@nullcc/diff2html

Fast Diff to colorized HTML

Usage no npm install needed!

<script type="module">
  import nullccDiff2html from 'https://cdn.skypack.dev/@nullcc/diff2html';
</script>

README

diff2html

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diff2html generates pretty HTML diffs from git or unified diff output.

NPM

Features

  • Supports git and unified diffs

  • Line by line and Side by side diff

  • New and old line numbers

  • Inserted and removed lines

  • GitHub like style

  • Code syntax highlight

  • Line similarity matching

  • Easy code selection

Online Example

Go to diff2html

Distributions

How to use

To load correctly in the Browser you always need to include the stylesheet in the final HTML.

Import the stylesheet

<!-- CSS -->
<link rel="stylesheet" type="text/css" href="dist/diff2html.css">

You can also refer to it from a CDN like CDNJS.

Browser Library

Import the stylesheet and the library code

<!-- CSS -->
<link rel="stylesheet" type="text/css" href="dist/diff2html.css">

<!-- Javascripts -->
<script type="text/javascript" src="dist/diff2html.js"></script>

It will now be available as a global variable named Diff2Html.

var diffHtml = Diff2Html.getPrettyHtml(
  '<Unified Diff String>',
  {inputFormat: 'diff', showFiles: true, matching: 'lines', outputFormat: 'side-by-side'}
);
document.getElementById("destination-elem-id").innerHTML = diffHtml;

Node Module

let diff2html = require("diff2html").Diff2Html

Angular

  • Typescript
// import diff2html
import {Diff2Html} from 'diff2html'
import {Component, OnInit} from '@angular/core';


export class AppDiffComponent implements OnInit {
  outputHtml: string;
  constructor() {
    this.init();
  }

  ngOnInit() {
  }

  init() {
    let strInput = "--- a/server/vendor/golang.org/x/sys/unix/zsyscall_linux_mipsle.go\n+++ b/server/vendor/golang.org/x/sys/unix/zsyscall_linux_mipsle.go\n@@ -1035,6 +1035,17 @@ func Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (\n \n // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n \n+func Pselect(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {\n+\tr0, _, e1 := Syscall6(SYS_PSELECT6, uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), uintptr(unsafe.Pointer(sigmask)))\n+\tn = int(r0)\n+\tif e1 != 0 {\n+\t\terr = errnoErr(e1)\n+\t}\n+\treturn\n+}\n+\n+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n+\n func read(fd int, p []byte) (n int, err error) {\n \tvar _p0 unsafe.Pointer\n \tif len(p) > 0 {\n";
    let outputHtml = Diff2Html.getPrettyHtml(strInput, {inputFormat: 'diff', showFiles: true, matching: 'lines'});
    this.outputHtml = outputHtml;
  }
}
  • HTML
<!DOCTYPE html>
<html>
  <head>
    <title>diff2html</title>
  </head>
  <body>
    <div [innerHtml]="outputHtml"></div>
  </body>
</html>
  • .angular-cli.json - Add styles
"styles": [
  "diff2html.min.css"
]

Vue.js

<template>
    <div v-html="prettyHtml" />
</template>

<script>
import { Diff2Html } from "diff2html";
import "diff2html/dist/diff2html.min.css";

export default {
  data() {
    return {
      diffs: "--- a/server/vendor/golang.org/x/sys/unix/zsyscall_linux_mipsle.go\n+++ b/server/vendor/golang.org/x/sys/unix/zsyscall_linux_mipsle.go\n@@ -1035,6 +1035,17 @@ func Prctl(option int, arg2 uintptr, arg3 uintptr, arg4 uintptr, arg5 uintptr) (\n \n // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n \n+func Pselect(nfd int, r *FdSet, w *FdSet, e *FdSet, timeout *Timespec, sigmask *Sigset_t) (n int, err error) {\n+\tr0, _, e1 := Syscall6(SYS_PSELECT6, uintptr(nfd), uintptr(unsafe.Pointer(r)), uintptr(unsafe.Pointer(w)), uintptr(unsafe.Pointer(e)), uintptr(unsafe.Pointer(timeout)), uintptr(unsafe.Pointer(sigmask)))\n+\tn = int(r0)\n+\tif e1 != 0 {\n+\t\terr = errnoErr(e1)\n+\t}\n+\treturn\n+}\n+\n+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT\n+\n func read(fd int, p []byte) (n int, err error) {\n \tvar _p0 unsafe.Pointer\n \tif len(p) > 0 {\n"
    };
  },
  computed: {
    prettyHtml() {
      return Diff2Html.getPrettyHtml(this.diffs, {
          inputFormat: "diff",
          showFiles: true,
          matching: "lines",
          outputFormat: "side-by-side"
        });
    }
  }
};
</script>

API

Intermediate Json From Git Word Diff Output

getJsonFromDiff(input: string, configuration?: Options): Result[]

Pretty HTML diff

getPrettyHtml(input: any, configuration?: Options): string

Check out the typescript/diff2html.d.ts for a complete API definition in TypeScript.

Check out the docs/demo.html for a demo example.

Configuration

The HTML output accepts a Javascript object with configuration. Possible options:

  • inputFormat: the format of the input data: 'diff' or 'json', default is 'diff'
  • outputFormat: the format of the output data: 'line-by-line' or 'side-by-side', default is 'line-by-line'
  • showFiles: show a file list before the diff: true or false, default is false
  • matching: matching level: 'lines' for matching lines, 'words' for matching lines and words or 'none', default is none
  • matchWordsThreshold: similarity threshold for word matching, default is 0.25
  • matchingMaxComparisons: perform at most this much comparisons for line matching a block of changes, default is 2500
  • maxLineSizeInBlockForComparison: maximum number os characters of the bigger line in a block to apply comparison, default is 200
  • maxLineLengthHighlight: only perform diff changes highlight if lines are smaller than this, default is 10000
  • templates: object with previously compiled templates to replace parts of the html
  • rawTemplates: object with raw not compiled templates to replace parts of the html
  • renderNothingWhenEmpty: render nothing if the diff shows no change in its comparison: true or false, default is false

For more information regarding the possible templates look into src/templates

** Diff2HtmlUI Helper Options **

  • synchronisedScroll: scroll both panes in side-by-side mode: true or false, default is false

For more information regarding the possible templates look into src/templates

Diff2HtmlUI Helper

Simple wrapper to ease simple tasks in the browser such as: code highlight and js effects

  • Invoke Diff2html
  • Inject output in DOM element
  • Enable collapsible file summary list
  • Enable syntax highlight of the code in the diffs

How to use

Mandatory HTML resource imports

<!-- CSS -->
<link rel="stylesheet" type="text/css" href="dist/diff2html.css">

<!-- Javascripts -->
<script type="text/javascript" src="dist/diff2html.js"></script>
<script type="text/javascript" src="dist/diff2html-ui.js"></script>

Init

var diff2htmlUi = new Diff2HtmlUI({diff: diffString});
// or
var diff2htmlUi = new Diff2HtmlUI({json: diffJson});

Draw

diff2htmlUi.draw('html-target-elem', {inputFormat: 'json', showFiles: true, matching: 'lines'});

Syntax Highlight

Add the dependencies. Choose one color scheme, and add the main highlight code. Note that the stylesheet for the color scheme must come before the main diff2html stylesheet. If your favourite language is not included in the default package also add its javascript highlight file.

<!-- Stylesheet -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.13.1/styles/github.min.css">
<link rel="stylesheet" type="text/css" href="dist/diff2html.css">

<!-- Javascripts -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.3/jquery.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.13.1/highlight.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.13.1/languages/scala.min.js"></script>
<script type="text/javascript" src="dist/diff2html-ui.js"></script>

Invoke the Diff2HtmlUI helper

$(document).ready(function() {
    var diff2htmlUi = new Diff2HtmlUI({diff: lineDiffExample});
    diff2htmlUi.draw('#line-by-line', {inputFormat: 'json', showFiles: true, matching: 'lines'});
    diff2htmlUi.highlightCode('#line-by-line');
});

Collapsable File Summary List

Add the dependencies.

<!-- Javascripts -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.3/jquery.js"></script>
<script type="text/javascript" src="dist/diff2html-ui.js"></script>

Invoke the Diff2HtmlUI helper

$(document).ready(function() {
    var diff2htmlUi = new Diff2HtmlUI({diff: lineDiffExample});
    diff2htmlUi.draw('#line-by-line', {inputFormat: 'json', showFiles: true, matching: 'lines'});
    diff2htmlUi.fileListCloseable('#line-by-line', false);
});

Troubleshooting

1. Out of memory or Slow execution

Causes:

  • Big files
  • Big lines

Fix:

  • Disable the line matching algorithm, by setting the option {"matching": "none"} when invoking diff2html

Contributions

This is a developer friendly project, all the contributions are welcome. To contribute just send a pull request with your changes following the guidelines described in CONTRIBUTING.md. I will try to review them as soon as possible.

Contributors ✨

Thanks goes to these wonderful people (emoji key):

Rodrigo Fernandes
Rodrigo Fernandes
πŸ’»		 stockmind
stockmind
πŸ’»		 Ivan Vorontsov
Ivan Vorontsov
πŸ’»		 Nick Brewer
Nick Brewer
πŸ’»		 Matt Wade
Matt Wade
πŸ›		 Rafael CortΓͺs
Rafael CortΓͺs
πŸ’»		 Nuno Teixeira
Nuno Teixeira
πŸ’»
Koki Oyatsu
Koki Oyatsu
πŸ›		 James Monger
James Monger
πŸ“–		 Wessel van der Pal
Wessel van der Pal
πŸ›‘οΈ		 jk-kim
jk-kim
πŸ’»		 Sergey Semenov
Sergey Semenov
πŸ›		 Nick Mitchell
Nick Mitchell
πŸ›		 Samir Aguiar
Samir Aguiar
πŸ“–
pubkey
pubkey
πŸ“–		 Илья
Илья
πŸ“–		 Mohamed Akram
Mohamed Akram
πŸ›		 Eugene Marcotte
Eugene Marcotte
πŸ’»		 Dima Sabanin
Dima Sabanin
🚧		 Ben Abbott
Ben Abbott
πŸ“–		 εΌ˜ζ ‘@ι˜Ώι‡Œ
εΌ˜ζ ‘@ι˜Ώι‡Œ
πŸ›
Mikko Rantanen
Mikko Rantanen
πŸ›

This project follows the all-contributors specification. Contributions of any kind welcome!

License

Copyright 2014-2016 Rodrigo Fernandes. Released under the terms of the MIT license.

Thanks

This project is inspired in pretty-diff by Scott GonzΓ‘lez.