Getting Started with a W3C WoT...
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Getting Started with a W3C WoT Project RIOT Summit, Berlin, Germany, 2016
Transcript of Getting Started with a W3C WoT...
GettingStartedwithaW3CWoT ProjectRIOTSummit,Berlin,Germany,2016
WhatistheWebofThings?
InternetofThings
IEEE802.15.4 Ethernet BluetoothWi-Fi LoRa …
:Connectivity
ApplicationLayer
WhatistheWebofThings?
InternetofThings
IEEE802.15.4 Ethernet BluetoothWi-Fi LoRa …
:Connectivity
WebofThings:Applications
WhatistheWebofThings?
InternetofThings
IEEE802.15.4 Ethernet BluetoothWi-Fi LoRa …
:Connectivity
W3CWoT Mission
…
“interconnectingexistingInternetofThingsplatformsandcomplementingavailablestandards”
WebofThings
Nottobeyetanotherstandard
WoT INTERFACE
IoTPlatformsandProtocolBindingshttp://w3c.github.io/wot/current-practices/wot-practices.html#wot-interface
WoT Interface
• InterfaceexposedbyServients tothenetwork
WoTServient
WoTInterface
WoTServient
WoTInterface
WoTInterface
• InterfaceexposedbyServients tothenetwork
WoTServient WoTServient
Protocol
WoTInterface WoTInterface
ProtocolBindings
• Interfacecanbeboundtovariousprotocols
WoTServient WoTServient
HTTP
WoTInterface WoTInterface
ProtocolBindings
ProtocolBindings
HTTP HTTP
ProtocolBindings
• Interfacecanbeboundtovariousprotocols
WoTServient WoTServient
WoTInterface
ProtocolBindings
ProtocolBindings
CoAP
CoAPWoTInterface
CoAP
ProtocolBindings
• MultiplebindingspossibleonThings
WoTServient WoTServient
WoTInterface WoTInterface
ProtocolBindings
ProtocolBindings
WebSocket
WS WSMQTT
ResourceModel
• InteractionpointsareWebresources
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ResourceModel
ResourceModel
WoTInterface WoTInterface··· ···
ServientRole• ExposingThingsareinserverrole• ConsumingThingsareinclientrole
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
InteractionResourcesWebLinks http://wot.example.com/res
ClientRole ServerRole··· ···
ServientRole
• Usuallybothrolesatthesametimeà Servient
WoTServient WoTServientWoTServient
ProtocolBindings
ProtocolBindings
WebLinks
ClientRole BothRoles
ProtocolBindings
BothRoles··· ······
InteractionResources
WebLinks
InteractionResources
WebLinks
THINGDESCRIPTION
MetadataandInteractionshttp://w3c.github.io/wot/current-practices/wot-practices.html#thing-description
WoTServient
ProtocolBindings
ResourceModel
WoTInterface···
HowtoInteractwithWoTServients?
Whoareyou?
Whatkindof functionsdoyouhave?
Whatkindofdatadoyouserve?
HowcanIaccessthedata/function?
Whatkindofprotocols/encodings doyousupport?
Aretheresomesecurityconstrains?
àW3CThingDescription
SemanticDescription
• ReachinteroperabilitythroughLinkedDatavocabularies– subject,predicate,objecttriples– rootedintheRDFmodel
• W3CThingDescription– describesWoTInterfacetointeractwithThings– extensiblewithdomain-specificvocabulary– differentserializationspossible
ThingDescription(TD)
• DescribesThingmetadataandinteractions
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ResourceModel
ResourceModel
WoTInterface WoTInterface··· ···
ThingDescription(TD)• ConsumingThingsareinclientrole• ExposedThingsareinserverrole
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ClientRole ServerRole
ThingDescription(TD)
• ExposedThingsprovideThingDescription
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ThingDescription
InteractionResources
ClientRole ServerRoleHTTPCoAP
ThingDescription(TD)
• ConsumingThingslearnWoTInterfacefromTD
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ThingDescription
InteractionResources
Metadata,WebLinks
ClientRole ServerRoleHTTP HTTPCoAP
ThingDescription(TD)
• Thing-to-thingcommunication
WoTServient WoTServient
ProtocolBindings
ProtocolBindings
ThingDescription
InteractionResources
Metadata,WebLinks
ClientRole ServerRoleHTTP HTTPCoAP
ThingDescription(TD)
• DefaultserializationisJSON-LD– basedonwellestablishedJSONformat– differentimplementationsandtoolsavailable–@contextdefinesvocabularies– SeeTDexample
TDExample{
"@context": ["http://w3c.github.io/wot/w3c-wot-td-context.jsonld",{ "actuator": "http://example.org/actuator#" }
],
"@type": "Thing","name": "MyLEDThing",
"uris": ["coap://myled.example.com:5683/","http://mything.example.com:8080/myled/"
],
"encodings": ["JSON", "EXI"],"security": {
"cat": "token:jwt","alg": "HS256","as": "https://authority-issuing.example.org"
},
"properties": [
"properties": [{"@type": "actuator:onOffStatus","name": "status","valueType": { "type": "boolean" },"writable": true,"hrefs": [ "pwr", "status" ]
}],"actions": [
{"@type": "actuator:fadeIn","name": "fadeIn","inputData": {
"valueType": { "type": "integer" },"actuator:unit": "actuator:ms"
},"hrefs": [ "in", "led/in" ]
},{"@type": "actuator:fadeOut","name": "fadeOut","inputData": {
"valueType": { "type": "integer" },"actuator:unit": "actuator:ms"
},"hrefs": [ "out", "led/out" ]
}],
Interactionresources
Property
Action
Action
Events(workinprogress)
TypeSystem
• DefaultcurrentlybasedonJSONSchemahttp://w3c.github.io/wot/current-practices/wot-practices.html#type-system
• Beststartwithsimpletypes– boolean– integer– number– string
• Othersystemscanbepluggedinunder“valueType“field
HowtoCreateaTD?
• Manuallycopy,paste,andmodify– http://w3c.github.io/wot/current-practices/wot-practices.html#td-examples
– orlookintotheTDrepositoryhttp://vs0.inf.ethz.ch:8080(developmentrepository,sometimesoffline)
• Generatefromdevelopmentframework– TDserializationbasedontheinteractionsprovided
SCRIPTINGAPI
RuntimeEnvironmentandPortableAppshttp://w3c.github.io/wot/current-practices/wot-practices.html#scripting-api
WithoutScriptingAPI
• Applicationlogicoftenimplementednatively
WoTServient
ProtocolBindings
ApplicationLogic
C/C++/Java/…
ResourceModel
WoTInterface···
ScriptingAPI
• Commonruntimeenablesportableapps
WoTServient
RuntimeEnvironment
AppScript
ProtocolBindings
ResourceModel
ClientAPI
ServerAPI
Disc.API
WoTInterface···
• Commonruntimeenablesportableapps
WoT Servient VendorB
RuntimeEnvironment
WoT Servient VendorA
RuntimeEnvironment
ScriptingAPI
ResourceModel ResourceModel
AppScript
ClientAPI
ServerAPI
Disc.API
ClientAPI
ServerAPI
Disc.API
WoTInterface···
WoTInterface···
ProtocolBindings ProtocolBindings
• Commonruntimeenablesportableapps
WoT Servient VendorB
RuntimeEnvironment
WoT Servient VendorA
RuntimeEnvironment
ScriptingAPI
ProtocolBindings
ResourceModel
ProtocolBindings
ResourceModel
AppScript
ClientAPI
ServerAPI
Disc.API
ClientAPI
ServerAPI
Disc.API
WoTInterface···
WoTInterface···
WoTRootElement(withDiscovery)interfaceWoT {
Promise<sequence<ConsumedThing>>discover(ThingFilterfilter);Promise<ConsumedThing>consumeDescription(Object td);Promise<ConsumedThing>consumeDescriptionUri(DOMStringuri);Promise<ExposedThing>createThing(DOMStringname);Promise<ExposedThing>createFromDescription(Object td);Promise<ExposedThing>createFromDescriptionUri(DOMStringuri);
};
ClientAPI:ConsumedThinginterfaceConsumedThing {
readonly attributeDOMStringname;Promise<any>getProperty(DOMStringpropertyName);Promise<any>setProperty(DOMStringpropertyName,anynewValue);Promise<any>invokeAction(DOMStringactionName,anyparameter);ConsumedThingaddListener(DOMStringeventName,
ThingEventListener listener);ConsumedThing removeListener(DOMStringeventName,
ThingEventListener listener);ConsumedThing removeAllListeners(DOMStringeventName);Object getDescription();
};
ServerAPI:ExposedThinginterface ExposedThing {
readonly attributeDOMStringname;ExposedThing addProperty(DOMStringname,object type);ExposedThing addAction(DOMStringname,Object input,Object output);ExposedThing addEvent(DOMStringname,Object output);Promise<any>getProperty(DOMStringpropertyName);Promise<any>setProperty(DOMStringpropertyName,anynewValue);Promise<any>emitEvent(DOMStringeventName,anypayload);ExposedThing onUpdateProperty(DOMStringn,PropertyChangeListener cb);ExposedThing onInvokeAction(DOMStringactionName,ActionHandler cb);Object getDescription();
};
ScriptExample(ConsumeThing)WoT.consumeDescriptionUri("http://servient.example.com/things/counter")
.then(function(counter) {counter
.invokeAction("increment", {}).then(function() {console.log("incremented");counter
.getProperty("count").then(function(count) {console.log("new count state is " + count);
});})._catch(console.error);
})._catch(function(err) {
console.error(err);});
ScriptExample(ExposeThing)WoT.newThing("counter")
.then(function(thing) {thing
.addProperty("count", {"type": "integer"})
.addAction("increment")
.onInvokeAction("increment", function() {console.log("incrementing counter");var value = thing.getProperty("count") + 1;thing.setProperty("count", value);return value;
});thing
.setProperty("count", 0)});
SUMMARYW3CWebofThings
ThingImplementation:WoT Servient
WoT Servient
Server RoleClient Role
Protocol Bindings
Resource Model
App Script
Legacy comm-
unication
Client API Server API
ThingDescription
Legacydevice
Web Server Web Client
Proprietary interface
Runtime Environment
WoT Servient WoT Servient
ApplicationLogic:CanconsumeremoteThingsthroughtheClientAPI,localhardwareandconnectedlegacydevices throughaPhysicalAPI(t.b.d.),andexposeThingsthroughtheServerAPI.Toallowportableappscripts, theServientmustpovide aruntimeenvironment.
ResourceModel:Provides acommonabstractionwithuniforminterfaceacrossthedifferentprotocols.LiketheWeb, itallowstoidentifyandaddressinteractionpointsthroughURIs.
ProtocolBinding:Converts abstractinteractionswithThingstodifferentprotocolsusing theinformationfromTD.
ThingDescription(TD):DeclaresWoT Interfaceforinteractionandprovides(semantic)metadatafortheThing.TDisusedbyWoTclientstoinstantiatelocalsoftwareobjectoftheThing.
WoT Interface
Discovery API(Physic. API)
• NativeWoTThingshostaServient directly• TDisprovidedbyThingorsupportinghostontheWeb
WoT ServientonThingItself
WoT Servient (Wot Device)
Client RoleServer Role
Protocol Bindings
Resource Model
Script
Runtime Environment
Browser
Client Role
ProtocolBindings
Resource Model
App Script
Runtime Env.
ThingDescription
• WoTServients canrunonhubs(e.g.,smartphone,gateway)• MultipleServients canbeinstantiatedthroughsandboxedapps• Appscanactasagents/proxiesforlegacydevices
WoT ServientonIntegrationHub
WoT Servient
Client RoleServer Role
Protocol Bindings
Resource Model
App Script
Legacycomm.
Legacydevice
Browser
Client Role
ProtocolBindings
Resource Model
App Script
Runtime Env. Runtime Environment
Hub Platform
ThingDescription
• Acloudmirror(deviceshadow)enablesscalableremoteaccess• IssynchronizedwithlocalServient• Canforwardinteractionsandcachedata
WoT Servient intheCloud
Browser
ClientRole
ProtocolBinding
ResourceModel
AppScript
RuntimeEnvi.
WoT Servient
ClientRoleServer Role
ProtocolBinding
ResourceModel
AppScriptWoT Servient
Client RoleServerRole
Protocol Binding
ResourceModel
AppScript
Legacycomm.
Legacydevice
Hub
Cloud
CloudPlatform
Runtime EnvironmentRuntimeEnvironment
ThingDescription
ThingDescription
LocalAnywhere
OnlineResources• InterestGroup
– https://www.w3.org/WoT/IG/– https://lists.w3.org/Archives/Public/public-wot-ig/ (subscribetomailinglist)
• Documents(forimplementers)– http://w3c.github.io/wot/architecture/wot-architecture.html– http://w3c.github.io/wot/current-practices/wot-practices.html (livingdocument)
Beijing2016Release:http://w3c.github.io/wot/current-practices/wot-practices-beijing-2016.html
• GitHub (documentsandproposals)– https://github.com/w3c/wot
• Wiki(organizationalinformation:WebConf calls,Face-to-Facemeetings,…)– https://www.w3.org/WoT/IG/wiki/Main_Page
• WoT Projects(implementingWoT CurrentPractices)– https://github.com/thingweb/– https://github.com/mkovatsc/wot-demo-devices– Pleaseaddyours!
PLUGFESTW3CWoTF2FBeijing2016
Scenario1– ‘Hello WoT‘
WoTTDinterpreterforhuman interaction
/voteTooHot /on
SetupservientinteractionbasedonTD
Scenario2– ‘Full WoT‘WoTServient providing
scriptforvotingWoTClient
consumesscript
/voteTooHot /on
TDRepositorySearch for Action@type=“tooHot“WoTServient searchs
avotingservient
Scenario3– ‘MiniAutomation‘
Consumebrightness sensortocontrolcurtain
OnlineResources• CurrentPractices(BeijingRelease)
– http://w3c.github.io/wot/current-practices/wot-practices-beijing-2016.html
• OrganizationWiki– https://www.w3.org/WoT/IG/wiki/F2F_meeting,_July_2016,_China,_Beijing#PlugFest
• TestCases– https://github.com/w3c/wot/blob/master/plugfest/2016-beijing/plugfest-test-cases-
beijing-2016.md
• ReportTemplate– https://github.com/w3c/wot/blob/master/plugfest/2016-beijing/TestCaseCoverage.xlsx
(t.b.d.)
