Difference between revisions of "Tutorial: Ontology Development"

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NEEDS TO BE REVISED TO MATCH CURRENT CONVENTIONS
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__NOTOC__  
 
__NOTOC__  
''"What's up folks."'' This tutorial series is composed of four parts. As it is a trail, you should learn them in order. Today we are going to create a movie database ontology for a client of your Acme company. Even though Simantics is intended for simulator integration platform, we decided to use movies as the theme. This basic level tutorial doesn't not go into simulation specifics and the subject is easier for a common developer to relate than some ''specific'' simulation domain.  
+
''"What's up folks."'' This tutorial series is composed of four parts. As it is a trail, you should study them in order. Today we are going to create a movie database ontology for a client of your Acme company. Even though Simantics is intended for simulator integration platform, we decided to use movies as the theme. This basic level tutorial doesn't go into simulation specifics, and the subject is more familiar for any developer to relate to than a simulation specific one. Before starting make sure you have installed [[Development_Environment_Setup_Guide#Install_Simantics_target_platform|Target Platform]] and [[Graph_Compiler|Graph Compiler]] to your Eclipse as instructed in [[Development Environment Setup Guide]].
 +
 
 +
 
 +
Related documents:
 +
* Complete [[Graph File Format]]
 +
* As ontology developer you must understand [[Version Migration#Ontology migration|ontology version migration]]
  
 
== Step 1: Setup Ontology Plug-in ==
 
== Step 1: Setup Ontology Plug-in ==
Ontologies are encapsulated in OSGi bundles. In eclipse we develop them as equinox plug-ins. An ontology bundle is a package that contains sources (graph/*.pgraph), compiled graph file (graph.tg), and Java resource files (src/ and bin/).
+
Ontologies are encapsulated in OSGi bundles. In Eclipse, we develop them as Eclipse plug-ins. An ontology bundle is a specialized package. It has the following content: graph source files (graph/*.pgraph), a compiled graph file (graph.tg), and Java files (src/ and bin/).
  
 
Open a New Plug-in Project wizard:
 
Open a New Plug-in Project wizard:
 
* Open Plug-in Development Perspective
 
* Open Plug-in Development Perspective
* '' Select '''File''' >> '''New''' >> '''Other'''  
+
* Select'' '''File''' >> '''New''' >> '''Other'''  
* '' Select '''Plug-in Development''' >> '''Plug-in Project''' ''
+
* Select'' '''Plug-in Development''' >> '''Plug-in Project''' ''
  
 
A ''New Plug-in Project'' wizard will open.  
 
A ''New Plug-in Project'' wizard will open.  
 
* Our organization is Acme Software ltd and from there is our plug-in name derived, ''com.acme.movie.ontology''. Insert that as project name. '''Next >'''
 
* Our organization is Acme Software ltd and from there is our plug-in name derived, ''com.acme.movie.ontology''. Insert that as project name. '''Next >'''
* In the following page you should know that this plugin does not contribute to UI, does not need an activator and is not a rich client application. '''Next >'''
+
* Set Version to ''0.1.0.qualifier''. In this page you should know that this plugin does not contribute to UI, does not need an activator and is not a rich client application. '''Next >'''
 
* Use template ''Plug-in with a Simantics Ontology''. '''Next >'''
 
* Use template ''Plug-in with a Simantics Ontology''. '''Next >'''
* Your company domain is ''com.acme.movie'' and ontology name ''Movie'', and the inital version is 1.0. '''Finish'''
+
* The domain of your company is ''www.acme.com'' and the name of the ontology ''Movie''. The initial version is 1.0. '''Finish'''
  
You have now a new project in Package Explorer. In it you will find META-INF/MANIFEST.MF, graph/Movie.pgraph, and graph.tg.  
+
You have now a new project in Package Explorer. You will find META-INF/MANIFEST.MF, graph/Movie.pgraph, and graph.tg in it.
  
 
== Step 2: Initialize Ontology ==
 
== Step 2: Initialize Ontology ==
 
Open Movie.pgraph and start editing.
 
Open Movie.pgraph and start editing.
  
As you are using Layer0 concepts, it is a good idea to capture its namespace:
+
You will be using Layer0 concepts. You can avoid writing full URIs for all references by defining an abbreviation. It is a good idea to declare all ontologies you will use in this way:
   L0 = <http://www.simantics.org/Layer0-1.0>
+
   L0 = <nowiki><http://www.simantics.org/Layer0-1.0></nowiki>
  
Your acme company has a namespace. You are creating a ''new'' one so it must be stated.
+
Your acme company has a domain that has to be declared. Because this is the first time the domain is used, you have to mark it "new" so that the graph compiler does not try to find it from dependencies.
   <http://com.acme> : L0.Library
+
   <nowiki><http://www.acme.com></nowiki> : L0.Library
 
       @L0.new
 
       @L0.new
  
The ontology has a representing resource, an instance of L0.Ontology. Don't forget to tell the compiler to create Resource file aswell.
+
The ontology has a representing resource, an instance of L0.Ontology. The second line tells the compiler to create a Resource file as well.
   mo = <http://com.acme/Movie-1.0> : L0.Ontology
+
   MO = <nowiki><http://www.acme.com/Movie-1.0></nowiki> : L0.Ontology
       L0.HasResourceClass "com.acme.ontology.Movie"
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       L0.HasResourceClass "com.acme.movie.ontology.Movie"
  
 
== Step 3: Export package ==
 
== Step 3: Export package ==
Now that you have some content, graph compiler has created a Resource class ''com.acme.ontology.Movie'' under ''src/'' folder. When developing database code you can gain access to your ontology concepts using this class. In OSGi plugin environment, the access to other plugins' classes is denied by default. To share, you must export its Java package.  
+
Now that you have some content, graph compiler has created a Resource class ''com.acme.movie.ontology.Movie'' under ''src/'' folder. When developing database code you can gain access to your ontology concepts using this class. In OSGi plugin environment, the access to other plugins' classes is denied by default. To share, you must export its Java package.  
 
* '' Open '''META-INF/MANIFEST.MF'''
 
* '' Open '''META-INF/MANIFEST.MF'''
 
* ''Add '''Exported Packages''' >> '''com.acme.ontology''' ''
 
* ''Add '''Exported Packages''' >> '''com.acme.ontology''' ''
Line 41: Line 48:
 
Manifest-Version: 1.0
 
Manifest-Version: 1.0
 
Bundle-ManifestVersion: 2
 
Bundle-ManifestVersion: 2
Bundle-Name: Ontology
+
Bundle-Name: http://www.acme.com/Movie
 
Bundle-SymbolicName: com.acme.movie.ontology
 
Bundle-SymbolicName: com.acme.movie.ontology
 
Bundle-Version: 1.0.0.qualifier
 
Bundle-Version: 1.0.0.qualifier
Line 47: Line 54:
 
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
 
Require-Bundle: org.simantics.layer0;bundle-version="1.0.0"
 
Require-Bundle: org.simantics.layer0;bundle-version="1.0.0"
Export-Package: com.acme.ontology
+
Export-Package: com.acme.movie.ontology
 
</pre>
 
</pre>
 +
 +
In this case the ontology's namespace root URI is '''<nowiki>http://www.acme.com/Movie-1.0</nowiki>'''.
 +
Due to ontology versioning support in the platform
 +
# '''Bundle-Name''' must match URI without the version number, i.e. '''<nowiki>http://www.acme.com/Movie</nowiki>'''
 +
# '''Bundle-Version''' first two digits (major.minor) must match the URI's version part, i.e. '''1.0'''.
 +
 +
Notice, in particular, that the ontology depends on Layer0. If other ontologies are needed, they have to be added to MANIFEST.MF.
  
 
== Step 4: Write your Movie Ontology ==
 
== Step 4: Write your Movie Ontology ==
In movie database we are going to store objects such as movies, actors, directors and producers. There is going to be a few properties about them, and a couple of relations. At this point it is a good idea to take a look at the [[Graph File Format|graph file format]] documentation. Good, open Movie.pgraph again.
+
In movie database, we are going to store objects such as movies, actors, directors and producers. There is going to be a few properties about them, and a couple of relations. At this point it is a good idea to take a look at the [[Graph File Format|graph file format]] documentation. Here is all we are going to define in one diagram:
 +
[[File:MovieOntology.png|center]]
 +
 
 +
Open Movie.pgraph again.
  
 
* Specify Types
 
* Specify Types
First we need to specify object types for the concepts ''Movie'', ''Character'', ''Cast'' and ''Person''. Actors, directors and producers are modelled as ''Persons''. A person becomes a representative of a classification, say actor, once he/she has acted in a motion picture (modeled as interrelation statement). Cast is a anonymous resource that links between Person (actor) and Character.  
+
First we need to specify the types ''Movie'', ''Character'', ''Cast'' and ''Person''. Actors, directors and producers are modelled as ''Persons''. A person becomes a representative of a classification, say actor, once he/she has acted in a motion picture (modeled as interrelation statement). Cast is a anonymous resource that links together Person (actor) and Character in one Movie. There is no inheritance between the concepts in our ontology, however every type in Simantics has to inherit the Entity type.
  
 
  // Types
 
  // Types
  mo.Movie <T L0.Entity
+
  MO.Movie <T L0.Entity
  mo.Character <T L0.Entity
+
  MO.Character <T L0.Entity
  mo.Person <T L0.Entity
+
  MO.Person <T L0.Entity
  mo.Cast <T L0.Entity
+
  MO.Cast <T L0.Entity
  
 
* Specify Properties
 
* Specify Properties
 +
The following relations define the basic properties that can be given to the types of our ontology. All properties are functional, i.e. every resource may have at most one statement of the relation.
 +
 
  // Properties
 
  // Properties
  mo.HasDobYear <R L0.HasProperty
+
  MO.HasYearOfBirth <R L0.HasProperty : L0.FunctionalRelation
 +
    L0.HasDomain MO.Person
 
     L0.HasRange L0.Integer   
 
     L0.HasRange L0.Integer   
  mo.HasAge <R L0.HasProperty
+
  MO.HasAge <R L0.HasProperty : L0.FunctionalRelation
 +
    L0.HasDescription "The age of the character during the movie."
 +
    L0.HasDomain MO.Character
 
     L0.HasRange L0.Integer   
 
     L0.HasRange L0.Integer   
  mo.HasGender <R L0.HasProperty
+
  MO.HasGender <R L0.HasProperty : L0.FunctionalRelation
     L0.HasRange mo.Gender
+
    L0.HasDescription "The gender of a person or a character."
  mo.HasTitle <R L0.HasProperty // The english title
+
     L0.HasRange MO.Gender
 +
  MO.HasTitle <R L0.HasProperty : L0.FunctionalRelation
 +
    L0.HasDescription "The English title of the movie."
 +
    L0.HasDomain MO.Movie
 +
    L0.HasRange L0.String
 +
MO.HasName <R L0.HasProperty : L0.FunctionalRelation
 +
    L0.HasDescription "The name of a person or a character."
 
     L0.HasRange L0.String
 
     L0.HasRange L0.String
  
* Specify Literals
+
* Specify Gender enumeration
Numberic primitives are defined in Layer0, eg. L0.Integer. Gender is a special case, since it is not defined in Layer0 you must do it yourself. The syntax is defined in [[Databoard_Specification#Datatypes|Datatype documentation]]. In it you will find out the format for your enumeration is ''|Male|Female''.
+
Enumerations are special kind of types: They have a fixed number of instances that are defined in the ontology. Gender is a prototypical example:
  
  // Literals
+
  // Enumeration
  mo.Gender <T L0.Literal
+
  MO.Gender <T L0.Property
     @L0.assert L0.HasDataType $(|Male|Female)
+
     @L0.tag L0.Enumeration
 +
MO.Gender.Male : MO.Gender
 +
MO.Gender.Female : MO.Gender
  
 
* Add the properties to your types
 
* Add the properties to your types
Add properties with ''@L0.singleProperty'' or ''@L0.optionalProperty''. They are actually restrictions. The former means that an instance of Role is a valid instance only it has a single HasAge relation to an integer literal.  
+
Add properties with ''@L0.singleProperty'' or ''@L0.optionalProperty''. They are actually restrictions. The former means that an instance of Character is a valid instance only it has exactly one HasName statement. Optional property requires only that the number of such statements is at most one.
  
  // Add properties
+
  // Constrainting property cardinalities
  mo.Character
+
  MO.Character
     @L0.singleProperty mo.HasAge
+
     @L0.singleProperty MO.HasName
     @L0.singleProperty mo.HasGender
+
    @L0.optionalProperty MO.HasGender
  mo.Person
+
    @L0.optionalProperty MO.HasAge  
     @L0.singleProperty mo.HasDobYear
+
MO.Person
     @L0.singleProperty mo.HasGender
+
     @L0.singleProperty MO.HasName
 +
    @L0.singleProperty MO.HasGender
 +
    @L0.singleProperty MO.HasYearOfBirth
 +
  MO.Cast
 +
     @L0.singleProperty MO.OfRole
 +
     @L0.singleProperty MO.IsPlayedBy
  
 +
* Specify Relations
 +
Specify then the relations of the ontology with their domains, ranges and inverses.
  
* Specify Relations
 
 
  // Relations
 
  // Relations
  mo.IsDirectedBy <R L0.IsRelatedTo
+
  MO.IsDirectedBy <R L0.IsRelatedTo
     L0.HasDomain mo.Movie
+
     L0.HasDomain MO.Movie
     L0.HasRange mo.Person
+
     L0.HasRange MO.Person
mo.IsDirectorOf <R L0.IsRelatedTo
+
    L0.InverseOf MO.IsDirectorOf <R L0.IsRelatedTo
    L0.HasDomain mo.Person
+
  MO.IsProducedBy <R L0.IsRelatedTo
    L0.HasRange mo.Movie
+
     L0.HasDomain MO.Movie
    L0.InverseOf mo.IsDirectedBy
+
     L0.HasRange MO.Person
+
    L0.InverseOf MO.IsProducerOf <R L0.IsRelatedTo
  mo.IsProducedBy <R L0.IsRelatedTo
+
  MO.HasCast <R L0.IsRelatedTo
     L0.HasDomain mo.Movie
+
     L0.HasDomain MO.Movie
     L0.HasRange mo.Person
+
     L0.HasRange MO.Cast
mo.IsProducerOf <R L0.IsRelatedTo
+
     L0.InverseOf MO.IsCastOf <T L0.IsRelatedTo
    L0.HasDomain mo.Movie
+
  MO.IsPlayedBy <R L0.IsRelatedTo : L0.FunctionalRelation
    L0.HasRange mo.Person
+
     L0.HasDomain MO.Cast
    L0.InverseOf mo.IsProducedBy
+
     L0.HasRange MO.Person
   
+
     L0.InverseOf MO.IsCastedTo <R L0.IsRelatedTo
mo.HasCast <R L0.IsRelatedTo
+
  MO.OfRole <R L0.IsRelatedTo : L0.FunctionalRelation
     L0.HasDomain mo.Movie
+
     L0.HasDomain MO.Cast
     L0.HasRange mo.Cast
+
     L0.HasRange MO.Character
+
    L0.InverseOf MO.HasCasting <R L0.IsRelatedTo
mo.IsPlayedBy <R L0.IsRelatedTo
 
     L0.HasDomain mo.Cast
 
    L0.HasRange mo.Person
 
  mo.IsCastedTo <R L0.IsRelatedTo
 
     L0.HasDomain mo.Person
 
     L0.HasRange mo.Cast
 
     L0.InverseOf mo.IsPlayedBy
 
   
 
mo.OfRole <R L0.IsRelatedTo
 
     L0.HasDomain mo.Cast
 
     L0.HasRange mo.Character
 
mo.HasCasting <R L0.IsRelatedTo
 
    L0.InverseOf mo.OfRole
 
    L0.HasDomain mo.Character
 
    L0.HasRange mo.Cast
 
  
 
* Create a template  
 
* Create a template  
 
Casting is a binding between a movie, a character and an actor. To state a casting in a database three statements and one instance is required. To make the code more readable, define a template.
 
Casting is a binding between a movie, a character and an actor. To state a casting in a database three statements and one instance is required. To make the code more readable, define a template.
  mo.Casting : L0.Template  
+
  MO.Casting : L0.Template  
 
     @template %movie %character %actor
 
     @template %movie %character %actor
 
         %movie
 
         %movie
             mo.HasCast _ : mo.Cast  
+
             MO.HasCast _ : MO.Cast  
                 mo.IsPlayedBy %actor
+
                 MO.IsPlayedBy %actor
                 mo.OfRole %character
+
                 MO.OfRole %character
  
Save file. Your Movie.java resource file should now contain a list of resources and URIs. Go on and take a look.  
+
Save file. Your Movie.java resource file should now contain a list of resources and URIs. Go on and take a look.
  
 
== Step 5: Setup Build Properties ==
 
== Step 5: Setup Build Properties ==
''build.properties'' determines what files are included with the binary and the source release. A new ontology plug-in needs some fixing, you must add graph.tg to the binary build and ''graph''-folder to source build. You can make the modification with the form editor.
+
''build.properties'' determines which files are included with the binary and the source release. A new ontology plug-in needs some fixing, you must add graph.tg to the binary build and ''graph''-folder to source build. You can make the modification with the form editor.
  
 
* Open ''build.properties'' and go to ''build''-page.
 
* Open ''build.properties'' and go to ''build''-page.
Line 161: Line 182:
 
We made a Movie Library for initial data. Download: [[file:MovieLibrary.pgraph]] and put in graph folder.
 
We made a Movie Library for initial data. Download: [[file:MovieLibrary.pgraph]] and put in graph folder.
  
If you take a look inside you'll find a root resource at http://com.acme/MovieLibrary. All movies, actors and other persons are linked to/from the library with L0.PartOf/L0.ConsistsOf relations.  
+
If you take a look inside you'll find a root resource at <nowiki>http://www.acme.com/MovieLibrary</nowiki>. All movies, actors and other persons are linked to/from the library with L0.PartOf/L0.ConsistsOf relations.  
  db = <http://com.acme/MovieLibrary> : L0.Library
+
  ML = <nowiki><http://www.acme.com/MovieLibrary></nowiki> : L0.Library
 
     @L0.new
 
     @L0.new
  
 
You'll also find an example of the template in use:
 
You'll also find an example of the template in use:
  db.tt0381061 : mo.Movie
+
  ML.tt0830515 : MO.Movie
     @mo.Casting      db."James Bond"       db."Daniel Craig"
+
     @MO.Casting      ML.JamesBond       ML.DanielCraig
     @mo.Casting      db."M"                db."Judi Dench"
+
     @MO.Casting      ML.M               ML.JudiDench
  
 +
== Exercises ==
 +
 +
There are some [[Ontology_Development_Exercises|exercises]] available related to this tutorial.
  
  
 
<hr />
 
<hr />
[[file:handshake.png]] '''Congratulations''' You have now set-up an ontology.
+
{{handshake| '''Congratulations''' You have now set-up an ontology.}}
  
 
Give your brains a break before proceeding to the next tutorial.<br/>
 
Give your brains a break before proceeding to the next tutorial.<br/>
 
[[file:next.png]] [[Tutorial: Project Development|Tutorial 2: Project Development]]
 
[[file:next.png]] [[Tutorial: Project Development|Tutorial 2: Project Development]]
 +
 +
[[Category: Ontology Development]]
 +
[[Category: Tutorials]]

Latest revision as of 06:19, 19 March 2014

NEEDS TO BE REVISED TO MATCH CURRENT CONVENTIONS


"What's up folks." This tutorial series is composed of four parts. As it is a trail, you should study them in order. Today we are going to create a movie database ontology for a client of your Acme company. Even though Simantics is intended for simulator integration platform, we decided to use movies as the theme. This basic level tutorial doesn't go into simulation specifics, and the subject is more familiar for any developer to relate to than a simulation specific one. Before starting make sure you have installed Target Platform and Graph Compiler to your Eclipse as instructed in Development Environment Setup Guide.


Related documents:

Step 1: Setup Ontology Plug-in

Ontologies are encapsulated in OSGi bundles. In Eclipse, we develop them as Eclipse plug-ins. An ontology bundle is a specialized package. It has the following content: graph source files (graph/*.pgraph), a compiled graph file (graph.tg), and Java files (src/ and bin/).

Open a New Plug-in Project wizard:

  • Open Plug-in Development Perspective
  • Select File >> New >> Other
  • Select Plug-in Development >> Plug-in Project

A New Plug-in Project wizard will open.

  • Our organization is Acme Software ltd and from there is our plug-in name derived, com.acme.movie.ontology. Insert that as project name. Next >
  • Set Version to 0.1.0.qualifier. In this page you should know that this plugin does not contribute to UI, does not need an activator and is not a rich client application. Next >
  • Use template Plug-in with a Simantics Ontology. Next >
  • The domain of your company is www.acme.com and the name of the ontology Movie. The initial version is 1.0. Finish

You have now a new project in Package Explorer. You will find META-INF/MANIFEST.MF, graph/Movie.pgraph, and graph.tg in it.

Step 2: Initialize Ontology

Open Movie.pgraph and start editing.

You will be using Layer0 concepts. You can avoid writing full URIs for all references by defining an abbreviation. It is a good idea to declare all ontologies you will use in this way:

 L0 = <http://www.simantics.org/Layer0-1.0>

Your acme company has a domain that has to be declared. Because this is the first time the domain is used, you have to mark it "new" so that the graph compiler does not try to find it from dependencies.

 <http://www.acme.com> : L0.Library
     @L0.new

The ontology has a representing resource, an instance of L0.Ontology. The second line tells the compiler to create a Resource file as well.

 MO = <http://www.acme.com/Movie-1.0> : L0.Ontology
     L0.HasResourceClass "com.acme.movie.ontology.Movie"

Step 3: Export package

Now that you have some content, graph compiler has created a Resource class com.acme.movie.ontology.Movie under src/ folder. When developing database code you can gain access to your ontology concepts using this class. In OSGi plugin environment, the access to other plugins' classes is denied by default. To share, you must export its Java package.

  • Open META-INF/MANIFEST.MF
  • Add Exported Packages >> com.acme.ontology

Your MANIFEST.MF should look like this.

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: http://www.acme.com/Movie
Bundle-SymbolicName: com.acme.movie.ontology
Bundle-Version: 1.0.0.qualifier
Bundle-Vendor: Acme Software ltd
Bundle-RequiredExecutionEnvironment: JavaSE-1.6
Require-Bundle: org.simantics.layer0;bundle-version="1.0.0"
Export-Package: com.acme.movie.ontology

In this case the ontology's namespace root URI is http://www.acme.com/Movie-1.0. Due to ontology versioning support in the platform

  1. Bundle-Name must match URI without the version number, i.e. http://www.acme.com/Movie
  2. Bundle-Version first two digits (major.minor) must match the URI's version part, i.e. 1.0.

Notice, in particular, that the ontology depends on Layer0. If other ontologies are needed, they have to be added to MANIFEST.MF.

Step 4: Write your Movie Ontology

In movie database, we are going to store objects such as movies, actors, directors and producers. There is going to be a few properties about them, and a couple of relations. At this point it is a good idea to take a look at the graph file format documentation. Here is all we are going to define in one diagram:

MovieOntology.png

Open Movie.pgraph again.

  • Specify Types

First we need to specify the types Movie, Character, Cast and Person. Actors, directors and producers are modelled as Persons. A person becomes a representative of a classification, say actor, once he/she has acted in a motion picture (modeled as interrelation statement). Cast is a anonymous resource that links together Person (actor) and Character in one Movie. There is no inheritance between the concepts in our ontology, however every type in Simantics has to inherit the Entity type.

// Types
MO.Movie <T L0.Entity
MO.Character <T L0.Entity
MO.Person <T L0.Entity
MO.Cast <T L0.Entity
  • Specify Properties

The following relations define the basic properties that can be given to the types of our ontology. All properties are functional, i.e. every resource may have at most one statement of the relation.

// Properties
MO.HasYearOfBirth <R L0.HasProperty : L0.FunctionalRelation
    L0.HasDomain MO.Person
    L0.HasRange L0.Integer  
MO.HasAge <R L0.HasProperty : L0.FunctionalRelation
    L0.HasDescription "The age of the character during the movie."
    L0.HasDomain MO.Character
    L0.HasRange L0.Integer  
MO.HasGender <R L0.HasProperty : L0.FunctionalRelation
    L0.HasDescription "The gender of a person or a character."
    L0.HasRange MO.Gender
MO.HasTitle <R L0.HasProperty : L0.FunctionalRelation 
    L0.HasDescription "The English title of the movie."
    L0.HasDomain MO.Movie
    L0.HasRange L0.String
MO.HasName <R L0.HasProperty : L0.FunctionalRelation
    L0.HasDescription "The name of a person or a character."
    L0.HasRange L0.String
  • Specify Gender enumeration

Enumerations are special kind of types: They have a fixed number of instances that are defined in the ontology. Gender is a prototypical example:

// Enumeration
MO.Gender <T L0.Property
    @L0.tag L0.Enumeration
MO.Gender.Male : MO.Gender
MO.Gender.Female : MO.Gender
  • Add the properties to your types

Add properties with @L0.singleProperty or @L0.optionalProperty. They are actually restrictions. The former means that an instance of Character is a valid instance only it has exactly one HasName statement. Optional property requires only that the number of such statements is at most one.

// Constrainting property cardinalities
MO.Character
    @L0.singleProperty MO.HasName
    @L0.optionalProperty MO.HasGender
    @L0.optionalProperty MO.HasAge    
MO.Person
    @L0.singleProperty MO.HasName
    @L0.singleProperty MO.HasGender
    @L0.singleProperty MO.HasYearOfBirth
MO.Cast 
    @L0.singleProperty MO.OfRole
    @L0.singleProperty MO.IsPlayedBy
  • Specify Relations

Specify then the relations of the ontology with their domains, ranges and inverses.

// Relations
MO.IsDirectedBy <R L0.IsRelatedTo
    L0.HasDomain MO.Movie
    L0.HasRange MO.Person
    L0.InverseOf MO.IsDirectorOf <R L0.IsRelatedTo
MO.IsProducedBy <R L0.IsRelatedTo
    L0.HasDomain MO.Movie
    L0.HasRange MO.Person
    L0.InverseOf MO.IsProducerOf <R L0.IsRelatedTo
MO.HasCast <R L0.IsRelatedTo
    L0.HasDomain MO.Movie
    L0.HasRange MO.Cast
    L0.InverseOf MO.IsCastOf <T L0.IsRelatedTo
MO.IsPlayedBy <R L0.IsRelatedTo : L0.FunctionalRelation
    L0.HasDomain MO.Cast
    L0.HasRange MO.Person
    L0.InverseOf MO.IsCastedTo <R L0.IsRelatedTo
MO.OfRole <R L0.IsRelatedTo : L0.FunctionalRelation
    L0.HasDomain MO.Cast
    L0.HasRange MO.Character
    L0.InverseOf MO.HasCasting <R L0.IsRelatedTo
  • Create a template

Casting is a binding between a movie, a character and an actor. To state a casting in a database three statements and one instance is required. To make the code more readable, define a template.

MO.Casting : L0.Template 
    @template %movie %character %actor
        %movie
            MO.HasCast _ : MO.Cast 
                MO.IsPlayedBy %actor
                MO.OfRole %character

Save file. Your Movie.java resource file should now contain a list of resources and URIs. Go on and take a look.

Step 5: Setup Build Properties

build.properties determines which files are included with the binary and the source release. A new ontology plug-in needs some fixing, you must add graph.tg to the binary build and graph-folder to source build. You can make the modification with the form editor.

  • Open build.properties and go to build-page.
  • Check graph.tg under Binary Build.
  • Check graph-folder under Source Build.

If you open the build.properties page, it should look like this.

source.. = src/
output.. = bin/
bin.includes = META-INF/,\
               .,\
               graph.tg
src.includes = graph/

Step 6: Download MovieLibrary

We made a Movie Library for initial data. Download: File:MovieLibrary.pgraph and put in graph folder.

If you take a look inside you'll find a root resource at http://www.acme.com/MovieLibrary. All movies, actors and other persons are linked to/from the library with L0.PartOf/L0.ConsistsOf relations.

ML = <http://www.acme.com/MovieLibrary> : L0.Library
    @L0.new

You'll also find an example of the template in use:

ML.tt0830515 : MO.Movie
    @MO.Casting      ML.JamesBond        ML.DanielCraig 
    @MO.Casting      ML.M                ML.JudiDench

Exercises

There are some exercises available related to this tutorial.



Handshake.png Congratulations You have now set-up an ontology.

Give your brains a break before proceeding to the next tutorial.
Next.png Tutorial 2: Project Development