detect-is-it-html-or-xhtml^3.9.61

Answers, is the string input string more an HTML or XHTML (or neither)

Install globally, via npm

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 require():

const detectIsItHTMLOrXhtml = require("detect-is-it-html-or-xhtml");

or as an ES Module:

import detectIsItHTMLOrXhtml from "detect-is-it-html-or-xhtml";

Install as a script, via CDN

Put this in your HTML:

<script src="https://cdn.jsdelivr.net/npm/detect-is-it-html-or-xhtml/dist/detect-is-it-html-or-xhtml.umd.js">

Then, you’ll get a global variable detectIsItHtmlOrXhtml in your Global object and you consume it like this:

const detectIsItHTMLOrXhtml = detectIsItHtmlOrXhtml;

This detectIsItHTMLOrXhtml is your main function. See its API in the main section.

Trivia

This program has 53 assertions in its unit tests. That's more than all unit test assertions' median (52) but less than geometric mean (71).

§ Example

const detect = require("detect-is-it-html-or-xhtml");
console.log(
  detect(
    '<img src="some.jpg" width="zzz" height="zzz" border="0" style="display:block;" alt="zzz"/>'
  )
);
// => 'xhtml'

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§ Purpose

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 null.

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§ API - Input

This package exports a function:

detect(str)

Input argument	Type	Obligatory?	Description
`htmlAsString`	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 null.

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§ API - Output

Type	Value	Description
String or `null`	'html', 'xhtml' or null	Identified type of your input

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§ 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 doctype or it's messed up beyond recognition, DO scan all singleton tags (<img>, <br> and <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 html.
If (there are no tags in the input) OR (there are no doctype tags and no singleton tags), return null.

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