How to Update Priority automatically when a cascading select is chosen

[Swarna Radha]

Hi,

I have priority matrix when i choose values :Test (Parent), Value1 (Child): from a cascading select custom field, priority should be changed automatically. I am using listener (Issue Updated) from script runner but am getting error as shown below

import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.config.PriorityManager
import com.atlassian.jira.issue.priority.Priority
import com.atlassian.jira.issue.customfields.option.Option
import com.atlassian.jira.issue.fields.CustomField
import com.atlassian.jira.issue.MutableIssue
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.issue.IssueManager
import com.atlassian.jira.issue.customfields.view.CustomFieldParams
import com.atlassian.jira.issue.customfields.option.Option
//def fpriority = getFieldById(getFieldChanged())
// FormField fpriority = getFieldById("priority")

def fpriority = getFieldById("priority")- this line shows error
//FormField fpriority0 = getFieldById("priority-field")
//def selectedOption1 = fieldA.getValue() as String
def priorityManager = ComponentAccessor.getComponent(PriorityManager)
def Priority
//def customFieldManager = ComponentAccessor.customFieldManager()

def optionsManager = ComponentAccessor.getOptionsManager()
def fieldName = "Impact and Urgency"
def field = getFieldByName(fieldName)
def customField = customFieldManager.getCustomFieldObjectByName(fieldName)
def fieldconfig= customField.getRelevantConfig(getIssueContext())
def options = optionsManager.getOptions(fieldconfig)

//MutableIssue mutableIssue = (MutableIssue) issue;
def parentOption = options.find {it.value == "Test"}
def childOption = parentOption?.childOptions?.find {it.value == "Value1"}
//def customFieldValue = issue.getCustomFieldValue(customField);

//def customFieldValue = issue.getCustomFieldValue(customField);
if (parentOption){
if (childOption)
{
//mutableIssue.setPriorityId("3")

fpriority.setFormValue("1")
}

}

Kindly advice 

Thanks

Swarna