convertUniversalLink documentation

[jetaix]

Do you plan to document the convertUniversalLink method ?

[RyanLinXiang]

I actually have the same question here. In my opinion the documentation in general regarding how Adjust transforms the links should be more transparent and should also be added into the documentation of this SDK. For me it was not clear in the beginning that for Android will will receive Adjust universal links in the customer schema format myApp://path and for iOS as universal link in the format: 'https://{myToken}.adj.st' so that I do need the convertUniversalLink method in order to have it for iOS as customer schema format and in order to align it with our Android deep link handling. I think that this definitely needs to be explained directly in the documentation here.

Also I think this convertUniversalLink method could be offered independent of the Adjust iOS SDK so that we can convert the links directly in the AppDelegate.mm of our React Native app before they reach the Linking deep link handler. In the following I would like to share my approach:

//AppDelegate.mm

- (BOOL)application:(UIApplication *)application continueUserActivity:(NSUserActivity *)userActivity
 restorationHandler:(void (^)(NSArray *restorableObjects))restorationHandler {

    if ([[userActivity activityType] isEqualToString:NSUserActivityTypeBrowsingWeb]) {
        NSURL *url = [userActivity webpageURL];

        NSURL *oldStyleDeepLink = [AppDelegate convertUniversalLink:url scheme:@"myApp"];

        NSDictionary<UIApplicationOpenURLOptionsKey,id> *options = @{@"UIApplicationOpenURLOptionsOpenInPlaceKey": @0};

        if (oldStyleDeepLink) {
            return [RCTLinkingManager application:application openURL:oldStyleDeepLink options:options];
        }
    }

    return [RCTLinkingManager application:application
                      continueUserActivity:userActivity
                        restorationHandler:restorationHandler];
}

The AppDelegate convertUniversalLink method from above can be just extracted from the iOS SDK and put as a standalone into AppDelegate.mm this way:

//AppDelegate.mm continue

static NSString * const kUniversalLinkPattern       = @"https://[^.]*\\.ulink\\.adjust\\.com/ulink/?(.*)";
static NSString * const kShortUniversalLinkPattern  = @"http[s]?://[a-z0-9]{4}\\.adj\\.st/?(.*)";
static NSString * const kDefaultScheme              = @"AdjustUniversalScheme";
static NSString * const kOptionalRedirectPattern    = @"adjust_redirect=[^&#]*";

+ (BOOL)isNull:(id)value {
    return value == nil || value == (id)[NSNull null];
}

+ (NSURL *)convertUniversalLink:(NSURL *)url scheme:(NSString *)scheme {
    NSError *error = NULL;

    NSRegularExpression *universalLinkRegex = [NSRegularExpression regularExpressionWithPattern:kUniversalLinkPattern
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];

    NSRegularExpression *shortUniversalLinkRegex = [NSRegularExpression regularExpressionWithPattern:kShortUniversalLinkPattern
                                                                           options:NSRegularExpressionCaseInsensitive
                                                                             error:&error];
    if ([AppDelegate isNull:url]) {
        NSLog(@"Received universal link is nil");
        return nil;
    }

    if ([AppDelegate isNull:scheme] || [scheme length] == 0) {
        NSLog(@"Non-empty scheme required, using the scheme \"AdjustUniversalScheme\"");
        scheme = kDefaultScheme;
    }

    NSString *urlString = [url absoluteString];

    if ([AppDelegate isNull:urlString]) {
        NSLog(@"Parsed universal link is nil");
        return nil;
    }

    NSArray<NSTextCheckingResult *> *matches = [universalLinkRegex matchesInString:urlString options:0 range:NSMakeRange(0, [urlString length])];
    if ([matches count] == 0) {
        matches = [shortUniversalLinkRegex matchesInString:urlString options:0 range:NSMakeRange(0, [urlString length])];
        if ([matches count] == 0) {
            NSLog(@"Url doesn't match as universal link or short version");
            return nil;
        }
    }

    if ([matches count] > 1) {
        NSLog(@"Url match as universal link multiple times");
        return nil;
    }

    NSTextCheckingResult *match = matches[0];
    if ([match numberOfRanges] != 2) {
        NSLog(@"Wrong number of ranges matched");
        return nil;
    }

    NSString *tailSubString = [urlString substringWithRange:[match rangeAtIndex:1]];
    NSString *finalTailSubString = [AppDelegate removeOptionalRedirect:tailSubString];
    NSString *extractedUrlString = [NSString stringWithFormat:@"%@://%@", scheme, finalTailSubString];
    NSLog(@"Converted deeplink from universal link %@", extractedUrlString);
    NSURL *extractedUrl = [NSURL URLWithString:extractedUrlString];
    if ([AppDelegate isNull:extractedUrl]) {
        NSLog(@"Unable to parse converted deeplink from universal link %@", extractedUrlString);
        return nil;
    }
    return extractedUrl;
}

+ (NSString *)removeOptionalRedirect:(NSString *)tailSubString {
    NSError *error = NULL;
    NSRegularExpression *optionalRedirectRegex = [NSRegularExpression regularExpressionWithPattern:kOptionalRedirectPattern
                                                                               options:NSRegularExpressionCaseInsensitive
                                                                                 error:&error];

    if (optionalRedirectRegex == nil) {
        NSLog(@"Remove Optional Redirect regex not correctly configured");
        return tailSubString;
    }

    NSArray<NSTextCheckingResult *> *optionalRedirectmatches = [optionalRedirectRegex matchesInString:tailSubString
                                                                                              options:0
                                                                                                range:NSMakeRange(0, [tailSubString length])];
    if ([optionalRedirectmatches count] == 0) {
        NSLog(@"Universal link does not contain option adjust_redirect parameter");
        return tailSubString;
    }
    if ([optionalRedirectmatches count] > 1) {
        NSLog(@"Universal link contains multiple option adjust_redirect parameters");
        return tailSubString;
    }

    NSTextCheckingResult *redirectMatch = optionalRedirectmatches[0];
    NSRange redirectRange = [redirectMatch rangeAtIndex:0];
    NSString *beforeRedirect = [tailSubString substringToIndex:redirectRange.location];
    NSString *afterRedirect = [tailSubString substringFromIndex:(redirectRange.location + redirectRange.length)];
    if (beforeRedirect.length > 0 && afterRedirect.length > 0) {
        NSString *lastCharacterBeforeRedirect = [beforeRedirect substringFromIndex:beforeRedirect.length - 1];
        NSString *firstCharacterAfterRedirect = [afterRedirect substringToIndex:1];
        if ([@"&" isEqualToString:lastCharacterBeforeRedirect] &&
            [@"&" isEqualToString:firstCharacterAfterRedirect]) {
            beforeRedirect = [beforeRedirect substringToIndex:beforeRedirect.length - 1];
        }
        if ([@"&" isEqualToString:lastCharacterBeforeRedirect] &&
            [@"#" isEqualToString:firstCharacterAfterRedirect]) {
            beforeRedirect = [beforeRedirect substringToIndex:beforeRedirect.length - 1];
        }
        if ([@"?" isEqualToString:lastCharacterBeforeRedirect] &&
            [@"#" isEqualToString:firstCharacterAfterRedirect]) {
            beforeRedirect = [beforeRedirect substringToIndex:beforeRedirect.length - 1];
        }
        if ([@"?" isEqualToString:lastCharacterBeforeRedirect] &&
            [@"&" isEqualToString:firstCharacterAfterRedirect]) {
            afterRedirect = [afterRedirect substringFromIndex:1];
        }
    }

    NSString *removedRedirect = [NSString stringWithFormat:@"%@%@", beforeRedirect, afterRedirect];
    return removedRedirect;
}