Developed and Maintained by Ipodishima Founder & CTO at Wasappli Inc. (If you need to develop an app, get in touch with our team!)

So what is this library useful for? Good question. Let's answer by asking an other question. Have you been struggled at some point by the following issues?

• Well, I need to add some shortcuts to some parts of my apps and it seems crappy to manually allocate the path and select the controllers I need.
• I'm tired of using the push view controller method.
• I wish I had some kind of url handling to get to specific parts of my app juste as easily as snapping a finger.
• If it could even handle a controller stack this would juste be awesome.
• I found a library but it's not working with my custom container...
• I found a great library but the route matching is not working with my requirements...

All this points are answered by WAAppRouting (and more)

Table of Contents

1. The story
2. Install and use
3. Go deeper

#The story

What motivated me

Let's be honest, there are several routing libraries on Github to handle some of the behaviors described. But none of them fitted all my requirements. So I wrote this library with some things in mind:

• Handle a stack of a controller.

This is not ok to open the app on a hotel detail if there is not even a back button, or if the back button sends me back to where I was before opening the app. I just want the app to be opened so that when I hit back, I'm on the hotels list for the hotel city...

• Do not force you to get this working with my route matcher, or my route handler.

If you want to provide your own, you should be able to do it. This last point is very important to me. I used (and use) too many libraries which are tighten to their technologies. Plus, the more they are dependant of their implementation, the less it is testable. This is why you'll see many protocols with a default implementation provided.

• iOS 9 is coming (or came when you are reading this). And with iOS 9 comes this great feature called universal links. Well, I wanted something clean to address this new feature.

Inspiration

Historically, I first used HHRouter and implemented my own stack controller management. Then, by rewriting code to support iOS 9, I saw that it was just a bunch of lines with no error management, tighten to the controller hierarchy, not much readable, etc.

I decided to drop it and get something more fun. I found DeepLinkKit and used it until I realized it wasn't fitting my stack requirement. So I rewrote a custom route handler to deal with it and finally arrived to the conclusion that 80% of deeplink was not used anymore. This is when I decided to drop it and write my own.

So you might recognize some concept of the two libraries especially in the router handler even if the implementation has nothing to do with DeepLinkKit.

Install and use

Requirements alongs with the default implementation

• The implementation I provide uses UINavigationController to handle the stack and can be used on UITabBarController as well.
• The route matching works on :itemID and uses * as the wildcard character.

Installation

Cocoapods

Use Cocoapods, this is the easiest way to install the router.

If you want to link WAAppRouting into an iOS app extension (or a shared framework that is linked to an app extension), you'll need to ensure that the WA_APP_EXTENSION flag is set when you compile the framework. To do so using Cocoapods, add this to your Podfile:

post_install do |installer|
  installer.pods_project.targets.each do |target|
    if target.name =~ /WAAppRouting/
      target.build_configurations.each do |config|
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= []
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] << 'WA_APP_EXTENSION=1'
      end
    end
  end
end

Older versions of cocoapods may require you to use installer.project instead of installer.pods_project, so if you get an error complaining that pods_project does not exist, update your cocoapods gem.

Setup the router: easiest method

Import #import <WAAppRouting/WAAppRouting.h> and you are good to start.

You also need to configure a URL scheme (I won't get back to this, there is plenty of documentation out there)

A navigation controller is a good start

UINavigationController *navigationController = [[UINavigationController alloc] init];

You'll need first to allocate a route matcher. You can use the default I wrote or create your own.

// Create the default router
self.router = [WAAppRouter defaultRouter];

Register you path using the syntax:

• url_path_component{ClassName}
• url_path_component1{ClassName1}/url_path_component2{ClassName2}

Optionaly, you can trigger the modal presentation using ! character. For example: url_path_component{ClassName}/modal{ModalClass}! would result when calling appscheme://url_path_component/modal to ModalClass instance presented modally after placing ClassName in navigation controller stack.

// Register the path
[self.router.registrar
 registerAppRoutePath:
 @"list{WAListViewController}/:itemID{WAListDetailViewController}/extra{WAListDetailExtraViewController}"
 presentingController:navigationController];

Add some block handler if needed

// Register some blocks
[self.router.registrar registerBlockRouteHandler:^(WAAppLink *appLink) {
    // Do something every time we are in list/something
}
                            			forRoute:@"list/*"];

Finally set the navigation controller as the root controller

self.window.rootViewController = navigationController;

You can now use it and open the app with

[self application:(UIApplication *)self openURL:[NSURL URLWithString:@"appscheme://list"] sourceApplication:nil annotation:nil];

Do not forget to use the router!

- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation {
    return [self.router handleURL:url];
}

Each controllers you use should implement WAAppRouterTargetControllerProtocol (it is a good idea to now to have a base view controller) So implement this method and voilà

- (void)reloadFromAppLinkRefresh {
    // You can do something with self.appLink
    // But more important: with self.appLinkRoutingParameters which has merged route|query|default parameters
    NSString *articleTitle = self.appLinkRoutingParameters[@"article_title"];
}

Setup the router: more control method

Start with the easiest method but replace the "create paths" by creating entities entities

// Create the entities
WAAppRouteEntity *list1Entity =
[WAAppRouteEntity routeEntityWithName:@"list"
                                 path:@"list"
                sourceControllerClass:nil
                targetControllerClass:[WAListViewController class]
                 presentingController:navigationController
             prefersModalPresentation:NO
             defaultParametersBuilder:nil
                    allowedParameters:nil];

WAAppRouteEntity *list1DetailEntity =
[WAAppRouteEntity routeEntityWithName:@"listDetail"
                                 path:@"list/:itemID"
                sourceControllerClass:[WAListViewController class]
                targetControllerClass:[WAListDetailViewController class]
                 presentingController:navigationController
             prefersModalPresentation:NO
             defaultParametersBuilder:^id<WAAppRouterParametersProtocol> {
                 
                 NSMutableDictionary *defaultParameters = [NSMutableDictionary new];
                 defaultParameters[@"defaultParam"]  = @1;
                 defaultParameters[@"defaultParam2"] = @"Default parameter 2";
                 return defaultParameters;
             }
                    allowedParameters:nil];

Add the entities to the registrar

// Register the entities
[self.router.registrar registerAppRouteEntity:list1Entity];
[self.router.registrar registerAppRouteEntity:list1DetailEntity];

Samples

Four samples are available

• SimpleExample: This is a sample which handle a list, it's detail and an extra. This could be seen as an article lists, its detail and comments.
• SimpleExampleParameters: This sample is the same as SimpleExample but is using the WAAppLinkParameters (the one more thing of this library).
• MoreComplexExample: This sample demonstrates how to deal with a tab bar controller + how to handle modals.
• PPRevealSample: This sample acts as a demonstration that with a little bit of effort, custom container can fit into the routing library?

Documentation

The code is heavily documented, you should find all your answers. Otherwise, open an issue and I'll respond as quickly as possible.

Go deeper

Pre configure all controllers with objects.

You might want to pass some values to the controllers when there are allocated. For example in a project I'm involved to, we have an image cache the controllers needs to display the image. This image cache is allocated by the App delegate (to avoid singletons and get more testable code). For doing this, you need to add a block implementation to the route handler

    [routeHandler setControllerPreConfigurationBlock:^(UIViewController *controller, WAAppRouteEntity *routeEntity, WAAppLink *appLink) {
        if ([controller isKindOfClass:[WABaseViewController class]]) {
            ((WABaseViewController *)controller).imageCache = imageCache;
        }
    }];

Forbid specific entities to be shown

You can ask not to handle some routes on runtime by setting this block (for example you might not want to display some controllers if not logged in)

    [routeHandler setShouldHandleAppLinkBlock:^BOOL(WAAppRouteEntity *entity) {
        // Could return NO if not logged in for example
        return YES;
    }];

Wildcard URL

You can have some wildcard urls like list/*/extra meaning that for any value instead of the *, the entity or the block would be executed. Avoid using it with entities but rather with block. An url in form of list/* will match both list/path and list/path/extra

Here is an example of an alert triggered each time we are after list/

[registrar registerBlockRouteHandler:^(WAAppLink *appLink) {
        [RZNotificationView showNotificationOn:RZNotificationContextAboveStatusBar
                                       message:[NSString stringWithFormat:@"You are dealing with item ID %@", appLink[@"articleID"]]
                                          icon:RZNotificationIconInfo
                                        anchor:RZNotificationAnchorNone
                                      position:RZNotificationPositionTop
                                         color:RZNotificationColorYellow
                                    assetColor:RZNotificationContentColorDark
                                     textColor:RZNotificationContentColorDark
                                withCompletion:^(BOOL touched) {
                                    
                                }];
    }
                                forRoute:@"list/*"];

Customize router behavior

As said, I hate libraries you cannot customize without forking and diverging from the original source. That said, you can customize the router in two ways: custom route matcher and custom route handler.

Custom route matcher

My implementation deals with basic. Meaning that it won't support key=value1, value2 for the query for example. It is also case sentitive. If you have your own URL configuration like list/$itemID implementing a new route matcher is a good idea!

To start, read WAAppRouteMatcherProtocol class. You have two methods you need to implement: matchesURL: fromPathPattern: and parametersFromURL: withPathPattern:. As you can see in my implementation, I'm using WARoutePattern to match the URL. It's kind of inspired by SocKit (for the naming convention).

Then, you can easily create the router with

// Allocate your route matcher
MyRouteMatcher *routeMatcher = [MyRouteMatcher new];

// Create the Registrar
WAAppRouteRegistrar *registrar  = [WAAppRouteRegistrar registrarWithRouteMatcher:routeMatcher];

// Create the route handler
WAAppRouteHandler *routeHandler = [WAAppRouteHandler routeHandlerWithRouteRegistrar:registrar];

// Create the router
WAAppRouter *router = [WAAppRouter routerWithRegistrar:registrar
                                          routeHandler:routeHandler];

Custom route handler

If for example, you don't want to handle a stack, or use something else than a UINavigationController, then consider creating your own route handler. Start by adopting WAAppRouteHandlerProtocol protocol. And then read WAAppRouteHandler to get inspiration.

iOS 9 support

I still need to run some tests, but the idea is to have a router for the classic url scheme, and an other one for universal links.

Special configuration consideration

Custom container controller

You should definitively take a look at the PPRevealSample project to get an idea of how to get this working. I'm also here to help if needed. Basic idea is try to allocate all the navigation controller you need and pass them as the presenting controller. Then, this would behave like the tab bar (see it's category). If not, then you are in the PPRevealSideViewController context where the navigation controller gets allocated in the fly. The idea is to pass the container as the presentingController property and implement the WAAppRoutingContainerPresentationProtocol protocol (you need the optional method as well).

Modal with navigation controller

You cannot (yet) present a modal and then push a detail. Like presenting a login view but pushed to the signup controller.

Reuse controllers at different locations

Because the stack retrieval is implemented as dealing with controller class unicity, you cannot have two or more WAAppRouteEntity with the same target class when the source controller class is not nil. If you need to reuse the controller at differents places, consider creating simple subclasses of a main controller which handles all the behavior.

The one more thing: avoid having parameters keys hardcoded

###Purpose There is a one more thing to this library which is WAAppLinkParameters class. The idea behind is to avoid hardcoding the values It's behavior is based on an implementation of WAAppRouterParametersProtocol protocol. Which means that you can provide your own or subclass WAAppLinkParameters which provides default behavior and all protocol methods implementation. Let's have a look to an example you can find on SimpleExampleParameters sample project.

Example

First, create a subclass

@interface ArticleAppLinkParameters : WAAppLinkParameters

@property (nonatomic, strong) NSNumber *articleID;
@property (nonatomic, strong) NSString *articleTitle;
@property (nonatomic, strong) NSNumber *displayType;

@end

You can see here three objects which should be mapped to the url keys You need to override the mappingKeyProperty getter to provide a mapping url_key: object_property

- (NSDictionary *)mappingKeyProperty {
    return @{
             @"articleID": @"articleID",
             @"article_title": @"articleTitle",
             @"display_type": @"displayType"
             };
}

There is a category I wrote on UIViewController which configure the object with merging for you. So, you can now get the value directly with

self.label.text = [NSString stringWithFormat:@"ArticleID: %@", ((ArticleAppLinkParameters *)self.appLinkRoutingParameters).articleID];`

You can copy the parameters, set values for a future use

ArticleAppLinkParameters *params = [(ArticleAppLinkParameters *)self.appLinkRoutingParameters copy];
params.articleTitle = [NSString stringWithFormat:@"My super article %ld", (long)indexPath.row];

Grab the query with a white list

NSString *query = [params queryStringWithWhiteList:@[@"articleID", @"articleTitle", @"displayType"];

Advantages

• Update any time the key on URLs without touching your code.
• Avoid regressions when you add new parameters in the URL.
• Easily build queries for moving from a controller to an other.
• Provide defaults values to a controller initialization. All your configuration is done in one place.

Notes

• Only NSString and NSNumber parameters are supported at this time (no NSDate for example)
• This could seems to be a pain in the ass to implement rather than using directly the parameters. True. Keep in mind I thought about this one in a large progress with a big maintenance and evolutions plan involved.

#Contributing : Problems, Suggestions, Pull Requests?

Please open a new Issue here if you run into a problem specific to WAAppRouting.

For new features pull requests are encouraged and greatly appreciated! Please try to maintain consistency with the existing code style. If you're considering taking on significant changes or additions to the project, please ask me before by opening a new Issue to have a chance for a merge.

#That's all folks !

• If your are happy don't hesitate to send me a tweet @ipodishima!
• Distributed under MIT licence.
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