Introduction

CastelAPI is a lightweight JavaScript library designed to simplify HTTP requests in web applications. It offers a clean and intuitive API for performing CRUD operations, handling loading states, caching responses, and managing retries. Whether you're building a small project or a large-scale application, CastelAPI helps streamline your API interactions. This library is framework-agnostic, so it can be used for both front-end and back-end projects. For front-end applications, it's SSR-friendly and can be used with Nuxt, Next, Nest, etc.

New Features

• [Cache Management]: This version adds two new strategies. You can now change the cache management strategy and use localStorage or sessionStorage for a front-end application. These features include a parser to make life easier for you, and it's still SSR-friendly. If window is not available, this feature won't be enabled. The cache management section has been updated.
• [TypeScript]: Better type tracking with TypeScript than in the previous version. Some changes in the build. You can now use the power of generic functions :smile: !

Table of Contents

• Installation
• Usage
  • Configuration
  • Use TypeScript to Keep Track of Types
  • GET Requests
  • POST Requests
  • PUT Requests
  • DELETE Requests
  • Loading Management
  • Cache Management
  • Retry Management
  • Transforming Responses
  • Options Type
  • Error Handling
• FAQ
  • How do I handle authentication?
  • Can I use CastelAPI with other libraries like Axios?
  • How do I enable CORS?
• Features in progress
• Contributing
• License

Key Features

• Simplified HTTP Requests: Easily perform GET, POST, PUT, DELETE, etc., requests.
• Loading Indicators: Automatically display loading indicators during requests.
• Caching: Cache request responses to improve your application's performance.
• Global Configuration: Configure global parameters such as default headers, base URL, and error handlers.
• Automatic Parser: Auto parser included to parse your data from JSON to plain JavaScript objects, text, boolean, etc.

Installation

You can install CastelAPI via NPM:

npm install castelapi

Usage

Configuration

Configuration is optional. The config object allows you to set global parameters for CastelAPI. Below are the available options:

• baseUrl: The base URL for all API requests.
• headers: Default headers to include with every request. Example:

import { apiInstance, config } from 'castelapi'

config.baseUrl = 'https://api.example.com'
config.headers = {
  'Content-Type': 'application/json',
}

Use TypeScript to Keep Track of Types

The following example demonstrates how to use TypeScript with generic functions:

// You can pass a type to the generic function
type User = { id: number; name: string }
const responseC: User = await get<User>('/endpoint')

Here how your IDE will describe this function :

(alias) get<User>(url: Endpoint<string> | string, options?: Options): Promise<ResponseWrapper<User>>
import get
// Fetches data from the specified URL.
// @param url — The endpoint or URL to fetch data from.
// @param options — The request options.
// @returns — - A promise that resolves with the fetched data.
// @throws — {Error} - Throws an error if the request fails.

GET Requests

To make a GET request, use the get function:

import { get } from 'castelapi'

async function fetchData() {
  try {
    const response = await get('https://api.example.com/endpoint')
    console.log(response)
  } catch (error) {
    console.error('Error fetching data:', error)
  }
}

fetchData()

Details:

// If the URL parameter starts with "/", it will be treated as an endpoint, and the baseUrl from the config will be added to it.

function get<T>(url: Endpoint<string> | string, options?: Options): Promise<ResponseWrapper<T>>

const response = await get('https://api.example.com/endpoint') // Works
const responseB = await get('/endpoint') // Works if config.baseUrl is set
const { data, status } = await get('/endpoint') // Destructure response from ResponseWrapper type

POST Requests

To make a POST request, use the post function:

import { post } from 'castelapi'

async function createData() {
  try {
    const data = { name: 'John Doe', age: 30 }
    const response = await post('https://api.example.com/users', {
      body: data,
    })
    console.log(response)
  } catch (error) {
    console.error('Error creating data:', error)
  }
}

createData()

function post<T>(url: Endpoint<string> | string, options?: PostOptions): Promise<ResponseWrapper<T>>

PUT Requests

To make a PUT request, use the put function:

async function updateData() {
  try {
    const data = { name: 'John Doe', age: 31 }
    const response = await put('https://api.example.com/users/1', {
      body: data,
    })
    console.log(response)
  } catch (error) {
    console.error('Error updating data:', error)
  }
}

updateData()

DELETE Requests

To make a DELETE request, use the remove function:

import { remove } from 'castelapi'

async function deleteData(id: string) {
  const parameters = new Map()
  parameters.set('id', id)
  try {
    const response = await remove('/endpoint', parameters)
    console.log(response)
  } catch (error) {
    console.error('Error deleting data:', error)
  }
}
const id = '1Ldhio1561dsfdsNUIsd'
deleteData(id)

Loading Management

To monitor the loading state of requests, use the loading function:

import { loading } from 'castelapi'

if (loading()) {
  console.log('Request is loading...')
} else {
  console.log('Request is not loading.')
}

Cache Management

You can use cache to prevent outgoing requests.

import { get } from 'castelapi'

const result = await get('/endpoint', {
  cache: { enabled: true, cacheTime: 3000 },
})
const cachedResult = await get('/endpoint')
setTimeout(async () => {
  // if cache value is expired, the request is made again
  const resultWithoutCache = await get('/endpoint')
}, 4000)

New features: cache strategy management. You can now choose what type of cache to use.

• instanceCache (Default): It should be used for SPA and back-end apps.
• localStorageCache: It should be used for front-end applications without SSR like Vue, React. If you want to keep your cache across multiple windows, see: localStorage documentation
• sessionStorageCache: It should be used for front-end applications without SSR like Vue, React. See: sessionStorage documentation

setCacheStrategy(cacheStrategy: InstanceCache | LocalStorageCache | SessionStorageCache): void

import { get, setCacheStrategy, localStorageCache } from 'castelapi'

setCacheStrategy(localStorageCache)
// Now cache used is localStorage with parser
const result = await get('/endpoint', {
  cache: { enabled: true, cacheTime: 3000 },
})
const cachedResult = await get('/endpoint')
setTimeout(async () => {
  // if cache value is expired, the request is made again
  const resultWithoutCache = await get('/endpoint')
}, 4000)

You can even use one of the three instances if you wish; they implement the cache interface with a parser included. This could be useful if you use localStorage or sessionStorage in your app:

type ResponseWrapper<T> = {
  data: T
  status: number
  url: string
}
type CachedValue<T> = ResponseWrapper<T> && {
  timeStamp: number
}

interface Cache {
  get<T>(key: string): CachedValue<T> | null
  set<T>(key: string, value: T, cacheTime: number): void
  isExpired(cachedResponse: CachedValue): boolean
  clear(): void
  delete(key: string): void
}

import { sessionStorageCache } from 'castelapi'

sessionStorageCache.set('id', { myId: 123 }, 1000)
const cachedValue = sessionStorageCache.get('id')

Retry Management

You can set an option to retry.

import { get } from 'castelapi'

// If the GET request to /endpoint fails, CastelAPI will retry 3 times.
const result = await get('/endpoint', {
  retry: 3,
})

Transforming Responses

You can transform responses before they are returned to your application.

import { config } from 'castelapi'

config.responseInterceptor = function <T>(response: ResponseWrapper<T>): ResponseWrapper<T> {
  response.data = transformData(response.data)
  return response
}

function transformData(data) {
  // Custom transformation logic
  return data
}

Options Type

Here the type option you can pass on:

type Options = {
  retry?: number
  headers?: Partial<Headers> | Record<string, string> | null | undefined
  method?: string
  parameters?: Map<string, any>
  cache?: { enabled: boolean; cacheTime: number }
}

type PostOptions = Options & {
  body?: Record<string, any>
}

Error Handling

CastelAPI throws errors for network issues, server errors, and other request failures. You can catch these errors using try-catch blocks.

Example:

import { get } from 'castelapi'

async function fetchData() {
  try {
    const response = await get('https://api.example.com/endpoint')
    console.log(response)
  } catch (error) {
    if (error instanceof NetworkError) {
      console.error('Network error:', error.message)
    } else if (error instanceof ServerError) {
      console.error('Server error:', error.message)
    } else {
      console.error('Unexpected error:', error)
    }
  }
}

fetchData()

FAQ

How do I handle authentication?

You can set authentication headers in the global configuration.

import { config } from 'castelapi'

config.headers = {
  Authorization: 'Bearer YOUR_API_KEY',
}

Can I use CastelAPI with other libraries like Axios?

yes, but CastelAPI is a standalone library for managing HTTP requests, and it does not depend on Axios or other libraries.

How do I enable CORS?

CORS must be enabled on the server-side. CastelAPI does not handle CORS directly.

For any other questions, feel free to open an issue on GitHub.

Features in progress

-Custom Request Interceptors -timeout config -disable parser with config -disable parser with option -expose parser

Contributions

Contributions are welcome! Here's how you can contribute:

1. Report Issues: If you find a bug, please open an issue on GitHub.
2. Suggest Features: If you have an idea for a new feature, please suggest it in the issues section.
3. Submit Pull Requests: If you'd like to contribute code, please fork the repository and submit a pull request.
4. Improve Documentation: Help us improve this documentation by suggesting changes or adding more examples.

License

This project is licensed under the MIT License - see the LICENSE file for details.