Example map with enum keys

CommonTagLib.groovy

import org.grails.common.ApprovalStatus
import static org.grails.common.ApprovalStatus.*

class CommonTagLib {
    static namespace = "common"

    static final STATUS_TO_CSS_CLASS = [
            (PENDING): "warning",
            (REJECTED): "important",
            (APPROVED): "success" ].asImmutable()

    def approvalStatus = { attrs ->
        def status = asEnum(attrs.status)
        def type = attrs.type ?: 'label'

        def labelClass = STATUS_TO_CSS_CLASS[status] ?: "inverse"
        ...
    }

    private asEnum(String value) { ApprovalStatus.valueOf(ApprovalStatus, value) }
    private asEnum(ApprovalStatus value) { return value }
}