append-field

What is append-field?

The append-field npm package is designed to facilitate the manipulation of form data, specifically for appending fields to an existing FormData instance. It is particularly useful in scenarios where you need to dynamically add fields to FormData before submitting it, such as in file uploads or when dealing with complex form structures.

What are append-field's main functionalities?

Appending fields to FormData

This feature allows you to append a new field to an existing FormData object. The code sample demonstrates how to append a simple key-value pair to FormData.

const appendField = require('append-field');
let formData = new FormData();
appendField(formData, 'key', 'value');

Appending nested fields to FormData

This feature enables appending nested fields to FormData, which is useful for representing complex data structures. The code sample shows how to append nested fields to represent a user's name and email.

const appendField = require('append-field');
let formData = new FormData();
appendField(formData, 'user[name]', 'John Doe');
appendField(formData, 'user[email]', '[e-mail]');

Other packages similar to append-field

form-data

The form-data package is similar to append-field in that it is used to create and manipulate FormData objects. However, form-data provides a broader set of functionalities for handling FormData, including the ability to directly append files and streams, making it more suitable for file uploads.

formidable

Formidable is another package that deals with form data but from a different angle. It is primarily focused on parsing incoming form data, especially file uploads. While append-field is about appending data to FormData, formidable excels in extracting and processing data from incoming forms.

README

append-field

A W3C HTML JSON forms spec compliant field appender (for lack of a better name). Useful for people implementing application/x-www-form-urlencoded and multipart/form-data parsers.

It works best on objects created with Object.create(null). Otherwise it might conflict with variables from the prototype (e.g. hasOwnProperty).

Installation

npm install --save append-field

Usage

import appendField from 'append-field'

const obj = Object.create(null)

appendField(obj, 'pets[0][species]', 'Dahut')
appendField(obj, 'pets[0][name]', 'Hypatia')
appendField(obj, 'pets[1][species]', 'Felis Stultus')
appendField(obj, 'pets[1][name]', 'Billie')

console.log(obj)

{ pets:
   [ { species: 'Dahut', name: 'Hypatia' },
     { species: 'Felis Stultus', name: 'Billie' } ] }

API

appendField(store, key, value)

• store (object, required)
• key (string, required)
• value (any, required)

Adds the field named key with the value value to the object store.

License

MIT