diff options
Diffstat (limited to 'lv2/lv2plug.in/ns/ext/patch')
| -rw-r--r-- | lv2/lv2plug.in/ns/ext/patch/patch.ttl | 71 |
1 files changed, 29 insertions, 42 deletions
diff --git a/lv2/lv2plug.in/ns/ext/patch/patch.ttl b/lv2/lv2plug.in/ns/ext/patch/patch.ttl index b5f5df2..8db1dae 100644 --- a/lv2/lv2plug.in/ns/ext/patch/patch.ttl +++ b/lv2/lv2plug.in/ns/ext/patch/patch.ttl @@ -21,40 +21,35 @@ ] ; doap:shortdesc "Messages for accessing and manipulating properties." ; lv2:documentation """ -<p>This extension defines messages which can be used to access and manipulate -property-based data. It is designed to provide a powerful dynamic control -interface for LV2 plugins, but is useful for RDF-like systems in general.</p> - -<p>The main feature of this design is that requests and responses are -themselves completely described in RDF. Thus, the complete <q>protocol</q> can -be expressed wherever RDF can without imposing additional implementation -burdens like a new syntax or binary formats. In particular, messages can be -serialised in Turtle, or as an <a -href="http://lv2plug.in/ns/ext/atom#Object">LV2 Object</a>.</p> - -<p>This set of patch types is deliberately small to avoid an explosion of -messages that all implementations would have to explicitly support. Instead, -the idea is to achieve control via manipulating properties rather than defining -custom commands. However, this is conceptual; there is no requirement that the -receiver actually implement a store of resources with properties.</p> +<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 an <a +href="http://lv2plug.in/ns/ext/atom#Object">LV2 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 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>Because changes are described in terms of properties, important -functionality like undo stacks or revision control are simple to implement -generically. Accordingly, plugins are strongly encouraged to use these -property-based messages rather than defining custom methods for every action -they require (or worse, defining entirely new formats for messages).</p> - -<p>These methods are deliberately very similar to HTTP methods, but defined -specifically for property-based resources. The <q>properties</q> used here are -RDF properties, thus predicates from any of the countless pre-existing -vocabularies may be used.</p> +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="http://lv2plug.in/ns/ext/atom">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 @@ -141,7 +136,7 @@ patch:Insert rdfs:label "Insert" ; rdfs:subClassOf [ a owl:Restriction ; - owl:maxCardinality 1 ; + owl:cardinality 1 ; owl:onProperty patch:subject ] ; lv2:documentation """ @@ -161,7 +156,7 @@ patch:Move rdfs:label "Move" ; rdfs:subClassOf [ a owl:Restriction ; - owl:maxCardinality 1 ; + owl:cardinality 1 ; owl:onProperty patch:subject ] , [ a owl:Restriction ; @@ -182,14 +177,6 @@ patch:Patch a owl:Restriction ; owl:minCardinality 1 ; owl:onProperty patch:subject - ] , [ - a owl:Restriction ; - owl:maxCardinality 1 ; - owl:onProperty patch:add - ] , [ - a owl:Restriction ; - owl:maxCardinality 1 ; - owl:onProperty patch:remove ] ; lv2:documentation """ <p>A method for modifying the properties of an object.</p> @@ -221,7 +208,7 @@ patch:Put rdfs:label "Put" ; rdfs:subClassOf [ a owl:Restriction ; - owl:maxCardinality 1 ; + owl:cardinality 1 ; owl:onProperty patch:subject ] ; lv2:documentation """ |