diffy

A tiny framework for building diff based interactive command line tools.

``
npm install diffy
`

![Build Status](https://travis-ci.org/mafintosh/diffy)

Basically React, but in the terminal powered by ansi-diff and neat-input.

Usage

` js
var diffy = require('diffy')()
var trim = require('diffy/trim')

diffy.render(function () {
return trim(
Hello user. The time is:
${new Date()}
That is all for now
)
})

// re-render every 1s
setInterval(() => diffy.render(), 1000)
`

You can also use diffy to query input from a user

` js
var diffy = require('diffy')()
var trim = require('diffy/trim')
var input = require('diffy/input')({style: style})
var names = []

input.on('update', () => diffy.render())
input.on('enter', (line) => names.push(line))

diffy.render(function () {
return trim(
Enter your name: ${input.line()}
List of names: ${names.join(', ')}
)
})

function style (start, cursor, end) {
return start + '[' + (cursor || ' ') + ']' + end
}
`

See the examples folder for more.

API

#### var diffy = require('diffy')([options])

Make a new diffy instance. Writes to stdout.

Options include:

` js
{
fullscreen: true // overtake the terminal like vim/less does
}
`

Note that if you use fullscreen: true, the terminal will be restored
on exit, even if your program crashes.

#### diffy.render([function])

Trigger a render and/or update the default render
function. A render function should simply return a string
containing the output you wish to display and then diffy will make sure to only print the diff.

#### diffy.width

Property containing the width of the terminal.

#### diffy.height

Property containing the height of the terminal.

#### diffy.on('resize')

Emitted when the terminal is resized. Triggers a render as well.

#### diffy.on('render')

Emitted just before a render happens.

#### var input = require('diffy/input')()

Get a neat-input instance. Use this if you want to accept interactive input.

#### var trim = require('diffy/trim')

Helper function that trims and removes the indentation of a multiline string. Useful if you have a render function that returns an indented string like in the above example.

#### var trim = require('diffy/trim+newline')`

Helper function that trims but adds a newline at the end

Components

With diffy, components are just strings you compose together to form your application.
A bunch of modules already exists for this pattern, providing useful features.

* watson/menu-string - Generate a menu with selectable menu items as a string.
* watson/progress-string - Generate a CLI progress bar as a string that you can then output in any way you like.
* mafintosh/scrollable-string - Generate a diff friendly string that is bounded by a configurable scroll box.

Credits

Thank you to @Fouad for donating the module name.

License

MIT