CSS Selector Generator

JavaScript object that creates a unique CSS selector for a given DOM element.

It also generates shorter selectors and is faster and/or more robust than many other libraries - see this comparison and select the best alternative for your use case.

Install

Add the library to your project via NPM or Yarn.

npm install css-selector-generator
yarn add css-selector-generator

Then include it in your source code:

import getCssSelector from 'css-selector-generator';

How to use

Simplest way to use it is to provide an element reference, without any options.

<body>
	<!-- targetElement -->
	<div class="myElement"></div>
</body>

getCssSelector(targetElement);
// ".myElement"

Typical example is to create a selector for any element that the user clicks on:

// track every click
document.body.addEventListener('click', function (event) {
  // get reference to the element user clicked on
  const element = event.target;
  // get unique CSS selector for that element
  const selector = getCssSelector(element);
  // do whatever you need to do with that selector
  console.log('selector', selector);
});

Usage without NPM

If you don't want to use this library with NPM, you can download it directly from the "build" folder and insert it to your HTML document directly. In this case, the library is wrapped in namespace CssSelectorGenerator. So the usage would look something like this:

<!-- link the library -->
<script src="build/index.js"></script>
<script>
	CssSelectorGenerator.getCssSelector(targtElement)
</script

Fallback

getCssSelector determines the shortest CSS selector for parent -> child relationship, from the input Element until the Root Element.

If there is no unique selector available for any of these relationships (parent -> child), a fallback of * will be used for this relationship.

#wrapper > * > div > .text

In some cases, this selector may not be unique (e.g. #wrapper > * > div > *). In this case, it will fall back to an entire chain of :nth-child selectors like:

":nth-child(2) > :nth-child(4) > :nth-child(1) > :nth-child(12)"

Selector types

You can choose which types of selectors do you want to use:

<body>
	<!-- targetElement -->
	<div class="myElement"></div>
</body>

getCssSelector(targetElement, {selectors: ['class']});
// ".myElement"
getCssSelector(targetElement, {selectors: ['tag']});
// "div"

Order of selector types defines their priority:

getCssSelector(targetElement, {selectors: ['class', 'tag']});
// ".myElement"
getCssSelector(targetElement, {selectors: ['tag', 'class']});
// "div"

Root element

You can define root element, from which the selector will be created. If root element is not defined, document root will be used:

<body>
	<div class="myRootElement">
		<!-- targetElement -->
		<div class="myElement"></div>
	</div>
</body>

getCssSelector(targetElement)
// ".myRootElement > .myElement"
getCssSelector(targetElement, {root: document.querySelector('.myRootElement')});
// ".myElement"

Blacklist

If you want to ignore some selectors, you can put them on the blacklist. Blacklist is an array that can contain either regular expressions, or strings. In strings, you can use an asterisk (*) as a wildcard that will match any number of any characters.

<body>
	<!-- targetElement -->
	<div class="firstClass secondClass"></div>
</body>

getCssSelector(targetElement, {blacklist: ['.firstClass']});
// ".secondClass"
getCssSelector(targetElement, {blacklist: ['.first*']});
// ".secondClass"
getCssSelector(targetElement, {blacklist: [/first/]});
// ".secondClass"

You can target selectors of any types using the blacklist.

getCssSelector(
  targetElement,
  { blacklist:
      [
        // ID selector
        '#forbiddenId',
        // class selector
        '.forbiddenClass',
        // attribute selector
        '[forbidden-attribute]',
        // tag selector
        'div'
      ]
  }
)

Whitelist

Same as blacklist option, but instead of ignoring matching selectors, they will be prioritised.

<body>
	<!-- targetElement -->
	<div class="firstClass secondClass"></div>
</body>

getCssSelector(targetElement, {whitelist: ['.secondClass']});
// ".secondClass"
getCssSelector(targetElement, {whitelist: ['.second*']});
// ".secondClass"
getCssSelector(targetElement, {whitelist: [/second/]});
// ".secondClass"

Combine within selector

If set to true, the generator will try to look for combinations of selectors within a single type (usually class names) to get better overall selector.

<body>
	<!-- targetElement -->
	<div class="aaa bbb"></div>
	<div class="aaa ccc"></div>
	<div class="bbb ccc"></div>
</body>

getCssSelector(targetElement, {combineWithinSelector: false});
// "body > :nth-child(1)" - in this case no single class name is unique
getCssSelector(targetElement, {combineWithinSelector: true});
// ".aaa.bbb"

This option is set to true by default. It can be set to false for performance reasons.

Combine between selectors

If set to true, the generator will try to look for combinations of selectors between various types (e.g. tag name + class name) to get better overall selector.

<body>
	<!-- targetElement -->
	<div class="aaa"></div>
	<div class="bbb"></div>
	<p class="aaa"></div>
</body>

getCssSelector(targetElement, {combineBetweenSelectors: false});
// "body > :nth-child(1)" - in this case no single class name or tag name is unique
getCssSelector(targetElement, {combineBetweenSelectors: true});
// "div.aaa"

This option is set to true by default. It can be set to false for performance reasons.

Include tag

This option will add tag selector type to every selector:

<body>
	<!-- targetElement -->
	<div class="myElement"></div>
</body>

getCssSelector(targetElement, {includeTag: true});
// "div.myElement"

Documentation

getCssSelector
- Parameters
updateIdentifiableParent
css_selector_generator_options
- Properties
css_selector_type

getCssSelector

Generates unique CSS selector for an element.

Parameters

element Element
custom_options css_selector_generator_options? (optional, default {})

Returns string

updateIdentifiableParent

Utility function to make subsequent calls shorter.

Returns {foundElement: Element, selector: string}