@prefix foaf:  <http://xmlns.com/foaf/0.1/> .
@prefix lv2:   <http://lv2plug.in/ns/lv2core#> .
@prefix owl:   <http://www.w3.org/2002/07/owl#> .
@prefix patch: <http://lv2plug.in/ns/ext/patch#> .
@prefix rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs:  <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd:   <http://www.w3.org/2001/XMLSchema#> .

<http://lv2plug.in/ns/ext/patch>
	a owl:Ontology ;
	rdfs:seeAlso <patch.h> ,
		<lv2-patch.doap.ttl> ;
	lv2:documentation """
<p>This vocabulary defines messages which can be used to access and manipulate
properties.  It is designed to provide a dynamic control interface for LV2
plugins, but is useful in many contexts.</p>

<p>The main feature of this design is that the messages themselves are
described in the same format as the data they work with.  In particular,
messages can be serialised as a binary <a
href="atom.html#Object">Object</a> or in Turtle (or any other RDF
serialisation).</p>

<p>The idea behind using a property-based interface for control is to prevent
an an explosion of message types.  Instead of a custom message for each action,
control is achieved via manipulating properties (which are likely already
defined for other reasons).  Note, however, that this is purely conceptual;
there is no requirement that the receiver actually implement a store of
resources with properties.</p>

<p>For example, consider an object that can blink.  Rather than define a
specific interface to control this (e.g. <code>obj.start_blinking();
obj.stop_blinking()</code>), set a <q>blinking</q> property to true or false
(e.g. <code>obj.set(blinking, true)</code>) to achieve the desired behaviour.
One benefit of this approach is that a persistent state model is available
<q>for free</q>: simply serialise the <q>blinking</q> property.</p>

<p>This specification is strictly metadata and does not define any binary
mechanism, though it can be completely expressed by standard types in the <a
href="atom.html">LV2 Atom</a> extension.  Thus, hosts can be expected
to be capable of transmitting it between plugins, or between a plugin and its
UI, making it a good choice for advanced plugin control.</p>
""" .

patch:Ack
	a rdfs:Class ;
	rdfs:subClassOf patch:Response ;
	rdfs:label "Ack" ;
	rdfs:comment """An acknowledgement that a request has been successfully processed.  This is returned as a reply when a specific reply type is not necessary or appropriate. """ .

patch:Copy
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Copy" ;
	rdfs:subClassOf [
		a owl:Restriction ;
		owl:minCardinality 1 ;
		owl:onProperty patch:subject
	] , [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:destination
	] ;
	rdfs:comment """Copy the patch:subject to patch:destination.  After this, patch:destination has the description patch:subject had prior to this request's execution, and patch:subject is unchanged.  It is an error if the subject does not exist or the destination already exists.

Multiple patch:subject properties may be given if the patch:destination is a container, the semantics of this use case are application defined.""" .

patch:Delete
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Delete" ;
	rdfs:comment "Request the subject(s) be deleted." .

patch:Error
	a rdfs:Class ;
	rdfs:subClassOf patch:Response ;
	rdfs:label "Error" ;
	rdfs:comment "A response indicating an error processing a request." .

patch:Get
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Get" ;
	rdfs:comment "Request a description of the subject." ;
	lv2:documentation """
<p>Request a description of the subject.</p>

<p>The detail of the response is not specified, it may be a flat description of
all the properties of the subject, or a more expressive description with
several subjects.  A good choice is a <q><a
href="http://www.w3.org/Submission/CBD/">concise bounded description</a></q>,
i.e. a description which recursively includes all properties with blank node
values.</p>

<p>The response should have the same patch:subject property as the request, and
a patch:body that is a description of that subject.  For example:</p>
<pre class="turtle-code">
&lt;get-request&gt;
    a patch:Get ;
    patch:subject &lt;something&gt; .
</pre>

<p>Could result in:</p>
<pre class="turtle-code">
[]
    a patch:Response ;
    patch:request &lt;get-request&gt; ;
    patch:subject &lt;something&gt; ;
    patch:body [
        eg:name "Something" ;
        eg:ratio 1.6180339887 ;
    ] .
</pre>

<p>Note the use of blank nodes is not required; the value of patch:body may be
the actual resource node.  Depending on the transport and syntax used this may
be preferable.  For example, the same response could be written:</p>

<pre class="turtle-code">
&lt;something&gt;
    eg:name "Something" ;
    eg:ratio 1.6180339887 .

[]
    a patch:Response ;
    patch:request &lt;get-request&gt; ;
    patch:subject &lt;something&gt; ;
    patch:body &lt;something&gt; .
</pre>

<p>If the patch:subject property is absent, then the Get implicitly applies to
the receiver.</p>
""" .

patch:Insert
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Insert" ;
	rdfs:subClassOf [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:subject
	] ;
	rdfs:comment """Insert the patch:body at patch:subject.  If the subject does not exist, it is created.  If the subject does already exist, it is added to.  This request only adds properties, it never removes them.  The user must take care that multiple values are not set for properties which should only have one value.""" .

patch:Message
	a rdfs:Class ;
	rdfs:label "Patch Message" .

patch:Move
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Move" ;
	rdfs:subClassOf [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:subject
	] , [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:destination
	] ;
	rdfs:comment "Move the patch:subject to patch:destination.  After this, patch:destination has the description patch:subject had prior to this request's execution, and patch:subject no longer exists.  It is an error if the subject does not exist or the destination already exists." .

patch:Patch
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ,
	[
		a owl:Restriction ;
		owl:minCardinality 1 ;
		owl:onProperty patch:subject
	] ;
	rdfs:label "Patch" ;
	rdfs:comment "Add and/or remove properties of the subject." ;
	lv2:documentation """
<p>Add and/or remove properties of the subject.</p>

<p>This method always has at least one patch:subject, and exactly one patch:add
and patch:remove property.  The value of patch:add and patch:remove are nodes
which have the properties to add or remove from the subject(s), respectively.
The special value patch:wildcard may be used as the value of a remove property
to remove all properties with the given predicate.  For example:</p>

<pre class="turtle-code">
[]
    a patch:Patch ;
    patch:subject &lt;something&gt; ;
    patch:add [
        eg:name "New name" ;
        eg:age 42 ;
    ] ;
    patch:remove [
        eg:name "Old name" ;
        eg:age patch:wildcard ;  # Remove all old eg:age properties
    ] .
</pre>
""" .

patch:Put
	a rdfs:Class ;
	rdfs:subClassOf patch:Request ;
	rdfs:label "Put" ;
	rdfs:subClassOf [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:subject
	] ;
	lv2:documentation """<p>Put the patch:body as the patch:subject.  If the subject does not already exist, it is created.  If the subject does already exist, the patch:body is considered an updated version of it, and the previous version is replaced.</p>

<pre class="turtle-code">
[]
    a patch:Put ;
    patch:subject &lt;something&gt; ;
    patch:body [
        eg:name "New name" ;
        eg:age 42 ;
    ] .
</pre>
""" .

patch:Request
	a rdfs:Class ;
	rdfs:label "Request" ;
	rdfs:subClassOf patch:Message ;
	rdfs:comment """A request.  A request may have a patch:subject property, which indicates which resource the request applies to.  The subject may be omitted in contexts where it is implicit (e.g. the recipient is the subject).""" .

patch:Response
	a rdfs:Class ;
	rdfs:subClassOf patch:Message ;
	rdfs:label "Response" ;
	rdfs:comment "A response to a message." .

patch:Set
	a rdfs:Class ;
	rdfs:label "Set" ;
	rdfs:subClassOf patch:Request ,
	[
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:property
	] , [
		a owl:Restriction ;
		owl:cardinality 1 ;
		owl:onProperty patch:value
	] ;
	rdfs:comment "Set one property to a specific value." ;
	lv2:documentation """
<p>A compact message for setting one property to a specific value.</p>

<p>This is equivalent to a patch:Patch which removes <em>all</em> pre-existing
values for the property before setting the new value.  For example:</p>

<pre class="turtle-code">
[]
    a patch:Set ;
    patch:subject &lt;something&gt; ;
    patch:property eg:name ;
    patch:value "New name" .
</pre>

<p>Which is equivalent to:</p>
<pre class="turtle-code">
[]
    a patch:Patch ;
    patch:subject &lt;something&gt; ;
    patch:add [
        eg:name "New name" ;
    ] ;
    patch:remove [
        eg:name patch:wildcard ;
    ] .
</pre>
""" .

patch:accept
	a rdf:Property ;
	rdfs:label "accept" ;
	rdfs:domain patch:Request ;
	rdfs:range rdfs:Class ;
	rdfs:comment "An accepted type for a response." .

patch:add
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:domain patch:Message .

patch:body
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:domain patch:Message ;
	rdfs:comment """The body of a message.

The details of this property's value depend on the type of message it is a
part of.""" .

patch:context
	a rdf:Property ,
		owl:ObjectProperty ;
	rdfs:domain patch:Message ;
	rdfs:comment """The context of properties in this message.

For example, a plugin may have a special context for ephemeral properties which
are only relevant during the lifetime of the instance and should not be saved
in state.

The specific uses for contexts are application specific.  However, the context
MUST be a URI, and can be interpreted as the ID of a data model where
properties should be stored.  Implementations MAY have special support for
contexts, for example by storing in a quad store or serializing to a format
that supports multiple RDF graphs such as TriG.
""" .

patch:destination
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:domain patch:Message .

patch:property
	a rdf:Property ;
	rdfs:label "property" ;
	rdfs:domain patch:Set ;
	rdfs:range rdf:Property ;
	rdfs:comment "The property for a Set message." .

patch:readable
	a rdf:Property ;
	rdfs:label "readable" ;
	rdfs:range rdf:Property ;
	rdfs:comment """Indicates that the subject may have a property that can be read via a
patch:Get message.  See the similar property patch:writable for details.""" .

patch:remove
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:label "remove" ;
	rdfs:domain patch:Message .

patch:request
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:label "request" ;
	rdfs:domain patch:Response ;
	rdfs:range patch:Request ;
	rdfs:comment """The request this is a response to.  This can be used if referring directly to the URI or blank node ID of the request is possible.  Otherwise, use patch:sequenceNumber.""" .

patch:sequenceNumber
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:label "sequence number" ;
	rdfs:domain patch:Message ;
	rdfs:range xsd:int ;
	rdfs:comment """The sequence number of a request or response.  This property is used to associate replies with requests when it is not feasible to refer to request URIs with patch:request.  A patch:Response with a given sequence number is the reply to the previously send patch:Request with the same sequence number.

The special sequence number 0 means no reply is desired. """ .

patch:subject
	a rdf:Property ,
		owl:ObjectProperty ,
		owl:FunctionalProperty ;
	rdfs:domain patch:Message ;
	rdfs:comment "The subject this message applies to." .

patch:value
	a rdf:Property ;
	rdfs:label "value" ;
	rdfs:domain patch:Set ;
	rdfs:range rdf:Property ;
	rdfs:comment "The value of a property in a patch:Set message." .

patch:wildcard
	a rdfs:Resource ;
	rdfs:comment """A wildcard which matches any resource.  This makes it possible to describe the removal of all values for a given property.""" .

patch:writable
	a rdf:Property ;
	rdfs:label "writable" ;
	rdfs:range rdf:Property ;
	lv2:documentation """
<p>Indicates that subject may have a property that can be written via a patch
message.  This is used to list supported properties, e.g. so user interfaces
can present appropriate controls.  For example:</p>

<pre class="turtle-code">
@prefix eg:   &lt;http://example.org/&gt; .
@prefix rdf:  &lt;http://www.w3.org/1999/02/22-rdf-syntax-ns#&gt; .
@prefix rdfs: &lt;http://www.w3.org/2000/01/rdf-schema#&gt; .

eg:title
    a rdf:Property ;
    rdfs:label "title" ;
    rdfs:range xsd:string .

eg:plugin
    patch:writable eg:title .
</pre>
""" .
