REST services and IBM Domino/XWork - DanNotes 19-20. november 2014

© 2014, Dalsgaard Data A/S DanNotes, 19-20 November 2014
REST services
and
IBM Domino/XWork
A presentation for DanNotes
by John Dalsgaard

Agenda
● About me
● Webservices
● REST & JSON
● Domino/XWork – out of the box...
– Domino Access Service (DAS)
– Extension Library controls
– Build your own
– Demos
● Round up

About me
● Worked with Notes since 1995
version 4.5
● Java since Notes 5.0.7 (2000)
● Large web-apps. (40.000+ users)
● Object Oriented approach since 1999 (yes,
in LotusScript...)
● XPages & mobile apps (Appcelerator
Titanium)....
● Certified Principal/advanced administrator
and developer – all versions 4.6 → 9.0
● Developer, project manager, IT manager –
own company since 1998.

Webservices
● What is a webservice?
– Program to program communication
– Implemementation independent
– ”Contract” about interface
● Traditionally SOAP & XML...
– Very ”verbose” (=not ”light”)
– Needs pre-/post processing to ”extract” data
→ Meet the ”new kid on the block”:

REST services using JSON
● REST = REpresentational State Transfer
● JSON = JavaScript Object Notation
● Why?? → Loose coupling...
– Angular, Ext.js, etc.
– Mobile apps/web apps
● Let's take a quick look at these terms:

REST
● Wikipedia:
Representational state transfer (REST) is an abstraction of the
architecture of the World Wide Web; more precisely, REST is an
architectural style consisting of a coordinated set of architectural
constraints applied to components, connectors, and data
elements, within a distributed hypermedia system. REST ignores
the details of component implementation and protocol syntax in
order to focus on the roles of components, the constraints upon
their interaction with other components, and their interpretation of
significant data elements.....
WHAT?????

REST
● Client-server architecture
– Uniform interface separates client from server
● Stateless
– All info in request
● Cacheable communications protocol
– Almost always HTTP
● Uniform interface...
– HTML, URIs, XML, JSON, MIME, meta-data....
● Actually, WWW via HTTP can also be viewed as a
REST-based architecture – so nothing new here that
you did not know... :-)

”RESTful” web-service
● Architectural style:
– URI structure (base URI)
– Internet media type. JSON – or: XML, Atom, …
– Standard HTTP methods:
● GET
● POST
● PUT
● DELETE
… also known as: CRUD (Create, Read,
Update, Delete) methods

● Designed for networked applications
● Using HTTP as a simple alternative to more
complex mechanisms to connect between
machines:
– WebServices (SOAP, WSDLs etc.)
– CORBA
– RPC

● Example – SOAP:
<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:body pb="http://www.acme.com/phonebook">
<pb:GetUserDetails>
<pb:UserID>12345</pb:UserID>
</pb:GetUserDetails>
</soap:Body>
</soap:Envelope>
– … must to be sent via a request (HTTP POST)
● Example – RESTful web-service:
http://www.acme.com/phonebook/UserDetails/12345
– … just a URL!! (HTTP GET) – simple....

JSON
● Wikipedia:
JSON (/ˈdʒeɪsən/ jay-sən), or JavaScript Object Notation,
is an open standard format that uses human-readable text
to transmit data objects consisting of attribute–value pairs.
It is used primarily to transmit data between a server and
web application, as an alternative to XML.
Although originally derived from the JavaScript scripting
language, JSON is a language-independent data format.
Code for parsing and generating JSON data is readily
available in a large variety of programming languages.

JSON
● A syntax for storing & exchanging data
● An easier to use alternative to XML
● Is a lightweight data interchange format
● Is language independant
● Is ”self-describing” and easy to understand
JSON uses JavaScript syntax, but the JSON format is
text only, just like XML. Text can be read and used as
a data format by any programming language...

JSON vs. XML
● XML
<employees>
<employee>
<firstName>John</firstName> <lastName>Doe</lastName>
</employee>
<employee>
<firstName>Anna</firstName> <lastName>Smith</lastName>
</employee>
<employee>
<firstName>Peter</firstName> <lastName>Jones</lastName>
</employee>
</employees>
● JSON
{"employees":[
{"firstName":"John", "lastName":"Doe"},
{"firstName":"Anna", "lastName":"Smith"},
{"firstName":"Peter", "lastName":"Jones"}
]}

JSON syntax
● Object: {}
{ 'text' : 'Hello world!',
'number' : 123,
'valid' : true }
● Array: []
{ 'numbers' : [ 1, 2, 3 ] }
{ 'objects' : [ {'a':1}, {'b':2}, {'c':3} ] }
● Value:
– string, number, object, array, boolean, null

JSON and JavaScript
var text = ”{ 'name' : 'DanNotes', current : 52 }”;
● Create an object:
– var danNotes = JSON.parse(text);
● Create text representation of an object:
– var danNotesText = JSON.stringify(danNotes);
● Refer to attributes:
– var name = danNotes.name;
● Add another attribute:
– danNotes['venue'] = 'Korsør'

Domino/XWork – out of the box
● Webservices (SOAP, XML, etc...)
– Consumer (client) – since 8.0
– Provider (server) – since 7.0
But for now: RESTful service using JSON →
● Domino Access Services (DAS)
– core service - since 9.0.1
– data service - since 8.5.3 UP1 (~DDS)
– calendar service - since 9.0.1

Domino Access Services
● Implemented as OSGi plugins/servlets
● Based on Apache Wink
● How to enable & configure
– Web access
– Enable Domino Access Service (DAS)
– Enable for database
– Enable for specific elements

Enable web access
● HTTP Server must be started.
– Check console: show tasks
HTTP Server Listen for connect requests on TCP Port:80
● Use internet sites – just do it!
– Activate in server document
– Create Internet site document for domain
● After changes: restart task http
● Check:
– Open the server on the port you saw on the
console
– http://server.dom.dk:80/ (leave out port if 80)

Check DAS
Open: server.dom.dk/api
– lists service and
their state

Enable data service
● On Internet site document (configuration tab):
● Need to refresh http to take effect
– tell http refresh

DAS: List all ”services” (db's)
● Open: server.dom.dk/api/data

DAS: Open a specific database
● Try: server.dom.dk/reports.nsf/api/data/collections
→ We need to enable DAS for the database

DAS: Enable for database
● On the advanced properties of the database:
● Select level in ”Allow Domino Data Service”:
● Important decision: Views and/or documents

DAS: Open database again
● Try: server.dom.dk/demo/json.nsf/api/data/collections

DAS: Enable for view
● We need to enable DAS for the view first
● Open the view in Domino Designer
● On the view properties – advanced tab
● Enable: ”Allow Domino Data Service
operations”:
● Save the view, open it using the url returned

DAS: Open a view
● Try: server.dom.dk/.../collections/unid/A892133953...
● Heureka!! - we see a list of all documents!
● Also try: server.dom.dk/.../collections/name/persons

DAS: Open a document
● Try: server.dom.dk/.../documents/unid/33735D0BC...
● Requires ”Views and documents” to be set in DB props.

DAS: Writing back...
● Remember content type MUST be:
– application/json
– Set ”Content-type” in header of request
● If you get ”405 Method not allowed”
– Enable method in internet site
● By default these are NOT enabled:
– PUT
– PATCH
– DELETE
– Or override header in your request
● ”X-HTTP-Method-Override” : ”POST”

DAS: Save existing document
● Use ”PATCH” to change specific fields
– url: …/documents/unid/33735D0BCE799....
– updates only the fields in the request
● Use ”PUT” to change ALL fields
– All fields are replaced with the fields from request
– fields not specified are blanked....

DAS: Create / delete document
● Use ”POST” to create a document with
specified fields
– url: …/documents?form=Person
– You MUST add form to url
● Use ”DELETE” to remove the document
entirely

DAS: Data service - more...
● See the design of a view:
– //.../collections/name/persons/design
● Compute values on update of document
– //.../documents/unid/33735D0BC...?
computewithform=true
● Use ”normal” url actions to control view
collection, e.g.
– //.../collections/name/persons?start=1&count=2

DAS: Calendar service
● There is a catch to enable this service...
– In the internet site document you have to type
”Calendar” as an option.... - it is not predefined

● Built on the new calendar backend classes in
Domino/XWork 9.0.1
● Current user's calendars, email address, and
services
server.dom.dk/api/calendar
● Events from specific calendar
server.dom.dk/demo/cal.nsf/api/calendar/events
● Events from specific calendar (iCal format)
server.dom.dk/.../events?format=iCalendar

● You can also CREATE new events!!!
– Using POST and specifiying all fields under an
”events” object
– Handles the various types: Meeting,
appointment, etc.
– Will send invites to participants of meetings
– Handles notifications
– Actions for complete workflow: Accept, decline,
delegate, etc.
– … and more!

Extension Library
● Comes with the Domino 9.0.x server (and
Domino Designer)
● Just needs to be enabled in XSP properties
● Does NOT require DAS to be enabled
● Provides easy to use controls:
– REST Service (data)
– Remote Service (JSON-RPC)
● Allow you to run serverside code as a REST
service...
● Also provide support for:
– NSF and OSGi servlets... - advanced stuff!!

Extension Library
● Why would you use it...????
● Allows further customizations
– Include/exclude certain data columns
– Include/exclude system columns (@....)
– Calculate contents of own columns
– Run code before/after CRUD operations
– Sort and search
– Create ”handles” (variable) to use in XPage as
datasources

Ext. Lib. REST Service
● Create a new XPage
● Drag a ”REST Service” component to it:
● Fill in ”the blanks”
– pathInfo → identifies the service
– Select service
– Fill in the info
needed for that
type of service

Ext. Lib. REST Service
● To call your service you open the XPage with
the REST Service control(s) and add the
pathInfo, e.g.:
server.dom.dk/db.nsf/yourpage.xsp/persons
– ...assuming you set pathInfo to ”persons” for
one of the REST Services on the ”yourpage”
XPage

Ext. Lib. NSF servlet
● You can register a servlet to e.g. give you a
JSON representation of a view
● Extends DefaultServletFactory
– add a factory that maps to a service (e.g. view
name)
– Register in Code/Java/META-INF/services
● file: com.ibm.xsp.adapter.servletFactory
→ Full name of servlet class
● Refer to using url, e.g.:
server.dom.dk/db.nsf/xsp/services/Persons

Build your own...
● Why??
– … using your own MVC – Java objects
– Full control
– Does NOT require DAS to be enabled
● Handy ”ingredients”
– Java
– XPages
● Use an ”XAgent” (or an NSF/OSGi servlet)
● Select a JSON ”package”
– Built-in with XPages
– Or others like GSON – (wrap as plugin!!)

Build your own...
● One use case:
– Generate JSON directly from your Java class
– Consume your JSON POSTs directly by
parsing them to the corresponding Java class
→ Ready to use in your logic
– Control e.g. date formating generally for all
Date fields

Build your own...
● LotusScript....
– You didn't expect me to say this!
– An option if you have existing systems with
business logic written in LotusScript
– Simple:
● print – correct content-type
● print …. your JSON (as text)
– … but I would not advice to build new this way
→ you would like to use a library/package to
build your JSON for you!

Demo... ● Server:
– Local VM with Domino 9.0.1FP1 on CentOS 6.6
– Extension Library (from IBM)
– OpenNTF Domino API installed
– OpenNTF Essentials installed
● A demo database
– Showing an MVC pattern I use
– Added a number of JSON demos
– Will be made available for download
● Tool for testing:
– Google Chrome Postman

Demo...
● DAS
– core
– data
– calendar
● Extension Library REST Service
● Build you own
– Built-in JSON classes
– GSON based on Java objects
– LotusScript...
● Download DB from Bitbucket.org

Live DEMO

Round Up
● What are REST and JSON
● GET, POST, PUT, DELETE – ~CRUD
● Domino Access Services – out of the box
– Data
– Calendar
● Extension Library
– REST Service
– (Remote Service)
● Build own solution
– Java & JSON ”package” - …. & LotusScript ;-)

Questions??
● Did you learn something?
● Could you use it?
?

Contact info
Please feel free to contact me:
John Dalsgaard
Dalsgaard Data A/S
Solbjergvej 42
Solbjerg
DK-4270 Høng
Phone: +45 4914-1271
Email: john@dalsgaard-data.dk
www.dalsgaard-data.dk
Blog: www.dalsgaard-data.eu
Twitter: @john_dalsgaard, @DalsgaardDataAS
Skype: john_dalsgaard

Sources & links
● Wikipedia: Representational state transfer
● Learn REST: A Tutorial
● VIEW Tips: Brad Balassaitis on JSON-RPC
● IBM Domino Access Services 9.0.1
● Wikipedia: JSON / JavaScript Object Notation
● Introducing JSON
● JSON Tutorial
● REST services in Domino - Domino Access Services (PDF)
● Extension Library REST Services (PDF)
● Extension Library on OpenNTF (includes demo db)
● JSON test client: Chrome Postman
● Wrap an existing jar into a plugin
● Demo-DB on Bitbucket.org

REST services and IBM Domino/XWork - DanNotes 19-20. november 2014

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