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In this video we are going to develop lambda function for the incoming rest API, even json object to

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perform business logic.

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Let's get started.

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For that purpose, open the Visual Studio code.

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I have created a new folder specific folder for the lecture and I have added the our incoming event

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object for the rest API to the lambda function.

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We can see these images object and in the index file index file we have created the lambda function

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and now we will develop our lambda function code.

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So this is the basic implementation 100 method of lambda function.

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This function designed for the API driven invocations to lambda function.

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So this is starting with the logging incoming event.

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After that we have tried cache block and in the tribe log we are returning to 100 success certificate

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with the body information and in the case below we are logging the error and return vector 400 code

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and the error message.

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So this is designed for the API driven services equal to the base lambda for example, API gateway or

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function from the lambda function.

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Okay.

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Now we are going to implement the actual business logic in here.

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So in the actual logic, we will basically accommodate the incoming request from coming from the rest

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API and we will accommodate these HTTP methods and implement the product related business logic into

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the lambda function.

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So as you remember that or even JSON objects are stored in here.

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So basically if we examine these folders, the important attributes are resource, pet and static methods.

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For example, this is the gate product and is the gate product by ID and this is the post product.

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So the idea there is that we should write the switch block according to the HTTP method and after that

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we will check the query string and pet parameters.

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So let's get start to development.

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Basically, I'm going to open the indexes and in here I have writing the switch statement in the K,

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we should look at the event that HTTP method to verify this attribute.

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You should get in here and copy from attribute name and come to code window and paste in here.

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And if you look at the case, we should check the HTTP methods.

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If you look at the exit method values in here in the method for the get request, it is get get the

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ID.

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It is again the same get post method.

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The method is post.

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So that means we should write the HTTP method case, get post and delete.

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After that we will develop additional conditions for gate by ID looking for the setting parameters and

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the parameters.

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Okay, let's get started.

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I'm going to copy these cases and after that I will explain one by one.

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Here.

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You can find the old case statement for our application.

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So let me copy all and make it clear.

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Yes.

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Here you can point our switch statement.

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Basically, we handle all incoming requests from the rest API by looking to our ATP method.

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And after that, if the method is get, we have also additional condition, which is the looking query

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setting parameters.

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It took our setting parameters, including this event JSON object.

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We are going to perform event parameters in here.

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But if there is no query string, we are looking for the checking for the parameters and after that

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apply the parameters.

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For example, this is for get by ID.

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If there is no parameters and setting parameters, that means we will return back to get all products

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so you can check these HTTP methods.

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Which condition is handled, which method?

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You can see this, you can check the these command sections, for example, this one is handled get

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product by ID and also create a setting parameter.

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And after that we only check, get product ID and last condition is get all products.

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So this is the first case for the gate condition, another case for the OR application looking for the

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post.

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You can see in here this is the post.

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So in the post block I'm going to.

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Check the event, buddy.

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So we are basically passing the event the in order to get the payload.

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After that, we are processing the payload for inserting a new item and so on.

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So another case we look is the delete.

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So in the delete method, http delete.

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We basically check the parameters to delete which ID of the product.

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So this is handled delete product by ID, this is handled post product.

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So as you can see that we have implemented the switch block in accommodating the incoming events from

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the rest API.

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So now we should copy this line of codes and paste to our lambda function in order to deploy and see

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how it is working in our application.

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So let me make it more clean and copy all codes, remove blank characters and I am going to copy all

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code.

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You can also copy from this index file of the lecture folder and go to the our lambda function product

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function go to functions, product function, open the code window and remove this code window copy

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from here and paste in here.

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So you can also check the codes and verify all with the codes in this place.

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So after that you can click the deploy button.

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Now we are ready for the test of our application.

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So as you can see that we have developed our lambda function that can handle all request incoming from

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the rest API.