last time on our template mini series we discussed creating a template and getting it to work in visual studio now we're going to talk about how you can continue expanding on that by adding parameters so learn more on this episode of visual studio toolbox hey everybody welcome back to another episode of visual studio toolbox i'm your host leslie richardson and i'm joined once again by senior pm syed hashimi welcome back hello great to be here thank you yep long time no see so in the last episode we talked about creating a template and then getting it to work within visual studio so what are we going to talk about today yeah that's right so today we're going to we're going to talk about you know how can i take an existing template uh and add you know one or two parameters to that and then we'll see uh how that works in visual studio as well all right well uh i'd love to just dive right in because i'm sure everyone wants templates that go beyond just the hello world type setup right there's no doubt about it all right so let's go let's go and jump right into it here so i've got my uh github open here and a reminder for how to get to this repository is ak dot ms slash net core templates let me basically just kind of show what we're going to do here so let me go into the to the my command here and inside the template.json file is where we're going to start adding these parameters so everything that i'm going to do here today is basically just right here inside this uh inside these files here i'm just going to snap it here let me open up my uh let me open up the the demo solution here that's got the templates and all that sort of stuff all right i'm going to go ahead and open up my template.json file here and here's where we're going to go ahead and start adding some parameters here and by the way the the first parameter that there's a very kind of special parameter here and that's for framework so what's the target framework for this project and uh you know it's important to add this for a number of reasons one um whenever you have parameters inside of a project and if you want those parameters to appear in visual studio uh the framework parameter always has to be uh it always has to be declared there and uh and it's also good for users just so that way they know you know what uh what target framework is going to be used here to create is going to be used uh when they create a project there so let me just go ahead and copy this content from here and then then we'll we'll kind of just describe more about this so symbols and paste that in let me uh double check my project here real quick so if i go take a look at my cs proj i can see the target framework is actually not five i'm going to take that and then we'll go ahead and fix this so instead of the choice being that core app 3.1 it should be net five and target net five and then the same for these replacements here all right so this is basically uh it's called the choice parameter that has one choice it's like a drop down with with one particular value there all right so now let's also go back and take a look at what can we do for other parameters here so in the code uh the the demo kind of project had an author name uh somewhere inside the code and then there was a replacement that was happening for that let's go and add let's go and add something like that to the code that we have here so let me just go and grab author new author name here you could say created by author name period all right so now what's going to happen is i'm going to create a parameter that users can uh specify a new value by who this has been created by right and you know what i'll do is let me take this and maybe we'll put it into there you know what i'll do is i'm actually just going to put this inside my um inside my project file as well maybe like you know as a comment or something all right there we go great all right so now what i'll do is let's go back to the template.json we're going to go ahead and add the the new parameter here author name uh the type here is parameter and you notice i'm just kind of intellisensing my way through all this stuff right yeah must be super helpful not having to remember every single piece of syntax yeah it's very difficult to remember all these things you know absolutely so i just specified a default value so um when this template gets instantiated you know either from or actually when this template gets used from.net new if that parameter is not specified this default value will be used and then that will be the default value and visual studio that gets kind of plugged in there as well cool so if you put author name anywhere else within this template it would also pick up on the schema or this uh rule would be applied to every instance that's right that's right that's right also file names as well so if you got a file that's called you know author name blah blah blah then author name part of that would get would get modified to whatever the user specified here and uh there's also clean up that happens to let's say for example uh you let's say for example the user specifies some value that can't be used in a file name the template engine will basically take care of fixing that up to where it would be a valid file name there right sorry so now i've added uh two parameters here we've got the framework parameter that's a choice and it's just got one choice for.net five we also got the author name parameter and the default is author demo and it's a text let's go ahead and reinstall we'll we're going to do uh pretty much everything here so i'll say reset templates and then i'll do a semicolon and i'm just going to copy the additional commands here so we can just do everything in kind of one go here and also with the correct order here all right what i did was i just combined those three commands with a semicolon so this will run and then this will run and then this will run all right we can see it reset the template uh and then it created the nuget package and then install the nuget package and we can see our we can see it's here so if i were to do dot net new syed con h i should see those new parameters here i see i've got author name here framework doesn't uh automatically appear here because because it's it's like um there's just one value there i think and i'm i'm really not sure why framework doesn't show up here i think it probably should this is probably a bug i'll kind of talk to the team about that so now i just reinstalled that template so i have to uh close visual studio and then reopen it so that way visual studio gets kind of you know the latest definition of that let me go into create a new project and if all goes well we should see uh in the additional info page those those parameters that we have defined here all right so now i see oh yeah that's right that's right that's right okay so yeah i see the target framework but i don't see my author name parameter so there's actually an additional step that needs to happen here let me open up that that solution so demo.solution so that's another thing that i forgot to mention here uh framework parameter you know that one's kind of special case then if you've got the framework parameter in your template.json it will just appear in visual studio itself uh but for the other parameters you know in visual studio where we're not sure what parameters should and shouldn't be shown so what we do is we have to actually put an indication in the ide.host.json and let me show you where that is in the samples here so all you have to do is basically define this simple symbol info property here and it's an array of values here so let's go ahead and do that so i'll say symbol this is not in the wow it's not in the intellisense for some reason okay so this is a another kind of bug here i definitely want to get that one fixed so i'll be bringing that up with the team of course all right so this is just an array of objects here so we give the id and you know the id here is uh author name and we'll check this real quick so id author name and then the the name is author name and then is visible to true so yeah that looks all good to me the schema declaration looks good too i'm not sure what's going on with the intel sense here but that's okay let me go ahead and close out of visual studio and then we'll go ahead and rerun that command to get it reset and then reinstalled yep author name okay so we'll say um demo author here okay and and uh we can see that there's just one choice in the target framework and i don't have the ability to uh to change that but you know if you wanted to you can definitely go through and and create a template that supports multiple target frameworks but you know it's definitely uh some additional work for those types of templates let's take a look at what we get out of here let's go ahead and just run this with ctrl f5 let me just run it here all right so we can see hello from console one created by demo author it's going to take a look at this make sure the replacements happen so we saw that the namespace and then this the string here got replaced with the project name as expected nothing see demo author has been uh replaced as expected and then inside the cs proj that string was replaced also a demo author here so that is really about it for you know how to create uh how to create parameters here uh and then get them to appear you know not only in dot net new but also in visual studio and uh one thing that i want to kind of point out that that i did point out in the previous video but let me go ahead and point it out one more time is you know let's say if you do want to support something that's more kind of complex right like if you want to create a template that supports more than one target framework or if you want to create a template that has different types of parameters right like maybe you want a checkbox instead of a text or or stuff like that the best thing to do is to go take a look at the existing asp.net core templates that have been created by microsoft here so this is the repository where all our kind of source templates appear and most of them that you'll probably be interested in are under project templates so that's definitely a great resource for how to create you know kind of a more kind of complex template uh but yeah you know we'll also kind of cover some some additional kind of info in the uh and the upcoming video as well that is exciting and yeah that's great once again it seems super easy to be able to continue expanding your template like that yeah definitely yeah exactly so it's kind of a grow up story here you know i wanted to make it very easy to kind of get started with a basic template but then also make it kind of easy to uh to grow that template as well and you know that's kind of what we're doing through these uh series of videos here yeah yeah so what's next what will be next is uh you know i think what we're going to cover next is uh kind of troubleshooting and analyzing templates here you know so what are the kind of common pitfalls and then what can we do to avoid those and and what's available so so i created a a.net core tool that that template authors can use uh to analyze their templates so i'll show how to install and use that and then uh go through just kind of the some of the uh the gotchas there yeah yeah that sounds like some good stuff to know because i don't think anyone ever gets it right on the first try you know yeah definitely definitely sweet so until then happy coding that's it thank you you
No comments:
Post a Comment