μ

Without μ: http://app.com/url#%7B%22lookingFor%22:%22bride%22,%22age%22:%5B25,30%5D,%22religion%22:%22Hindu%22,%22motherTongue%22:%22Bengali%22,%22onlyProfileWithPhoto%22:true%7D

With μ: http://app.com/url#bHhc9I-aqa

μ is a JavaScript library for encoding/decoding state (JavaScript object) in URL. Define a spec for the state, based on which the encoding is done. Manage the state with versioning.

Example

Import the library

import { fromJson, encode, decode } from "u-node";

Define the spec.

const spec = {
  lookingFor: ["oneOf", "bride", "groom"],
  age: ["tuple", ["integer"] /* min */, ["integer"] /* max */],
  religion: ["oneOf", "Hindu", "Muslim", "Christian", "Sikh", "Parsi", "Jain", "Buddhist", "Jewish", "No Religion", "Spiritual", "Other" ],
  motherTongue: ["oneOf", "Assamese", "Bengali", "English", "Gujarati", "Hindi", "Kannada", "Konkani", "Malayalam", "Marathi", "Marwari", "Odia", "Punjabi", "Sindhi", "Tamil", "Telugu", "Urdu"],
  onlyProfileWithPhoto: ["boolean"],
};

const v1 = fromJson(1, spec);

Encode the object/state.

const encodedv1 = encode(v1, {
  lookingFor: "bride",
  age: [25, 30],
  religion: "Hindu",
  motherTongue: "Bengali",
  onlyProfileWithPhoto: true,
});
// => 'bHhc9I-aqa'

decode([v1], encodedv1);
// => { lookingFor: 'bride', age: [25, 30], religion: 'Hindu', motherTongue: 'Bengali', onlyProfileWithPhoto: true }

Update your spec as your application state space grows. Use versioning to encode/decode state.

const newSpec = {
  ...spec,
  maritialStatus: ["oneOf", "Doesn't Matter", "Never Married", "Divorced", "Widowed", "Awaiting Divorce", "Annulled"],
};

const v2 = fromJson(2, newSpec, (old) => {
  old.maritialStatus = "Doesn't Matter";
  return old;
});

decode([v1, v2], encodedv1);
// => { lookingFor: 'bride', age: [25, 30], religion: 'Hindu', motherTongue: 'Bengali', onlyProfileWithPhoto: true, maritialStatus: "Doesn't Matter" }

const encodedv2 = encode(v2, {
  lookingFor: "bride",
  age: [25, 30],
  religion: "Hindu",
  motherTongue: "Bengali",
  onlyProfileWithPhoto: true,
  maritialStatus: "Never Married",
});
// => 'cHlc9I-aHaa'

decode([v1, v2], encodedv2);
// => { lookingFor: 'bride', age: [25, 30], religion: 'Hindu', motherTongue: 'Bengali', onlyProfileWithPhoto: true, maritialStatus: 'Never Married' }

Recursive structure

const node = {
  name: ["varchar"],
  children: ["array", ["ref", "node"]],
};

const v1 = fromJson(1, node, (a) => a, { node });

API

fromJson(version, spec, [migrate], [definitions])

• version - spec version number

• spec - used to define the structure and domain of the data.

  • structure

    • object is defined using { key: specForValue, ... }
    • array is defined using ["array", specForValue]
    • tuple is defined using ["tuple", specForValueAtIndexZero, specForValueAtIndexOne, ...]

  • domain domain is defined using [domainName, arg1, arg2, ...]

    | Domain | Args | Description | | --------- | ------------------ | --------------------------------------- | | oneOf | allowed values | similar to enum; encodes index position | | integer | | any integer | | float | | any float | | boolean | | true or false | | fixedchar | size of the string | fixed length string | | varchar | | variable length string |

• migrate (optional) - called when decoding older versions. Each subsequent version’s migrate runs in sequence.

• definitions (optional) - object mapping names to specs for recursive structures. Reference via ["ref", name].

encode(coder, object)

• coder - coder created using fromJson
• object - object to encode

decode(coders, blob)

• coders - array of coders
• blob - encoded string returned by encode