Clear Grid

import com.atlassian.crowd.embedded.api.User
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.IssueManager
import com.atlassian.jira.security.JiraAuthenticationContext
import com.atlassian.plugin.PluginAccessor
import com.atlassian.jira.user.ApplicationUser;
  
// get an issue
IssueManager issueManager = ComponentAccessor.getOSGiComponentInstanceOfType(IssueManager.class);
Issue issue = issueManager.getIssueObject("TEST-1");
  
// find TGE custom fields
PluginAccessor pluginAccessor = ComponentAccessor.getPluginAccessor();
Class tgeConfigManagerClass = pluginAccessor.getClassLoader().findClass("com.idalko.jira.plugins.igrid.api.config.grid.TGEGridConfigManager");
def tgeConfigManager = ComponentAccessor.getOSGiComponentInstanceOfType(tgeConfigManagerClass);
List<Long> tgeCustomFieldIds = tgeConfigManager.getGridCustomFieldIds();
  
// get current user
JiraAuthenticationContext jiraAuthenticationContext = ComponentAccessor.getOSGiComponentInstanceOfType(JiraAuthenticationContext.class);
Object userObject = jiraAuthenticationContext.getLoggedInUser();
User user = userObject instanceof ApplicationUser ? ((ApplicationUser) userObject).getDirectoryUser() : (User) userObject;
  
// clear all grids
Class dataManagerClass = pluginAccessor.getClassLoader().findClass("com.idalko.jira.plugins.igrid.api.data.TGEGridTableDataManager");
def tgeGridDataManager = ComponentAccessor.getOSGiComponentInstanceOfType(dataManagerClass);
  
StringBuilder result = new StringBuilder();
for (Long tgeCustomFieldId : tgeCustomFieldIds) {
    try {
        tgeGridDataManager.clearAll(issue.getId(), tgeCustomFieldId, user);
        result.append("Grid ID=" + tgeCustomFieldId + " is cleared.\n");
    } catch (Exception e) {
        result.append("Grid ID=" + tgeCustomFieldId + " cannot be cleared: " + e.getMessage() + "\n");
    }
}
  
println(result.toString());
return result.toString();