Chapter 5. Liferay Services

Table of Contents

1. Security and Permissions Service
1.1. Introduction
1.2. Overview
1.3. Implementing Permissions
1.4. Summary
1.5. Information
2. User service

Portlet applications may invoke the services provided by Liferay Portal by using the portal-client.jar client library.

It is also possible to use Liferay Service Builder to develop your portlets using the same service oriented architecture that Liferay Portal is based on.

The following sections describe the most important services that can be used. Refer the documentation in the public Liferay wiki for more information

1. Security and Permissions Service

The Permissions service is provided by Liferay Portal to developers to write security related functionality in their own portlets. Currently this functionality is only provided for portlets developed within the Liferay sources or through the extension environment.

1.1. Introduction

Fine grain permissioning is one of the main new features of Liferay Portal 4. Developers can now implement access security into their custom portlets, giving administrators and users a lot more control over their portlets and contents. This document will provide a reference for implementing this new security feature into their custom portlets. Developers should first read the Security and Permissions section of the Liferay User Guide before continuing with this document.

1.2. Overview

Adding fine grain permissioning to custom portlets consists of four main steps (also known as DRAC):

  1. Define all resources and their permissions.

  2. For all the resources defined in step 1, register them into the permission system. This is also known simply as “adding resources.”

  3. Associate the necessary permissions to these resources.

  4. Check permission before returning resources.

1.3. Implementing Permissions

In this section, each of the four main steps in adding Liferay’s security feature into custom portlets (built on top of the Liferay portal) will be explained. The following are two definitions that are important to remember.

Resouce

A generic term for any object represented in the portal. Example of resources includes portlets (e.g., Message Boards, Calendar, etc.), Java classes (e.g., Message Board Topics, Calendar Events, etc.), and files (e.g., documents, images, etc.)

Permission

An action acting on a resource. For example, the view in “viewing the calendar portlet” is defined as a permission in Liferay.

Keep in mind that the permission for a portlet resource is implemented a little differently from the other resources such as Java classes and files. In each of the subsections below, the permission implementation for the portlet resource is explained first, then the model (and file) resource.

Defining Resources and Actions

For your custom portlet, Liferay portal needs to know whether there are resources that require permission and whether there are custom permissions. The default configuration is encapsulated in an XML file found in the portal/portal-ejb/classes/resource-actions directory, you might use it as a reference to create a similar file for your portlet. If your portlet only needs the view and the configuration permission, and that the portlet doesn’t use any models with permission, then you do not need to create this XML file. The reason is that all portlets in Liferay automatically inherit these permissions. However, if your portlet does have custom permission and/or uses models that have custom permissions, then you will need to create an XML file defining the resources and actions. Let’s take a look at blogs.xml in portal/portal-ejb/classes/resource-actions and see how the blogs portlet defined these resources and actions:

<?xml version="1.0"?>

<resource-action-mapping>
	<portlet-resource>
		<portlet-name>33</portlet-name>
		<supports>
			<action-key>ADD_ENTRY</action-key>
			<action-key>CONFIGURATION</action-key>
			<action-key>VIEW</action-key>
		</supports>
		<community-defaults>
			<action-key>VIEW</action-key>
		</community-defaults>
		<guest-defaults>
			<action-key>VIEW</action-key>
		</guest-defaults>
		<guest-unsupported>
			<action-key>ADD_ENTRY</action-key>
		</guest-unsupported>
	</portlet-resource>
	<model-resource>
		<model-name>com.liferay.portlet.blogs.model.BlogsCategory</model-name>
		<portlet-ref>
			<portlet-name>33</portlet-name>
		</portlet-ref>
		<supports>
			<action-key>DELETE</action-key>
			<action-key>PERMISSIONS</action-key>
			<action-key>UPDATE</action-key>
			<action-key>VIEW</action-key>
		</supports>
		<community-defaults>
			<action-key>VIEW</action-key>
		</community-defaults>
		<guest-defaults>
			<action-key>VIEW</action-key>
		</guest-defaults>
		<guest-unsupported>
			<action-key>UPDATE</action-key>
		</guest-unsupported>
	</model-resource>
	<model-resource>
		<model-name>com.liferay.portlet.blogs.model.BlogsEntry</model-name>
		<portlet-ref>
			<portlet-name>33</portlet-name>
		</portlet-ref>
		<supports>
			<action-key>ADD_COMMENT</action-key>
			<action-key>DELETE</action-key>
			<action-key>PERMISSIONS</action-key>
			<action-key>UPDATE</action-key>
			<action-key>VIEW</action-key>
		</supports>
		<community-defaults>
			<action-key>VIEW</action-key>
		</community-defaults>
		<guest-defaults>
			<action-key>VIEW</action-key>
		</guest-defaults>
		<guest-unsupported>
			<action-key>UPDATE</action-key>
		</guest-unsupported>
	</model-resource>
</resource-action-mapping>
Portlet Resource

In the XML, the first thing defined is the portlet itself. Right under the root element <resource-action-mapping>, we have a child element called <portlet-resource>. In this element, we define the portlet name, which is 33 in our case. Next, we list all the actions this portlet supports under the <supports> tag. Keep in mind that this is at the portlet level. To understand what should be listed here, developers should ask themselves what actions belong to the portlet itself or what actions are performed on the portlet that may require a security check. In our case, users need permission to add an entry (ADD_ENTRY), configure blogs portlet settings (CONFIGURATION), and view the blogs itself (VIEW). Each of these supported permissions is within its own <action-key> tag. After we’ve defined all the actions that require a check, we move on to define some of the default permission settings. The community-defaults tag defines what actions are permitted by default for this portlet on the community (group) page the portlet resides. Put it another way, what should a user that has access to the community this portlet resides be able to do minimally? For the blogs portlet, a user with access to the community containing the blogs portlet should be able to view it. Likewise, the guest-defaults tag defines what actions are permitted by default to guests visiting a layout containing this portlet. So if a guest has access to the community page that contains a blogs portlet, the guest should, at the very least, be able to view the portlet according to blogs.xml (not necessarily the content of the portlet). Otherwise, the guest will see an error message within the portlet. Depending on your custom portlet, you may add more actions here that make sense. The guest-unsupported tag contains actions that a visiting guest should never be able to do. For example, the guest visiting the blogs portlet should never be able to add a blog entry since the blog belongs to either a user or a group of users. So even if a user wants to grant guests the ability to add a blog entry to her blog, there is no way for her to grant that permission because the blogs.xml doesn’t permit such an action for guests.

Model Resource

After defining the portlet as a resource, we move on to define models within the portlet that also require access check. The model resource is surrounded by the <model-resource> tag. Within this tag, we first define the model name. This must be the fully qualified Java class name of the model. Next we define the portlet name that this model belongs to under the portlet-ref tag. Though unlikely, a model can belong to multiple portlets, which you may use multiple <portlet-name> tags to define. Similar to the portlet resource element, the model resource element also allows you to define a supported list of actions that require permission to perform. You must list out all the performable actions that require a permission check. As you can see for a blog entry, a user must have permission in order to add comments to an entry, delete an entry, change the permission setting of an entry, update an entry, or simply to view an entry. The <community-defaults> tag, the <guest-defaults> tag, and the <guest-unsupported> tag are all similar in meaning to what’s explained for portlet resource in section 3.1.1.

Default.xml

After defining your permission scheme for your custom portlet, you then need to tell Liferay the location of this file. For Liferay core, the XML file would normally reside in portal/portal-ejb/classes/resource-actions and a reference to the file would appear in the default.xml file. For the extension environment, the recommended setup is to put your XML file in ext/ext-ejb/classes/resource-actions. Create a file called default-ext.xml and model it after the default.xml file. Add all your custom resource-action XML files in the default-ext.xml file. Then copy the property resource.actions.configs found in portal.properties and paste it into portal-ext.properties. Lastly, add a comma to the end of the property value and then add the path to your default-ext.xml file. (i.e. resource.actions.configs=resource-actions/default.xml,resource-actions/default-ext.xml) Below is an example of the default.xml file.

<?xml version="1.0"?>

<resource-action-mapping>
	<resource file="resource-actions/portal.xml" />
	<resource file="resource-actions/blogs.xml" />
	<resource file="resource-actions/bookmarks.xml" />
	<resource file="resource-actions/calendar.xml" />
	<resource file="resource-actions/communities.xml" />
	<resource file="resource-actions/documentlibrary.xml" />
	<resource file="resource-actions/imagegallery.xml" />
	<resource file="resource-actions/journal.xml" />
	<resource file="resource-actions/messageboards.xml" />
	<resource file="resource-actions/polls.xml" />
	<resource file="resource-actions/shopping.xml" />
	<resource file="resource-actions/wiki.xml" />
</resource-action-mapping>

Adding Resources

After defining resources and actions, the next task is to write code that adds resources into the permissioning system. A lot of the logic to add resources is encapsulated in the ResourceLocalServiceImpl class. So adding resources is as easy as calling the add resource method in ResourceLocalServiceUtil class.

public void addResources(
	String companyId, String groupId, String userId, String name,
	String primKey, boolean portletActions,
	boolean addCommunityPermissions, boolean addGuestPermissions);

For all the Java objects that require access permission, you need to make sure that they are added as resources every time a new one is created. For example, every time a user adds a new entry to her blog, the addResources(…) method is called to add the new entry to the resource system. Here’s an example of the call from the BlogsEntryLocalServiceImpl class.

ResourceLocalServiceUtil.addResources(
	entry.getCompanyId(), entry.getGroupId(), entry.getUserId(),
	BlogsEntry.class.getName(), entry.getPrimaryKey().toString(),
	false, addCommunityPermissions, addGuestPermissions);

The parameters companyId, groupId, and userId should be self explanatory. The name parameter is the fully qualified Java class name for the resource object being added. The primKey parameter is the primary key of the resource object. As for the portletActions parameter, set this to true if you’re adding portlet action permissions. In our example, we set it to false because we’re adding a model resource, which should be associated with permissions related to the model action defined in blogs.xml. The addCommunityPermissions and the addGuestPermissions parameters are inputs from the user. If set to true, ResourceLocalService will then add the default permissions to the current community group and the guest group for this resource respectively.

UI Interface

If you would like to provide your user the ability to choose whether to add the default community permission and the guest permission for the resources within your custom portlet, Liferay has a custom JSP tag you may use to quickly add that functionality. Simply insert the <liferay-ui:input-permissions /> tag into the appropriate JSP and the checkboxes will show up on your JSP. Of course, make sure the tag is within the appropriate <form> tags.

Deleting Resources

To prevent having a lot of dead resources taking up space in the Resource_ database table, you must remember to remove them from the Resource_ table when the resource is no longer applicable. Simply call the deleteResource(…) method in ResourceLocalServiceUtil. Here’s an example of a blogs entry being removed:

ResourceLocalServiceUtil.deleteResource(
	entry.getCompanyId(), BlogsEntry.class.getName(),
	Resource.TYPE_CLASS, Resource.SCOPE_INDIVIDUAL,
	entry.getPrimaryKey().toString());

Adding Permission

Portlet Permission

On the portlet level, no code needs to be written in order to have the permission system work for your custom portlet. Your custom portlet will automatically have all the permission features. If you’ve defined any custom permissions (supported actions) in your portlet-resource tag in section 3.1, those are automatically added to a list of permissions and users can readily choose them. Of course, for your custom permissions to have any value, you’ll need to show or hide certain functionality in your portlet. You can do that by checking the permission first before performing the intended functionality. This will be covered in section 3.4.

Model Permission

In order to allow a user to set permissions on the model resources, you will need to expose the permission interface to the user. This can be done by adding two Liferay UI tag to your JSP. The first one is the <liferay-security:permissionsURL> tag which returns a URL that takes the user to the page to configure the permission settings. The second tag is the <liferay-ui:icon> tag that shows a permission icon to the user. Below is an example found in the file view_entry_content.jsp.

<liferay-security:permissionsURL
	modelResource="<%= BlogsEntry.class.getName() %>"
	modelResourceDescription="<%= entry.getTitle() %>"
	resourcePrimKey="<%= entry.getPrimaryKey().toString() %>"
	var="entryURL"
/>

<liferay-ui:icon image="permissions" url="<%= entryURL %>" />

The attributes you need to provide to the first tag are modelResource, modelResourceDescription, resourcePrimKey, and var. The modelResource attribute is the fully qualified Java object class name. It then gets translated in Language.properties to a more readable name (underlined in red in figure 3.3.2.1).

model.resource.com.liferay.portlet.blogs.model.BlogsEntry=Entry

As for the modelResourceDescription attribute, you can pass in anything that best describes this model instance. In the example, the blogs title was passed in, which is reflected in figure 3.3.2.1 with the blue underline. The resourcePrimKey attribute is simply the primary key of your model instance. The var attribute is the variable name this URL String will get assigned to. This variable is then passed to the <liferay-ui:icon> tag so the permission icon will have the proper URL link. There’s also an optional attribute redirect that’s available if you want to override the default behavior of the upper right arrow link shown in figure 3.3.2.1. That is all you need to do to enable users to configure the permission settings for model resources!!

Checking Permissions

The last major step to implementing permission to your custom portlet is to check permission. This may be done in a couple of places. For example, your business layer should check for permission before deleting a resource, or your user interface should hide a button that adds a model (e.g., a calendar event) if the user does not have permission to do so.

Checking Portlet Resource Permission

Similar to the other steps, the default permissions for the portlet resources are automatically checked for you. You do not need to implement anything for your portlet to discriminate whether a user is allowed to view or to configure the portlet itself. However, you do need to implement any custom permission you have defined in your resource-actions XML file. In the blogs portlet example, one custom supported action is ADD_ENTRY. There are two places in the source code that check for this permission. The first one is in the file view_entries.jsp. The presence of the add entry button is contingent on whether the user has permission to add entry (and also whether the user is in tab one).

<%
boolean showAddEntryButton = tabs1.equals("entries") && PortletPermission.contains(permissionChecker, plid, PortletKeys.BLOGS, ActionKeys.ADD_ENTRY);
%>

The second place that checks for the add entry permission is in the file BlogsEntryServiceImpl. (Notice the difference between this file and the BlogsEntryLocalServiceImpl.) In the addEntry(…) method, a call is made to check whether the incoming request has permission to add entry.

PortletPermission.check(
	getPermissionChecker(), plid, PortletKeys.BLOGS,
	ActionKeys.ADD_ENTRY);

If the check fails, it throws a PrincipalException and the add entry request aborts. You’re probably wondering what the PortletPermission class and the PermissionChecker class do. Let’s take a look at these two classes.

PermissionChecker

The PermissionChecker class has a method called hasPermission(…) that checks whether a user making a resource request has the necessary access permission. If the user is not signed in (guest user), it checks for guest permissions. Otherwise, it checks for user permissions. This class is available to you in two places. First in your business logic layer, you can obtain an instance of the PermissionChecker by calling the getPermissionChecker() method inside your ServiceImpl class. This method is available because all ServiceImpl (not LocalServiceImpl) extends the PrincipalBean class, which implements the getPermissionChecker() method. The other place where you can obtain an instance of the PermissionChecker class is in your JSP files. If your JSP file contains the portlet tag <portlet:defineObjects /> or includes another JSP file that does, you’ll have an instance of the PermissionChecker class available to you via the permissionChecker variable. Now that you know what the PermissionChecker does and how to obtain an instance of it, let’s take a look at Liferay’s convention in using it.

PortletPermission

PortletPermission is a helper class that makes it easy for you to check permission on portlet resources (as oppose to model resources, covered later in section 3.4.2). It has two static methods called check(…) and another two called contains(…). They are all essentially the same. The two differences between them are:

  1. Only one check(…) method and one contains(…) method take in the portlet layout ID variable (plid).

  2. The check(…) methods throw a new PrincipalException if user does not have permission, and the contains(…) methods return a boolean indicating whether user has permission.

The contains(…) methods are meant to be used in your JSP files since they return a boolean instead of throwing an exception. The check(…) methods are meant to be called in your business layer (ServiceImpl). Let’s revisit the blogs portlet example below. (The addEntry(…) method is found in BlogsEntryServiceImpl.)

public BlogsEntry addEntry(
		String plid, String categoryId, String[] tags, String title,
		String content, int displayDateMonth, int displayDateDay,
		int displayDateYear, int displayDateHour, int displayDateMinute,
		boolean addCommunityPermissions, boolean addGuestPermissions)
throws PortalException, SystemException {
	
	PortletPermission.check(
		getPermissionChecker(), plid, PortletKeys.BLOGS,
		ActionKeys.ADD_ENTRY);

	return BlogsEntryLocalServiceUtil.addEntry(
		getUserId(), plid, categoryId, tags, title, content,
		displayDateMonth, displayDateDay, displayDateYear, displayDateHour,
		displayDateMinute, addCommunityPermissions, addGuestPermissions);
}

Before the addEntry(…) method calls BlogsEntryLocalServiceUtil.addEntry(…) to add a blogs entry, it calls PortletPermission.check(…) to validate user permission. If the check fails, a PrincipalException is thrown and an entry will not be added. Note the parameters passed into the method. Again, the getPermissionChecker() method is readily available in all ServiceImpl classes. The plid variable is passed into the method by its caller (most likely from a PortletAction class). PortletKeys.BLOGS is just a static String indicating that the permission check is against the blogs portlet. ActionKeys.ADD_ENTRY is also a static String to indicate the action requiring the permission check. You’re encouraged to do likewise with your custom portlet names and custom action keys.

Whether you need to pass in a portlet layout ID (plid) depends on whether your custom portlet supports multiple instances. Let’s take a look at the message board portlet for example. A community may need three separate page layouts, each having a separate instance of the message board portlet. Only by using the portlet layout ID will the permission system be able to distinguish the three separate instances of the message board portlet. This way, permission can be assigned separately in all three instances. Though in general, most portlets won’t need to use the portlet layout ID in relation to the permission system.

Service vs. LocalService

Since the ServiceImpl class extends the PrincipalBean class, it has access to information of the current user making the service request. Therefore, the ServiceImpl class is the ideal place in your business layer to check user permission. Liferay’s convention is to implement the actual business logic inside the LocalServiceImpl methods, and then the ServiceImpl calls these methods via the LocalServiceUtil class after the permission check completes successfully. Your PortletAction classes should make calls to ServiceUtil (wrapper to ServiceImpl) guaranteeing that permission is first checked before the request is fulfilled.

Checking Model Resource Permission

Checking model resource permission is very similar to checking portlet resource permission. The only major difference is that instead of calling methods found in the PortletPermission class mention previously, you need to create your own helper class to assist you in checking permission. The next section will detail how this is done.

Custom Permission Class

It is advisable to have a helper class to help check permission on your custom models. This custom permission class is similar to the PortletPermission class but is tailored to work with your custom models. While you can implement this class however you like, we encourage you to model after the PortletPermission class, which contains four static methods. Let’s take a look at the BlogsEntryPermission class.

public class BlogsEntryPermission {

	public static void check(
			PermissionChecker permissionChecker, String entryId,
			String actionId)
		throws PortalException, SystemException {

		if (!contains(permissionChecker, entryId, actionId)) {
			throw new PrincipalException();
		}
	}

	public static void check(
			PermissionChecker permissionChecker, BlogsEntry entry,
			String actionId)
		throws PortalException, SystemException {

		if (!contains(permissionChecker, entry, actionId)) {
			throw new PrincipalException();
		}
	}

	public static boolean contains(
			PermissionChecker permissionChecker, String entryId,
			String actionId)
		throws PortalException, SystemException {

		BlogsEntry entry = BlogsEntryLocalServiceUtil.getEntry(entryId);

		return contains(permissionChecker, entry, actionId);
	}

	public static boolean contains(
			PermissionChecker permissionChecker, BlogsEntry entry,
			String actionId)
		throws PortalException, SystemException {

		return permissionChecker.hasPermission(
			entry.getGroupId(), BlogsEntry.class.getName(),
			entry.getPrimaryKey().toString(), actionId);
	}
}

Again, the two check(…) methods are meant to be called in your business layer, while the two contains(…) methods can be used in your JSP files. As you can see, it’s very similar to the PortletPermission class. The two notable differences are:

  1. Instead of having the portletId as one of the parameters, the methods in this custom class take in either an entryId or a BlogsEntry object.

  2. None of the methods need to receive the portlet layout ID (plid) as a parameter. (Your custom portlet may choose to use the portlet layout ID if need be.)

Let’s see how this class is used in the blogs portlet code.

public BlogsEntry getEntry(String entryId) throws PortalException, SystemException {

	BlogsEntryPermission.check(
		getPermissionChecker(), entryId, ActionKeys.VIEW);

	return BlogsEntryLocalServiceUtil.getEntry(entryId);
}

In the BlogsEntryServiceImpl class is a method called getEntry(…). Before this method returns the blogs entry object, it calls the custom permission helper class to check permission. If this call doesn’t throw an exception, the entry is retrieved and returned to its caller.

<c:if test="<%= BlogsEntryPermission.contains(permissionChecker, entry, ActionKeys.UPDATE) %>">
	<portlet:renderURL windowState="<%= WindowState.MAXIMIZED.toString() %>" var="entryURL">
		<portlet:param name="struts_action" value="/blogs/edit_entry" />
		<portlet:param name="redirect" value="<%= currentURL %>" />
		<portlet:param name="entryId" value="<%= entry.getEntryId() %>" />
	</portlet:renderURL>

	<liferay-ui:icon image="edit" url="<%= entryURL %>" />
</c:if>

In the view_entry_content.jsp file, the BlogsEntryPermission.contains(…) method is called to check whether or not to show the edit button. That’s all there is to it!

1.4. Summary

Let’s review what we’ve just covered. Implementing permission into your custom portlet consists of four main steps. First step is to define any custom resources and actions. Next step is to implement code to register (or add) any newly created resources such as a BlogsEntry object. The third step is to provide an interface for the user to configure permission. Lastly, implement code to check permission before returning resources or showing custom features. Two major resources are portlets and Java objects. There is not a lot that needs to be done for the portlet resource to implement the permission system since Liferay Portal has a lot of that work done for you. You mainly focus your efforts on any custom Java objects you’ve built. You’re now well on your way to implement security to your custom Liferay portlets! For other user guides, please visit the Liferay documentation page

1.5. Information

Roles

If you’re wondering how the Liferay user roles, community roles, and organization / location roles should be implemented in your custom portlet, this brief section will address that. The short answer is, nothing needs to be developed specifically for user, community, and organization / location roles to work with your custom portlets. Liferay’s permission system has all that provided for you. When the hasUserPermission(…) method is called within the PermissionChecker class, Liferay checks all the roles the current user has, whether they’re organization / location roles, community roles, or user roles.

Using Your Own Security System in Liferay

Here’s a brief outline of how you can use your own security system in Liferay.

  • Create your own PermissionChecker class that extends Liferay’s PermissionChecker class.

  • Register this new class in portal.properties (or portal-ext.properties for the EXT environment) under the permissions.checker property.

  • Override the hasUserPermission(…) method and the hasGuestPermission(…) method with your own calls to your permission system.

  • You can call the setValues(…) method to pull in parameters from the request object that your permission checker might need (e.g., userId, projected, etc).

  • You can call the resetValues(…) method to wipe out old parameters.

  • Override the isAdmin(…) method.

Database Schema View

Reviewing how Liferay stores all the permission information in the database may help you gain a better understanding to the entire permission system.

  • The resource_ table contains all the registered resources outlined in section 3.2.

  • Every possible secure action that can be done to a resource will result in a row in the permission_ table. For example, a BlogsEntry resource may have a row in permission_ for the view action, and another for the update action.

  • Whether a user has permission to a resource depends on the roles the user has, or the community (groups) and organization the user is in (green tables). If those roles or groups contain the needed permissionId in the permissions table (in blue), then the user has access to the resource.