How to encode and parse / decode a nested query string Javascript - urlencode

Question

I'm sending form data from React Hook Form to Netlify via their submission-created function. I don't have any problem with encoding individual form field values, but now I'm trying to encode an array of objects.
Here is an example of my form data:
{
_id: "12345-67890-asdf-qwer",
language: "Spanish",
formId: "add-registration-form",
got-ya: "",
classType: "Private lessons",
size: "1",
days: [
{
day: "Monday",
start: 08:00",
end: "09:30"
},
{
day: "Wednesday",
start: "08:00",
end: "09:30"
}
]
}
The only problem I have is with the "days" array. I've tried various ways to encode this and this is the function I've currently been working with (which isn't ideal):
const encode = (data) => {
return Object.keys(data).map(key => {
let val = data[key]
if (val !== null && typeof val === 'object') val = encode(val)
return `${key}=${encodeURIComponent(`${val}`.replace(/\s/g, '_'))}`
}).join('&')
}
I tried using a library like qs to stringify the data, but I can't figure out how to make that work.
And here is the function posting the data to Netlify:
// Handles the post process to Netlify so I can access their serverless functions
const handlePost = (formData, event) => {
event.preventDefault()
fetch(`/`, {
method: "POST",
headers: { "Content-Type": "application/x-www-form-urlencoded" },
body: encode({ "form-name": 'add-registration-form', ...formData }),
})
.then((response) => {
if(response.status === 200) {
navigate("../../")
} else {
alert("ERROR!")
}
console.log(response)
})
.catch((error) => {
setFormStatus("error")
console.log(error)
})
}
Finally, here is a sample of my submission-created file to receive and parse the encoded data:
const sanityClient = require("#sanity/client")
const client = sanityClient({
projectId: process.env.GATSBY_SANITY_PROJECT_ID,
dataset: process.env.GATSBY_SANITY_DATASET,
token: process.env.SANITY_FORM_SUBMIT_TOKEN,
useCDN: false,
})
const { nanoid } = require('nanoid');
exports.handler = async function (event, context, callback) {
// Pulling out the payload from the body
const { payload } = JSON.parse(event.body)
// Checking which form has been submitted
const isAddRegistrationForm = payload.data.formId === "add-registration-form"
// Build the document JSON and submit it to SANITY
if (isAddRegistrationForm) {
// How do I decode the "days" data from payload?
let schedule = payload.data.days.map(d => (
{
_key: nanoid(),
_type: "classDayTime",
day: d.day,
time: {
_type: "timeRange",
start: d.start,
end: d.end
}
}
))
const addRegistrationForm = {
_type: "addRegistrationForm",
_studentId: payload.data._id,
classType: payload.data.classType,
schedule: schedule,
language: payload.data.language,
classSize: payload.data.size,
}
const result = await client.create(addRegistrationForm).catch((err) => console.log(err))
}
callback(null, {
statusCode: 200,
})
}
So, how do I properly encode my form data with a nested array of objects before sending it to Netlify? And then in the Netlify function how do I parse / decode that data to be able to submit it to Sanity?

Answer 1

So, the qs library proved to be my savior after all. I just wasn't implementing it correctly before. So, with the same form data structure, just make sure to import qs to your form component file:
import qs from 'qs'
and then make your encode function nice and succinct with:
// Transforms the form data from the React Hook Form output to a format Netlify can read
const encode = (data) => {
return qs.stringify(data)
}
Next, use this encode function in your handle submit function for the form:
// Handles the post process to Netlify so we can access their serverless functions
const handlePost = (formData, event) => {
event.preventDefault()
fetch(`/`, {
method: "POST",
headers: { "Content-Type": "application/x-www-form-urlencoded" },
body: encode({ "form-name": 'add-registration-form', ...formData }),
})
.then((response) => {
reset()
if(response.status === 200) {
alert("SUCCESS!")
} else {
alert("ERROR!")
}
console.log(response)
})
.catch((error) => {
console.log(error)
})
}
Finally, this is what your Netlify submission-created.js file should look like more or less:
const sanityClient = require("#sanity/client")
const client = sanityClient({
projectId: process.env.GATSBY_SANITY_PROJECT_ID,
dataset: process.env.GATSBY_SANITY_DATASET,
token: process.env.SANITY_FORM_SUBMIT_TOKEN,
useCDN: false,
})
const qs = require('qs')
const { nanoid } = require('nanoid');
exports.handler = async function (event, context, callback) {
// Pulling out the payload from the body
const { payload } = JSON.parse(event.body)
// Checking which form has been submitted
const isAddRegistrationForm = payload.data.formId === "add-registration-form"
// Build the document JSON and submit it to SANITY
if (isAddRegistrationForm) {
const parsedData = qs.parse(payload.data)
let schedule = parsedData.days
.map(d => (
{
_key: nanoid(),
_type: "classDayTime",
day: d.day,
time: {
_type: "timeRange",
start: d.start,
end: d.end
}
}
))
const addRegistrationForm = {
_type: "addRegistrationForm",
submitDate: new Date().toISOString(),
_studentId: parsedData._id,
classType: parsedData.classType,
schedule: schedule,
language: parsedData.language,
classSize: parsedData.size,
}
const result = await client.create(addRegistrationForm).catch((err) => console.log(err))
}
callback(null, {
statusCode: 200,
})
}