Using External Repositories

Liferay DXP’s Documents and Media lets you store files in a number of different ways and lets you access external repositories in addition to the built in document repository. Your administrator can learn how to set options for storing the Documents and Media Library’s files here. To connect the Documents and Media library to external repositories, read on.

Documents and Media allows users to connect to multiple third-party repositories. Some of the features supported with third-party repositories include:

• Reading/writing documents and folders
• Document check-in, check-out, and undo check-out
• Downloading documents
• Moving folders and documents within the repository
• Getting revision history
• Reverting to a revision

Liferay DXP’s Documents and Media can inter-operate with repositories that support the Content Management Interoperability Services (CMIS) standard. CMIS defines a model for interacting with repository files. Liferay DXP supports interoperability through CMIS version 1.1 (the current CMIS version) and earlier. Liferay DXP can access CMIS repositories using AtomPub and Web Services protocols.

Figure 1: In Documents and Media, external repositories look similar to folders. You can perform supported operations on their files. This figure shows an Alfresco CMIS repository named *My Alfresco*.

Here are the CMIS repository integration steps:

1. Adjust portal properties
2. Synchronize user accounts between Liferay DXP and the repository
3. Add the repository to Documents and Media

Interoperability with SharePoint and Documentum repositories is available to EE subscribers with the Liferay SharePoint Connector and Liferay Documentum Connector apps, available on the Marketplace.

Let’s start with setting portal properties.

Step 1: Adjust Portal Properties

In order to authenticate with the third-party repository, you need to store passwords for the user sessions. You must configure an authentication type that supports storing passwords to the user sessions.

Important: Since authentication with single sign-on (SSO) does not store encrypted passwords in the user sessions, SSO can’t be used with the external repository types.

Let’s configure Liferay Portal for what’s required in authentication. In a portal-ext.properties file in your Liferay Home, set a session.store.password portal property to true:

session.store.password=true

Next, make sure to authenticate the same way on both Liferay DXP and the repository. You can do so by authenticating based on screen name. Set the following company.security.auth.type portal property:

company.security.auth.type=screenName

Alternatively, you can configure both of these properties in the Control Panel under Instance Settings → Authentication.

Step 2: Synchronize the User Accounts

External repository integration requires Liferay DXP users use the same screen name and password as their external repository user. For details on adding and managing users, refer to User Mangement. Make sure to sign in to Liferay DXP as such a user whenever you’re accessing the repository from it.

Important: Use lowercase for user names in the external repository, as Liferay screen names are lowercase.

Note: In the external repository, make sure to associate users with necessary roles for accessing repository files. In Nuxeo, for example, a user must belong to the Nuxeo Administrators group to access Nuxeo repository files via CMIS.

Adding a Repository mapped to the external repository is the final step.

Step 3: Add the Repository to Documents and Media

The last step is adding a to Documents and Media a Repository to inter-operate with the external repository. Documents and Media can connect with a CMIS repository using the Atom Publishing (AtomPub) protocol or Web Services protocol. Let’s explore accessing a CMIS Repository using AtomPub.

Adding a CMIS Repository that Uses AtomPub

AtomPub is the easiest protocol to specify for communicating with a CMIS repository.

Follow these steps to access a repository with CMIS AtomPub:

1. Sign in to Liferay DXP as a user that also exists in the external repository and can access files you want to use in that repository.

2. In Documents and Media Home, click the Add icon () and select Repository. The New Repository screen appears.

   

   Figure 2: Here's the form for accessing a CMIS repository using AtomPub.

3. Enter an arbitrary Name for the repository and optionally enter a Description.

4. Click on the Repository Configuration section to access its form. Specify values for the following fields:

   • Repository Type: CMIS Repository (AtomPub)
   • Repository ID: Leave this blank, as Liferay DXP generates the ID automatically
   • AtomPub URL: Enter the AtomPub URL for CMIS per the repository’s documentation. Example URLs are listed below. If you copy them, make sure to replace the [host] and [port] values with your own.
     • Alfresco 5.1 CMIS 1.0: http://[host]:[port]/alfresco/cmisatom
     • Alfresco 5.1 CMIS 1.1: http://[host]:[port]/alfresco/api/-default-/public/cmis/versions/1.1/atom
     • Nuxeo 7.10: http://[host]:[port]/nuxeo/atom/cmis

5. Click Save

The external repository appears in Documents and Media. You can navigate the repository and manage files.

Figure 3: Documents and Media lets you perform CMIS supported actions on external repository files.

Next, let’s access a CMIS repository with Web Services.

Adding a CMIS Repository that Uses Web Services

After adjusting your portal properties and adding any user accounts required by the repository, you can add a Documents and Media Repository that inter-operates with an external repository that supports CMIS with Web Services.

Follow these steps to add such a repository:

1. In Documents and Media Home, click the Add button and select Repository. The New Repository screen appears.

2. Enter an arbitrary Name for the repository and optionally enter a Description.

3. Click on the Repository Configuration section to access its form

4. For Repository Type:, select CMIS Repository (Web Services).

5. Enter the web service URLs (WSDL URLs) per your CMIS repository’s documentation. Example URLs are listed after these steps. Make sure to enter URLs for the following services:

   • Web Services ACL Service
   • Web Services Discovery Service
   • Web Services Multi-Filing Service
   • Web Services Navigation Service
   • Web Services Object Service
   • Web Services Policy Service
   • Web Services Relationship Service
   • Web Services Repository Service
   • Web Services Versioning Service

   Tips: In a browser, you can open the repository’s WSDL file and verify each service in it. Also make sure to specify the entire URLs–they all end with ?wsdl.

   

   Figure 4: Here's an example of the web service URLs for an Alfresco repository.

6. Leave Repository ID blank, as Liferay DXP generates the ID automatically.

7. Click Save

Your repository appears in Documents and Media. You can navigate into the repository and work with files as you do other files in Documents and Media.

Liferay DXP’s CMIS repository integration gives you flexibility to access external repository files in addition to your existing Documents and Media files.