The problem that I have is with versioning of a single mobile application (created with Cordova) and the WCF web services that it consumes.
Situation: The latest version of the mobile app is always obtainable through the app store. The web services are distributed to customers, which do not update the web services very often. However the web services are under constant development and newer versions will be released in the future. In some time there will be a lot of different versions of the web services deployed and only one most recent version of the mobile app in the app store. I can force people to update the mobile app, but not to update the web services that the app must connect to.
Problem example: For instance, there are several versions of the web services deployed. The most recent version of the web services provides some kind of fantastic operation, that the most recent version of the app obviously wants to use. When the app tries to do this operation with an older version of the web services, the app will produces errors.
Question: The problem that I encounter is how I can make the app compatible with all the services that are deployed on all the different services?
Solutions I know of:
- Of course there is the solution to always make the app backwards compatible. The app will have to know which version of web service it connects to and can, depending on the version, show different data, retrieve different data or behave differently. This can however create a nightmare to manage if the versions of the web services will stack up.
- Another option, that is possible because the app is created with Cordova, is to only put a shell app in the app store. This shell will only give the user the opportunity to connect with the web service that it has, and will download the code of the corresponding app version from the web services. This will resolve the versioning problem, but will introduce other problems. For example, the shell will sometimes have to be updated for the Cordova libraries to support newer OS versions (iOS 8/ Android 6 for example). It is possible that this will introduce breaking changes in the Cordova code. When this happens, every version of the app code on every deployed web services will have to be updated, which is to much work because there are just to many services. In addition to the second solution is to only load all the app code, except for the some wrapper API for the Cordova API. This Cordova API will reside in the shell app that is published to the app stores. When there are any breaking changes in the Cordova API's, these can be encapsulated in these API's in the shell app. Although this is a better solution, I still don't know if it is any good to load most of the mobile app from a web service to support multiple versions.
In my opinion none of these solutions are perfect.
There will probably solutions that I have not thought of and I am interested to hear those.