Fetch class

An ES6 wrapper class for simplified fetch API requests.

Example

This example shows you how to extend the fetch class and create an instances with different URL prefixes.

JavaScript

import Fetch from 'fetch-class'

let apis = {
    local:       new Fetch(), // Instance with no prefix
    placeholder: new Fetch('http://jsonplaceholder.typicode.com') // Instance with jsonplaceholder prefix
}

apis.placeholder.get('/posts/', (response) => {
    // Application logic to deal with array of posts from http://jsonplaceholder.com/posts/
})


apis.local.get('/posts/', (response) => {
    // Application logic to deal with array of posts from local server - /posts/
})

Parameters

baseUrl

Base URL prefix for all instance requests.

defaultOptions

Default options for all instance requests. Supports all options defined in the fetch API documentation, not listed here.

• method: Request method - GET, POST, PUT, PATCH, DELETE
• data: Data to add to request body or query string, depending on request type
• queryParams: Associative object of properties to add to the query string, regardless of request method
• alwaysTriggerCallback: Trigger the callback, even if request fails
• callback: Callback to trigger when request completes - is provided with the promise, response and what's provided in extraCallbackParams option
• extraCallbackParams: Extra parameters to provide to the callback arguments object
• headers: HTTP headers object to set on the request

Defaults

{
    method:                'GET',
    data:                  {},
    queryParams:           {},
    alwaysTriggerCallback: false,
    callback:              undefined,
    extraCallbackParams:   {},
    headers: {
        'Accept':       'application/json',
        'Content-Type': 'application/json'
    }
}

Controls

Public control methods to be accessed on an instance are as follows:

request

Perform a request with the provided URL and options.

get

Perform a GET request with the provided URL and options.

post

Perform a POST request with the provided URL and options.

put

Perform a PUT request with the provided URL and options.

patch

Perform a PATCH request with the provided URL and options.

del

Perform a DELETE request with the provided URL and options.

Events

The class triggers the following events:

request:pre

Triggered before request is sent.

Receives

{
    url:     url,    // URL to send request to - appended to the instance's base URL
    options: options // Request options
}

request:post

Triggered before request is sent.

Receives

{
    url:     url,     // URL to send request to - appended to the instance's base URL
    options: options, // Request options
    args:    args     // Callback arguments object
}