Imagine this: you launched a website. And now, you don’t know what to do with a connection bandwidth limitation. Or maybe you use AJAX and have too many requests to cache. Or the system implies significant scaling, and you are worried about its security. Or you need to configure the interaction between a website and a mobile app based on the website. And you don't know how to deal with it.

It might sound scary. Yet, the solution for it is the REST API WordPress plugin. No, it is not another terrifying technical term (well, it’s technical, but not that terrifying as it might seem). You need the JetEngine REST API.

Let me tell you why:

• it ensures smooth scalability of system or app components interaction;
• the similarity of the interfaces;
• independent components incorporation;
• intermediate components that reduce delay and enhance security. 

And now, let’s start from the very beginning.

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What Is WordPress REST API?

In case you know nothing about it

Imagine you are developing some kind of big web application, for instance, a social network or email marketing service. At the initial stage, everything may be fine. Yet, as soon as it comes to the point where it is necessary to allow some other services or apps to interact with yours, the problems may appear.

Suppose you need to enable the users to change the settings of your web app through a third-party mobile app. Or, probably, you want to display some internal parts of the app on third-party sites. If you are developing a social network, you may need to showcase the number of subscribers in a certain group on a particular website. 

How can you enable another app or website to request the info from your web server so that it can display it? How to ensure your app can communicate with an external database, save and get some data from there?

In order to make this possible, your service needs some kind of interface that will provide all third-party apps with the opportunity to receive data from the server, update and exchange them.

But here we have a problem: the systems that need to interact in this client-server data structure can be very different. Each client can use its own programming language, operating system, etc., so it is quite difficult to share data with all these systems smoothly.

How can you make all these systems understand each other even if they speak different languages? If these systems are able to work using HTTP over the internet, the so-called REST can help solve the problem of attaching these different systems.

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If you heard something about REST API WordPress plugin

REST (REpresentational State Transfer) is the architecture, that is, the principles of constructing distributed hypermedia systems (World Wide Web), including universal methods for processing and transferring resource states via HTTP.

In fact, the REST API WordPress plugin defines a set of rules for writing code. There are 6 basic rules, how the developer organizes the writing of the application server code so that all systems exchange data smoothly and can be easily scaled and enlarged. The application code can either comply with these rules (the so-called RESTful service) or not.

For a distributed system to be considered REST-designed (Restful) architecture, it must meet the following criteria:

• Client-Server. The system must be divided into clients and servers. Interface splitting means that, for example, clients are not associated with the storage that remains within each server, so that the mobility of the client code is improved. Servers are not associated with a user interface or state, so servers can be simpler and scalable. Servers and clients can be replaced and developed independently until the interface changes.
• Stateless. The server must not store any client information. The request has to contain all critical information for processing the request and, if necessary, identifying the client.
• Cache․ Each response must be marked as cached or not to prevent clients from reusing out-of-date or incorrect data in response to further requests.
• Uniform Interface. A single interface defines the interface between clients and servers. It simplifies and splits the architecture that allows each part to develop independently.

Of course, you can exchange data with different services without REST. In this case, you may have difficulty communicating between these devices. REST is a standard that brings everything into line, and devices can exchange the data without problems.

If you have developed RESTful, you will have a list of URLs that you can use to communicate with your web server. The server can use them to receive, update, add, or delete data. Using the list of such addresses, you provide a particular interface, which other services can interact with.

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Where This Is All Starting: What is API?

I can’t go further without shedding the light on the API itself. So, all those tech-savvy guys who know everything about it, you may skip this part and jump straight to the “How Rest API WordPress Plugin Works” part.

Now, talking about the API. There is much debate around this explanation because it is:

• not a specification (can be modified);
• not a protocol (doesn’t belong to them);
• not HTTP (too different).

That's why there are so many questions. So what is API? It is a kind of human-made architecture that is created using constraints and extensions. Its tasks are to represent the transmission state. From its name, it becomes clear how well-developed software should work. Even a network of pages can be considered as a finite-state machine:

• the user sees the first index message;
• using software, follows the link;
• gets the result on the screen.

So, API is a web application that represents resources in a format suitable for other computers and includes different interfaces.

Those options that are used for broadcasting can also be considered as web services. The client, using it, can request anything, and the server responds and provides results. It uses any convenient programming language or suitable platforms, no matter which one was used.

It is generally the best part of everything created in the IT world. Since APIs don’t depend on languages, they can be combined with a variety of systems. When the API is documented, it doesn’t matter what the developers used when creating it — Ruby, Java, Python, or something fundamentally different. All requests are sent through the same HTTP, and solutions come in the same way.

The fact is that this protocol is used precisely to implement transmission; this is a kind of template. The server can speak any programming language; it analyzes in its own way, while itself is not dependent on them, so the incoming and outgoing information is similar.

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REST in terms of sources

If you use this data view type, you need to think about the application from the resource component position. It is necessary to determine which you would like to show to the outside world and other users. When the protocol-fitting parts are selected, the service is implemented in the following way:

• How the exchange is performed — it defines limitations. You can choose JSON as the most popular one, but no one forbids using others, such as XML.
• How the broadcast is provided — all packets are transported via HTTP (REST API WordPress plugin is always built on it).
• How the service is defined — there is no single standard; the architecture is flexible and adaptable. In some scenarios, this turns out to be a rather critical drawback. You may need to understand the formats in which requests and responses are sent. But it is a convenient mechanism where the programming languages of web apps and sites are widely used.

If you are still confused, feel free to check the WordPress REST API Handbook for additional clarifications.

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HTTP component structure

The websites on the REST API example are built according to a specific structural scheme. It has:

• a string — it defines the type of message broadcasting;
• a header — it describes what the body of future text looks like, with what parameters it is planned to transfer the data packet and other important information;
• a message itself — it is an optional field and can be ignored.

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JSON: what is it

Each guide indicates that JSON is the format in which the information a person can read is stored. The file contains only text, and the extension is the same as the paragraph title. JSON stores structured data and transfers it from the server to the client and back. These packages are a simpler alternative to another extension with similar functionality — XML.

Also, JSON is used to achieve asynchronous data loading, necessary for the sites to update their media files without reloading the page.

Now JSON is a very popular format because it takes up less space, and productivity grows several times with it. Using JSON, the users request information from other domains applying script-type tags. No other features can be enabled because there are domain restriction rules.

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How REST API WordPress Plugin Works

Now we are going to understand how the REST API WordPress plugin operates. The essence of the framework is a pair of actions, depending on the type of request. The functionality and capabilities of the architecture depend on the server. There are 4 main types of information:

• GET — to read more information about what is being asked. After receiving the data, GET returns and provides the resource as XML or JSON. If an error is detected, error 404 (not found) or 400 (bad register) will appear.
• POST — if you want to create a new or nested site or page. When organizing a new one, the requirement moves to the parent content and assumes the responsibility to organize communication.
• PUT — update what already exists. The body must have updated data from the original site. Use the previous option to create new instances.
• DELETE — erase an existing object that has a specific URL. If everything is successful, code 200 is returned along with the reaction containing the remote item. Another possible option is 204 if there is no body. When this query is executed, the resource is deleted.

As a package, a JSON array is usually sent to a specific URL. A so-called function is triggered there, and depending on the data already sent and the current request, a certain action begins.

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JetEngine’s REST API

JetEngine’s REST API feature can replace any full-fledged REST API WordPress plugin and guarantees everything I mentioned above. Yet, among other things, this feature has some unique functionality that I will promote shamelessly.

REST API Listings

It is a separate module, which will help you to display the data from third-party REST API via JetEngine’s Listing Grid widget. You can query the Grid easily, defining Endpoint Parameters, and pull the data from the Custom Content Types database. 

Let’s dive in some other features:

• you can register new endpoint connections using the specific module;
• configure the endpoint URL to get data from it;
• set the path to a particular items list in the API;
• define the authentication parameters for the users if they want to submit personal requests;
• try a test request to check the connection and configure API connection;
• cache the API responses automatically to save time on the repeated server requests;
• display the REST API Endpoint data in the listings, using Text, Date, and Radio meta field types;
• apply Lazy Load option to ensure stable page speed;
• style dynamic widgets and listing grids that display your REST API data.

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REST API Endpoint Management for CCT

Using this functionality, you can activate/deactivate multiple endpoints to CCT. With the help of this method, it is possible to get the list of the necessary CCT items, add new, edit or delete the required ones from the database remotely.

The features of REST API Endpoint Management for CCT is as follows:

• manage access for a particular Endpoint — make it accessible only to logged-in users, or leave it public;
• use one of the available HTTP methods to manage CCT items: Register CREATE item REST API Endpoint; Register UPDATE item REST API Endpoint; Register DELETE item REST API Endpoint; Register GET item REST API Endpoint;
• apply additional options to search string, sort the items and define the sorting order (ascending/descending), field type to sort, filter a custom query in JSON format.

More info on how to add and edit CCT remotely with REST API is in Crocoblock’s Knowledge Base.

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REST API Notifications/Actions for Forms

With this feature, you can integrate JetEngine Forms and any API to send the submitted data to the required URL. All the data submitted in the form are easily managed by the HTTP actions we already knew: GET, POST, PUT, and DELETE.

• make the Endpoint URL dynamic with the relevant macros;
• use visual JSON editor to customize the request’s body and meet the API standards to get the data in the required format;
• set the authorization parameters for the users to submit personal requests.

Read how and where you can apply JetEngine’s REST API in Crocoblock’s blog.

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Instead of Conclusions — REST API Benefits

• No additional internal layers, which means sending data in the same form as the data itself. I.e., the data is not wrapped in XML, as SOAP and XML-RPC do it; AMF is not used (Flash), etc.
• Each unit of information (resource) is uniquely defined by the URL. It means that the URL is essentially the primary key for the data unit. Moreover, it doesn’t matter what format the data at the address is — it can be HTML and JPEG, and a Microsoft Word document.
• The data protocol defines how resource information is managed entirely. The most common protocol is, of course, HTTP. For HTTP, the data action is set using the methods GET, PUT, POST, DELETE. Thus, Create-Read-Update-Delete (CRUD) actions can be performed with all 4 methods, or only with GET and POST.

As you can see, REST API plays a decisive role in cases where the loading speed is paramount. JetEngine’s REST API functionality provides both high responsiveness and unique features for managing your data effortlessly. Besides it, JetEngine provides a set of tools for creating dynamic websites and developing complex site structures — don’t hesitate to try it. With this feature, you can integrate JetEngine Forms and any API to send the submitted data to the required URL. All the data submitted in the form are easily managed by the HTTP actions we already knew: GET, POST, PUT, and DELETE.

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