Key Parameter Types
There are multiple types of parameters, mainly related to the data type required; for example integer, float, string. However, a notable parameter type for a self-serve setup is "Choice with Alias."
Choice with Alias
A Choice parameter is one in which a user is presented with a list of choices, and their selection is returned directly to FME. A Choice with Alias parameter is the same thing - the user is presented with a choice - but this time a different value is returned to FME based on a lookup table.
For example, here the author wishes the user to select the height of labels to be created in the output dataset:
The user is presented with the list of (more intuitive) options on the left, but the value returned to FME will be the (more useful) number on the right.
On FME Server, this parameter type is very useful for Data Download tasks. That's because many of the values we want to pass to FME - for example, format or coordinate system names - have an abbreviated format that wouldn't make sense if presented to the user. A Choice with Alias parameter allows us to provide a user-friendly list of options that hides a more complex response to the server.
| TIP |
| Scripted parameters are a way to generate a parameter value using a Python or Tcl script. These parameters can be useful for generating values in a more complex way, e.g. creating a list of feature types from other parameters, or creating a parameter that depends on the value of other user parameters submitted at runtime. |