Understanding APIs Through a Restaurant Analogy
Written on
Chapter 1: What Are APIs?
APIs play a crucial role in the functionality of applications, similar to how a restaurant operates.
Imagine entering a restaurant where you are promptly seated. A waiter approaches and hands you a menu, allowing you to explore the variety of options available. After making your choice, you inform the waiter of your selections. The waiter then relays your order to the kitchen, which prepares your meal and returns it to you exactly as you requested.
This scenario serves as an effective analogy for how APIs (Application Programming Interfaces) function. In this case, you represent the application, the menu symbolizes the API, and the kitchen is the service from which the application requests data. The order placed with the waiter mirrors an API call, while the food returned is akin to the data response from the service. This data is then utilized by the application, much like you enjoy your meal. APIs serve as the connecting element between various applications across the internet.
Now, let’s clarify some common questions regarding APIs.
Section 1.1: What Exactly Is an API?
An API, or application programming interface, consists of a set of protocols and definitions designed to facilitate the building and integration of applications.
Subsection 1.1.1: Understanding API Calls
An API call refers to a request sent to a server that holds the information required for the web application.
Section 1.2: Types of APIs
Yes, there are four primary types of APIs, categorized based on the access they provide to developers:
- Public APIs are accessible to anyone.
- Partner APIs are available to businesses that have a partnership with the API provider.
- Private APIs are limited to applications developed within a specific organization, promoting data sharing among internal entities.
- Composite APIs enable multiple API calls in a single request, yielding one consolidated response.
Chapter 2: API Protocols
Various protocols, often referred to as architectures, exist for APIs:
- REST (Representational State Transfer): This is the most widely used method for developing APIs. REST operates on a client-server model, differentiating between the front end (user interface) and the back end (data processing). It does not maintain data or statuses on requests but does allow for caching to enhance performance when responses are delayed.
- RPC (Remote Procedural Call): This protocol provides a straightforward way to send and receive datasets. RPC APIs call executable actions and can utilize JSON (JavaScript Object Notation) or XML (Extensible Markup Language) for coding. This results in JSON-RPC and XML-RPC APIs.
- SOAP (Simple Object Access Protocol): Defined by the World Wide Web Consortium, SOAP is a standard used for creating web APIs, primarily employing XML. It supports communication protocols such as HTTP, SMTP, and TCP but does not enforce a specific style, allowing developers to implement APIs flexibly.
The first video titled "Making a billion dollar app in SwiftUI (tutorial) | Restaurant App Tutorial" dives into the process of building a restaurant application using SwiftUI, providing insights and practical examples.
The second video "Develop Restaurant App Using Rest API | Android Development" explores how to create a restaurant application on Android, focusing on the integration of REST APIs.
Section 2.1: JSON and XML Formats
An API call can retrieve various data formats. The following example demonstrates JSON:
{
"glossary": {
"title": "example glossary",
"GlossDiv": {
"title": "S",
"GlossList": {
"GlossEntry": {
"ID": "SGML",
"SortAs": "SGML",
"GlossTerm": "Standard Generalized Markup Language",
"Acronym": "SGML",
"Abbrev": "ISO 8879:1986",
"GlossDef": {
"para": "A meta-markup language, used to create markup languages such as DocBook.",
"GlossSeeAlso": ["GML", "XML"]
},
"GlossSee": "markup"
}
}
}
}
}
The same data can be represented in XML format as follows:
<glossary>
<title>example glossary</title>
<GlossDiv>
<title>S</title>
<GlossList>
<GlossEntry>
<ID>SGML</ID>
<SortAs>SGML</SortAs>
<GlossTerm>Standard Generalized Markup Language</GlossTerm>
<Acronym>SGML</Acronym>
<Abbrev>ISO 8879:1986</Abbrev>
<GlossDef>
<para>A meta-markup language, used to create markup languages such as DocBook.</para></GlossDef>
</GlossEntry>
</GlossList>
</GlossDiv>
</glossary>
Section 2.2: Application Data Processing
Developers can review all available API offerings prior to coding. The application requests specific data through the API, which then responds with the information in a defined format. Developers utilize this returned data, integrating it into designated areas of their applications.
Section 2.3: Real-World API Applications
A prime example of API use is in sports data for gambling or fantasy football applications. Limited sources provide real-time sports data, prompting football app developers to purchase access rights. By leveraging APIs, these developers can retrieve the necessary data and incorporate it into their applications.
Are there other instances where you notice the use of APIs? Share your thoughts in the comments!
Connect with Technologic on Twitter for more insights.
P.S. To receive my posts directly in your inbox, subscribe here! All articles are initially shared with my email list. If you enjoy Medium and want to support writers like me, consider a membership for just $5 a month. This supports us directly without any additional cost to you. Thank you immensely for your support!