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And up next, I want to work on a cigarette, rappers for all our controllers.

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Why?

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Well, because we have asynchronous operations and yes, it's very useful to use these try catch blocks.

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But you have to agree with me that he had become somewhat redundant pretty much for every controller

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setting up.

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Try and then catch on.

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As you can see, essentially, I'm just copying pasting the code around.

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So there has to be a better solution.

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A better solution is to create a middleware function that essentially will wrap our controllers in there,

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will disrupt functionality where we don't have to repeat ourselves.

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And before we continue, let me just say that there are some NBN packages that do that for us and most

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likely in the upcoming project will use them instead, since that way we can save some time on a set

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up.

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But I think it's very important to have at least a general idea of what the package is doing instead

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of blindly installing it.

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And therefore, in our first project will set up the basic logic ourselves.

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And I'll start over here with new file and I'll call this async jurors.

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And then inside of it, I'm just going to go const a sink or wrapper so I simply create a function.

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At the moment, nothing's happening here and then I want to export it.

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Module exports and then a sink wrapper and once we set up the export.

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Now, of course, I just want to go to my comptrollers and import that.

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Magloire So I'm looking in the middle and I'm looking for a sink in here.

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Let's just call this a sink wrapper again.

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And that is equal to require that we navigate to our middle order folder.

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And of course, we're looking for your sink.

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And now what we want to do is wrap all of our comptrollers.

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Now, I'm not going to wrap all of them right away.

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I'll just start with get all tasks just so I understand how it is going to work.

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So what do we want to do here is just to take this async wrapper list function and just wrap our current

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controller and essentially is going to look like this where we go with a sink or wrapper and we pass

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in the controller, the current controller as an argument.

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And since we know that we can do that in JavaScript, we are in good shape.

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So we pass it in and then back in the sink, of course, and it set up the parameter.

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So since I'm passing in already in the controllers, my function, my controller has an argument back

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in my singes, my middleware.

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I just need to go with some kind of parameter.

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Now, are you going to call this callback?

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You can call this function.

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Doesn't really matter.

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In my case.

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I'm just going to go with F and.

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And what am I trying to do here?

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Well, I'm trying to avoid this try catch.

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So essentially I want to have my cake and eat it too, where I can still use this.

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And I await syntax, but I don't have to set up the try catch block.

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How can we do that?

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Well, we set up the tri box inside of the wrapper and the first thing that I want to do from this function

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is to return the one screen here also return async.

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And then if you remember in the express by default, we right away it got request response as well as

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the next.

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So that's what I'm trying to do over here since I wrapped my controller in my middleware.

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And if you pay close attention, we're actually invoking the async wrapper right away.

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Now, of course, I want to pass in those requests response and next down to my function down to this

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controller.

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Correct.

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Because now, of course, I wrap my controller in my Millau.

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And the way we do that, we return another function since I will use a wait inside of the function body.

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That's why I set it up here as a sync.

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And please, please, please keep something in mind where these ones, the Iraq rise and next we'll

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have access to right away, because at the end of the day, we return another function from async wrapper.

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And that inside of the function by one of the things that I want to do is pass the Iraq address and

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next from express down to this function.

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So hopefully that is clear.

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Again, we get these ones by default.

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The reason why we have access to them, because from our async wrapper, we actually return another

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function.

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So that's how we will have right away access to them.

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And that is the function body will decide what to do with our parameter.

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We.

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Argument, which is our current comptroller and as far as logic, I want to go with try catch block

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and then instead of the tribe block, I'm going to go with a wait and function and herel person, Rick

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or and I'm next.

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And then once we have passed all of these things down to our controller, of course, now have access

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to them in here as well.

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And then also, since there might be a case for an error, we'll go with next and then we'll pass in

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here.

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And if you're wondering what's happening over here, essentially we're passing this to a next maneuver,

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which we haven't set up yet in our abcess.

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So that's what's coming up in the following videos, we'll set up another set of middleware.

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And in this case, we will deal with errors.

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So once we save over here, we can go back to the controllers and now I can remove the try, catch block.

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So remove the try catch block completely.

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And at this point, you should only have these two lines of code where we are waiting to find all the

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tasks.

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And if we're successful, we send back those tasks.

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And as far as the async wrapper, we take our controller as a argument.

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And since we return the function, we have access to REC or as a act of that are coming from the Express

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and we set up to try catch block.

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And in here we have a wait because our controller is still async and we know that by default, async

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function will always, always return a promise.

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SERN here I just have a wait and I'm waiting for that promise to be settled, either resolved or rejected.

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And since my controller will still need to access arrack address and possibly next, since I get them

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from Express, I pass it down to my controller and then if there is an error.

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So in here, if we trigger some kind of error, whether in get all tasks or any of the controllers,

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then of course we'll catch it over here and we'll pass it to a next set of Middler, which we haven't

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set up yet.

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And now, of course, once we have everything in place now, we just want to apply these changes to

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all the rules.

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Now, I fully understand that some people are very negative about refactoring the code.

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And to some degree I sympathize with that because I also hold the opinion where it's not very useful

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if we're all the time refactoring the application.

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But it was important for me to show you the long way first, because that way you have a good understanding

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of how everything works.

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And now we just set up the middleware that actually handles that.

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So let's go back to the controllers.

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And slowly but surely, let's add this, a single wrapper to all the routes and the setup is going to

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be following for all of them, or we start with a single wrapper.

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So we set up our two parentheses here and we need to make sure that second parentheses, the closing

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one is a write off thirty curly brace.

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Correct.

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Then we want to remove the try block as well as the catch block.

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And again, we'll be just left with a weight that does not create if we're successful, we send back

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the task and fact that we want to do that for all our controllers.

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So let me go here with a single wrapper.

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Same deal for this guy here.

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And we have try and we remove the catch, but we are leaving this one.

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So we'll work with this one a little bit later.

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For the time being, we'll leave it as it is with this response.

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And once we set up our customer, there is going to be some changes here as well.

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Let's keep on scrolling.

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We're looking for the async wrapper.

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And again, we want to be closing one right after the curly brace.

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We still passing the function.

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Our move might try or might catch here and we'll save it.

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And the same goes for updating a task as well.

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So we go here with a single wrapper and we'll close it.

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Then we want to try.

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And we want to remove Kuch.

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And just to try it out, why don't we go to create a task and then I'm just going to go with creating

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task, creating task.

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Let's try it out.

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Everything still works.

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I can create my task, but if I'll try to add a task with an empty string value, I should get the error.

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And I do.

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But of course, this is not the error that we're sending.

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So that's something that we're going to work on in the upcoming videos.