Version workflow data with ease

 A common scenario when working with workflows is to handle data objects and their changes. In most of the situations workflow instance will only keep the last value of it and to realise use cases like comparing what was just sent to the instance with what was already in there requires having duplicated data object definitions. This is not the best approach as it makes the workflow definition "corrupted" with details less important from the business goal perspective.

With Automatiko (since version 0.3.0) there is an alternative way to this problem. This is to version data objects by annotating it with data object tag called versioned.

So what happens when you make data object versioned?

Automatiko engine will record every change to the variable as new version. These versions are then available to be accessed as any other variable but will require additional suffix to the variable name

• suffix $ will give access to complete version list of the variable e.g. person$
• suffix $X where X is a number of the version to retrieve it can be a negative (-1) to fetch latest version e.g. person$5 or person$-1

Sometimes referring to versions directly might result in errors like attempting to get the version that does not exist. To make it simpler, Automatiko provides ready to use functions that can be used from 

• script tasks
• gateway conditions

The functions you can use are as follows:

• previousVersion(versions) allows to get latest version of the variable list - previousVersion(person$)
• variableVersion(versions, number) allows to get variable version stored under version number - variableVersion(person$, 4) - note that this one is safe and will return null when given version number does not exist
• isEqual(var1, var2) allows to easily compare two versions of the variable - isEqual(person, previousVersion(person$))

Another aspect is that you can easily create your custom functions by simply implementing io.automatiko.engine.api.Functions interface and implementing public static methods that will become functions and will be available in the workflow definition. You can read up more in Automatiko documentation.

In addition to that Process Management UI also provides quick access to variable versions and allows to also revert to given version of the data object. Once you have process management addon in your service it provides both UI and REST api to interact with versions of the data objects.

Following video shows this in action and the value it brings.

Stay tuned for more updates around Automatiko project. If you have any questions or comments join our community either on mailing list or GitHub discussions.