json-edit-react

json-edit-react

A React component for editing or viewing JSON/object data

Features include:

• edit individual values, or whole objects as JSON text
• fine-grained control over which elements can be edited, deleted, or added to
• customisable UI, through simple, pre-defined themes, or specific CSS overrides
• self-contained — rendered with plain HTML/CSS, so no dependance on external UI libraries
• provide your own custom component to integrate specialised UI for certain data.

Explore the Demo

• Installation
• Implementation
• Usage
• Props overview
• Update functions
  • Copy function
• Filter functions
  • Examples
• Themes
  • Fragments
  • A note about sizing and scaling
  • Icons
• Localisation
• Custom nodes
• Undo functionality
• Issues, bugs, suggestions?
• Roadmap
• Inspiration
• Changelog

Installation

npm i json-edit-react

or

yarn add json-edit-react

Implementation

import { JsonEditor } from 'json-edit-react'

// In your React components:
<JsonEditor
  data={ myData }
  onUpdate={ ({newData} ) => {
    // Set "myData" state, plus
    // any desired side-effects.
}}
{ ...otherProps } />

You are responsible for maintaining the data state — in your onUpdate function, use the newData property to set data, which should update inside the editor.

Usage

(for end user)

It's pretty self explanatory (click the "edit" icon to edit, etc.), but there are a few not-so-obvious ways of interacting with the editor:

• Double-click a value (or a key) to edit it
• When editing a string, use Cmd/Ctrl/Shift-Enter to add a new line (Enter submits the value)
• It's the opposite when editing a full object/array node (which you do by clicking "edit" on an object or array value) — Enter for new line, and Cmd/Ctrl/Shift-Enter for submit
• Escape to cancel editing
• When clicking the "clipboard" icon, holding down Cmd/Ctrl will copy the path to the selected node rather than its value

Props overview

The only required value is data.

prop	type	default	description
data	object|array		The data to be displayed / edited
rootName	string	"data"	A name to display in the editor as the root of the data object.
onUpdate	UpdateFunction		A function to run whenever a value is updated (edit, delete or add) in the editor. See Update functions.
onUpdate	UpdateFunction		A function to run whenever a value is edited.
onDelete	UpdateFunction		A function to run whenever a value is deleted.
onAdd	UpdateFunction		A function to run whenever a new property is added.
enableClipboard	boolean|CopyFunction	true	Whether or not to enable the "Copy to clipboard" button in the UI. If a function is provided, true is assumed and this function will be run whenever an item is copied.
indent	number	4	Specify the amount of indentation for each level of nesting in the displayed data.
collapse	boolean|number|FilterFunction	false	Defines which nodes of the JSON tree will be displayed "opened" in the UI on load. If boolean, it'll be either all or none. A number specifies a nesting depth after which nodes will be closed. For more fine control a function can be provided — see Filter functions.
restrictEdit	boolean|FilterFunction	false	If false, no editing is permitted. A function can be provided for more specificity — see Filter functions
restrictDelete	boolean|FilterFunction	false	As with restrictEdit but for deletion
restrictAdd	boolean|FilterFunction	false	As with restrictEdit but for adding new properties
restrictTypeSelection	boolean|DataType[]|TypeFilterFunction	false	For restricting the data types the user can select. This varies slightly from the above restrictions in that the value (or output of the TypeFilterFunction) can be a list of data types or a boolean.
keySort	boolean|CompareFunction	false	If true, object keys will be ordered (using default JS .sort()). A compare function can also be provided to define sorting behaviour.
showArrayIndices	boolean	true	Whether or not to display the index (as a property key) for array elements.
showCollectionCount	boolean|"when-closed"	true	Whether or not to display the number of items in each collection (object or array).
defaultValue	any	null	When a new property is added, it is initialised with this value.
stringTruncate	number	250	String values longer than this many characters will be displayed truncated (with ...). The full string will always be visible when editing.
translations	LocalisedStrings object	{ }	UI strings (such as error messages) can be translated by passing an object containing localised string values (there are only a few). See Localisation
theme	string|ThemeObject|[string, ThemeObject]	"default"	Either the name of one of the built-in themes, or an object specifying some or all theme properties. See Themes.
className	string		Name of a CSS class to apply to the component. In most cases, specifying theme properties will be more straightforward.
icons	{[iconName]: JSX.Element, ... }	{ }	Replace the built-in icons by specifying them here. See Themes.
minWidth	number|string (CSS value)	250	Minimum width for the editor container.
maxWidth	number|string (CSS value)	600	Maximum width for the editor container.
customNodeDefinitions	CustomNodeDefinition[]		You can provide customised components to override specific nodes in the data tree, according to a condition function. See see Custom nodes for more detail.

Update functions

A callback to be executed whenever a data update (edit, delete or add) occurs can be provided. You might wish to use this to update some state, or make an API call, for example. If you want the same function for all updates, then just the onUpdate prop is sufficient. However, should you require something different for editing, deletion and addition, then you can provide separate Update functions via the onEdit, onDelete and onAdd props.

The function will receive the following object as a parameter:

{
    newData,      // data state after update
    currentData,  // data state before update 
    newValue,     // the new value of the property being updated
    currentValue, // the current value of the property being updated
    name,         // name of the property being updated
    path          // full path to the property being updated, as an array of property keys
                  // (e.g. [ "user", "friends", 1, "name" ] ) (equivalent to "user.friends[1].name")
}

The function needn't return anything, but if it returns false, it will be considered an error, in which case an error message will displayed in the UI and the internal data state won't actually be updated. If the return value is a string, this will be the error message displayed (i.e. you can define your own error messages for updates).

Copy function

A similar callback is executed whenever an item is copied to the clipboard (if passed to the enableClipboard prop), but with a different input parameter:

    key         // name of the property being copied  
    path        // path to the property
    value       // the value copied to the clipboard
    type        // Either "path" or "value" depending on whether "Cmd/Ctrl" was pressed 
    stringValue // A nicely stringified version of `value`  
                // (i.e. what the clipboard actually receives)

Since there is very little user feedback when clicking "Copy", a good idea would be to present some kind of notification in this callback.

Filter functions

You can control which nodes of the data structure can be edited, deleted, or added to, or have their data type changed, by passing Filter functions. These will be called on each property in the data and the attribute will be enforced depending on whether the function returns true or false (true means cannot be edited).

The function receives the following object:

{
    key,   // name of the property
    path,  // path to the property (as an array of property keys)
    level, // depth of the property (with 0 being the root)
    value, // value of the property
    size   // if a collection (object, array), the number of items (null for non-collections)
}

A Filter function is available for the collapse prop as well, so you can have your data appear with deeply-nested collections opened up, while collapsing everything else, for example.

For restricting data types, the (Type) filter function is slightly more sophisticated. The input is the same, but the output can be either a boolean (which would restrict the available types for a given node to either all or none), or an array of data types to be restricted to. The available values are:

• "string"
• "number"
• "boolean"
• "null"
• "object"
• "array"

There is no specific restriction function for editing object key names, but they must return true for both restrictEdit and restrictDelete (and restrictAdd for collections), since changing a key name is equivalent to deleting a property and adding a new one.

Using all these restriction filters together can allow you to enforce a reasonably sophisticated data schema.

Examples

• A good case would be ensure your root node is not directly editable:

// in <JsonEditor /> props
restrictEdit = { ({ level }) => level === 0 }

• Don't let the id field be edited:

restrictEdit = { ({ key }) => key === "id" }
// You'd probably want to include this in `restrictDelete` as well

• Only individual properties can be deleted, not objects or arrays:

restrictDelete = { ({ size }) => size !== null }

• The only collections that can have new items added are the "address" object and the "users" array:

restrictAdd = { ({ key }) => key !== "address" && key !== "users" }
// "Adding" is irrelevant for non-collection nodes

• Multiple type restrictions:
  • string values can only be changed to strings or objects (for nesting)
  • null is not allowed anywhere
  • boolean values must remain boolean
  • data nested below the "user" field can be any simple property (i.e. not objects or arrays), and doesn't have to follow the above rules (except no "null")

restrictTypeSelection = { ({ path, value }) => {
  if (path.includes('user')) return ['string', 'number', 'boolean']
  if (typeof value === 'boolean') return false
  if (typeof value === 'string') return ['string', 'object']
  return ['string', 'number', 'boolean', 'array', 'object'] // no "null"
} }

Themes

There is a small selection of built-in themes (as seen in the Demo app). In order to use one of these, just pass the name into the theme prop (although realistically, these exist more to showcase the capabilities — I'm open to better built-in themes, so feel free to create an issue with suggestions). The available themes are:

• default
• githubDark
• githubLight
• monoDark
• monoLight
• candyWrapper
• psychedelic

However, you can pass in your own theme object, or part thereof. The theme structure is as follows (this is the "default" theme definition):

{
  displayName: 'Default',
  fragments: { edit: 'rgb(42, 161, 152)' },
  styles: {
    container: {
      backgroundColor: '#f6f6f6',
      fontFamily: 'monospace',
    },
    property: '#292929',
    bracket: { color: 'rgb(0, 43, 54)', fontWeight: 'bold' },
    itemCount: { color: 'rgba(0, 0, 0, 0.3)', fontStyle: 'italic' },
    string: 'rgb(203, 75, 22)',
    number: 'rgb(38, 139, 210)',
    boolean: 'green',
    null: { color: 'rgb(220, 50, 47)', fontVariant: 'small-caps', fontWeight: 'bold' },
    input: ['#292929', { fontSize: '90%' }],
    inputHighlight: '#b3d8ff',
    error: { fontSize: '0.8em', color: 'red', fontWeight: 'bold' },
    iconCollection: 'rgb(0, 43, 54)',
    iconEdit: 'edit',
    iconDelete: 'rgb(203, 75, 22)',
    iconAdd: 'edit',
    iconCopy: 'rgb(38, 139, 210)',
    iconOk: 'green',
    iconCancel: 'rgb(203, 75, 22)',
  },
}

The styles property is the main one to focus on. Each key (property, bracket, itemCount) refers to a part of the UI. The value for each key is either a string, in which case it is interpreted as the colour (or background colour in the case of container and inputHighlight), or a full CSS style object for fine-grained definition. You only need to provide properties you wish to override — all unspecified ones will fallback to either the default theme, or another theme that you specify as the "base".

For example, if you want to use the "githubDark" theme, but just change a couple of small things, you'd specify something like this:

// in <JsonEditor /> props
theme={[
        'githubDark',
        {
            iconEdit: 'grey',
            boolean: { color: 'red', fontStyle: 'italic', fontWeight: 'bold', fontSize: '80%' },
        },
      ]}

Which would change the "Edit" icon and boolean values from this:

into this:

Or you could create your own theme from scratch and overwrite the whole theme object.

So, to summarise, the theme prop can take either:

• a theme name e.g. "candyWrapper"
• a theme object:
  • can be structured as above with fragments, styles, displayName etc., or just the styles part (at the root level)
• a theme name and an override object in an array, i.e. [ "<themeName>, {...overrides } ]

You can play round with live editing of the themes in the Demo app by selecting "Edit this theme!" from the "Demo data" selector.

Fragments

The fragments property above is just a convenience to allow repeated style "fragments" to be defined once and referred to using an alias. For example, if you wanted all your icons to be blue and slightly larger and spaced out, you might define a fragment like so:

fragments: { iconAdjust: { color: "blue", fontSize: "110%", marginRight: "0.6em" }}

Then in the theme object, just use:

{
    ...,
    iconEdit: "iconAdjust",
    iconDelete: "iconAdjust",
    iconAdd: "iconAdjust",
    iconCopy: "iconAdjust",
}

Then, when you want to tweak it later, you only need to update it in one place!

Fragments can also be mixed with additional properties, and even other fragments, like so:

iconEdit: [ "iconAdjust", "anotherFragment", { marginLeft: "1em" } ]

A note about sizing and scaling

Internally, all sizing and spacing is done in ems, never px. This makes scaling a lot easier — just change the font-size of the main container (either via the className prop or in the container prop of the theme) (or its parent), and watch the whole component scale accordingly.

Icons

The default icons can be replaced, but you need to provide them as React/HTML elements. Just define any or all of them within the icons prop, keyed as follows:

 icons={{
  add: <YourIcon /> 
  edit: <YourIcon /> 
  delete: <YourIcon />
  copy: <YourIcon />
  ok: <YourIcon />
  cancel: <YourIcon />
  chevron: <YourIcon />
}}

The Icon components will need to have their own styles defined, as the theme styles won't be added to the custom elements.

Localisation

Localise your implementation by passing in a translations object to replace the default strings. The keys and default (English) values are as follows:

{
  ITEM_SINGLE: '{{count}} item',
  ITEMS_MULTIPLE: '{{count}} items',
  KEY_NEW: 'Enter new key',
  ERROR_KEY_EXISTS: 'Key already exists',
  ERROR_INVALID_JSON: 'Invalid JSON',
  ERROR_UPDATE: 'Update unsuccessful',
  ERROR_DELETE: 'Delete unsuccessful',
  ERROR_ADD: 'Adding node unsuccessful',
  DEFAULT_STRING: 'New data!',
  DEFAULT_NEW_KEY: 'key',
}

Custom nodes

You can replace certain nodes in the data tree with your own custom components. An example might be for an image display, or a custom date editor, or just to add some visual bling. See the "Custom Nodes" data set in the interactive demo to see it in action.

Custom nodes are provided in the customNodeDefinitions prop, as an array of objects of following structure:

{
  condition,            // a FilterFunction, as above
  element,              // React Component
  props,                // object (optional)
  hideKey,              // boolean (optional)
  showInTypesSelector,  // boolean (optional)
  defaultValue,         // JSON value for a new instance of your component
  name                  // string
}

The condition is just a Filter function, with the same input parameters (key, path, level, value, size), and element is a React component. Every node in the data structure will be run through each condition function, and any that match will be replaced by your custom component. Note that if a node matches more than one custom definition conditions (from multiple components), the first one will be used, so place them in the array in priority order.

The component will receive all the same props as a standard node component (see codebase), but you can pass additional props to your component if required through the props object.

By default, your component will be presented to the right of the property key it belongs to, like any other value. However, you can hide the key itself by setting hideKey: true, and the custom component will take the whole row. (See the "Presented by" box in the "Custom Nodes" data set for an example.)

You can allow users to create new instances of your special nodes by selecting them as a "Type" in the types selector when editing/adding values. Set showInTypesSelector: true to enable this. However, if this is enabled you need to also provide a name (which is what the user will see in the selector) and a defaultValue which is the data that is inserted when the user selects this "type". (The defaultValue must return true if passed through the condition function in order for it to be immediately displayed using your custom component.)

Undo functionality

Even though Undo/Redo functionality is probably desirable in most cases, this is not built in to the component, for two main reasons:

1. It would involve too much additional UI and I didn't want this component becoming opinionated about the look and feel beyond the essentials (which are mostly customisable/style-able anyway)
2. It is quite straightforward to implement using existing libraries. I've used use-undo in the Demo, which is working well.

Issues, bugs, suggestions?

Please open an issue: https://github.com/CarlosNZ/json-edit-react/issues

Roadmap

The main features I'd like to introduce are:

1. JSON Schema validation. We can currently specify a reasonable degree of control over what can be edited using Filter functions with the restriction props, but I'd like to go a step further and be able to pass in a JSON Schema and have the data be automatically validated against it, with the results reflected in the UI. This would allow control over data types and prevent missing properties, something that is not currently possible.
2. Visibility filter function — hide properties from the UI completely based on a Filter function. This should arguably be done outside the component though (filter the data upstream), so would be less of a priority (though it would be fairly simple to implement, so 🤷‍♂️)
3. Search — allow the user to narrow the list of visible keys with a simple search input. This would be useful for very large data objects, but is possibly getting a bit too much in terms of opinionated UI, so would need to ensure it can be styled easily. Perhaps it would be better if the "Search" input was handled outside this package, and we just accepted a "search" string prop?

Inspiration

This component is heavily inspired by react-json-view, a great package that I've used in my own projects. However, it seems to have been abandoned now, and requires a few critical fixes, so I decided to create my own from scratch and extend the functionality while I was at it.

Changelog

• 1.1.0: Don't manage data state within component
• 1.0.0:
  • Custom nodes
  • Allow editing of keys
  • Option to define restrictions on data type selection
  • Option to hide array/object item counts
  • Improve keyboard interaction
• 0.9.6: Performance improvement by not processing child elements if not visible
• 0.9.4:
  • Layout improvements
  • Better internal handling of functions in data
• 0.9.3: Bundle as ES6 module
• 0.9.1: Export more Types from the package
• 0.9.0: Initial release