jsonp

What is jsonp?

The jsonp npm package is a simple JSONP implementation for making cross-domain requests in JavaScript. JSONP (JSON with Padding) is a technique used to overcome the limitations of the same-origin policy in web browsers, allowing you to request data from a server in a different domain.

What are jsonp's main functionalities?

Basic JSONP Request

This feature allows you to make a basic JSONP request to a specified URL. The callback function is automatically appended to the URL, and the response is handled in the provided callback function.

const jsonp = require('jsonp');

const url = 'https://api.example.com/data?callback=callbackFunction';

jsonp(url, null, function (err, data) {
  if (err) {
    console.error(err.message);
  } else {
    console.log(data);
  }
});

JSONP Request with Options

This feature allows you to make a JSONP request with additional options such as a custom callback parameter name and a timeout duration. The options object can be used to customize the request.

const jsonp = require('jsonp');

const url = 'https://api.example.com/data';
const options = { param: 'customCallback', timeout: 5000 };

jsonp(url, options, function (err, data) {
  if (err) {
    console.error(err.message);
  } else {
    console.log(data);
  }
});

Handling JSONP Errors

This feature demonstrates how to handle errors in a JSONP request. If an error occurs, it is passed to the callback function as the first argument, allowing you to handle it appropriately.

const jsonp = require('jsonp');

const url = 'https://api.example.com/data?callback=callbackFunction';

jsonp(url, null, function (err, data) {
  if (err) {
    console.error('Error occurred:', err.message);
  } else {
    console.log('Data received:', data);
  }
});

Other packages similar to jsonp

fetch-jsonp

fetch-jsonp is a JSONP implementation based on the Fetch API. It provides a similar functionality to jsonp but uses the modern Fetch API for making requests. It offers a promise-based interface, making it easier to work with asynchronous code.

jsonp-client

jsonp-client is another JSONP library that provides a simple interface for making JSONP requests. It is lightweight and easy to use, similar to jsonp, but with a slightly different API.

axios-jsonp

axios-jsonp is a JSONP adapter for the popular Axios HTTP client. It allows you to make JSONP requests using Axios, providing a consistent API for both JSONP and regular HTTP requests. This can be useful if you are already using Axios in your project.

README

jsonp

A simple JSONP implementation.

Installation

Install for node.js or browserify using npm:

$ npm install jsonp

Install for component(1) using component:

$ component install LearnBoost/jsonp

Install for browser using bower:

$ bower install jsonp

API

jsonp(url, opts, fn)

• url (String) url to fetch
• opts (Object), optional
  • param (String) name of the query string parameter to specify the callback (defaults to callback)
  • timeout (Number) how long after a timeout error is emitted. 0 to disable (defaults to 60000)
  • prefix (String) prefix for the global callback functions that handle jsonp responses (defaults to __jp)
  • name (String) name of the global callback functions that handle jsonp responses (defaults to prefix + incremented counter)
• fn callback

The callback is called with err, data parameters.

If it times out, the err will be an Error object whose message is Timeout.

Returns a function that, when called, will cancel the in-progress jsonp request (fn won't be called).

License

MIT