Communicating with other iOS apps using URL Schemes

[paschmann]

When I started developing iOS apps a couple of years ago, I was concerned that enterprise apps were going to quickly succumb to the world of development scope creep. Since the apps were fairly focused and provided a single function or process solution, what if the business wanted more? For example, you have a CRM app displaying your customer contact information and some high level details regarding order history and credit limits, but what if the user wanted some additional details from your BI solution drilling down into historical orders and profit analysis? Well, in that case, you had a few options:

1) Extend the scope of the app - by adding functionality and options, sometimes a reasonable option if the scope is not excessive or the functionality is relative to the app. In our  above example, probably not.

2) Build another app with replicated functionality - duplicate code to display the customers and overview details in both apps.

3) Build 2 separate apps - But this would require the user to re-enter information (such as searching for and entering the Customer ID) in the 2nd app.

The fourth option is to use option 3 but with a twist, by enabling communication between the 2 apps by using URL Schemes. As the majority of iOS developers know, you can open other standard iOS apps like Safari, Mail or the Phone using the UIApplication SharedApplication class, what many developers and mobility architects overlook is that, not only standard apps can be called from your code, but any app which has a URL scheme defined. This gives you the ability to separate processes by application, and in the event a user would like drill deeper into additional information or functions, you can pass information to another app where that can be handled. What if the app is not installed? Good question ... You device will smartly open the Apple App Store giving you the ability to install the missing app. Configuring and consuming the communication between 2 apps is very simple and straight forward.

You can read about the URL Schemes within the apple documentation here:

http://developer.apple.com/library/ios/#featuredarticles/iPhoneURLScheme_Reference/Introduction/Intr...

and here: http://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/Adv...

Within the SAP Suite of iOS Apps you can also find URL Schemes already configured and in use, some examples of these are:

CRM @ SAP

Find account by number: crmatsap://openAccount?accountid=<number>

Open opportunity by number: crmatsap://openOpportunity?opportunityid=<number>

Open account by number: crmatsap://openAccount?accountid=<number>

SAP Pricing

Open Product by ID: pricingapp://openProduct?productid=<productid>

If you are still not sure if iOS URL Schemes are right for you here are a couple of Pro's and Con's

Pros:

- Use other custom apps to augment yours

- Use other companies apps to augment yours

- No need to redevelop similar functionality

- Communicate between apps

- Launch your app from a hyperlink (online/in a web page?)

- No need to be online for base functionality

Cons:

- Shouldn't pass sensitive data

- Clearly define the scope of each app and avoid over simplifying (e.g. an app for searching for customers by name, another for searching by ID.)

- Should not be a critical function, since there is no guarantee that the data is being received by the other application

I am curious to know how many app developers out there are using URL Schemes within their custom development?