Gantt OnDemand uses standard JIRA links to render dependencies between issues. All “blocked by” and “blocks” links are processed by the plugin and visualised on gantt chart in appropriate way. In example below, Issue NGM-2 is Issues EP-3 and EP-4 are blocked by NGMEP-1 2 and at the same time it EP-3 sub-task blocks the NGMEP-3 Story30 Epic. Rendered dependency chain for these issues would look like this:
Issue links can be edited directly from the Add-on via Issue dialog (opened when issue is clicked). Read more about editing issue links.