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We've got this nice query written out right here that will determine whether or not a given ticket is

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already reserved.

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And as I mentioned at the end of last video there's very likely going to be some other scenarios where

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we need to decide whether or not a given ticket has been reserved.

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So we're going to extract this logic into a separate file.

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In particular we're going to extract it into the ticket model file.

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It's going to go back over to models ticket to yes we're going to add a new method onto the ticket model.

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This is going to allow us to decide whether or not a ticket has actually been reserved.

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Let me show you how this is going to work.

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I'm going to go down to the interface of ticket doc right here and on the ticket talk interface.

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We're going to add in some new method that's going to exist on a individual ticket document and say

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that we're going to add in a new method called is reserved.

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If this thing ever gets called we're going to return a promise that is going to resolve with a boolean

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so once we implement this is reserved method I'm going to flip back over to our right handler really

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quickly once we implement that method we will be able to write out some code like is reserved is a wait

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ticket dot is reserved.

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That is the goal.

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That's what we're going to try to eventually add in.

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So we're going to build a ticket ticket called Method and that's going to return to us whether or not

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this has been already assigned to some other valid order inside of rap so inside of that is reserved

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method that we can write in just a second.

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We're going to essentially just run this exact query right here that's gonna make it a lot easier to

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figure out whether or not a ticket has been reserved and really shorten down the code we have inside

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of this root handler.

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So that's the idea.

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So let's go back over to the ticket model file.

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We're gonna go down towards the bottom and right after we define that build method on statics the statics

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object is how we add a new method directly to the ticket model itself.

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Remember this is the ticket model.

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If the object that allows us get to get access to the overall collection if you want to add a new method

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to a document then we're going to add in a method or a property to ticket schema methods that is reserved.

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We're gonna set the sequel to a keyword function supercritical here.

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Please make sure you write out a function keyword instead of an era.

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Function so by putting in ticket schema methods is reserved.

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We can now run what you saw just over here a moment ago.

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We can do something like this.

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This is how we add a method directly to the ticket document itself.

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So why did we add in a function keyword.

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Well Mongoose has you seen several times is kind of stuck in the ways of old so to speak in the old

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ways of writing javascript I suppose.

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So in order to actually get information about the ticket document that we're operating on when we call

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this method right here we're going to access this so inside this function this is equal to the ticket

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document that we just called is reserved on in the context of our new route handler.

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We're just looking at a moment ago when we write out something like this right here the value of this

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inside of that function is going to be equal to that ticket document that we just found inside the database.

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A moment ago the reason we have to use a function keyword inside of here is because if we use an arrow

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function it's going to mess around with the value of this inside of the function.

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So that's what we have to use a keyword function.

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We're going to also mark this function as being async so we can use the async await syntax than inside

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of here.

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We're gonna write out essentially the same query that we were looking at a moment ago inside of our

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root handler.

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Let's just go and copy paste thing to save a little bit of time don't find the query that we just wrote

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here it is right here.

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I'm going to cut that whole thing go back over to our ticket model file and then paste it inside of

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your

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it's now inside this function.

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The ticket document that we're trying to look for is going to be equal to this inside this function.

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So we're gonna replace ticket with this like so.

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We also need to make sure we import the order model and the order status you name at the top as well

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so go to the top.

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I'm going to import order from same directory order and now we could get order status from our common

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module inside of here.

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But there's another thing we could do very easily in the context of this orders service right here.

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There are several different files that are going to need to access the order status.

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It's a little bit confusing to have the definition of exactly what an order is coming from either the

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order bottle file and then in some cases our common module instead you'll make a lot more sense if we

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could do something like order status.

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Like so you know just make a little bit more sense because now the implication here is that we have

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one file that has a definition of everything order relayed inside of application.

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So rather than having the separate import same right here we're going to try to do this.

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So we're going to try to get order status in the order file.

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So in order to write this right here that means we have to go back over to our order model file.

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We already imported order status over here.

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Now we're just going to re export that thing like so.

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So now we go back over to the ticket model file that import is now working.

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So again the idea here is just to have one source for everything order related okay.

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Let's get back on track here.

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So now those errors to be gone so inside this is reserve function.

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We should now have our existing order that again that thing is going to be either some order document

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or null.

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If we do not actually find a value from is reserved we don't really care necessarily about the ordered

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that this ticket is associated with the name of is reserved kind of just implies that we're going to

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return a boolean value of either true.

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Yes this thing is reserved or false.

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No it is not reserved and as a matter of fact that's even what we wrote out inside of our method signature

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right fort as well.

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We said it the promise was going to reserve a similar result with a billion rather than just returning

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the existing order.

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We're going to return not not existing order that's essentially going to take existing order.

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If that thing is equal to no it will be flip to true by the first exclamation and then flip back to

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FALSE with the second one and then if existing order is defined we're gonna flip at first a false and

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then flip it to true.

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So we're just doing that to the side or seeming to return a boolean true Yes it is reserved or false.

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No it is not.

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So that should be it is going to save this file we can now go back over to our new root handler

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and now we can write out something right underneath that comment where we just had a really long query

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we could say something like is reserved is a weight ticket dot is reserved and then on the if statement

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will say if is reserved.

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Well I don't know about you but this is a lot easier to read than what we had before.

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It's not really as clear what it means to be reserved.

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So this comment being right here does it really make a lot of sense.

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We might want to move that comment over to the model file.

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I'm going to delete it.

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You can certainly move it over if you wish.

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But this right here a lot easier to understand what is going on.

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We've got a very well-known method that's going to tell us with a simple boolean.

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Yep.

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It's reserved or no it's not.

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So this is a definite good and prevent still a little bit to take care of inside of this handler.

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Let's continue in just a moment.