Answers, is the string input string more an HTML or XHTML (or neither)
Table of Contents
npm i detect-is-it-html-or-xhtml
The default is exported, so instead of "
detectIsItHTMLOrXhtml" below, you can name the consumed function however you want.
Consume via a
const detectIsItHTMLOrXhtml = ;
or as an ES Module:
or for web pages, as a production-ready minified script file (so-called "UMD build"), straight from CDN:
// in which case you get a global variable "detectIsItHtmlOrXhtml" which you consume like this:const detectIsItHTMLOrXhtml = detectIsItHtmlOrXhtml;
This package has three builds in
|Main export - CommonJS version, transpiled to ES5, contains
|ES module build that Webpack/Rollup understands. Untranspiled ES6 code with
|UMD build for browsers, transpiled, minified, containing
const detect = ;console;// => 'xhtml'
As you know, XHTML is slightly different from HTML: HTML (4 and 5) does not close the
<img> and other single tags, while XHTML does. There are more to that, but that's the major thing from developer's perspective.
When I was working on the email-comb, I was parsing the HTML and rendering it back. Upon this rendering-back stage, I had to identify, is the source code of the HTML-type, or XHTML, because I had to instruct the renderer to close all the single tags (or not close them). Ignoring this setting would have nasty consequences because, roughly, in only half of the cases my library would produce the correct code.
I couldn't find any library that analyses the code, telling is it HTML or XHTML. That's how
detect-is-it-html-or-xhtml was born.
Feed the string into this library. If it's more of an HTML, it will output a string
"html". If it's more of an XHTML, it will output a string
xhtml. If your code doesn't contain any tags, or it does, but there is no
doctype, and it's impossible to distinguish between the two, it will output
;// => 'html'|'xhtml'|null
API - Input
||String||yes||String, hopefully containing some HTML code|
If the input is not String type, this package will throw an error. If the input is missing completely, it will return
API - Output
|String or null||'html', 'xhtml' or null||Identified type of your input|
Under the hood
The algorithm is the following:
- Look for
doctype. If recognised, Bob's your uncle, here's your answer.
- IF there's no
doctypeor it's messed up beyond recognition, DO scan all singleton tags (
<hr>) and see which type the majority is (closed or not closed).
- In a rare case when there is an equal amount of both closed and unclosed tags, lean for
- If (there are no tags in the input) OR (there are no doctype tags and no singleton tags), return
- If you see an error, raise an issue.
- If you want a new feature but can't code it up yourself, also raise an issue. Let's discuss it.
- If you tried to use this package, but something didn't work out, also raise an issue. We'll try to help.
- If you want to contribute some code, fork the monorepo via GitLab, then write code, then file a pull request on GitLab. We'll merge it in and release.
In monorepo, npm libraries are located in
packages/ folder. Inside, the source code is located either in
src/ folder (normal npm library) or in the root,
cli.js (if it's a command-line application).
The npm script "
"dev": "rollup -c --dev" builds the development version retaining all
console.logs with row numbers. It's handy to have js-row-num-cli installed globally so you can automatically update the row numbers on all
Copyright (c) 2015-2020 Roy Revelt and other contributors