Out of the box, Service Portal ships with an implementation of the ServiceNow Form, entirely contained within a widget. The Form widget works in much the same way as the forms you are probably already familiar with in the ServiceNow platform.
However, there are a few caveats, which will be described in depth below.
Here, we will go over different types of form scripts and what is supported in Service Portal.
Service Portal has support for Client Scripts that are marked with a UI Type of either Mobile or Both. Client Scripts marked Desktop will not be executed, as those scripts rely on legacy APIs that are not supported by Service Portal.
All Server-side UI Actions are supported, with one important distinction - setRedirectURL() operations are ignored, due to the fact that Service Portal forms do not handle redirection the same way that forms in the platform do.
Any UI Actions marked Client are not compatible with Service Portal and will be ignored by the Form widget.
UI Macros are not supported in Service Portal (they use Jelly, and Service Portal doesn't).
UI Policies are supported in Service Portal forms.
Formatters are not supported in Service Portal (they use Jelly, and Service Portal doesn't).