToTypeIdentifier:(NSString *)kUTTypePropertyList]) {
                [itemProvider loadItemForTypeIdentifier:(NSString *)kUTTypePropertyList options:nil completionHandler:^(NSDictionary *dictionary, NSError *error) {
                    [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                        [self itemLoadCompletedWithPreprocessingResults:dictionary[NSExtensionJavaScriptPreprocessingResultsKey]];
                    }];
                }];
                found = YES;
            }
            break;
        }
        if (found) {
            break;
        }
    }

    if (!found) {
        // We did not find anything - signal that we're done
        [self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
        // Don't hold on to this after we finished with it
        self.extensionContext = nil;
    }
}

- (void)itemLoadCompletedWithPreprocessingResults:(NSDictionary *)javaScriptPreprocessingResults
{
    // Get the URL
    if ([javaScriptPreprocessingResults[@"currentURL"] length] != 0) {
        NSLog(@"*** URL: %@", javaScriptPreprocessingResults[@"currentURL"]);
    }

    // Signal that we're done
    [self.extensionContext completeRequestReturningItems:@[] completionHandler:nil];
    // Don't hold on to this after we finished with it
    self.extensionContext = nil;
}

@end

Hope it will help somebody to save couple of hours struggling with the completionHandler issue.