obj-serialize
is a library containing utility functions and building blocks in to serialize objects to be passed around to another context, between applications or between APIs.
but what does the library description mean...?
Let's take a Next.js for an example and let's assume you have some kind of service that queries your database and returns some data about dogs.
// services/get-dogs.js
const dogs = [
{
name: 'fafik',
size: 'small',
birth: new Date('1995-12-17T03:24:00'),
},
{
name: 'pimpek',
size: 'big',
birth: new Date('1995-12-17T03:24:00'),
},
]
export function getDogs(size) {
// In real world scenario, this probably will be a call to the database
return dogs.filter(({ size: dogSize }) => dogSize === size)
}
Then you want to execute this service and pass the data to your frontend application via getServerSideProps
// pages/index.js
import { getDogs } from 'services/get-dogs'
export async function getServerSideProps() {
const smallDogs = getDogs('small')
return {
props: {
smallDogs,
},
}
}
export default function Home({ smallDogs }) {
return <div>hello {smallDogs[0].name}</div>
}
Next.js won’t serialize Date
object that is present in the smallDogs
variable. It can only serialize JSON serializable data types.
The error when opening the home page would look like this:
Caution
Error: Error serializing .smallDogs[0].birth
returned from getServerSideProps
in “/“.
Reason: object
(“[object Date]”) cannot be serialized as JSON. Please only return JSON serializable data types.
Here comes the obj-serialize
library. You can just do
import { nextServerSideSerialize } from 'obj-serialize'
and use it somewhere in your code in order to make any object viable for Next.js to pass around!
// pages/index.js
import { nextServerSideSerialize } from 'obj-serialize'
import { getDogs } from '../services/get-dogs'
export async function getServerSideProps() {
const smallDogs = getDogs('small')
return {
props: {
smallDogs: smallDogs.map((dog) => nextServerSideSerialize(dog)),
},
}
}
export default function Home({ smallDogs }) {
return <div>siema {smallDogs[0].name}</div>
}
This will work flawlessly ✅
Apart from providing out-of-the-box working utility for serialisation that takes place in Next.js applications, the obj-serialize
also provides option to create your own serializers.
All you have to do is to import base building block of the library (serialize
function) and use it as you want.
import { serialize } from 'obj-serialize'
The function accepts data to be serialized as a first parameter and serialization rules as the second parameter. The rules parameter is nothing else but function that is used to “walk” through the object, be executed for each occurrence and eventually convert unserialized data into proper one by returning it.
Note
ℹ️ There is a special value called SkipSerialization
. It is a unique token that is intended to be used when serialisation traverse does not meet any condition in your serialisation rules and you just need to skip the process for particular case. It has to be this token and not null
or undefined
since these two can also have impact on desired data after the serialization.
Let’s assume that you want to convert all Date
objects not toISOString()
(as nextServerSideSerialize does) but rather toLocaleString()
.
import { serialize, SkipSerialization } from 'obj-serialize'
export function customSerialize(data) {
return serialize(data, (unserializedData) => {
if (unserializedData instanceof Date) {
return unserializedData.toLocaleString()
} else {
return SkipSerialization
}
})
}
and thats all! Now you can use your own serializer in the same way as presented here
The project is licensed under the MIT License. All contributions are welcome