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Description:

drccmis 1.9.0

Version:
1.9.0
Source:
https://github.com/open-zaak/cmis-adapter

Keywords:
CMIS, Documenten API, VNG, Common Ground

PythonVersion:
3.7

A CMIS backend-connector for the Documenten API.
Developed by Maykin Media B.V. commissioned by the municipality of Utrecht
with support of the municipality of Súdwest-Fryslân and the Open Zaak project
team.

Introduction
The Documenten API CMIS adapter allows Django implementations of the Documenten
API to easily connect to a CMIS-compatible Document Management System (DMS).
Most notably it’s used by Open Zaak to use a DMS as backend for the
Documenten API rather then using its own backend.

Features
Both CMIS 1.0 and CMIS 1.1 are supported but not for all bindings. Below
is a list of supported bindings for each CMIS version.

CMIS 1.0
CMIS 1.1

Web Services binding
Supported
Untested

AtomPub binding
Untested
Untested

Browser binding
N/A
Supported

For the supported bindings, the following features are implemented:

Retrieve from and store documents in a CMIS-compatible DMS.
Supports reading and writing of documents.
Supports checking out/in of documents.
Supports custom data-model for storing additional meta data.

Tested against:

Corsa platform using CMIS 1.0 Web Services binding (Thanks to BCT)
Alfresco Enterprise 5.2.3 using CMIS 1.1 Browser binding (Thanks to
Contezza)
Alfresco CE 6.1.2-ga (Used for CI)

Installation
NOTE: If you are using Open Zaak 1.3.1 or above, the CMIS-adapter is already
included and does not require separate installation.

Requirements

Python 3.7 or above
setuptools 30.3.0 or above
Django 3.2 or newer

Install

Install the library in your Django project:

$ pip install drc-cmis

Add to INSTALLED_APPS in your Django settings.py:

INSTALLED_APPS = [
...
"drc_cmis",
...
]

Create a mapping file to match Documenten API attributes to custom
properties in your DMS model. See Mapping configuration.
In your settings.py, add these settings to enable it:

# Enables the CMIS-backend and the Django admin interface for configuring
# the DMS settings.
CMIS_ENABLED = True

# Absolute path to the mapping of Documenten API attributes to (custom)
# properties in your DMS content model.
CMIS_MAPPER_FILE = /path/to/cmis_mapper.json

Login to the Django admin as superuser and configure the CMIS backend.

Mapping configuration
There are 2 important concepts:

Content model - The DMS configuration to store (custom) properties on folders
and documents. These properties are called CMIS properties.
CMIS-mapper - a JSON-file containing the translation from Documenten API
attributes to CMIS properties.

Mapping the Documenten API attributes to (custom) CMIS properties in the DMS
content model should be done with great care. When the DMS stores these
properties, the Documenten API relies on their existance to create proper responses.
Below is a snippet of the CMIS-mapper:
{
"DOCUMENT_MAP": {
"titel": "drc:document__titel"
}
}
The DOCUMENT_MAP describes the mapping for the
EnkelvoudigInformatieObject resource in the Documenten API. In this
snippet, only the EnkelvoudigInformatieObject.titel attribute is mapped to
a custom CMIS property called drc:document_titel.
Communication between the Documenten API using the CMIS-adapter, is done via
CMIS. Therefore, when creating a document via the Documenten API, the
attributes are translated to CMIS properties as shown below (note that this is
a stripped down request example).
<?xml version="1.0"?>
<soapenv:Envelope xmlmsg:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlmsg:msg="http://docs.oasis-open.org/ns/cmis/messaging/200908/" xmlmsg:core="http://docs.oasis-open.org/ns/cmis/core/200908/">
<soapenv:Header />
<soapenv:Body>
<msg:createDocument>
<msg:repositoryId>d6a10501-ef36-41e1-9aae-547154f57838</msg:repositoryId>
<msg:properties>
<core:propertyString propertyDefinitionId="drc:document__titel">
<core:value>example.txt</core:value>
</msg:properties>
<msg:folderId>workspace://SpacesStore/7c6c7c86-fd63-4eec-bcf8-ffb59f6f6b90</msg:folderId>
</msg:createDocument>
</soapenv:Body>
</soapenv:Envelope>
An example of the mapping configuration, with all possible Documenten API
resources and attributes is shown in test_app/cmis_mapper.json
(cmis_mapper.json). The related DMS content model, that has the definitions
for all these CMIS properties, for Alfresco (an open source DMS) is in
/alfresco/extension/alfreso-zsdms-model.xml (alfreso-zsdms-model.xml).
Both the mapping and the model should be aligned.

Mappings
The content model and the CMIS-mapper configurations need to be aligned. For
each object, the API resource, the CMIS objecttype, CMIS basetype and the
(configuratble) CMIS-mapper object is described.
Document
The document itself, its content and meta data.

Documenten API resource
EnkelvoudigInformatieObject

CMIS objecttype *
drc:document

CMIS basetype
cmis:document

CMIS-mapper object
DOCUMENT_MAP

The mapping between API-attributes and CMIS properties can be found in the cmis_mapper.json.
Gebruiksrechten
Usage rights. These rights don’t need to be enforced by the DMS but are stored
for use outside the DMS.

Documenten API resource
Gebruiksrechten

CMIS objecttype *
drc:gebruiksrechten

CMIS basetype
cmis:document

CMIS-mapper object
GEBRUIKSRECHTEN_MAP

The mapping between API-attributes and CMIS properties can be found in the cmis_mapper.json.
ObjectInformatieObject
Relation between a document and another object, like a Zaak, Besluit or
something else.

Documenten API resource
ObjectInformatieObject

CMIS objecttype *
drc:oio

CMIS basetype
cmis:document

CMIS-mapper object
OBJECTINFORMATIEOBJECT_MAP

The mapping between API-attributes and CMIS properties can be found in the cmis_mapper.json.
Zaaktype folder
Contains all Zaken from this Zaaktype and has itself some meta data about the
Zaaktype. API-attributes are from the Catalogi API Zaaktype-resource.

Catalogi API resource
Zaaktype

CMIS objecttype *
drc:zaaktypefolder

CMIS basetype
cmis:folder

CMIS-mapper object
ZAAKTYPE_MAP

The mapping between API-attributes and CMIS properties can be found in the cmis_mapper.json.
Zaak folder
Contains all Zaak-related documents and has itself some meta data about the
Zaak. API-attributes are from the Zaken API Zaak-resource.

Zaken API resource
Zaak

CMIS objecttype *
drc:zaakfolder

CMIS basetype
cmis:folder

CMIS-mapper object
ZAAK_MAP

The mapping between API-attributes and CMIS properties can be found in the cmis_mapper.json.
* CMIS objecttype: cmis:objectTypeId

DMS Content model configuration
The CMIS mapper configuration must match the content model in the DMS. Each
property, like drc:document__titel in the example above, must be defined
in the content model.
The example shown in /alfresco/extension/alfreso-zsdms-model.xml
indicates all attributes, types and whether the property is indexed (queryable)
or not. If these attributes are incorrectly configured, the Documenten API
might not work correctly.

DMS folder structure
Open Zaak uses a folder structure in the DMS similar to the
Zaak- en Documentservices 1.2. However, due to way the Documenten API works
there are differences.
Creating a document
When a document is created via the Documenten API, the document is placed in a
temporary folder. By default this is:
CMIS Root
+-- DRC (cmis:folder)
+-- [year] (cmis:folder)
+-- [month] (cmis:folder)
+-- [day] (cmis:folder)
+-- [filename] (drc:document)
For example:
CMIS Root > DRC > 2020 > 12 > 31 > document.txt
If nothing else happens, this document will remain here.
Creating gebruiksrechten
A document can have Gebruiksrechten. These are stored as a separate document
(gebruiksrechten) in a folder called Related data. This folder is
always in the same folder as the document itself and is of type cmis:folder.
The Gebruiksrechten will always be moved or copied along with the document.
For example:
CMIS Root > DRC > 2020 > 12 > 31 > document.txt
CMIS Root > DRC > 2020 > 12 > 31 > Related data > document.txt-gebruiksrechten
Relating a document to a Zaak
Relating a document to a Zaak (by creating an ObjectInformatieObject
instance in the Documenten API) will cause the document and its Gebruiksrechten
if it exists, to be moved or copied to the zaak folder.
CMIS Root
+-- DRC (cmis:folder)
+-- [zaaktype-folder] (drc:zaaktypefolder)
+-- [year] (cmis:folder)
+-- [month] (cmis:folder)
+-- [day] (cmis:folder)
+-- [zaak-folder] (drc:zaakfolder)
+-- [filename] (drc:document)
+-- Related data (cmis:folder)
+-- [filename]-gebruiksrechten (drc:gebruiksrechten)
+-- [filename]-oio (drc:oio)
A document is moved when the document was not related to a Zaak before
(and thus it was in the temporary folder). The document is copied to the
new zaak folder when the document was already related to a Zaak.
The relation of a document to a Zaak is implicitly described by its path. In
addition however, this relation is stored as a separate document (oio) in
the Related data folder.
For example:
CMIS Root > DRC > Melding Openbare Ruimte > 2020 > 12 > 31 > ZAAK-0000001 > document.txt
CMIS Root > DRC > Melding Openbare Ruimte > 2020 > 12 > 31 > ZAAK-0000001 > Related data > document.txt-gebruiksrechten
CMIS Root > DRC > Melding Openbare Ruimte > 2020 > 12 > 31 > ZAAK-0000001 > Related data > document.txt-oio
Relating a document to a Besluit
When a document is related to a Besluit, there’s a few different scenario’s:

The Besluit is related to a Zaak and…

The document is not related to a Zaak (and thus the document is in
the temporary folder): The document is moved to the Zaak folder of
the Zaak that is related to the Besluit.
The document is already related to a Zaak: The document is copied
to the new Zaak folder.

The Besluit is not related to a Zaak and…

The document is not related to a Zaak: The document stays in its
temporary folder.
The document is related to a Zaak: The document is copied to the
temporary folder.

In all cases, the relation of a document to a Besluit is stored as a separate
document (oio) in the Related data folder, relative to wherever the new
document is stored.
Relating a document to another object
When a document is related to any other object, the document is not moved or
copied and stays in its temporary folder.
Deleting a Zaak Informatie Object
When a document is related to a zaak, it is located in the zaak folder and has an OIO in the ‘Related Data’
folder. If the ZIO relating the zaak and the document is deleted, the OIO is deleted, and the document
should not remain in the zaak folder. This is done as follows:

If the document is NOT a copy (i.e. it’s the original document), it should be moved to the default folder.
If there are related gebruiksrechten, then they should also be moved.
If the document IS a copy, then it should be deleted. Related gebruiksrechten should also be deleted.

DMS folder structure overview
You can configure the folders used by the CMIS adapter via the admin interface.
Some folders are templated (indicated with {{ }}) which means their value
depends on the current date or the related Zaak.
A complete overview of all default folders and documents are shown below:
Zaak folder path
Storage location for documents related to a Zaak.
Default: /DRC/{{ zaaktype }}/{{ year }}/{{ month }}/{{ day }}/{{ zaak }}/
CMIS Root
+-- DRC (cmis:folder)
+-- [zaaktype-folder] (drc:zaaktypefolder)
+-- [year] (cmis:folder)
+-- [month] (cmis:folder)
+-- [day] (cmis:folder)
+-- [zaak-folder] (drc:zaakfolder)
+-- [filename] (drc:document)
+-- Related data (cmis:folder)
+-- [filename]-gebruiksrechten (drc:gebruiksrechten)
+-- [filename]-oio (drc:oio)
You can for example change this to: /DRC/{{ zaaktype }}/{{ zaak }}/ to
remove the year/month/day folder structure entirely.
Other folder path
Storage location for documents not (yet) related to a Zaak.
Default: /DRC/{{ year }}/{{ month }}/{{ day }}/
CMIS Root
+-- DRC (cmis:folder)
+-- [year] (cmis:folder)
+-- [month] (cmis:folder)
+-- [day] (cmis:folder)
+-- [filename] (drc:document)
+-- Related data (cmis:folder)
+-- [filename]-gebruiksrechten (drc:gebruiksrechten)
+-- [filename]-oio (drc:oio)

Notes on differences between DMSs
SQL queries support
The SQL queries that are not supported in Alfresco can be found here. In addition, queries such as:
SELECT * FROM drc:document WHERE cmis:parentId = '<folder.objectId>' don’t seem to work.
The SQL queries that seem not to be supported in Corsa are:

IN queries
IN_FOLDER('<folder objectId>')
OR queries

References

Issues
Code

License
Copyright © Dimpact 2019 - 2020
Licensed under the EUPL