06-Change-Serialization.md

name	order
Change the serialization functions	6

Change the serialization functions

The library allow different serialization functions to use to transform input data into string before saving then in the storage.

• The default serialization library since version 2.0.0 is @macfja/serializer.
• In the version 1.3.0 the serializer was esserializer.
• In versions before 1.3.0 the serializer was the Native JSON serialization.

Serialization functions signature

To change the serialization, you need to use setSerialization from @macfja/svelte-persistent-store.

declare function setSerialization(
    serializer: (data: any) => string,
    deserializer: (input: string) => any,
    addSerializableClass?: (classConstructor: FunctionConstructor) => void
): void

• The serializer parameter MUST be a function that take one parameter which is the data to transform, and MUST return a string.
• The deserializer parameter MUST be a function that take one parameter which is the serialized data to revert, and MUST return tha original data.
• The addSerializableClass parameter is optional. It's a function that take one parameter which is a class.

Examples

Using JSON for serialization

import { setSerialization } from "@macfja/svelte-persistent-store"

setSerialization(JSON.stringify, JSON.parse)

Using esserializer for serialization

import { setSerialization } from "@macfja/svelte-persistent-store"
import ESSerializer from "esserializer"

const allowed = []
setSerialization(
    ESSerializer.serialize,
    (data) => ESSerializer.deserialize(data, allowed),
    (aClass) => allowed.push(aClass)
)

Using esserializer for serialization as it was implemented in 1.3.0

import { setSerialization } from "@macfja/svelte-persistent-store"
import ESSerializer from "esserializer"

const allowedClasses = []
setSerialization(
    ESSerializer.serialize,
    (value) => {
        if (value === "undefined") {
            return undefined
        }

        if (value !== null && value !== undefined) {
            try {
                return ESSerializer.deserialize(value, allowedClasses)
            } catch (e) {
                // Do nothing
                // use the value "as is"
            }
            try {
                return JSON.parse(value)
            } catch (e) {
                // Do nothing
                // use the value "as is"
            }
        }
        return value
    },
    (classDef) => {
        allowedClasses.push(classDef)
    }
)

Using @macfja/serializer for serialization

import { setSerialization } from "@macfja/svelte-persistent-store"
import { serialize, deserialize, addGlobalAllowedClass } from "@macfja/serializer"

setSerialization(serialize, deserialize, addGlobalAllowedClass)