Understanding Appian expression rules

In Appian, expression rule objects are more code-oriented than any other object type. An important difference to normal software development is that, in Appian, we only use code to add the flexibility we need for building great business applications, instead of developing everything from scratch.

Let's have a look at expression rules. Go to the Appian Designer browser tab and check the Expression Rule filter checkbox.

Figure 3.27 – Expression rules in Appian Designer

We are now going to open two expression rules. The first one is IM_FormatName. Its purpose is to take the internal name of a user (the name that you used to log in to Appian) and translate it into a human-readable string. This expression rule is used nine times in the Quick App. You already know one of these: the record list of your improvement record.

Figure 3.28 – The improvement record list using the IM_FormatName...