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We've got a listener put together for order created.

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We're not gonna repeat that same process for order canceled.

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The only thing we're going to do inside the order cancel that listener is update the status of the order

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that we had previously saved to canceled.

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That's pretty much it.

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Then whenever a user makes a request to pay an order or essentially create a charge we're going to check

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to see if the order they are trying to pay for has a status of canceled or not.

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And of course if it has it as a cancelled we will reject the payment.

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That's pretty much it.

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Let's get started on this order canceled.

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Listener feedback inside my listeners directory I'll make a new file of order canceled

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listener and listener is going to vary so much.

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The one we just put together.

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So let's just get right to it.

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At the very top we'll import our order canceled event.

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Our subjects enum and the listener base class from our common module will then export a new class of

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order canceled.

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Listener that will extend listener and plug in our order canceled event we can then set up our subject

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as subject start.

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Order canceled assign it a value as well.

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After that we'll import our Q Group Name

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from Q Group name and then assign that in the body so cougar name is you.

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Group name.

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As usual you know what comes next.

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Async on message.

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We're going to receive a data object that has type order canceled event and then our message which is

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up type message.

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And again let's import our message site.

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Now let's take a look at what data is available to us just as a really quick reminder on the order cancel

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the event object so I'll do a command click on order cancel event at the very top.

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Looks like we are told the idea of the order that was cancelled.

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We're also given a version and then presumably well the status is going to be cancelled.

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So all we have to do is take a look in our collection of orders.

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We're going to try to find some order but to give an I.D. and the appropriate version number as well

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and we're going to update it status to.

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That's pretty much all we have to do so inside of on message we're going to begin by making a query

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and trying to find the appropriate order for that.

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We of course need our order model so I will import.

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Order from up to directories.

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Order at the top.

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Now we can find in order as a weight order.

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Find one the reason we're using a find one here.

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You might remember we ran into this a little bit ago when we make this query.

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We want to find a record with the appropriate I.D. So the idea that is lost inside this data object

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and the appropriate version as well.

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Just make sure that we're processing all these events in the correct order.

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Now with the order itself it doesn't really make a big difference to worry about the version too much

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does remember around in order.

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All we really have is the order created in the order cancelled.

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That is it.

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There's not really any ordering of events per say because if we fail to find the order at all that means

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that well we probably have not correctly process that create order event just yet.

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And if we find the right order does really matter what the version is because there's never ever going

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to be an end or in any intermediate update events inside there either so we don't strictly need the

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version thing this time around or we're going to include it anyways just to possibly prepare our code

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for some particular new event we might introduce into our app at some point in time the future of something

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like maybe order updated or something like that.

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So if we ever had some kind of update event that's in the version starts to get really important.

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So we're gonna write out some code here that's just going to assume possibly at some future point time

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we might have the ability to update and order okay.

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So far find one right here we'll try to find some appropriate I.D. of underscore I.D. and we'll come

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from data I.D. and then our version will be a data version minus one once again.

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We might want to extract this find one helper method into a separate function inside of our model file

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itself but I'll leave that up to you if you want to go through that process.

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So after we got our order.

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Well then make sure that we actually did find an order so that if there is no order let's throw a new

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error and just say order not found and then.

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Otherwise we'll update the status of this order manually to update the status manually.

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We need to import the status or the order status you name from our common module

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will then do an order set of status to order status dot cancelled and we can save the order.

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So I'll do an a wait order.

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Dot safe naturally right after that we will act the message and that's pretty much it.

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All right.

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So at this point we could definitely write a test here but very much like the last listener we put together

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not super necessary.

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So once again we will write a test but it is 100 percent optional.

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So if you do want to write the test no problem whatsoever.

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We'll take a pause right here.

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Come back next video.

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Go through the optional test and then move on from there.