CMIS

CMIS is the OASIS specification for content management interoperability. It allows client and servers to talk together in HTTP (REST with JSON, AtomPub or SOAP) using a unified domain model. The latest published version is CMIS 1.1.

Nuxeo supports CMIS through the following modules:

• The Apache Chemistry OpenCMIS library, maintained by Nuxeo and others, which is a general-purpose Java library allowing developers to easily write CMIS clients and servers,
• Specific Nuxeo OpenCMIS connector bundles, allowing the Nuxeo Platform to be used as a CMIS server with the help of OpenCMIS. The CMIS connector is included in the Nuxeo Platform 5.8+ versions.

Usage

Start your Nuxeo Platform and connect to it at the URL http://localhost:8080/nuxeo .

The following documentation uses http://localhost:8080/nuxeo as the URL of the Nuxeo server but you can replace it with http://NUXEO_SERVER/nuxeo if you have another instance available.

You can access the different services from the following URLs:

• Browser Binding root URL: http://localhost:8080/nuxeo/json/cmis
• AtomPub service document: http://localhost:8080/nuxeo/atom/cmis
• SOAP WSDL for the repository service: http://localhost:8080/nuxeo/webservices/cmis/RepositoryService?wsdl

JSON

You can use a CMIS 1.1 Browser Binding (JSON) client and point it at http://localhost:8080/nuxeo/json/cmis.

If you want to check the JSON returned using the command line, this can be done using curl or wget:

curl -u Administrator:Administrator http://localhost:8080/nuxeo/json/cmis | json_pp

This will give you the description of the default repository:

{
   "default" : {
      "cmisVersionSupported" : "1.1",
      "productName" : "Nuxeo OpenCMIS Connector",
      "productVersion" : "6.0",
      "vendorName" : "Nuxeo",
      "repositoryName" : "Nuxeo Repository default",
      "repositoryDescription" : "Nuxeo Repository default",
      "repositoryUrl" : "http://localhost:8080/nuxeo/json/cmis/default/",
      "thinClientURI" : "http://localhost:8080/nuxeo/",
      "repositoryId" : "default",
      "rootFolderId" : "fe7944e0-3d44-4abc-90d4-64e0e07c63c7",
      "rootFolderUrl" : "http://localhost:8080/nuxeo/json/cmis/default/root",
      "latestChangeLogToken" : "1415109467897",

      "capabilities" : {
         "capabilityChanges" : "objectidsonly",
         "capabilityVersionSpecificFiling" : false,
         "capabilityMultifiling" : false,
         "capabilityContentStreamUpdatability" : "pwconly",
         "capabilityQuery" : "bothcombined",
         "capabilityACL" : "manage",
         "capabilityRenditions" : "read",
         "capabilityPWCSearchable" : true,
         "capabilityOrderBy" : null,
         "capabilityPWCUpdatable" : true,
         "capabilityGetDescendants" : true,
         "capabilityUnfiling" : false,
         "capabilityAllVersionsSearchable" : true,
         "capabilityGetFolderTree" : true,
         "capabilityJoin" : "none"
         "capabilityNewTypeSettableAttributes" : { ... },
         "capabilityCreatablePropertyTypes" : {
            "canCreate" : []
         },
      },
      "aclCapabilities" : {
         "propagation" : "propagate",
         "supportedPermissions" : "repository",
         "permissionMapping" : [ ... ],
         "permissions" : [ ... ]
         ]
      },
      "changesIncomplete" : false,
      "changesOnType" : [
         "cmis:document",
         "cmis:folder"
      ],
      "principalIdAnyone" : "Everyone",
      "principalIdAnonymous" : "Guest",
      "extendedFeatures" : [
         {
            "description" : "Adds an additional DateTime format for the Browser Binding.",
            "commonName" : "Browser Binding DateTime Format",
            "versionLabel" : "1.0",
            "id" : "http://docs.oasis-open.org/ns/cmis/extension/datetimeformat",
            "url" : "https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=cmis"
         }
      ]
   }
}

To do a query you can do:

curl -u Administrator:Administrator "http://localhost:8080/nuxeo/json/cmis/default?cmisselector=query&succinct=true&q=SELECT+cmis:objectId,+dc:title+FROM+cmis:folder+WHERE+dc:title+=+'Workspaces'" | json_pp

Which returns:

{
   "numItems" : 1,
   "hasMoreItems" : false,
   "results" : [
      {
         "succinctProperties" : {
            "cmis:objectTypeId" : "WorkspaceRoot",
            "cmis:objectId" : "96e9e7b9-75be-4123-888d-ca89af7c8da3",
            "dc:title" : "Workspaces"
         }
      }
   ]
}

AtomPub

You can use a CMIS 1.1 AtomPub client and point it at http://localhost:8080/nuxeo/atom/cmis .

If you want to check the AtomPub XML returned using the command line, this can be done using curl or wget:

curl -u Administrator:Administrator http://localhost:8080/nuxeo/atom/cmis

To do a query you can do:

curl -u Administrator:Administrator "http://localhost:8080/nuxeo/atom/cmis/default/query?q=SELECT+cmis:objectId,+dc:title+FROM+cmis:folder+WHERE+dc:title+=+'Workspaces'&searchAllVersions=true"

You should probably pipe this through tidy if you want a readable output:

... | tidy -q -xml -indent -wrap 999

Notes

• The searchAllVersions=true part is mandatory if you want something equivalent to what you see in Nuxeo (which often contains mostly private working copies).

• In order to fetch custom metadata, you must restrict the selection to document types that contain the metadata. For example, if you have a metadata "custom" in a document type "mytype", then your query would be something like:

  curl -u Administrator:Administrator "http://localhost:8080/nuxeo/atom/cmis/default/query?q=SELECT+cmis:objectId,+mytype:custom+FROM+mytype+&searchAllVersions=true"
  

SOAP

The following SOAP endpoints are available:

• http://NUXEO_SERVER/nuxeo/webservices/cmis/RepositoryService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/DiscoveryService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/ObjectService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/NavigationService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/VersioningService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/RelationshipService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/MultiFilingService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/ACLService?wsdl
• http://NUXEO_SERVER/nuxeo/webservices/cmis/PolicyService?wsdl

Authentication is done using Web Services Security (WSS) UsernameToken.

Here is a working example of a SOAP message to the DiscoveryService:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns="http://docs.oasis-open.org/ns/cmis/messaging/200908/">
  <soapenv:Header>
    <Security xmlns="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">
      <UsernameToken>
        <Username>Administrator</Username>
        <Password>Administrator</Password>
      </UsernameToken>
    </Security>
  </soapenv:Header>
  <soapenv:Body>
    <ns:query>
      <ns:repositoryId>default</ns:repositoryId>
      <ns:statement>SELECT cmis:objectid, dc:title FROM cmis:document WHERE dc:title = 'Workspaces'</ns:statement>
      <ns:maxItems>20</ns:maxItems>
      <ns:skipCount>0</ns:skipCount>
    </ns:query>
  </soapenv:Body>
</soapenv:Envelope>

CMIS Clients

Several free clients for CMIS 1.1 are available. The best one is the CMIS Workbench, part of OpenCMIS.

And of courseyou can use the Chemistry libraries to produce your own client (Java, Python, PHP, .NET). Documentation and sample for using OpenCMIS libraries can be found on the OpenCMIS developer wiki with also example code and how-to guides.

From Java Code Within a Nuxeo Component

To create, delete or modify documents, folders and relations just use the regular CoreSession API of Nuxeo. To perform CMISQL queries (for instance to be able to perform JOIN that are not supported by the default NXQL query language) have a look at the page How to Make CMISQL Queries Using Java.

Capabilities

The Nuxeo OpenCMIS connector implements the following capabilities from the specification:

Model Mapping

The following describes how Nuxeo documents are mapped to CMIS objects and vice versa.

• Only Nuxeo documents including the "dublincore" schema are visible in CMIS.
• Complex properties are not visible in CMIS, as this notion does not exist in CMIS.
• Proxy documents are not visible in CMIS.
• Secondary content streams are not visible as renditions. Only the Nuxeo thumbnail and renditions explicitly made available through the Nuxeo RenditionService are visible.
• Documents in the Nuxeo trash (those whose nuxeo:lifecycleState is deleted) are not visible in CMIS, unless an explicit query using the nuxeo:lifecycleState property is done.

This mapping may change to be more comprehensive in future Nuxeo Platform versions.

Nuxeo-Specific System Properties

In addition to the system properties defined in the CMIS specification under the cmis: prefix, the Nuxeo Platform adds some additional properties under the nuxeo: prefix:

• nuxeo:isVersion: To distinguish between archived (read-only revision) and live documents (that can be edited);
• nuxeo:lifecycleState: To access the life cycle state of a document. By default only document in non deleted state will be returned in CMISQL queries unless and explicit nuxeo:lifecycleState predicate is specified in the WHERE clause of the query;
• nuxeo:secondaryObjectTypeIds: Makes it possible to access the facets of a document. Those facets can be static (as defined in the type definitions) or dynamic (each document instance can have declared facets);

• nuxeo:contentStreamDigest: The low level, MD5 or SHA1 digest of blobs stored in the repository. The algorithm used to compute the digest is dependent on the configuration of the BinaryManager component of the Nuxeo repository.

• nuxeo:isCheckedIn: For live documents, distinguishes between the checked-in and checked-out state.

• nuxeo:parentId: Like cmis:parentId but also available on Document objects (which is possible because the Nuxeo Platform does not have direct multi-filing).
• nuxeo:pathSegment: The last path segment of the document (ecm:name in NXQL).
• nuxeo:pos: The position of an object in its containing folder, if that folder is ordered, or null otherwise (since Nuxeo 6.0).

All these properties can be used as regular CMIS properties and in a CMISQL query (in a SELECT, WHERE or ORDER BY clause where relevant), except for nuxeo:contentStreamDigest which can only be read in query results or by introspecting the properties of the ObjectData representation of a document.

Resources

• The Nuxeo OpenCMIS connector source code on GitHub: https://github.com/nuxeo/nuxeo-chemistry.
• The Apache Chemistry OpenCMIS source code on Apache's Subversion server: https://svn.apache.org/repos/asf/chemistry/opencmis/trunk.

• Documentation: CMIS 1.1 (HTML) or CMIS 1.1 (PDF) (1.3 MB).

• CMIS: Overview of a Rapidly Evolving ECM Standard, presentation on SlideShare

• CMIS and Apache Chemistry (ApacheCon 2010), presentation on SlideShare
• Nuxeo World Session: CMIS - What's Next?, presentation on SlideShare