IoT Physical Servers and Cloud Offerings.pdf

Introduction to Cloud Storage models
• Communication APIs
• Webserver-Web server for IoT
• Cloud for IoT
• Python web application framework
• Designing a RESTful web API.

1. Unit -V
IoT Physical Servers &
CloudOfferings
6/7/2022 1

2. Outline
•Introduction to Cloud Storage models
•Communication APIs
•Webserver-Web server for IoT
•Cloud for IoT
•Python web application framework
•Designing a RESTful web API.
6/7/2022 2

3. Introduction to Cloud Computing
•TheInternetofThings(IoT)involvestheinternet-connecteddeviceswhichareused
toperformtheprocessesandservicesthatsupportswayoflife.
•AnothercomponentsettohelpIoTsucceediscloudcomputing,whichactsasasort
offrontend.
•Cloudcomputingisanincreasinglypopularservicethatoffersseveraladvantagesto
IOT,andisbasedontheconceptofallowinguserstoperformnormalcomputing
tasksusingservicesdeliveredentirelyovertheinternet.
6/7/2022 3

4. Introduction to Cloud Computing
•Insimplewords,CloudComputingmeansprovidingcomputingservicesoverthe
internet(calledascloud).
•ThecomputingservicesincludeServers,Software,Storage,Database,
Networking,Analytics,Intelligenceetc.,
6/7/2022 4

5. Introduction to Cloud Computing
•Aworkermayneedtofinishamajorprojectthatmustbesubmittedtoamanager,
butperhapstheyencounterproblemswithmemoryorspaceconstraintsontheir
computingdevice.
•Memoryandspaceconstraintscanbeminimizedifanapplicationisinsteadhosted
ontheinternet.
•Theworkercanuseacloudcomputingservicetofinishtheirworkbecausethedatais
managedremotelybyaserver.
6/7/2022 5

6. Introduction to Cloud Computing
•Anotherexample-youhaveaproblemwithyourmobiledeviceandyouneedto
reformatitorreinstalltheoperatingsystem.
•YoucanuseGooglePhotostouploadyourphotostointernet-basedstorage.
•Afterthereformatorreinstall,youcantheneithermovethephotosbacktoyou
deviceoryoucanviewthephotosonyourdevicefromtheinternetwhenyouwant.
6/7/2022 6

7. Features of Cloud Computing
6/7/2022 7

8. Types of Cloud Computing Storage Services
6/7/2022 8

9. Types of Cloud Services
6/7/2022 9
•Infrastructure-as-a-service(IaaS)providesuserstheabilitytoprovisioncomputing
andstorageresources.Theseresourcesareprovidedtotheusersasavirtual
machineinstancesandvirtualstorage.
•Platform-as-a-Service(PaaS)providesuserstheabilitytodevelopanddeploy
applicationincloudusingthedevelopmenttools,APIs,softwarelibrariesand
servicesprovidedbythecloudserviceprovider.
•Software-as-a-Service(SaaS)providestheuseracompletesoftwareapplicationor
theuserinterfacetotheapplicationitself.

10. Types of Cloud Services
6/7/2022 10

11. Advantages
•Cost
•Speed
•Security
•Scalability
•Reliability
6/7/2022 11

12. Cloud Storage API
•AcloudstorageAPIisanapplicationprograminterfacethatconnectsa
locally-basedapplicationtoacloud-basedstoragesystem,sothatauser
cansenddatatoitandaccessandworkwithdatastoredinit.
•Totheapplication,thecloudstoragesystemisjustanothertargetdevice,
liketapeordisk-basedstorage.
•Anapplicationprograminterface(API)iscodethatallowstwosoftware
programstocommunicatewitheachother.
6/7/2022 12

13. Cloud Storage API
•TheAPIdefinesthecorrectwayforadevelopertowriteaprogramthat
requestsservicesfromanoperatingsystem(OS)orotherapplication.
•APIsareimplementedbyfunctioncallscomposedofverbsandnouns.
•Therequiredsyntaxisdescribedinthedocumentationoftheapplication
beingcalled.
6/7/2022 13

14. How APIs Works
•APIsaremadeupoftworelatedelements.
•Thefirstisaspecificationthatdescribeshowinformationisexchanged
betweenprograms,doneintheformofarequestforprocessinganda
returnofthenecessarydata.
•Thesecondisasoftwareinterfacewrittentothatspecificationand
publishedinsomewayforuse.Thesoftwarethatwantstoaccessthe
featuresandcapabilitiesoftheAPIissaidtocallit,andthesoftwarethat
createstheAPIissaidtopublishit.
6/7/2022 14

15. Why APIs are important
•Theweb,softwaredesignedexchangeinformationviatheinternetand
cloudcomputinghaveallcombinedtoincreasetheinterestinAPIsin
generalandservicesinparticular.
•Softwarethatwasoncecustom-developedforaspecificpurposeisnow
oftenwrittenreferencingAPIsthatprovidebroadlyusefulfeatures,
reducingdevelopmenttimeandcostandmitigatingtheriskoferrors.
6/7/2022 15

16. Why APIs are important
•APIshavesteadilyimprovedsoftwarequalityoverthelastdecade,andthe
growingnumberofwebservicesexposedthroughAPIsbycloudproviders
isalsoencouragingthecreationofcloud-specificapplications,internetof
things(IoT)effortsandappstosupportmobiledevicesandusers.
6/7/2022 16

17. Basic Types of APIs
•APIstakethreebasicforms:local,web-likeandprogram-like.
•LocalAPIsaretheoriginalform,fromwhichthenamecame.Theyoffer
OSormiddlewareservicestoapplicationprograms.Microsoft's.NETAPIs,
theTAPI(TelephonyAPI)forvoiceapplications,anddatabaseaccess
APIsareexamplesofthelocalAPIform.
6/7/2022 17

18. Basic Types of APIs
•WebAPIsaredesignedtorepresentwidelyusedresourceslikeHTML
pagesandareaccessedusingasimpleHTTPprotocol.AnywebURL
activatesawebAPI.
•WebAPIsareoftencalledREST(representationalstatetransfer)or
RESTfulbecausethepublisherofRESTinterfacesdoesn'tsaveanydata
internallybetweenrequests.Assuch,requestsfrommanyuserscanbe
intermingledastheywouldbeontheinternet.
6/7/2022 18

19. Basic Types of APIs
•ProgramAPIsarebasedonremoteprocedurecall(RPC)technologythat
makesaremoteprogramcomponentappeartobelocaltotherestofthe
software.
•Serviceorientedarchitecture(SOA)APIs,suchasMicrosoft'sWS-seriesof
APIs,areprogramAPIs.
6/7/2022 19

20. WAMP-AutobahnforIoT
•WebApplicationMessagingProtocol(WAMP)isasub-protocolofWebsocket
whichprovidespublish-subscribeandremoteprocedurecall(RPC)messaging
patterns.
•WAMPenablesdistributedapplicationarchitectureswheretheapplication
componentsaredistributedonmultiplenodesandcommunicatewithmessaging
patternsprovidedbyWAMP.
6/7/2022 20

21. WAMPSession Between Client and Router
6/7/2022 21

22. WAMP -Concepts
•Transport:Transportischannelthatconnectstwopeers.Thedefaulttransport
forWAMPisWebsocket.WAMPcanrunoverthetransportsaswellwhich
supportmessagebasedreliablebidirectionalcommunication.
•Session:Sessionisaconversationbetweentwopeersthatrunsovera
transport.
6/7/2022 22

23. WAMP -Concepts
•Client:Clientsarepeersthatcanhaveoneormoreroles.Inpublish-subscribe
modelclientcanhavefollowingroles:
–Publisher:Publisherpublishesevents(includingpayload)tothetopic
maintainedbytheBroker.
–Subscriber:Subscribersubscribestothetopicsandreceivestheevents
includingthepayload.
6/7/2022 23

24. WAMP -Concepts
•InRPCmodelclientcanhavefollowingroles:
–Caller:Callerissuescallstotheremoteproceduresalongwithcallarguments.
–Callee:Calleeexecutestheprocedurestowhichthecallsareissuedbythecaller
andreturnstheresultsbacktothecaller.
6/7/2022 24

25. WAMP -Concepts
•Router:Routersarepeersthatperformgenericcallandeventrouting.Inpublish-
subscribemodelRouterhastheroleofaBroker:
–Broker:Brokeractsasarouterandroutesmessagespublishedtoatopictoall
subscriberssubscribedtothetopic.
6/7/2022 25

26. WAMP Protocol Interaction between the Peers
6/7/2022 26

27. WAMP Protocol Interaction between the Peers
•Inthisprotocol,WAMPtransportusedisWebsocket.
•WAMPsessionsareestablishedoverWebsockettransportwithinthe
lifetimeofWebsockettransport.
6/7/2022 27

28. Publish Subscribe Messaging using WAMP -
Autobahn
6/7/2022 28

29. Publish Subscribe Messaging using WAMP -
Autobahn
•TheclientinPublisherrolerunsaWAMPapplicationcomponentthat
publishesmessagestotherouter.
•Therouterinbrokerrolerunsontheserverandroutesthemessagesto
thesubscribers.
•Therouterdecouplesthepublisherfromthesubscribers.
•Thecommunicationbetweenpublisher-brokerandbrokersubscribers
happensoveraWAMPwebsocketsession.
6/7/2022 29

30. Commands used for installing Auto Bahnin
Python
6/7/2022 30

31. Commands used for installing Auto Bahnin
Python
6/7/2022 31

32. WAMP -Autobahn
•CreateaWAMPPublisherComponent.
•Thepublishercomponentwillpublishamessagecontainingthecurrent
timestamptoatopicnamed‘test–topic’.
•CreateaWAMPSubscribercomponent.
•Thesubscribercomponentthatsubscribestothe‘test-topic’
6/7/2022 32

33. WAMP Publisher Component
6/7/2022 33

34. WAMP Subscriber Component
6/7/2022 34

35. WAMP Subscriber Component
•Run the application router on a websocketserver as follows:
6/7/2022 35

36. Xively Cloud for IoT
•Itisacommercialplatformasaservice(PAAS)thatcanbeusedfor
creatingsolutionsforIoT.
•WithXivelycloud,IoTdeveloperscanfocusonthefrontendinfrastructure
anddevicesforIoT(thatgeneratethedata),whilethebackenddata
collectioninfrastructureismanagedbyXively.
6/7/2022 36

37. Xively Cloud for IoT
•Xivelyplatformcomprisesofamessagebusforreal-timemessage
managementandrouting,dataservicesfortimeseriesarchiving,directory
servicesthatprovidesasearch-abledirectoryofobjectsandbusiness
servicesfordeviceprovisioningandmanagement.
•Xivelyprovidesanextensivesupportforvariouslanguagesandplatforms
•TheXivelylibrariesleveragestandardsbasedAPIoverHTTP,socketsand
MQTTforconnectingIoTdevicestotheXivelyCloud.
6/7/2022 37

38. Xively Cloud for IoT
•TostartusingXivelypythonlibrary,firstweneedtoregisteradeveloper
accountandthencreatedevelopmentdevicesonXively.
•Whenanewdeviceiscreated,XivelyautomaticallycreatesaFeedIDand
anAPIkeytoconnecttothedevice.
•FeedIDisacollectionofchannelsordatastreamsdefinedforadevice
andassociatedmetadata.
•APIkeysareusedtoprovidedifferentlevelsofpermissions.
•ThedefaultAPIkeyhasread,update,createanddeletepermissions.
6/7/2022 38

39. Xively Cloud for IoT
6/7/2022 39

40. Xively Cloud for IoT
6/7/2022 40

41. Xively Cloud for IoT
•Xivelydeviceshaveoneormorechannelsandeachchannelenables
bidirectionalcommunicationbetweentheIoTdevicesandXivelycloud.
•IoTdevicescansenddatatoachannelusingtheXivelyAPIs.
•Foreachchanneloneormoretriggerscanbecreated.Atrigger
specificationincludesachanneltowhichthetriggercorresponds,trigger
conditionandanHTTPpostURLtowhichtherequestissentwhenthe
triggerfires.
•Triggerareusedtoprovideintegrationforthirdpartyapplications.
6/7/2022 41

42. Xively Cloud for IoT
•LetusconsideranexampleofusingXivelycloudforanIoTsystemthat
monitorstemperatureandsendsthemeasurementstoaXivelychannel.
•Temperaturemonitoringdevicecanbebuiltbyraspberrypiboardanda
temperaturesensorisconnectedtotheboard.
•Theraspberrypirunsacontrollerprogramthatreadsthesensorvalues
everyfewsecondsandsendsthemeasurementstoaXivelychannel.
•Box8.4showsthepythonprogramforsendingthetemperaturedatato
XivelycloudbyusingXivelypythonlibrary.
6/7/2022 42

43. Xively Cloud for IoT
•Tokeeptheprogramsimpleandwithoutgoingintothedetailsofthe
temperaturesensor,syntheticdataisused(generatedrandomlyin
readTempSensor()function).
•AfeedobjectiscreatedbyprovidingtheAPIkeyandFeedID.Thena
channelnamedtemperatureiscreated.
•ThetemperaturedataissenttothischannelintherunController()function
every10seconds.
6/7/2022 43

44. Xively Cloud for IoT
6/7/2022 44

45. Xively Cloud for IoT
6/7/2022 45

46. Xively Cloud for IoT
6/7/2022 46

47. Xively Cloud for IoT
•Figure8.6showsthetemperaturechannelintheXivelydashboard.Inthis
exampleasingleXivelydevicewithonechanneliscreated.Xivelycanalso
havemultiplechannelsandmultipledevices.
6/7/2022 47

48. Xively Cloud for IoT
6/7/2022 48

49. Python Web Application Framework -Django
•Djangoisanopensourcewebapplicationframeworkfordevelopingweb
applicationsinPython.
•A"webapplicationframework"ingeneralisacollectionofsolutions,
packagesandbestpracticesthatallowsdevelopmentofweb
applicationsanddynamicwebsites.
•DjangoisbasedontheModel-Template-Viewarchitectureandprovidesa
separationofthedatamodelfromthebusinessrulesandtheuser
interface.
6/7/2022 49

50. Python Web Application Framework -Django
•DjangoprovidesaunifiedAPItoadatabasebackend.
•ThuswebapplicationsbuiltwithDjangocanworkwithdifferentdatabases
withoutrequiringanycodechanges.
•Withthisfiexibilityinwebapplicationdesigncombinedwiththepowerful
capabilitiesofthePythonlanguageandthePythonecosystem,Djangoisbest
suitedforcloudapplications.
•Djangoconsistsofanobject-relationalmapper,awebtemplatingsystemand
aregular-expression-basedURLdispatcher.
6/7/2022 50

51. DjangoArchitecture
•DjangoisModel-Template-View(MTV)framework.
Model
•Themodelactsasadefinitionofsomestoreddataandhandlesthe
interactionswiththedatabase.Inawebapplication,thedatacanbe
storedinarelationaldatabase,non-relationaldatabase,anXMLfile,
etc.ADjangomodelisaPythonclassthatoutlinesthevariablesand
methodsforaparticulartypeofdata.
6/7/2022 51

52. DjangoArchitecture
Template
•InatypicalDjangowebapplication,thetemplateissimplyanHTML
pagewithafewextraplaceholders.Django’stemplatelanguagecan
beusedtocreatevariousformsoftextfiles(XML,email,CSS,
Javascript,CSV,etc.)
6/7/2022 52

53. DjangoArchitecture
View
•Theviewtiesthemodeltothetemplate.Theviewiswhereyouwritethe
codethatactuallygeneratesthewebpages.Viewdetermineswhat
dataistobedisplayed,retrievesthedatafromthedatabaseandpasses
thedatatothetemplate.
6/7/2022 53

54. Starting Development with Django
CreatingaDjangoProjectandApp
•WhenanewDjangoprojectiscreated,anumberoffilesarecreatedas
describedbelow
6/7/2022 54

55. Starting Development with Django
•ADjangocanhavemultipleApps,wheretheseAppsareusedtowritethe
codethatmakeswebsitefunction.
•Whenanewapplicationiscreatedanewdirectoryfortheapplicationis
alsocreatedwhichhasanumberoffilesincluding–
6/7/2022 55

56. Starting Development with Django
6/7/2022 56

57. Starting Development with Django
•Djangocomeswithabuiltin,lightweightwebserverthatcanbeusedfor
developmentpurposes.
•WhentheDjangodevelopmentserverisstartedthedefaultprojectcanbe
viewedattheURL:http://localhost:8000.
6/7/2022 57

58. Starting Development with Django
6/7/2022 58

59. Starting Development with Django
ConfiguringaDatabase
•Developershaveawidechoiceofdatabasesthatcanbeusedforweb
applicationsincludingbothrelationalandnonrelationaldatabases.
•DjangoprovidesaunifiedAPIfordatabasebackendthusgivingthe
freedomtochoosethedatabase.
•DjangosupportsvariousrelationaldatabaseenginesincludingMySQL,
PostgreSQL,OracleandSQLite3.
6/7/2022 59

60. Starting Development with Django
•SupportfornonrelationaldatabasessuchasMongoDBcanbeaddedby
installingadditionalengines(Eg.Django-MongoDBenginefor
MkongoDB).
•Thefirststepinsettingupadatabaseistoinstallandconfigurea
databaseserver.
•Afterinstallingthedatabase,thenextstepistospecifythedatabase
settingsinthesetting.pyfileintheDjangoproject.
6/7/2022 60

61. Commands to setup My SQL
6/7/2022 61

62. Database setting to use MySQL with a
DjangoProject
6/7/2022 62

63. 6/7/2022 63

64. Starting Development with Django
6/7/2022 64

65. Defining a Model
•AModelactsasadefinitionofthedatainthedatabase.
•Box8.10showsanexampleofaDjangomodelforTemperatureData
collectedbyanIoTDevice.
•TheTemperatureDatatableinthedatabaseisdefinedasaclassinthe
DjangoModel.
•Eachclassthatrepresentsadatabasetableisasubclassof
django.db.models.Modelwhichcontainsallthefunctionalitythatallows
themodelstointeractwiththedatabase.
6/7/2022 65

66. Defining a Model
•TheTemperatureDataclasshasfieldstimestamp,temperature,latandlon
allofwhichareCharField.
•Tosyncthemodelswiththedatabase,runthefollowingcommand:
•>pythonmanage.pysyncdb
•Whenthesyncdbcommandisrunforthefisttime,itcreatesallthetables
definedintheDjangomodelintheconfigureddatabase.
6/7/2022 66

67. Defining a Model
6/7/2022 67

68. DjangoAdmin Site
•Djangoprovidesanadministrationsystemthatallowstomanagethe
websitewithoutwritingtheadditionalcode.
•This“admin”systemreadstheDjangomodelandprovidesaninterface
thatcanbeusedtoaddcontenttothesite.
•TheDjangoadminsiteisenabledbyaddingdjango.contrib.adminandd
jango.contrib.admindocstotheINSTALLED_APPS sectioninthe
settings.pyfile.
6/7/2022 68

69. DjangoAdmin Site
•TheadminsitealsorequiresURLpatterndefinitionsintheurl.pyfile.
•Todefinewhichapplicationmodelstobeeditableintheadmininterface,a
newfilenamedadmin.pyiscreatedintheapplicationfolder.
•
6/7/2022 69

70. DjangoAdmin Site
6/7/2022 70

71. DjangoAdmin Site
6/7/2022 71

72. Defining a View
•Theviewcontainsthelogicthatgluesthemodeltothetemplate.
•Theviewdeterminesthedatatobedisplayedinthetemplate,retrieves
thedatafromthedatabaseandpassesittothetemplate.
•Conversely,theviewalsoextractsthedatapostedinaforminthe
templateandinsertsitinthedatabase.
•Typically,eachpageinthewebsitehasaseparateview,whichis
basicallyapythonfunctionintheviews.pyfile.
6/7/2022 72

73. Defining a View
•Viewscanalsoperformadditionaltaskssuchasauthentication,sending
emails,etc.,
•Box8.12showsanexampleofaDjangoviewfortheWeatherStation
app.
•Thisviewcorrespondstothewebpagethatdisplayslatestentryinthe
TemperatureDatatable.
•InthisviewtheDjango’sbuiltinobject-relationalmappingAPIisusedto
retrievethedatafromtheTemperatureDataTable.
•
6/7/2022 73

74. Defining a View
•Theobject-relationalmappingAPIallowsthedeveloperstowritegeneric
codeforinteractingwiththedatabasewithoutworryingaboutthe
underlyingdatabaseengine.
•Sothesamecodefordatabaseinteractionsworkswithdifferentdatabase
backends.
•Aspecificpythonlibrarycanbechosetothedatabasebackendused(eg.
MySQLdbforMySQL,PyMongoforMongoDBetc.)towritedatabase
backedspecificcode.
6/7/2022 74

75. Defining a View
•In the view shown in Box 8.12, the
TemperatureData.objects.order_by(‘_id’)queryreturnsthelatestentryin
thetable.
•Toretrieveallentries,canusetable.objects.all().
•Toretrievespecificentries,usetable.objects.filter(**Kwargs)tofilterout
queriesthatmatchthespecifiedcondition.
6/7/2022 75

76. Defining a View
•Torendertheretrievedentriesinthetemplate,therender_to_response
functionisused.
•Thisfunctionrendersagiventemplatewithagivencontextdictionaryand
returnsanHttpResponseobjectwiththatrenderedtext.
•Box8.13showsanalternativeviewthatretrievesdatafromtheXively
cloud.
6/7/2022 76

77. Defining a View
6/7/2022 77

78. Defining a View
6/7/2022 78

79. Defining a View
6/7/2022 79

80. Defining a Template
•ADjangoTemplateistypicallyanHTMLfile(itcanbeanysortoftextfile
suchasXML,email,CSS,Javascript,CSVetc,).
•Djangotemplatesallowseparationofthepresentationofdatafromthe
actualdatabyusingplaceholdersandassociatedlogic(Usingtemplate
tags).
•Atemplatereceivesacontextfromtheviewandpresentsthedatain
contextvariablesintheplaceholders.
6/7/2022 80

81. Defining a Template
•Box8.14showsanexampleofatemplatefortheWeatherStationapp
andthevariablescontainingtheretrievedtemperature,latitudeand
longitudearepassedtothetemplate.
6/7/2022 81

82. Defining a Template
6/7/2022 82

83. Defining a Template
6/7/2022 83

84. Defining a Template
6/7/2022 84

85. Defining a Template
6/7/2022 85

86. Defining the URL Patterns
•URLpatternsareawayofmappingtheURLstotheviewsthatshould
handletheURLrequests.
•TheURLsrequestedbytheuserarematchedwiththeURLpatternsand
theviewcorrespondingtothepatternthatmatchestheURLisusedto
handletherequest.
6/7/2022 86

87. Defining the URL Patterns
•Box8.15showsanexampleoftheURLpatternsfortheWeatherStation
ProjectandtheURLpatternsareconstructedusingregularexpressions.
•Thesimplestregularexpression(r’^$’)correspondstotherootofthe
websiteorthehomepage.
6/7/2022 87

88. Defining the URL Patterns
6/7/2022 88

89. Defining the URL Patterns
•WiththeDjangomodels,views,templatesandURLpatternsdefinedfor
theDjangoproject,theapplicationfinallyrunswiththecommandsshown
inBox8.16.
•
6/7/2022 89

90. Designing a RESTfulWeb API
•DjangoRESTframeworkcanbeinstalledasfollows:
6/7/2022 90

91. Designing a RESTfulWeb API
•AfterinstallingtheDjangoRESTframework,createanewDjangoproject
namedrestfulapi,andthenstartanewappcalledmyapp,asfollows:
6/7/2022 91

92. Designing a RESTfulWeb API
•TheRESTAPIallowstocreate,view,updateanddeleteacollectionof
resourceswhereeachresourcerepresentsasensordatareadingfroma
weathermonitoringstation.
•Box8.17showstheDjangomodelforsuchastation.
•Thestationmodelcontainsfourfields–stationname,timestamp,
temperature,latitudeandlongitude
6/7/2022 92

93. Designing a RESTfulWeb API
6/7/2022 93

94. Designing a RESTfulWeb API
•Box8.18showstheDjangoviewsfortheRESTAPI.
•ViewSetsareusedfortheviewsthatallowstocombinethelogicforaset
ofrelatedviewsinasingleclass.
•
6/7/2022 94

95. Designing a RESTfulWeb API
•
6/7/2022 95

96. Designing a RESTfulWeb API
6/7/2022 96

97. Designing a RESTfulWeb API
•Box8.19showstheserializersfortheRESTAPI.
•Serializersallowcomplexdata(suchasquerysetsandmodelinstances)
tobeconvertedtonativepythondatatypesthatcanbeeasilyrendered
intoJSON,XMLorothercontenttypes.
•Serializersalsoprovidede-serialization,allowingparseddatatobe
convertedbackintocomplextypes,afterfirstvalidatingtheincoming
data.
6/7/2022 97

98. Designing a RESTfulWeb API
6/7/2022 98

99. Designing a RESTfulWeb API
•Box8.20showstheURLpatternsfortheRESTAPI.
•Since,ViewSetsareusedinsteadofviews,itcanautomaticallygenerate
theURLconfforAPI,byregisteringtheViewSetswitharouterclass.
•RoutersautomaticallydetermininghowtheURLsforanapplication
shouldbemappedtothelogicthatdealswithhandlingincoming
requests.
6/7/2022 99

100. Designing a RESTfulWeb API
6/7/2022 100

101. Designing a RESTfulWeb API
•Box8.21showsthesettingsfortheRESTAPIDjangoproject.
6/7/2022 101

102. Designing a RESTfulWeb API
•Box8.21showsthesettingsfortheRESTAPIDjangoproject.
6/7/2022 102

103. Designing a RESTfulWeb API
•AftercreatingthestationRESTAPIsourcefiles,thenextstepistosetup
thedatabaseandthenruntheDjangodevelopmentwebserveras
follows:
6/7/2022 103

104. Designing a RESTfulWeb API
•Box8.22showsexamplesofinteractingwiththeStationRESTAPIusing
CURL.
•TheHTTPPOSTmethodisusedtocreateanewresource,GETmethod
isusedtoobtaininformationaboutaresource,PUTmethodisusedto
updatearesourceandDELETEmethodisusedtodeletearesource.
6/7/2022 104

105. Designing a RESTfulWeb API
6/7/2022 105

106. Designing a RESTfulWeb API
6/7/2022 106

107. Designing a RESTfulWeb API
6/7/2022 107

108. Designing a RESTfulWeb API
6/7/2022 108

109. Designing a RESTfulWeb API
6/7/2022 109

110. Designing a RESTfulWeb API
6/7/2022 110

111. Designing a RESTfulWeb API
6/7/2022 111