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Learn the Basics of REST in a CodeIgniter Tutorial


The first step in learning the basics of REST is to understand the concept of getting, POST, and PATCH. This tutorial will also cover GET, PUT, and PATCH operations. Understanding how these operations work is important to developing the best application. Once you’ve understood these concepts, you’ll be able to write and test REST API calls. If you’re new to REST, you’ll want to begin with a smaller project.


You must create a GET request to access the Jira Server Platform API. This will give you statistics on your projects. For example, if you want to know the many issue types in your project, you can use the rest API. You will need the API key, request body, and key-value pair to test this. Once you have these, you can test your API by triggering various responses from the service. The results of the request will be shown in the bottom pane.

The REST API protocol supports GET requests, POST requests, and PUT and PATCH requests. These methods make it easy for you to create a rich API that is easy to use for all types of applications. The REST syntax is simple and enables developers to build an API that works for them and their customers. The REST standard also simplifies building and maintaining hypermedia and other applications.

A RESTful API will allow you to create multiple routes to manipulate the application and its data. Bad clients can send thousands of requests per second, causing a server to crash. Implementing the REST API will determine how much data can be returned, so you will need to limit the number of API calls you make. Also, the response may contain more data than you need, so you must make further requests to get the complete data. This is called the N+1 problem because you must make N API requests for one result.


REST API stands for Rest Application Protocol, a web service that supports GET, POST, and DELETE methods. CodeIgniter requires this type of service to interact with other applications or different platforms. This tutorial covers the POST method. The purpose of this method is to create new resources. The response will be HTTP status 201, meaning the resource is created.

In the example above, we will create a table and a new user. The URL will be localhost/Codeigniter/API. The username and password will be “admin” and “1234”. Lastly, we will use curl to create a new cURL resource and set its options to CURLOPT_TIMEOUT, CURLOPT_RETURNTRANSFER, and HTTPAUTH_ANY.

The HTTP Request type specifies the type of request. For instance, application/x-www-form-urlencoded accepts form data in the HTTP body during POST requests. The parameter passed to the method binds to the value of a query parameter or an HTTP matrix parameter. The context can also be the HTTPRequest, a JS object, or an enum. You should also be aware of any synchronization problems that may arise while designing an application.


The PUT method is an HTTP method used to update or create resources. A PUT request will update the whole object rather than just some of its properties. It replaces an existing object with a new one, and the response is not cacheable. This makes PUT requests useful for creating or updating resources that have multiple versions. However, you should be aware that you should avoid using this method when the change is not necessary. You may prefer to use POST, which is more appropriate for such situations.

You can use HTTP methods to define your operations in a well-formed REST API. For example, if you want to create an employee record, you can use the GET method. GET URLs must include the base URL /API/tutorial/1.0/employees. You can enforce data integrity by using HTTP methods to create a well-formed REST API.

The GET method is the most basic type of HTTP request. Your browser uses it when you click on a link or type a URL into the address bar. With this method, you instruct the server to transmit the desired data. You should not modify this data on the server. Formatting it for display is done by the client. The DELETE method should be used in the opposite manner of PUT. A DELETE request should be used if you want to delete the resource you’re trying to access.


The PATCH method updates existing objects. This method requires a request body that includes data to update the object. The data can either be new or the same as before. You can also learn about retrieving an object’s data with this method. It is also important to remember that the PATCH method does not support dynamic structures or null values. Instead, you can use a local variable to hold the data that you are looking for.

PUT, and PATCH is two types of requests. PUT is a way to update individual fields, while PATCH replaces a whole entity. PUT is usually the better choice when you want to update a single field. PATCH will reduce the bandwidth you need and will return a successful response. This tutorial will look at how to use PUT and PATCH in the corresponding methods. Once you’ve mastered the basics of PUT and PATCH, you’ll be able to use them for more complex tasks, such as replacing a single field with another.

Unlike PUT, PATCH does not have idempotent properties. That means if you make multiple identical requests for the same resource, the resource will remain in the same state. However, the result will always be the same if the input is auto-incremented. PATCH requests may also have side effects on other resources, such as changing the content of other files or folders. In either case, you should include a condition and use the ETag HTTP response header to indicate that the action was idempotent.


In this REST API tutorial, we will explore the DELETE method, which is useful for deleting collections of resources. This method is similar to the GET and POST operations. In the case of a DELETE operation, the service should return a response with the 200 or 202 response code. Similarly, the GET request will return the corresponding result code with the 204 response code.

DELETE is a special method that allows you to delete records. You’ll need to call it in a GET request to delete a resource. If the request is unsuccessful, it will return an error message. The GET method is useful for retrieving resources that you’ve deleted. The GET method is used to retrieve all resources from a server. It can also be used to create new resources.


Metadata is information that is conveyed through HTTP headers and media types. There are many different types of metadata. HTTP headers specify the request and response message versions. Some provide information about the requested resource, while others are directives for intermediary caches. In this tutorial, we’ll look at the different kinds of metadata. In Table 4-1, you’ll find a quick reference to the terms and definitions used in this chapter.

To access the REST API, you’ll need to have a subscription to Talend Cloud. Once you have access, click More Actions in the top right corner of the screen, and select REST API. The REST API documentation will display. After reading it, you can use the corresponding methods to create and access data. You can also browse the metadata and register DOIs using this REST API.

Once you’ve set up the REST API, you’ll need to populate the table with its data. Metadata API will pull details about business objects and group them under different OData elements. The Actions and NavigationProperty elements contain relationship details and templates. The Nullable column is not included in the mapping table and will remain on the default value. After you’ve populated the table, you can use the Metadata API to fetch information about a specific object.

Exception handling

Exception handling in the REST API is the process of responding to errors. You can customize your response to handling exceptions. To do this, your method must be annotated with an @ExceptionHandler annotation. This annotation specifies the type of exception that has occurred. You can also define your logic for handling the exception, including returning it as a response. The REST API allows you to customize any response, including the body. This flexibility allows you to test your application’s response.

Various REST APIs follow similar conventions, although the fields’ names and the response body information can vary. This makes it difficult to handle errors uniformly. However, IETF developed RFC 7807 to standardize how REST APIs handle errors. This RFC contains three properties: a type field for the type of error, an instance for the specific occurrence of an error, and a message for the user.

Using an error handler in the REST API is essential in handling errors. It ensures that your program can recover errors and inform users about these. The REST API’s error handlers are implemented as subflows, and are used with standard message flow nodes. The catch and failure error handlers return an HTTP 500 Internal Server Error status code by default. The timeout error handler throws an HTTP 504 Gateway Timeout status code.