Tags and categories are two important tools you can use to help organize information on your portal. These tools help users to easily find the content they’re looking for through search or navigation. Tagging and categorizing assets is easy. You can tag or categorize an asset at creation time or when editing an existing asset. If you click on the Categorization section of the form for creating or editing an asset, you’ll find an interface for adding tags and categories. If no categories are available to be added to the asset (e.g., if no categories have been created), the Categories heading won’t appear.
Figure 6.1: Here, the Web Content Display portlet's form for categorizing a new web content instance doesn't include a Categories heading since no categories have been created.
The Control Panel contains an interface for managing tags and categories for each site in the portal. This interface can be used to manage all your tags and categories in one place. It is important that you both tag and categorize your content when you enter it. Let’s take a closer look at tags and categories.
Tags
Tags are an important tool that can help organize information on your portal and make it easier for users to find the content that they’re interested in. Tags are words or phrases that you can attach to any content on the website. Tagging content makes your search results more accurate and enables you to use tools like the Asset Publisher to display content in an organized fashion on a web page. There are two ways to create tags: you can do it through the administrative console in the Control Panel or on the fly as content is created. By default, tags can be created by regular users and users can apply them to any assets which they have permission to create or edit.
While regular users can, by default, create new tags by applying them to any assets that they have permission to create or edit, only site administrators can access the Tags portlet in the Content section of the Site Administration area of the Control Panel. Here, site administrators can create new tags and edit any existing site tags. To create tags in the Control Panel, visit the site for which you want to create tags and then click on Admin → Content. Then click on Tags in the Content section on the left. From this screen, you can view existing tags and create new ones. To create a new tag, click Add Tag and enter a name for the tag.
You can also customize a tag’s permissions and properties. This configuration,
however, must be done by a server administrator. To implement this
configuration, add a portal-ext.properties file to your Liferay Home directory
with the following contents and then restart the server:
asset.tag.permissions.enabled=true
asset.tag.properties.enabled=true
Once this is done, you can change the permissions on a tag to make it viewable by guests, site members, or owner. You can also assign other permissions for managing tags, including permission to delete the tag, edit the tag, or edit the tag’s permissions. You can also add properties to a tag. Properties are a way to add information to specific tags. You can think of tag properties as tags for your tags. Structurally, tag properties are key-value pairs associated with specific tags that provide information about the tags.
Figure 6.2: The Add Tag interface with editing of tag properties and permissions enabled. When managing a site's content, click on *Tags* and then *Add Tag* to create a new tag. The Add Tag interface allows you to enter a name for the tag, define permissions for the tag, and add properties to the tag.
Tags are not the only portal-wide mechanism for describing content: you can also use categories.
Categories
Categories are similar in concept to tags, but are designed for use by administrators, not regular users. Hierarchies of categories can be created, and categories can be grouped together in vocabularies. While tags represent an ad hoc method for users to group content together, categories exist to allow administrators to organize content in a more official, hierarchical structure. You can think of tags like the index of a book and categories like its table of contents. Both serve the same purpose: to help users find the information they seek.
Adding vocabularies and categories is similar to adding tags. Visit the site for which you want to create categories and then click on Admin → Content. Then click on Categories in the Content section on the left to view the categories administration portlet.
Figure 6.3: When managing a site's content, click on *Categories* and then on *Add Vocabulary* to create a new vocabulary. By default, a vocabulary called *Topic* already exists. When adding new categories, make sure you're adding them to the correct vocabulary.
Clicking on a vocabulary on the left displays any categories that have been created under that vocabulary. To create a new vocabulary, click on the Add Vocabulary button. Enter a name and, optionally, a description. By default, the Allow Multiple Categories box is checked. This allows multiple categories from the vocabulary to be applied to an asset. If the box is unchecked, only one category from the vocabulary can be applied to add asset. The Associated Asset Types lets you choose which asset types the categories of the vocabulary can be applied to and which asset types are required to have an associated asset from the vocabulary. Lastly, you can configure the permissions of the vocabulary. Should the vocabulary be viewable by guests? Only site members? Only owners? Which of these roles should be able to delete the vocabulary, update it, or edit its permissions? By default, guests can view the vocabulary but only the owner can delete it, update it, or configure its permissions.
Creating new categories is similar to creating new tags except that categories must be added to an existing vocabulary and they can only be create by site administrators. However, once created, regular users can apply categories to any assets they have permission to create or edit. To create a new category, click the Add Category button in the categories administration portlet. Enter a name for the new category and, optionally, a description. Use the To Vocabulary dropdown list to select a vocabulary to which to add the category. Just as with tags, you can configure the permissions of the category, choosing which roles (guest, site member, owner) can view the category, apply it to an asset, delete it, update it, or configure its permissions. By default, categories are viewable by guests and site members can apply categories to assets. Also, you can add properties to categories, just as with tags. Category properties are a way to add information to specific categories. You can think of category properties as tags for your categories. Structurally, category properties are just like tag properties: they are key-value pairs associated with specific categories that provide information about the categories.
Once you have created some vocabularies and categories, you can take advantage of the full capabilities of categories by creating a nested hierarchy of categories. To nest categories, select the category that you’d like to be the parent category. Then drag any category that should be a child category onto it. You will see a plus sign appear next to the name of the category you are dragging if you can add it to the selected parent category; if you see a red x that means that you cannot add that category as a subcategory of parent category that you have selected.
After you have created a hierarchy of categories, your content creators will have them available to apply to content that they create. Click on Web Content in the Content section of the Site Administration area the Control Panel and click Add → Basic Web Content. Click on Categorization from the right-side menu and click Select on the vocabulary you’d like to apply. A dialog box appears with your categories. Select any relevant categories by checking the box next to them, and they’ll be applied to the content.
Liferay 6.1 added several new features to vocabularies and categories. We mentioned a few of these already when we were discussing the Allow Multiple Categories and Required checkboxes for vocabularies and categories. The three new features are targeted vocabularies, single/multi-valued vocabularies, and separated widgets for every vocabulary.
Targeted Vocabularies
Targeted Vocabularies allow you to decide which vocabularies can be applied to an asset type and which vocabularies are required for an asset type. To configure these settings, go to the categories administration portlet in the Control Panel and mouse over the vocabulary in the list until you see the edit icon to the right. Select the icon to reveal a dialog box like the one below.
Figure 6.4: You can target vocabularies by checking the *Allow Multiple Categories* checkbox and then selecting the Asset Types.
The default value for Associated Asset Types is All Asset Types. You can fine tune your choices by using the + and - buttons, which narrows the scope of the vocabulary to specific assets. In the screenshot above, notice that the vocabulary is configured to be available for Web Content instances and Blog entries, but it is not required. It is mandatory, however, for Documents and Media files.
Single and Multi-valued Vocabularies
You can also decide if users can choose one or more categories from the same vocabulary to apply to an asset. If a vocabulary is single-valued you can only choose one. If it allows more, you can choose several categories from the vocabulary to apply to an asset.
Figure 6.5: Multi-valued vocabularies allow multiple categories from the vocabulary to be applied to an asset. Single-valued vocabularies only allow one category from the vocabulary to be applied. Here, the *Cinema* and *Music* categories are selected to be applied but the *Sports* category is not.
You can configure the single-valued or multi-valued status of a vocabulary through the categories administration portlet. Edit a vocabulary and deselect the Allow Multiple Categories checkbox to create a single-valued vocabulary. Use the default option to create a multi-valued vocabulary.
Separated Widgets
A third feature of vocabularies and categories is that every vocabulary has its own separated widget. These widgets appear in the Categorization section of the form for editing an asset and they allow users to easily select appropriate categories for that asset.
Figure 6.6: Vocabularies have their own widgets, making it easy to select available categories.
It’s important to use tags and categories with all your content, so that content is easier for users to find. Let’s look at one of the ways users will make use of tags and categories: searching for content.