Sources process the incoming information from whatever the source of data is into useful predefined values. For example, these are the predefined values for a Kinetic Platform CE (Front-End) Source:
And these are the values for a JIRA Source:
Each provides formatted/processed information that was provided from the webhook/API from that source system. These can then be used in parameters and connectors to pass information or do logic.
This is an example of a predefined parameter being used in a connector:
This means the workflow will only execute the Retrieve Referring Submission node if the Referring Id provided was not empty (which could mean null or empty string). The Referring Id was pulled from the menu like this:
Note that there are functions being performed on this value. These are Ruby functions. Workflow connectors and parameters (and handlers) are coded in Ruby.
An example for the node looks like this:
This node has each parameter being set to a predefined value. We will specifically look at the first value, Space. This is being pulled from the predefined drop downs like this:
You may note that there are additional symbols around the parameter predefined value that weren't around the connector predefined value (<%= %&rt;). You may hear these refered to as ERB tags. These are present in the parameter because the parameter also allows text (the connectors are all ruby code). These symbols define/separate the code from any text that may appear.