JSONUI

This is a Json markup language to define User Interface as a canvas where you can draw with Json definition.

When you change the Json definition, the interface immediately reflects on what you defined/changed.

Actually JSONUI is available for react and react-native. It will be able to integrate to 99% of the cross-platform environments, thanks for reactjs ecosystem

The UI definition contains a layout definition and components configuration as well. The most important it has a built in state management system. Data can be persistent or not, depends on the name of the store.

Core concept

Build a data driven UI. The "definition" is changeable by developer anytime and any reason. If you would like to build a remote controlled app or a form generator app, I hope you will love it.

Installation

npm install @jsonui/reactnative @react-native-async-storage/async-storage

yarn add @jsonui/reactnative @react-native-async-storage/async-storage

Basic Usage

The JsonUI Component is a canvas and the model parameter contains the UI definition in Json format.

import {JsonUI} from '@jsonui/reactnative';

const Canvas = () => <JsonUI model={
    { "$comp": "Text",
      "$children": "Hello World",
      "style": { "fontSize": 30 }
    } />

How it works

The Json Markup language has 3 important part

1, Components

The "$comp" key represents the name of a predefined react component. The predefined components:

• View: it's a simple View component in react-native
• Button: it's a simple Button component in react-native
• Fragment: it's a simple React.Fragment react component
• Image: it's a simple Image component in react-native
• Text: it's a simple Text component in react-native

The props of the components are the same as in the normal react world.

The "$children" key represents the children of the component. It can be array, object or primitive like text, number, boolean

{ "$comp": "Text", "$children": "Hello World" }
{ "$comp": "Text", "$children": 124 }
{ "$comp": "Text", "$children": [1,2,3] }
{ "$comp": "Text", "$children": null }
{ "$comp": "View", "$children": [
   { "$comp": "Text", "$children": "Hello World" }
  ]
}

2, Actions

When the component has an interaction with user or a triggered event, the "$action" key will represent it, for example onClick, onChange or onPress

{ "$comp": "Button", "$children": "Login", "onPress": { "$action": "navigate", "route": "LoginPage" } }

The action is really a predefined function when it will fire, when the event has triggered.

3, Modifiers

The "$action" can add a dynamic value for properties or components. It's a function which will be called at render time of the component. Depends on environment data. For example JSONUI contains a basic internalisation solution.

{ "$comp": "Text", "$children": "Hello World" }
{ "$comp": "Text", "$children": { "$modifier": "t", "key": "Helló Világ" } }

How can you customise it?

Easily.

const Canvas = () => <JsonUI model={jsonData}
  "components"={
    {
     nagivate: ({route}) => navigate(route)
    }
  }
  "functions"={
    {
     t: ({key}) => t(key)
    }
  }/>

State management or data storage

The state management is another layer of the JSNOUI. It's represent a permissive and dynamic tree graf structure. Like a JSON file. Each app has a separated data space, based on the id param of JsonUI component. Each app has multiple store represent multiple data tree or separate storage. Actually the data store is persistent. (it will be configurable soon if there is interest in it) You can define unlimited data store. What you need is, just use a specific name in JSON Definition, and it will automatically create at the first use. JSONUI use json-pointer to tell the path what kind of data we need.

We have 2 built-in function which can help to read and write your state management.

Let's see some example

Read data

Your data store Looks like:

{ "users": [{ "username": "John Doe" }] }

Use /username in text field

{ "$comp": "Text", "$children": { "$modifier": "get", "store": "data", "path": "/users/0/username" } }

Write data

When the user click on the button, it will modify the data

{ "$comp": "Button", "$children": "Change username", "onPress": { "$modifier": "set", "store": "data", "path": "/users/0/username", "value": "John Doe 2" } }

Data will be:

{ "users": [{ "username": "John Doe2" }] }

A simple input field solution

{
  "$comp": "Input",
  "value": { "$name": "get", "store": "questionnaire1", "path": "/firstName" },
  "onChange": { "$action": "set", "store": "questionnaire1", "path": "/firstName" }
}

You can manipulate the data when read or write it with jsonata.

{ "$comp": "Text", "children": { "$modifier": "get", "store": "data", "path": "/prevNumber", "jsonataDef": "'Next Number: ' & (1+$)" } }

Advanced technique

Relative, absolute

You can use absolute, relative path and ./ ../ still works. few examples

{  "path": "/prevNumber" }
{  "path": "prevNumber" }
{  "path": "../prevNumber" }
{  "path": "../../prevNumber" }

List

Somethimes we need to handle dynamic data for example a list.

Your data store looks like:

{ "subscribed": { "list": [{ "name": "John Doe" }] } }

{
  "$comp": "Fragment",
  "isList": true,
  "$pathModifiers": {
    "data": { "path": "/subscribed/list" }
  },
  "listItem": {
    "$comp": "Input",
    "value": { "$modifier": "get", "store": "data", "path": "name" },
    "onChange": { "$action": "set", "store": "data", "path": "name" }
  }
}

This little technique can change the relative path nestedly as well.

LICENSE MIT

Copyright (c) 2022 Istvan Fodor.