Сompares two HTML.
html-differ compares HTML using the following criteria:
<!DOCTYPE>
declarations are case-insensitive, so the following two code samples will be considered to be equivalent:
<!DOCTYPE HTML PUBLIC "_PUBLIC" "_SYSTEM">
<!doctype html public "_PUBLIC" "_SYSTEM">
- Whitespaces (spaces, tabs, new lines etc.) inside start and end tags are ignored during the comparison.
For example, the following two code samples will be considered to be equivalent:
<span id="1"></span>
<span id=
"1" ></span >
- Two respective lists of attributes are considered to be equivalent even if they are specified in different order.
For example, the following two code samples will be considered to be equivalent:
<span id="blah" class="ololo" tabIndex="1">Text</span>
<span tabIndex="1" id="blah" class="ololo">Text</span>
- Two respective attributes
class
are considered to be equivalent if they refer to the same groups of CSS styles.
For example, the following two code samples will be considered to be equivalent:
<span class="ab bc cd">Text</span>
<span class=" cd ab bc">Text</span>
CAUTION!
html-differ does not check the validity of HTML, but compares them using the above shown criteria and specified options (see the list of possible options in the API).
$ npm install html-differ -g
###HtmlDiffer###
var HtmlDiffer = require('html-differ').HtmlDiffer,
htmlDiffer = new HtmlDiffer(options);
where options
is an object:
- ignoreAttributes: [ Array ]
Sets what kind of respective attributes' content will be ignored during the comparison (default: []
).
Example: ['id', 'for']
The following two code samples will be considered to be equivalent:
<label for="random">Text</label>
<input id="random">
<label for="sfsdfksdf">Text</label>
<input id="sfsdfksdf">
- compareAttributesAsJSON: [ Array ]
Sets what kind of respective attributes' content will be compared as JSON objects, but not as strings (default: []
).
In cases when the value of the attribute is an invalid JSON or can not be wrapped into a function, it will be compared as undefined
.
Example: [{ name: 'data', isFunction: false }, { name: 'onclick', isFunction: true }]
The following two code samples will be considered to be equivalent:
<div data='{"bla":{"first":"ololo","second":"trololo"}}'></div>
<span onclick='return {"aaa":"bbb","bbb":"aaa"}'></span>
<button data='REALLY BAD JSON'></button>
<button onclick='REALLY BAD FUNCTION'></button>
<div data='{"bla":{"second":"trololo","first":"ololo"}}'></div>
<span onclick='return {"bbb":"aaa","aaa":"bbb"}'></span>
<button data='undefined'></button>
<button onclick='undefined'></button>
REMARK!
The first element of the array could be written in a short form as string:
['data', { name: 'onclick', isFunction: true }]
.
- ignoreWhitespaces: Boolean
Makes html-differ ignore whitespaces (spaces, tabs, new lines etc.) during the comparison (default: true
).
Example: true
The following two code samples will be considered to be equivalent:
<html>Text Text<head lang="en"><title></title></head><body>Text</body></html>
<html>
Text Text
<head lang="en">
<title> </title>
</head>
<body>
Text
</body>
</html>
- ignoreComments: Boolean
Makes html-differ ignore HTML comments during the comparison (default: true
).
Example: true
The following two code samples will be considered to be equivalent:
<!DOCTYPE html>
<!-- comments1 -->
<html>
<head lang="en">
<meta charset="UTF-8">
<title><!-- comments2 --></title>
</head>
<body>
Text<!-- comments3 -->
</body>
</html>
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
Text
</body>
</html>
- ignoreEndTags: Boolean
Makes html-differ ignore end tags during the comparison (default: false
).
Example: true
The following two code samples will be considered to be equivalent:
<span>Text</span>
<span>Text</spane>
- ignoreDuplicateAttributes: Boolean
Makes html-differ ignore tags' duplicate attributes during the comparison.
From the list of the same tag's attributes, the attribute which goes the first will be taken for comparison, others will be ignored (default: false
).
Example: true
For example, the following two code samples will be considered to be equivalent:
<span id="blah" id="ololo">Text</span>
<span id="blah">Text</span>
BEM preset
You can set predefined options for BEM using the preset:
var HtmlDiffer = require('html-differ').HtmlDiffer,
htmlDiffer = new HtmlDiffer('bem');
The options wiil be predefined:
{
ignoreAttributes: ['id', 'for', 'aria-labelledby', 'aria-describedby'],
compareAttributesAsJSON: [
'data-bem',
{ name: 'onclick', isFunction: true },
{ name: 'ondblclick', isFunction: true }
],
ignoreWhitespaces: true,
ignoreComments: true,
ignoreEndTags: false,
ignoreDuplicateAttributes: false
}
####Methods####
htmlDiffer.diffHtml
@param {String} - the 1-st HTML code
@param {String} - the 2-nd HTML code
@returns {Array of objects} - array with diffs between HTML
htmlDiffer.isEqual
@param {String} - the 1-st HTML code
@param {String} - the 2-nd HTML code
@returns {Boolean}
###Logger###
var logger = require('html-differ/lib/logger');
####Methods####
logger.getDiffText
@param {Array of objects} - the result of the work of the method htmlDiffer.diffHtml
@param {Object} - options:
- charsAroundDiff: Number - the number of characters around the diff result between two HTML (default:
40
).
@returns {String}
logger.logDiffText
@param {Array of objects} - the result of the work of the method htmlDiffer.diffHtml
@param {Object} - options:
- charsAroundDiff: Number - the number of characters around the diff result between two HTML (default:
40
).
@returns - pretty logging of diffs:
###Example###
var fs = require('fs'),
HtmlDiffer = require('html-differ').HtmlDiffer,
logger = require('html-differ/lib/logger');
var html1 = fs.readFileSync('1.html', 'utf-8'),
html2 = fs.readFileSync('2.html', 'utf-8');
var options = {
ignoreAttributes: [],
compareAttributesAsJSON: [],
ignoreWhitespaces: true,
ignoreComments: true,
ignoreEndTags: false,
ignoreDuplicateAttributes: false
};
var htmlDiffer = new HtmlDiffer(options);
var diff = htmlDiffer.diffHtml(html1, html2),
isEqual = htmlDiffer.isEqual(html1, html2),
res = logger.getDiffText(diff, { charsAroundDiff: 40 });
logger.logDiffText(diff, { charsAroundDiff: 40 });
##Usage as a program##
$ html-differ --help
Compares two HTML
Usage:
html-differ [OPTIONS] [ARGS]
Options:
-h, --help : Help
-v, --version : Shows the version number
--config=CONFIG : Path to configuration JSON file
--bem : Uses predefined options for BEM
--chars-around-diff=CHARSAROUNDDIFF : The number of characters around the diff (default: 40)
Arguments:
PATH1 : Path to the 1-st HTML file (required)
PATH2 : Path to the 2-nd HTML file (required)
###Example###
$ html-differ path/to/html1 path/to/html2
$ html-differ --config=path/to/config --chars-around-diff=40 path/to/html1 path/to/html2
$ html-differ --bem path/to/html1 path/to/html2
###Configuration file##
Study the following config.json
file:
{
"ignoreAttributes": [],
"compareAttributesAsJSON": [],
"ignoreWhitespaces": true,
"ignoreComments": true,
"ignoreEndTags": false,
"ignoreDuplicateAttributes": false
}