Convert JS Object to form data

Question

How can I can convert my JS Object to FormData?

The reason why I want to do this is, I have an object that I constructed out of the ~100 form field valu

Answer 1

Recursively

const toFormData = (f => f(f))(h => f => f(x => h(h)(f)(x)))(f => fd => pk => d => {
  if (d instanceof Object) {
    Object.keys(d).forEach(k => {
      const v = d[k]
      if (pk) k = `${pk}[${k}]`
      if (v instanceof Object && !(v instanceof Date) && !(v instanceof File)) {
        return f(fd)(k)(v)
      } else {
        fd.append(k, v)
      }
    })
  }
  return fd
})(new FormData())()

let data = {
  name: 'John',
  age: 30,
  colors: ['red', 'green', 'blue'],
  children: [
    { name: 'Max', age: 3 },
    { name: 'Madonna', age: 10 }
  ]
}
console.log('data', data)
document.getElementById("data").insertAdjacentHTML('beforeend', JSON.stringify(data))

let formData = toFormData(data)

for (let key of formData.keys()) {
  console.log(key, formData.getAll(key).join(','))
  document.getElementById("item").insertAdjacentHTML('beforeend', `
${key} = ${formData.getAll(key).join(',')}
`)
}