Why sometimes issue interface and sometimes issueservice

[John Strzempa]

I'm reading a book that says use IssueService for dealing with issues but I created a customfield and it generated a file that injects an Issue interface

getVelocityParameters(final Issue issuepublic Map<String, Object> getVelocityParameters(final Issue issue,
 final CustomField field,
 final FieldLayoutItem fieldLayoutItem)

I'm wondering why one or the other and which one are you supposed to use?

[John Strzempa · Accepted solution]

Figured it out. I was confusing two different actions here. The Issue is already created using the IssueService and then the instance is passed into this method.