Building Blazor applications on a Mac

hello so welcome to the building fleas their applications on a Mac and definitely check out the weather app that Scott hunter just mentioned it's really cool but we have some kind of simpler stuff to get started to talk more about what blazer is and take you through an intro app how to get your feet wet and then we'll move to a more realistic app and make some changes there as well yeah oh and I'm Kendra havens I'm a program manager on dotnet and Visual Studio and I'm Dan Roth I'm a program manager on the asp.net team cool okay so Dan what is blazer is boy so much talk about it and so much excitement so Blazers a modern web framework for building client-side web apps using c-sharp and net instead of JavaScript it's cross-platform it's open source and it's based only on open web standards now we've had ways to build web apps with dotnet for a long time a traditional don''t web app you take your dotnet code and you put it on the server and then the browser sends requests to your server and it responds with dynamically generated HTML or Jason that's pretty typical dotnet web application but if you wanted to do anything that ran in the browser well that meant you had to use some Java scripts like using one of whatever the popular JavaScript framework of the day is and that's cool I mean Java scripts great I mean yeah it's great you kind of have to switch context though and that can kind of slow you down so they can stay in dotnet code that's kind of convenient if you can use the same language the same frameworks the same tools same build system across your entire application that's what blazer is all abouts enabling you to build full stack web apps using Donette and c-sharp that's what we've been working on sweet okay so Blazer you build client-side web apps using just net and c-sharp code it also comes with a component model so you can build reusable web UI components you can package them up as NuGet packages and libraries and share them with your friends it also enables you to use the same code on both sides of the wire if you have some common logic like validation logic or data models that you want to use both on the client and on the server you can do that with Blaser it's full stack web development with net at the same time if you have existing JavaScript code or you want right so we're sharing dotnet code so even like working and like f-sharp or Visual Basic if I have libraries that I want to call from blazer yeah you can do that it's just normal donít assemblies that you're calling is your into in your blazer application absolutely and also if you have JavaScript you can still use that as well you can call into existing JavaScript libraries from your blazer code and even call back from the JavaScript code back into net through JavaScript Interop you can use that to also leverage all of the native functionality of the browser okay so if I'm not-like or if I'm slowly migrating my app to blazer alright trying it out in some section I can still use javascript elicit don't have to throw your JavaScript away you can just you reuse it in your existing blazer application how does that work is that possible I know it seems like magic well there's two ways that blazer apps function the first mode we call blazer server the way blazer server works is that we set up a real time connection with the browser we use signal R to do that it's basically a WebSocket connection Brady has a talk on all on signal once we've got that real time connection with the browser we run your blazer UI components on the server any UI events that happen in the browser we send them over to the server dispatch them to your components the components run they render and then blaze are very cleverly figures out just the parts of your UI that have changed and see arises that diff back down to the browser to then be rendered and updated so it's a kind of a thin client model you're you're still running your UI components on the server but you get that rich interactive field that you would expect from like a JavaScript based single page application ok and in server all of my c-sharp is compiling on the server still not at all inside the browser all the compiled compilation happens at Build time but your build code is gonna be running on the server on dotnet core it's not actually going to execute in the browser right but you still get the rich interactivity of being able to handle all the UI events and update the Dom seamlessly without having to do a full browser refresh but I have heard about things you started to do that you know I are not compiling but executing executing that's right in the browser with blazer webassembly your web assembly what we do is we we can download with your app a full dotnet runtime that's implemented in web assembly now web assembly is an open web standard it's basically a bytecode for the web if you can compile your code to web assembly that code can now run in any browser on any platform at near native speeds native as in like browser natives well pretty close to the wire like it's almost like an assembly language that's been standardized for the web so it's pretty fast super fast and it's so we built a dotnet runtime in web assembly that you can bring with your app it's small and compact and then you just download normal dotnet assemblies into the browser and execute them using that runtime the same come you I components the blazer components in this case they're running in the browser itself they do they handle UI events they calculate the diff in process in the browser client side so I see our little slide here says preview that's right so please our web assembly is in previews lays our web assemblies in preview laser server however is ready to go for production I want to use which one here server versus web assembly so Blaser server shipped with dotnet core 300k also shipped with three one LTS LTS is a long-term support release so Blaser server is ready for production use today you can put it in your websites put it out in production it's fully supported with a long-term support life cycle blazer web assemblies still in preview isn't quite done yet but we're working real hard on it we expect to have that finished up in just a few months later this this year how do you pick between the two well there's there's some some trade-offs with blazer server the benefits there is well your your well first of all its production yeah if you can actually use it right now but if your code is also running on a full dotnet core runtime so it's super fast on the server and it treats the client as a basically a thin client it has less demands on what the the browser or the client device needs to do so for example if you want to support older browsers like IE 11 you can do that with the blazer server application because there's no requirement to support web assembly blazer web assembly on the other hand gives you that option of pushing and offloading load from your server onto the client because it's a true client-side application it can support things like offline scenarios that's still in preview so it's not ready for use today but it will open up some really cool scenarios in the future oh my gosh I'm so pumped now regardless of which model you pick though like don't don't get too hung up I'm picking one versus the other because the component model is the same you write your components once and then you can use them in either hosting models so you could start out for example with the blazer server app and if you want to switch the Blazer web assembly in the future that's pretty trivial maybe when it goes to production we can switch our components over if that's what you wanted a oh my gosh I'm so pumped shall we get let's get started ok you say laser I know you can get started by going to blazer dotnet so we have a really simple URL to remember just Blazer dotnet and it'll take you to our main blazer and I guess landing page and we can go to this get started documentation and this will walk you through everything that you need to do to get started with blazer all the stuff you need to install and if you're on a Mac like I see that you are there's a tab there that gives us to do for Mac that has all the steps for getting Visual Studio for Mac set up with blazer so it's already installed dotnet core 3.1 and actually since you're here I won't read this I'll just I'll just launch Visual Studio and you can walk me through since you've already done it you've already installed Visual Studio from that you have dotnet core 3-1 on your machine which comes with Visual Studio for Mac so you're all ready to actually to go with blazer development right now alright so since I got 3.1 installed I already have a blazer server template and if I didn't see that there I could actually just find that in just the regular app templates blazer server under dotnet core that's right oh ok didn't see it's already targeting 3.1 they have a little authentication tab so on the latest preview of Visual Studio for Mac we they now have support for the authentication options for blazer server so you can create blazer server apps that support auth using asp.net core identity cool all right I'll go ahead and initialize one I called it blazer at seven that's a one seven just my favorite number it's nothing to do with the precise number of times we practice nothing at all just lucky it is so this will create you a new blazer server application it's all ready to go a blazer surfer app is just an asp.net core application with a couple of additional things wired up to support blazer server why don't we go ahead and just run it so we can see what the application looks like yeah that sounds good so the visual studio can now build your application get it running you can debug you have full support for blazer development within Visual Studio for Mac once this gets building and actually running we should see a sort of you know standard single page app style style UI and give it a second it's coming slowly will blame blame that on the browser yes you can tap around you have different tabs for different different pages this is all being handled through client-side routing on the home page you have some simple static markup nothing too fancy going on there on the counter page though you have a a button that you can click and as you click the count goes up there's no page refresh happening here the Dom is just getting fluidly updated normally that would require some JavaScript to do but that's all happening using c-sharp and on that neat not to see how that's working yeah and then this is fetch data page is basically a dynamically generated table of weather forecast data so let's take a look at that counter page so that's implemented in this counter dot raiser file and you can see it's pretty simple it's mostly just H standard HTML markup at the top it says that this is a routable component so app page says that we browse to slash counter we should end up here so if you go to the browser you should see in the URL at the counter tab yep slash counter that's where we're at and then you have some normal HTML markup we've got a button that we can click and there's that onclick attribute normally that standard HTML onclick attribute would have some JavaScript in it but here we're using razor syntax a little at sign to say no no I would like to use some c-sharp we've got c-sharp code here go down to that and it's pointing to your c-sharp method increment count that's incrementing the current count field which then gets rear-ended on the page now to show that that really is running c-sharp code whenever every time we click that button set that breakpoint let's see we can hit a breakpoint counter page yeah there you go we're in our C sharp method neat writing client-side web UI using using blazer let's see what else is going on here well the nice thing about these components like all these don't razor files they they get turned into normal dotnet classes as part of the build and now you can reuse them like you if you wanted to have another counter component someplace in your app you can do that by just adding that component wherever you'd like it to be so for example if we wanted to add a counter component to the home page like let's say we wanted two counters one on the counter tab bone on the home page if you go back to the let's go to the index dot razor file that's the home page for the application okay so here it just has markup there's nothing really interesting going on but let's start typing bracket counter angle bracket counter on here so yeah and you can see you get awesome intellisense in Visual Studio for mac and now it's showing up purple that's that's signaling to you that this is a component yeah you know what a blazer component if we rerun the application is purple or brown I think I might be a little bit color dot net purple everyone you learn new things about how you perceive the world yeah okay so I added the counter component and I'm going to go ahead and f5 again and so now when I go to the index yeah it has a completely new component a part of it so I didn't need to like copy in the counter code or anything it's just inheriting that component a reusable chunk of UI you can click on it it works just like the other one did and if you go to the other counter page you see it has a an independent count that's separate from from counter on the home page you can also pass data into components like components can have parameters to define a parameter on the on a component let's let's go to counter and make it configurable you parameterised how much it counts with each click so to do that you just add a property and the property can be made a component parameter by attributed it with the parameter attribute gotcha I have a little tip I want to show in here Visual Studio for Mac does indeed have snippets so if i just type prop and tap Todd OH it automatically loads in my property okay save some typing what st. yeah and let's call it increment amount I think would be good and let's default the value of that property to just one yeah give it give it the parameter attribute to that's that's cool that's what's really gonna make this a parameter for the component that we can pass in so by default it'll be one and now in the increment count method instead of incrementing by one each time doing a standard increment will increment by increment amounts of current count plus command amount perfect you get lovely intellisense for your c-sharp code inside your razor for local variables now go back to the index page and let's use that parameter let's pass in an argument so if we go to index now just add some space after they are and you can see incremental mount shows up wait way you set parameters and blazars just using standard attributes in tax and now the counter on the home page or in commit by 10 whereas the one on the counter tab should just default to the standard increment domenica the one i just kind of chose 10 I hope that's a good number that is a great number 10 times better that was before and we should see okay let's check this yes and now it's incrementing by increments of 10 whereas the counter on the the counter tab should still be doing by 1 because we didn't pass of past any parameter value the houses working like we said this was all based on that magic real time pipe we can actually see that happening if you yeah inspect the in the browser dev tools let's look at the network and if do a do a full reload so we can see all the stuff that's being downloaded holding a shift key or something there we go so you can see that this app's pretty thin it's not downloading very much stuff it's just a little over 400 kilobytes of download and all the magic is really happening in that first request that underscore Blaser WebSocket request yeah you see when you look at the messages you can see there's all these binary messages flying on that WebSocket connection yeah it's updating as you speak if you clear it lets clear them all out and then go click on the button on the sorry there's lots of try the yeah a lot of work yeah then click clear I'll click me thank me but nothing you clever every time you click we send the UI event to the server your counter component gets the message it rear Enders itself and then the Dom updates get sent back to the client that's what's happening here this is how that's how this app is working this is ablaze every base that cool so that's that's counter now I know if you go back to the code real quick on the counter dot razor file some people really like you notice that there was that act code block at the bottom yeah right there so at code that's basically a chunk of code that's going to get added to the generated class for this counter dot razor file it's like a bunch of class members and some people really like that that code lives in the same file because all your UI codes in one place other people would prefer to have that in like a normal C sharp file like in a code behind file which is totally cool you can do that in blazer as well what you can do is add a let's add a c-sharp file to the pages directory let's call it counter crazier dot CS that's sort of this the standard naming convention for a code behind file look good yeah it's good what it automatically put it underneath I put a whole bunch of they got Razer license information I was messing with my header demo later today for the productivity talk a delete that we won't you don't get to see this yet you have to wait till this afternoon I'll talk about how to put header and we don't automatically license like all your c-sharp files I'll get at it no no no that would be bananas right specifically chose that mighty license cool well we have a counter a class now now this matches the name of the class that would be generated from counter dot razor so let's make it a partial class ok grab you grab that code go ahead and grab that that's fine go ahead and copy that out of there and we're gonna move it into here we don't need the constructor so we can just copy over the constructor but make the class a partial class so it'll be combined with the generated class for the component and then you probably need to resolve some namespaces right and I can do that with alt enter so that opens up the little light bulb that I get so I can automatically add using beautiful so I guess all the normal C sharp productivity enhancements and features now are available to you in this I'm getting another little suggestion so this actually might have annoyed some people and I did this originally use a compound assignment it was all part of my plan yeah so vo Cermak gave me the suggestion that I can simplify that it does look better yeah well so this should be the same as what you had before like there's no difference in their code it's just that we've refactored they run it to prove it yeah go ahead and run it to make sure it's still working that's pretty nice like the C sharp so I've got a lot of nice features my gosh all of the little things that's what I work on that's nice t-shirt little things productivity that looks like it was before so she should still have like you know income increment looks good what other c-sharp stuff can you can you do and in yester Mac does it support all the the visual studio it does so right now we actually share the same editor so basically everything that we've added actually latest and like Visual Studio and Windows 16.5 preview 2 I believe is what we're on all of those are actually already piped into Visual Studio for Mac I can demo those later today with Mikaela there's a whole talk on that yeah there's like a shared editor so it's all piped in okay yeah so like like adding an overload like is that is that oh yeah so if I do alt enter um our keyboard shortcut to open the little tooltips I can't override sorry terminologies do something like as you can see all of the component life cycle events in this UI like the on initialize on parameter set these are all standard events in the life cycle of a component so yeah if you wanted to like run some code when this counter component is first and after it's initialized you would override on initialize or on initialize async if you have some async logic I think the fetch data component actually does that so this is this is the component that was generating that dynamic table of weather forecast data and if you look at the bottom all the way at the bottom there's a yeah there so you see uninitialized async there's exam distracted by how cool it was to have a c-sharp for each blue printing out your people we're cool okay continue so yeah there's uninitialized async that's that's when this component gets initialized you see it's using that weather forecasts service to get all the weather forecast data where's that forecast service coming from if you scroll all the way back up to the top there's this @inject directive what @inject is doing is it is a way to do dependency injection into your components you can get services that you've configured here we have a weather forecast service that we're injecting into this particular component and then below it's just normal razor syntax lucky where you were saying it's mostly standard HTML markup but intermingled with C sharp logic statement yeah if statements for each loops like we're just looping over each weather forecast instance to generate the rows in that table that's how that weather forecast table is being generated super cool so we started sort of to get more into realistic scenarios this was just the file new template is the basics they're like a level 2 app that we can use and show us short so I've been working on a recipe app in Glazer to like you know manage the list of recipes and do recipe ratings and those types of things why don't you pull that up yeah that's my repo you give you guys one if you want to download it and see my code like ok got it best for you recipes best for you recipe all right so let's see if I can open this up now usually I've been developing this on window is actually on Visual Studio but it opens great on Visual Studio for Mac builds runs debugs all those things just work as expected once this opens up why don't we just go ahead and run it first just to see what the app is capable of I'm gonna wait till I load my workspace documents perfect and maybe restore my new get packages that's probably always kind of always that restore your new get packages before you build and run its lifestyle choice okay so I'll try to it's saving might have gotten a weird thing well we're yeah we for that we can go ahead and look at the home page of these let's sit let's open on index dot dot razor so we can see a little bit what the when we see the app we'll have an idea of what the code looks like this is the home page for the application and you can see at the top it's mostly just there's a search box and then a little bit of an if else then just to see if the recipes have loaded and once they've loaded it's just generating an unordered list with the list item for each recipe that it loads from a recipe store and again we're using dependency injection to get a recipe store service and to initialize the the list of recipes so that's all that's doing that search box at the top is a custom component for handling the searches once you scroll back up to the top and we can look at that real quick yeah so you can see that on the search box we're passing in normal HTML attributes to like specify a placeholder but we're also able to specify a delegate for when a search has occurred so that we can hook into that and actually then run the query against our store so looks like the app is now up and running yeah so here's that home page that they actually read beautiful nice nice images design is not my forte you can put down recipes you can see details about the recipes some basic functionality you sort of search bar search for chocolate stuff yeah now notice that as you type the search is updating like you're not hitting enter as your house your typing is just looking at the current state of the search query and running a search but it's not doing it on every single keystroke it's like a little visible pause then it waits to see if you're done typing and then it does a search and that's nice because it's throttling all the searches to your database you're not just hammering the database with every single keystroke so it's interesting to see how that's implemented in Blaser if we look at the search box component that's where all that logic is encapsulated so search box that razor there's off now this is that component that just implements the search text box and it's handling all that debouncing logic where every time you search it'll wait a little bit until the even two you're done typing so mostly you can see that this is just an input like Scrolls we'll see the mark up at the top is an input and that's not about timers yeah and it's bringing in the timer's namespace the attributes attributes attribute there what that's doing is allowing you to grab any additional attributes that are passed on the component and sort of splatting them wherever you want them to be that's how that place total holder attribute is getting on to the input and then that app bind is binding the value of the put to the search query text search group property so as you type blazer we'll see that the text has changed and then set that text on to the search query property which I think you have below yeah right there it's actually even specified as a parameter so if you want to pass it in you can do that and we know that it's gonna do that on every single keystroke because after at bind back at the top at the end of the the input all the way the end see that at bind : event that's specifying which event we want to use for the bind like by default we will do it on change here we're saying no no no I want it on every single input every time you type please update the value of the search query uh property and then now let's look at search query cuz there's some of that's where the little bit of cleverness is happening search query when it's set like when the value gets bound it just starts a normal net timer and this is just you know like you saw up above system timers or whatever whoever the name space is it's a normal dotnet timer from the base class library where it will stop the timer if it's already been started and start a new one and if that timer completes then you know there was a pause without any keystrokes hit and that's when it'll actually call back into the the search query changed then call back that was passed in so I thought that debounce parameter there about 300 milliseconds that's that's the the amount of time we want to wait and you can see in an on initialize there's that component life cycle event again that's where we're moving up the timer setting up the defense time frame and wiring up the event handler for when the timer actually completes so all the event handler does is call into your delegate that you passed in and then you get your search results that's the balancing logic and you know 50 some odd lines of code all done in c-sharp no JavaScript required that's great and so should we go back to slides are we short on time I think we want to make one change oh we got five minutes okay let's make a change to this out okay so um if you go back to the yeah let's go back to the app and look at the reload oh right I stopped yeah so the we can click on the recipe that brings you to a recipe details page okay and most of that's just markup and there's even a form where you can do star ratings but there's also these tags and currently if you click on a tag they are links but they don't they don't go Oh like they don't think okay so what we want to do it is it is going to a new URL it's going to slash tag and then the name of the tag that we that you clicked on let's wire that up so that we actually end up on the search page but with the correct list yeah of recipes okay so go back to index dot razor what we want to do is grab that value out of the URI so in order to do that we're gonna add another route so add another app page directive and make a slash tag and then slash now if that's in curly braces cuz this is the value we want to grab out and we'll call the value that we're gonna grab out tag okay now to get that value we're gonna bind it to as a parameter on this component so add a new parameter remember we added a property before to create a parameter do in the code block let's create a new property so property anywhere thank you drink call it tag okay so and then put the parameter attribute on it so now what the Blazer will do is it will take the value from the route and set it on that property so now we can just pass it in to the get recipes yeah it's no it's not specified yet then we probably just will pass empty that will give us all the recipes when the attack is initialized one more thing is up above in the in the search box let's make sure we populate the search box with the tag if there's one there so set the search query parameter a little space in there [Music] sign and tag oh so we're actually getting into the c-sharp property there you go that's all you so now it should populate the tag so go ahead and run it okay let me start it and that should populate the search box with the tag as you click on tags that will filter the search to just that tag whenever you click on a tag like on the page and it should be just that easy okay so click on a recipe let's go down to the tags let's know fruit there's only one food that that works and it populated it you just added a feature to my heart right you're welcome now top back to slides real quick sure so that was getting started as blazer and some blazer in action um we know the number one question on a lot of people might people's minds if we have time for Q&A and stuff as um what is an expert blazer webassembly when wouldn't cute when we get it when will it be out of preview yeah so so this was all blazer server work that we were doing with Visual Studio for Mac Visual Studio for Mac fully supports blaze a server which is great blazer web assembly is still in preview it hasn't shipped yet it is the the focus of the blazer team right now and we are planning to release it in May of this year as a supported release and that will include full support in Visual Studio for Mac the initial release of blaze our web assembly will be based on dotnet course redone in fact we plan to add the template in an update to the dotnet core 3.1 SDK it will be a current release not on LTS release so it's not gonna inherit the LTS status of the rest of dotnet core 3.1 it is the first release of blaze or webassembly we want to give it a little bake time before we bless it as an LTS release to try and make that clear we're going to update the versions of the packages to be 3.2 we've actually already started doing that so the latest previews our version does 3.2 after may blazer web assembly will become part of down to 5 and will then be just part of the normal dotnet update release cycle so you just need to remember to keep clicking YES on that update prompt keep updating and look in May for the the released version of a blazar webassembly got it so in summary we talked a little bit about being productive in blazer on vs or mac blazer server is what we show today it is in production you can go and use it with dotnet core 3.1 and get excited for May 20 2002 a time question in turquoise that's exactly I'm glad I actually start with a statement somebody said I won't Don Ross Visual Studio you know what we have some exciting t-shirts for this event and we'll be giving them out as part of our party so make sure you stick around for until the end of the day so notice but more and we actually have some questions as well so the first one is habeas from a is there any way I can explore on blazer webassembly in Visual Studio Mac that we were just talking about that you can actually open a blazer webassembly app in vs for mac today you'll need to do is the a smith core hosted version of the template the standalone version of the blazer webassembly template isn't working just yet mb/s for mac but it will by the time we ship blazer webassembly in the May time frame you don't have the ability to create laser webassembly apps from vs for Mac just yet but that is coming as well so you can create apps from the command line as long as they're hosted in a nascent core app and run and develop your components and all that the rest of the functionality will be cut will be coming later as we get closer to the may release that's great well there you have it and next one is just close this one down is there performance benefit using blazer server over a blazer webassembly yeah so blazer server runs on a full dotnet core runtime your components are running on the server so you get all the performance benefits of dotnet core which is honestly one of the fastest stacks on the planet it really treats the the client machine also as a thin client so it has very little requirements on the client side of the of the application blazer webassembly runs on an isle interpreter based runtime today so if you have components that are doing really computationally intensive stuff it can drag a little bit when you're running that type of code in the browser so you might want to offload that to like a web api somehow on to your server so you're running on the folder core runtime perfect I think we have time for just one more question so yep question is is there a benefit using blazer over angular react or some other spa oh yeah I mean you see sharp yeah context you get all that syntactic goodness like productivity features in Visual Studio yeah it's a full stack solution for web app development with net and c-sharp I think also there's just a lot of really nice simplicity that comes from the the blazer programming model and tooling like it's really easy to get started file new project and you're up and running in less than five minutes so that can be really nice that said if you if you love angular and react in view and you want to continue to use those for your front-end development you can absolutely still do that and still use net core for your back in api's G RPC services signal our hubs and so forth great well thank you very much for your time it was fantastic to hear about all the Blazer cool myths out there and I'm looking forward to the 2020 build announcements that we're probably gonna have