Leichtgewichtige Architekturen mit ASP.NET Web API & SignalR

Die Entwicklungen vor allem rund um mobile Anwendungen und Devices sowie Cloud Computing bedeuten für viele Softwareprojekte ein Umdenken, vor allem in der Architektur. Wer das heute ignoriert, könnte sich morgen in Kalamitäten befinden. Wie bekomme ich eine leichtgewichtige Integration meiner Systeme mit interoperabler Kommunikation gestemmt? Wie kann ich Daten von meinen Services mittels Real-Time-Webkommunikation in meine Clients hinein pushen? In diesem Vortrag wird Christian Weyer aufzeigen, wie man diesen neuen Anforderungen architekturell begegnen kann. Dabei kommen Frameworks wie ASP.NET Web API, SignalR oder das neue ASP.NET 5 zum Einsatz.

Transcript

1. Christian)Weyer)|)Thinktecture AG Für)alle Leichtgewichtige)Architekturen) mit)ASP.NET)Web)API)&)SignalR
2. Christian)Weyer • Co$founder,,co$owner and principal consultant at Thinktecture AG • Focus,on – Mobile,&,web$based,application,architectures – Interoperability,,cross$device – Pragmatic,end$to$end,solutions • Microsoft,MVP,for ASP.NET,(Architecture) ASP.NET,Web,API,/,vNext Advisory,Board,Member ASPInsider,,AzureInsider • Google,GDE,for Web,Technologies • christian.weyer@thinktecture.com @christianweyer http://blogs.thinktecture.com/cweyer 2
3. Architectures for… • Enterprise • ISV • Web • …"any difference today?
   Services 3
7. Modern)Business) Applications Reach!
8. Ubiquitous Access • .NET,clients • Silverlight,clients • Pure,HTML(5) • JavaScript,&,jQuery • Android,(Java) • iOS,(Objective$C) • Embedded, (C/C++) • Java • Any client,,any device,,actually 8
9. MacOS X Windows"Desktop iOS Android Windows"Mobile Browser Browser Browser Windows"10"/"UWP Linux
11. Web/HTTP)APIs with ASP.NET)Web)API
12. Architectural)Approaches)to)Service)Orientation • „SOAP“,/,WS$* – transport,protocol,independent – „secure,,reliable,and,transacted“,(WS$*) – sophisticated,and,complex,protocol,stack – interoperability,may,become,difficult – „the,best,RPC,so,far“ • Web/HTTP,(„REST“,,anyone?) – fully,embrace,HTTP – least,common,denominator,technologies – less,functionality,(KISS?) – reach,and,interoperability,said,to,be,better – „easier,to,use“ 12
13. Which)one)is)‚better‘? 13
14. Which)one)is)more%‚polite‘? 14
16. Distributed)Application Architectures for Modern)Applications • Reach,vs.,rich • Base,foundation,vs.,features • Light$weight,vs.,heavy$weight 16
18. HTTP)– the Application Protocol • Application,protocol • URIs • Verbs • Headers • Content,types • Content,negotiation • Status,codes 18
19. Web)API)Framework)Requirements • Need,a,first,class,HTTP,programming,model • Easily,map,resources,to,URIs,and,implement, the,uniform,interface • Rich,support,for,formats,and,HTTP,content, negotiation • Separate,out,cross,cutting,concerns • Lightweight,,Internet,scale • Realize,REST$ful or,RPC$ish architectures – Being,pragmatic,,not,idealistic 19
20. Implementing)a)Web)API • ASP.NET,Web,API,technology,stack – Based,on,OWIN • Derive,from,ApiController • Implement,your,actions – Actions,map,to,HTTP,methods – Prefix,method,name,with,desired,HTTP,method,– e.g., PostComment – Use,[HttpGet/Post/Put/Delete] if,you,prefer,a, different,name – Supports,async with,Task<T> – Actions,expose explicit,DTO,data,, HttpResponseMessage or JsonValue / dynamic 20
21. Hosting)&)Clients • Several,hosting,options,,e.g. – ASP.NET,Web,Application,(IIS) – Self$host,server,option,(console,application,, Windows,service,,etc.) • HttpConfiguration defines,behavior • OWIN,as,base,for,hosting,Web,API,,SignalR etc. • HttpClient is,a,cross$.NET,HTTP,client,API • JavaScript:,jQuery’s,$.ajax,,or,$http in, AngularJS 21
22. Routing • Maps,a,URL,space,to,your,Web,API, controllers – {controller} + “Controller” • Can,be,tailored,using,actions,,default,values, and,route,constraints – Like,more,RPC$ish behavior • Alternative:,attribute$based,routing – Defines,routes,with,.NET,attributes 22
23. Working)with HTTP • “First,class,experience”,for,using,HTTP – exposing,HTTP,as,an,application, protocol,in,its,full, glory,and,not,hiding,it • Use,of HttpRequestMessage and HttpResponseMessage – way,of,giving,direct,access,to,the,HTTP,protocol,, without,parsing,and,encoding,complexity • Use,IHttpActionResult – Better,testabilityn,pre$defined, action,results 23
24. Model)Binding)&)Formatters • Model,binding,can,“shred”,the,request,and,bind,it, to,individual,parameters • Values,are,taken,from,the,URL,(route,variables,, query,parameters),or,from,the,body • MediaTypeFormattersare,used,to,deserialize the,request,body,based,on,the,content,type – XML,,JSON,,form$url$encoded, supported,out,of,the, box • Request,data,is,validated,as,it,is,bound,to,the, parameters 24
25. Content)Negotiation • Response,format,is,determined,based,on,HTTP, content,negotiation • Request,Accept header,expresses,desired,format(s) • Server,selects,a,format,for,the,response,based,on, the,request,and,the,available, MediaTypeFormatters • Help/documentation, page,optionally,available,at, /help • Use,Swagger,for,open,documentation, standard 25
26. Push)Services with ASP.NET)SignalR
27. Push)Services)Pattern • ‘Push,Services’,are,really,not,an,official,pattern – Observer,pattern,,anyone? • Model,a,service,that – accepts,incoming,connections,from,callers – is,able,to,push,data,down,to,callers – abstracts,from,communication,nitty$gritty,details • Realize,Publish$Subscribe,semantics – Based,on,standard,web,technologies,with,reach,in,mind – With,maximum,reach,into,any,device,,platform Push Service Consumer Send data External event (Database) External event (Message queue) External event (Other actor) Notify [data] 27
28. Technical)Approaches)for)Push • Periodic,Polling • Long,Polling – HTTP,Streaming,/,Comet 28
29. Long)Polling Poll,but,don’t,respond,untill, there’s,data • Server,holds,on,to,the,HTTP,request,until,there,is,data,to,return • (Re$)Poll,after,data,received,or,after,the,connection,times,out • Consumes,server,threads,&,connection,resources Server Client 29
30. Technical)Approaches)for)Push • Periodic,Polling • Long,Polling – HTTP,Streaming,/,Comet • Forever,Frame • Server$Sent,Events,(SSE) • Web,Sockets • Easy:,Web,Sockets,are,the way,to,go! – Only,with,Windows,8/Server,2012 – Network,considerations – Maybe,some,time,,but,not,today • Alright,,let’s,just,write,code,for,any,technology,&,technique! – Erm…,really?,For"any"server"and"any"client"platform? 30
31. ASP.NET)SignalR as)a)Solution • SignalR is – a,server$side,framework,to,write,push,services – a,set,of,client,libraries,to,make,push,service,communication,easy,to, use,on,any,platform – optimized,for,asynchronous,processing • Abstracts,from,the,different,techniques,to,implement,pushing, data – Mental,model,is,a,persistent,connection – Volatile,,non$durable • ‘Signal’,,anyone? – Sending,data,to,a,signal.,E.g.,represented,by,a,connection,ID • Part,of,the,ASP.NET,brand,,but,not,tied,into,ASP.NET,runtime, and,APIs 31
32. ASP.NET)SignalR Development • Extensible,framework,&,pipeline – Based,on,interfaces,&,DI • Two,programming,models – Persistent,connections – Hubs • Hubs,offer,a,pre$defined,application$level, protocol,in,an,RPC$ish style – Easy$to$get$going, means,for,80/20,situations 32
33. Hubs)Concept • Hubs,are,classes,to,implement,push,services,in,SignalR – Abstraction,on,top,of,persistent,connection – Convention$over$configuration • Hubs,provide,a,higher,level,RPC,framework – Perfect,for,different,types,of,messages,to,send,between,server,and, client • Hub,conventions – Public,methods,are,callable,from,the,outside, – Send,messages,to,clients,by,invoking,client$side,methods • Simple,steps,to,get,going 1. Write,hub,class 2. Add,route,in,host,process 3. Done 33
34. Programming)Model • Hub,name,reflected,into,external,API – [HubName] can,alias,name • Return,simple,type,,complex,type,or,Task • Complex,objects,and,arrays,of,objects automatically,serialized/deserialized to/from,JSON – Default,is,JSON.NET • Context holds,connection$ and,request$specific,information – ConnectionId – Request – Headers – RequestCookies – QueryString – User 34
35. Pushing)Data:)Clients • Clients property,as,dispatching, point,to,send, messages,to,clients • Holds,dynamicEproperties,and,methods • Target,method,with,parameters,is,dynamically,‘injected’, into,code,path,,serialized,,and,embedded, into,response public void SendMessage(string message)E {E var msg = string.Format("{0}: {1}", Context.ConnectionId, message); Clients.All.newMessage(msg);E } 35
36. Hub)Consumers • Consumers,can,be,classic,client,applications,or,other, services/hubs • SignalR provides,a,variety,of,client,libraries • Microsoft,SignalR team – .NET,4.0+ – WinRT – Windows,Phone,8 – Silverlight,5 – jQuery – C++ • Community – iOS native – iOS via,Mono – Android,via,Mono 36
37. jQuery)Client • HTML5$based,applications,often,use,jQuery • JSON$based,wire,protocol,makes,it,easy,to, integrate,with,JavaScript • SignalR jQuery plugin,offers,two,approaches – Proxy$based,with,generated, proxy – Without,proxy,but,‘late,binding’ 37
38. jQuery)without)Proxy)File • Late,binding,approach • Simple,steps,to,get,going 1. Create,hubConnection • Derived,from,$.connection 2. Get,dynamic,proxy 3. Wire,up,events,based,on,method/event,handler,name,via,on 4. Start,&,invoke,methods,based,on,method,name,via,invoke • Same,connection$related,event,handlers • Cross$domain,support,same,as,with,static,proxy var connection = $.hubConnection(); var proxy = connection.createHubProxy('chat'); proxy.on('newMessage', onNewMessage); connection.start();E proxy.invoke('sendMessage', $('#message').val()); 38
39. .NET)Client • Client,NuGet package,contains,binaries for,all,supported,.NET,flavors – .NET,4.x,,SL5 – WP8,,WinRT • Mental,model,resembles,proxy$less,JavaScript,approach • Simple,steps,to,get,going 1. Create,HubConnection 2. Create,hub,proxy,via,CreateHubProxy 3. Wire,up,event,handlers,via,On 4. Start,connection,with,Start 5. Call,methods,via,Invoke var hubConnection = new HubConnection("http://localhost/services"); var chat = hubConnection.CreateHubProxy("chat");E chat.On<string>("newMessage", …);E hubConnection.Start().Wait(); … 39
40. Hosting • Hosting,sits,on,top,of,OWIN – IAppBuilder API • Simple,steps to get going 1. Define startup class with IAppBuilder method signature 2. Map hubs onto IAppBuilder (route) • In,ASP.NET:,Startup,class used in, WebApplication.Start to spin up server – HTTP,or HTTPS,base URL 40
41. Summary • Flexible,lightweight,architectures – Based,on,the,Web • Web,,APIs,for,exposing,services,with,reach – ASP.NET,Web,API,as,lean,technology,stack • Push,Services,for,implementing,bi$directional, communication – ASP.NET,SignalR as,enabling,framework • Good,base,for,a,number,of,different, application,architectures – Web$based,,native,,Desktop,,mobile 41
43. Resources • christian.weyer@thinktecture.com • http://www.thinktecture.com • Thinktecture’s GitHub,Repositories – https://github.com/thinktecture • Christian,Weyer’s GitHub,Repositories – https://github.com/ChristianWeyer • ASP.NET,Web,API – http://www.asp.net/web$api • WebApiContrib – https://github.com/WebApiContrib • ASP.NET,SignalR – http://www.asp.net/signalr 43