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All right, and up next, I want to talk about a Synchronoss patterns in Algiers.

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So if we remember when we were setting up the filesystem module, we covered how we have to flavour's.

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We have the Synchronoss one and the asynchronous one.

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And while asynchronous one is great, since we're not blocking the event loop, the problem is that

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if we're using this callback approach, well, it gets messy pretty quickly because we're not getting

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one callback inside of the other one.

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So now in the following videos, I would want to show you the alternative that we'll use throughout

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the course and why, in my opinion, it is much cleaner syntax and that's why, of course, we'll use

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it.

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And first, what I would want is just to kill everything here.

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And I'll start with the Nordman since I'm done showing you the event loop and we're just going to go

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out and start, right.

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That was the proper one.

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And now I'll delete everything that I currently have not.

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Yeah, sorry.

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So I'll leave this one.

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The async one.

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I would want to remove everything in the app and now I just want to quickly show you the code that would

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block that amental.

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Again, this is going to be the video where if you don't want to go to long after, you can just sit

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back and relax and effectively you'll be in good shape.

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And again, we'll set up the server, like I mentioned before, already twenty thousand times.

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Don't worry about specific commands.

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We have rest of the course.

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We'll be building server.

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So trust me, you'll get sick of it.

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So go with HP and require.

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And of course we're looking for HTP model and then remember the methods create server and listen.

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So we go with CONSED and we create the server that is HTP and create a server we pass in callback.

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Callback takes two objects, request object and response object.

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So again, essentially request object is what is coming in response.

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Object just represents what we're sending out, what essentially we are responding.

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And then I would want to listen on a board again.

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So I run server that listen and then I'll pass in the port of five thousand and then of course we have

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that callback once the server is ready and here we can just go.

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So log on or simply say server is listening on Port 5000, server is listening or just listening is

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listening.

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And worked online course, in my case, forty five thousand, let's set it up so we should have this

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listening on for 5000 men, of course, in my callback function, I would want to check for you URLs

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because I would want to show you how even if we try to get a different resource, we're still blocked

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by other user if he or she is requesting some kind of resource where we have the blocking code.

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And don't worry, if this sounds like gibberish, you'll see what I mean in a second.

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So remember, on the request object we could check for, you are all so effectively you could check

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what is the resource that the user is requesting.

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So, for example, home page would be forward slash and the about page would be forgotten about.

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And that is sitting in the property by the name of request.

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And you are also requesting the object and then you URL is the property.

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So again, we'll do a quick and dirty way.

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We'll just say request.

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The URL is equal to a force.

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That means it's a home page and then we just need to go with a red dot.

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And um, I will say home page again later.

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We'll have way more sophisticated approach.

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But for now this will do.

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And we're checking for the about page.

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Click some.

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So this is going to be an about page.

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And then if there is a page that doesn't match any of the resources, then of course I'll just send

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back, I don't know, error page.

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I'm not going to set up the whole link.

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Nothing like that.

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All right, we say it, and this should send back about page some and of course, in homepage, I can

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just respond with the homepage.

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So life is beautiful.

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Users can come here and sign out.

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Multiple users are presenting with these tabs.

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So imagine these are my users and life is beautiful.

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We are requesting resources and we're just going on about our day.

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Now, the problem is going to be if I go to about and if I set up some kind of blocking code now, what

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would be a blocking code?

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Well, that could be a nested for loop.

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So I'm just going to go with blocking code and then I'll add some exclamation points and let's simply

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set up a up, let's say I is equal to zero and then let's say I is less than a thousand and I plus plus.

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So every iteration will increase by one hour.

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I'll set it up as a nested portal.

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So copy and paste and I'll just change these values to J.

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So Joe here and Joe here.

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And this just comes along and we'll say, Jini, again, doesn't really matter what we type there and

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just say I am J now, no question, what do you think is going to happen?

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So if the user navigates to about.

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I mean, we can kind of see that this will take some time.

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Right now, you would expect, though, that only the user who navigates here gets blocked.

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And you would be wrong, because we'll also block the other suckers who are just trying to get to the

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homepage.

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So let me navigate here and check this out.

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So I run this one to notice how we're loading now.

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The same thing happens here now and here.

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OK, and only when we are done here, then these two can get the resource again.

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Now, of course, if I go to my project, I can see that in the console.

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I have all these values right.

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Because I have this blocking code.

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I have the synchronous code that just takes a long time.

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And this is just a representation of why we prefer this asynchronous now.

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Yes, the moment this is messy and the worry in the next video will fix it.

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But this hopefully gives you an idea of why you should always strive setting up your code asynchronously,

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because what we've learned in the previous videos, if we do that, then those tasks are uploaded online.

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Only when the data is back, only when it's ready, then we invoke it.

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And that way we're not blocking the other users.

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Hopefully it is clear.

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And now, of course, let's take a look at some other patterns we can use so we still get the benefits.

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So we're not blocking that event loop, but we also have a cleaner code where we don't have this nested

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callback mess.