/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jbpm.identity.assignment;
import java.util.Set;
import org.jbpm.JbpmContext;
import org.jbpm.graph.exe.ExecutionContext;
import org.jbpm.graph.exe.Token;
import org.jbpm.identity.Entity;
import org.jbpm.identity.Group;
import org.jbpm.identity.User;
import org.jbpm.identity.hibernate.IdentitySession;
import org.jbpm.security.SecurityHelper;
import org.jbpm.taskmgmt.def.AssignmentHandler;
import org.jbpm.taskmgmt.exe.Assignable;
import org.jbpm.taskmgmt.exe.SwimlaneInstance;
/**
* implements an expression language for assigning actors to tasks based on this identity
* component.
*
* <pre>
* syntax : first-term --> next-term --> next-term --> ... --> next-term
*
* first-term ::= previous |
* swimlane(swimlane-name) |
* variable(variable-name) |
* user(user-name) |
* group(group-name)
*
* next-term ::= group(group-type) |
* member(role-name)
* </pre>
*/
public class ExpressionAssignmentHandler implements AssignmentHandler {
private static final long serialVersionUID = 1L;
protected String expression;
protected ExecutionContext executionContext;
protected ExpressionSession expressionSession;
protected TermTokenizer tokenizer;
protected Entity entity;
public void assign(Assignable assignable, ExecutionContext executionContext) {
expressionSession = getExpressionSession();
if (expressionSession == null) {
throw new ExpressionAssignmentException("no expression session");
}
this.tokenizer = new TermTokenizer(expression);
this.executionContext = executionContext;
entity = resolveFirstTerm(tokenizer.nextTerm());
while (tokenizer.hasMoreTerms() && entity != null) {
entity = resolveNextTerm(tokenizer.nextTerm());
}
// if the expression did not resolve to an actor
if (entity == null) {
// complain!
throw new ExpressionAssignmentException("could not resolve assignment expression: "
+ expression);
}
// else if the expression evaluated to a user
else if (entity instanceof User) {
// do direct assignment
assignable.setActorId(entity.getName());
}
// else if the expression evaluated to a group
else if (entity instanceof Group) {
// put the group in the pool
assignable.setPooledActors(new String[] {
entity.getName()
});
}
}
/**
* serves as a hook for customizing the way the identity session is retrieved. overload this
* method to reuse this expression assignment handler for your user data store.
*/
protected ExpressionSession getExpressionSession() {
JbpmContext jbpmContext = JbpmContext.getCurrentJbpmContext();
if (jbpmContext == null) {
throw new ExpressionAssignmentException("no current jbpm context");
}
return (IdentitySession) jbpmContext.getServices()
.getPersistenceService()
.getCustomSession(IdentitySession.class);
}
protected Entity resolveFirstTerm(String term) {
Entity entity;
if (term.equalsIgnoreCase("previous")) {
String userName = SecurityHelper.getAuthenticatedActorId();
entity = getUserByName(userName);
}
else if (term.startsWith("swimlane(") && term.endsWith(")")) {
String swimlaneName = term.substring(9, term.length() - 1).trim();
String userName = getSwimlaneActorId(swimlaneName);
entity = getUserByName(userName);
}
else if (term.startsWith("variable(") && term.endsWith(")")) {
String variableName = term.substring(9, term.length() - 1).trim();
Object value = getVariable(variableName);
if (value instanceof String) {
entity = getUserByName((String) value);
}
else if (value instanceof Entity) {
entity = (Entity) value;
}
else {
throw new ExpressionAssignmentException(value + " is neither user name nor entity");
}
}
else if (term.startsWith("user(") && term.endsWith(")")) {
String userName = term.substring(5, term.length() - 1).trim();
entity = getUserByName(userName);
}
else if (term.startsWith("group(") && term.endsWith(")")) {
String groupName = term.substring(6, term.length() - 1).trim();
entity = getGroupByName(groupName);
}
else {
throw new ExpressionAssignmentException("could not interpret first term: " + term);
}
return entity;
}
protected Entity resolveNextTerm(String term) {
if (term.startsWith("group(") && term.endsWith(")")) {
String groupType = term.substring(6, term.length() - 1).trim();
User user = (User) entity;
Set groups = user.getGroupsForGroupType(groupType);
if (groups.isEmpty()) {
throw new ExpressionAssignmentException("no groups for type: " + groupType);
}
entity = (Entity) groups.iterator().next();
}
else if (term.startsWith("member(") && term.endsWith(")")) {
String role = term.substring(7, term.length() - 1).trim();
Group group = (Group) entity;
entity = expressionSession.getUserByGroupAndRole(group.getName(), role);
if (entity == null) {
throw new ExpressionAssignmentException("no users in role: " + role);
}
}
else {
throw new ExpressionAssignmentException("could not interpret term: " + term);
}
return entity;
}
protected Object getVariable(String variableName) {
Token token = executionContext.getToken();
return executionContext.getContextInstance().getVariable(variableName, token);
}
protected Entity getGroupByName(String groupName) {
Group group = expressionSession.getGroupByName(groupName);
if (group == null) {
throw new ExpressionAssignmentException("no such group: " + groupName);
}
return group;
}
protected Entity getUserByName(String userName) {
User user = expressionSession.getUserByName(userName);
if (user == null) {
throw new ExpressionAssignmentException("no such user: " + user);
}
return user;
}
protected String getSwimlaneActorId(String swimlaneName) {
SwimlaneInstance swimlaneInstance = executionContext.getTaskMgmtInstance()
.getSwimlaneInstance(swimlaneName);
if (swimlaneInstance == null) {
throw new ExpressionAssignmentException("no such swimlane: " + swimlaneName);
}
return swimlaneInstance.getActorId();
}
}